--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/memory/DefNewGeneration.java Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/memory/DefNewGeneration.java Mon Nov 03 15:53:48 2014 +0100
@@ -64,8 +64,8 @@
}
// Accessing spaces
- public EdenSpace eden() {
- return (EdenSpace) VMObjectFactory.newObject(EdenSpace.class, edenSpaceField.getValue(addr));
+ public ContiguousSpace eden() {
+ return (ContiguousSpace) VMObjectFactory.newObject(ContiguousSpace.class, edenSpaceField.getValue(addr));
}
public ContiguousSpace from() {
--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/memory/EdenSpace.java Fri Oct 31 08:00:09 2014 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,40 +0,0 @@
-/*
- * Copyright (c) 2000, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-package sun.jvm.hotspot.memory;
-
-import java.util.*;
-import sun.jvm.hotspot.debugger.*;
-import sun.jvm.hotspot.runtime.*;
-import sun.jvm.hotspot.types.*;
-
-/** <P> Class EdenSpace describes eden-space in new
- generation. (Currently it does not add any significant
- functionality beyond ContiguousSpace.) */
-
-public class EdenSpace extends ContiguousSpace {
- public EdenSpace(Address addr) {
- super(addr);
- }
-}
--- a/hotspot/src/cpu/ppc/vm/templateTable_ppc_64.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/cpu/ppc/vm/templateTable_ppc_64.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -3513,7 +3513,7 @@
Rtags = R3_ARG1,
Rindex = R5_ARG3;
- const bool allow_shared_alloc = Universe::heap()->supports_inline_contig_alloc() && !CMSIncrementalMode;
+ const bool allow_shared_alloc = Universe::heap()->supports_inline_contig_alloc();
// --------------------------------------------------------------------------
// Check if fast case is possible.
--- a/hotspot/src/cpu/sparc/vm/macroAssembler_sparc.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/cpu/sparc/vm/macroAssembler_sparc.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -3196,7 +3196,7 @@
assert(0 <= con_size_in_bytes && Assembler::is_simm13(con_size_in_bytes), "illegal object size");
assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0, "object size is not multiple of alignment");
- if (CMSIncrementalMode || !Universe::heap()->supports_inline_contig_alloc()) {
+ if (!Universe::heap()->supports_inline_contig_alloc()) {
// No allocation in the shared eden.
ba(slow_case);
delayed()->nop();
@@ -3331,7 +3331,7 @@
assert_different_registers(top, t1, t2, t3, G4, G5 /* preserve G4 and G5 */);
Label do_refill, discard_tlab;
- if (CMSIncrementalMode || !Universe::heap()->supports_inline_contig_alloc()) {
+ if (!Universe::heap()->supports_inline_contig_alloc()) {
// No allocation in the shared eden.
ba(slow_case);
delayed()->nop();
--- a/hotspot/src/cpu/sparc/vm/templateTable_sparc.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/cpu/sparc/vm/templateTable_sparc.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -3309,7 +3309,7 @@
// (creates a new TLAB, etc.)
const bool allow_shared_alloc =
- Universe::heap()->supports_inline_contig_alloc() && !CMSIncrementalMode;
+ Universe::heap()->supports_inline_contig_alloc();
if(UseTLAB) {
Register RoldTopValue = RallocatedObject;
--- a/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -2964,7 +2964,7 @@
Label& slow_case) {
assert(obj == rax, "obj must be in rax, for cmpxchg");
assert_different_registers(obj, var_size_in_bytes, t1);
- if (CMSIncrementalMode || !Universe::heap()->supports_inline_contig_alloc()) {
+ if (!Universe::heap()->supports_inline_contig_alloc()) {
jmp(slow_case);
} else {
Register end = t1;
@@ -4437,7 +4437,7 @@
assert_different_registers(top, thread_reg, t1, t2, /* preserve: */ rbx, rdx);
Label do_refill, discard_tlab;
- if (CMSIncrementalMode || !Universe::heap()->supports_inline_contig_alloc()) {
+ if (!Universe::heap()->supports_inline_contig_alloc()) {
// No allocation in the shared eden.
jmp(slow_case);
}
--- a/hotspot/src/cpu/x86/vm/templateTable_x86_32.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/cpu/x86/vm/templateTable_x86_32.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -3214,7 +3214,7 @@
// (creates a new TLAB, etc.)
const bool allow_shared_alloc =
- Universe::heap()->supports_inline_contig_alloc() && !CMSIncrementalMode;
+ Universe::heap()->supports_inline_contig_alloc();
const Register thread = rcx;
if (UseTLAB || allow_shared_alloc) {
--- a/hotspot/src/cpu/x86/vm/templateTable_x86_64.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/cpu/x86/vm/templateTable_x86_64.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -3269,7 +3269,7 @@
// (creates a new TLAB, etc.)
const bool allow_shared_alloc =
- Universe::heap()->supports_inline_contig_alloc() && !CMSIncrementalMode;
+ Universe::heap()->supports_inline_contig_alloc();
if (UseTLAB) {
__ movptr(rax, Address(r15_thread, in_bytes(JavaThread::tlab_top_offset())));
--- a/hotspot/src/share/vm/Xusage.txt Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/Xusage.txt Mon Nov 03 15:53:48 2014 +0100
@@ -7,7 +7,6 @@
-Xbootclasspath/p:<directories and zip/jar files separated by ;>
prepend in front of bootstrap class path
-Xnoclassgc disable class garbage collection
- -Xincgc enable incremental garbage collection
-Xloggc:<file> log GC status to a file with time stamps
-Xbatch disable background compilation
-Xms<size> set initial Java heap size
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -89,9 +89,3 @@
_gc_policy_counters = new GCPolicyCounters("Copy:CMS", 2, 3);
}
}
-
-// Returns true if the incremental mode is enabled.
-bool ConcurrentMarkSweepPolicy::has_soft_ended_eden()
-{
- return CMSIncrementalMode;
-}
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -42,9 +42,6 @@
virtual void initialize_size_policy(size_t init_eden_size,
size_t init_promo_size,
size_t init_survivor_size);
-
- // Returns true if the incremental mode is enabled.
- virtual bool has_soft_ended_eden();
};
#endif // SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_CMSCOLLECTORPOLICY_HPP
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -2083,17 +2083,13 @@
}
// Support for compaction
-
void CompactibleFreeListSpace::prepare_for_compaction(CompactPoint* cp) {
- SCAN_AND_FORWARD(cp,end,block_is_obj,block_size);
+ scan_and_forward(this, cp);
// Prepare_for_compaction() uses the space between live objects
// so that later phase can skip dead space quickly. So verification
// of the free lists doesn't work after.
}
-#define obj_size(q) adjustObjectSize(oop(q)->size())
-#define adjust_obj_size(s) adjustObjectSize(s)
-
void CompactibleFreeListSpace::adjust_pointers() {
// In other versions of adjust_pointers(), a bail out
// based on the amount of live data in the generation
@@ -2101,12 +2097,12 @@
// Cannot test used() == 0 here because the free lists have already
// been mangled by the compaction.
- SCAN_AND_ADJUST_POINTERS(adjust_obj_size);
+ scan_and_adjust_pointers(this);
// See note about verification in prepare_for_compaction().
}
void CompactibleFreeListSpace::compact() {
- SCAN_AND_COMPACT(obj_size);
+ scan_and_compact(this);
}
// Fragmentation metric = 1 - [sum of (fbs**2) / (sum of fbs)**2]
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -73,6 +73,13 @@
friend class CMSCollector;
// Local alloc buffer for promotion into this space.
friend class CFLS_LAB;
+ // Allow scan_and_* functions to call (private) overrides of the auxiliary functions on this class
+ template <typename SpaceType>
+ friend void CompactibleSpace::scan_and_adjust_pointers(SpaceType* space);
+ template <typename SpaceType>
+ friend void CompactibleSpace::scan_and_compact(SpaceType* space);
+ template <typename SpaceType>
+ friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp);
// "Size" of chunks of work (executed during parallel remark phases
// of CMS collection); this probably belongs in CMSCollector, although
@@ -288,6 +295,28 @@
_bt.freed(start, size);
}
+ // Auxiliary functions for scan_and_{forward,adjust_pointers,compact} support.
+ // See comments for CompactibleSpace for more information.
+ inline HeapWord* scan_limit() const {
+ return end();
+ }
+
+ inline bool scanned_block_is_obj(const HeapWord* addr) const {
+ return CompactibleFreeListSpace::block_is_obj(addr); // Avoid virtual call
+ }
+
+ inline size_t scanned_block_size(const HeapWord* addr) const {
+ return CompactibleFreeListSpace::block_size(addr); // Avoid virtual call
+ }
+
+ inline size_t adjust_obj_size(size_t size) const {
+ return adjustObjectSize(size);
+ }
+
+ inline size_t obj_size(const HeapWord* addr) const {
+ return adjustObjectSize(oop(addr)->size());
+ }
+
protected:
// Reset the indexed free list to its initial empty condition.
void resetIndexedFreeListArray();
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -167,16 +167,6 @@
};
-// Wrapper class to temporarily disable icms during a foreground cms collection.
-class ICMSDisabler: public StackObj {
- public:
- // The ctor disables icms and wakes up the thread so it notices the change;
- // the dtor re-enables icms. Note that the CMSCollector methods will check
- // CMSIncrementalMode.
- ICMSDisabler() { CMSCollector::disable_icms(); CMSCollector::start_icms(); }
- ~ICMSDisabler() { CMSCollector::enable_icms(); }
-};
-
//////////////////////////////////////////////////////////////////
// Concurrent Mark-Sweep Generation /////////////////////////////
//////////////////////////////////////////////////////////////////
@@ -363,7 +353,6 @@
_cms_used_at_gc0_end = 0;
_allow_duty_cycle_reduction = false;
_valid_bits = 0;
- _icms_duty_cycle = CMSIncrementalDutyCycle;
}
double CMSStats::cms_free_adjustment_factor(size_t free) const {
@@ -442,86 +431,17 @@
return work - deadline;
}
-// Return a duty cycle based on old_duty_cycle and new_duty_cycle, limiting the
-// amount of change to prevent wild oscillation.
-unsigned int CMSStats::icms_damped_duty_cycle(unsigned int old_duty_cycle,
- unsigned int new_duty_cycle) {
- assert(old_duty_cycle <= 100, "bad input value");
- assert(new_duty_cycle <= 100, "bad input value");
-
- // Note: use subtraction with caution since it may underflow (values are
- // unsigned). Addition is safe since we're in the range 0-100.
- unsigned int damped_duty_cycle = new_duty_cycle;
- if (new_duty_cycle < old_duty_cycle) {
- const unsigned int largest_delta = MAX2(old_duty_cycle / 4, 5U);
- if (new_duty_cycle + largest_delta < old_duty_cycle) {
- damped_duty_cycle = old_duty_cycle - largest_delta;
- }
- } else if (new_duty_cycle > old_duty_cycle) {
- const unsigned int largest_delta = MAX2(old_duty_cycle / 4, 15U);
- if (new_duty_cycle > old_duty_cycle + largest_delta) {
- damped_duty_cycle = MIN2(old_duty_cycle + largest_delta, 100U);
- }
- }
- assert(damped_duty_cycle <= 100, "invalid duty cycle computed");
-
- if (CMSTraceIncrementalPacing) {
- gclog_or_tty->print(" [icms_damped_duty_cycle(%d,%d) = %d] ",
- old_duty_cycle, new_duty_cycle, damped_duty_cycle);
- }
- return damped_duty_cycle;
-}
-
-unsigned int CMSStats::icms_update_duty_cycle_impl() {
- assert(CMSIncrementalPacing && valid(),
- "should be handled in icms_update_duty_cycle()");
-
- double cms_time_so_far = cms_timer().seconds();
- double scaled_duration = cms_duration_per_mb() * _cms_used_at_gc0_end / M;
- double scaled_duration_remaining = fabsd(scaled_duration - cms_time_so_far);
-
- // Avoid division by 0.
- double time_until_full = MAX2(time_until_cms_gen_full(), 0.01);
- double duty_cycle_dbl = 100.0 * scaled_duration_remaining / time_until_full;
-
- unsigned int new_duty_cycle = MIN2((unsigned int)duty_cycle_dbl, 100U);
- if (new_duty_cycle > _icms_duty_cycle) {
- // Avoid very small duty cycles (1 or 2); 0 is allowed.
- if (new_duty_cycle > 2) {
- _icms_duty_cycle = icms_damped_duty_cycle(_icms_duty_cycle,
- new_duty_cycle);
- }
- } else if (_allow_duty_cycle_reduction) {
- // The duty cycle is reduced only once per cms cycle (see record_cms_end()).
- new_duty_cycle = icms_damped_duty_cycle(_icms_duty_cycle, new_duty_cycle);
- // Respect the minimum duty cycle.
- unsigned int min_duty_cycle = (unsigned int)CMSIncrementalDutyCycleMin;
- _icms_duty_cycle = MAX2(new_duty_cycle, min_duty_cycle);
- }
-
- if (PrintGCDetails || CMSTraceIncrementalPacing) {
- gclog_or_tty->print(" icms_dc=%d ", _icms_duty_cycle);
- }
-
- _allow_duty_cycle_reduction = false;
- return _icms_duty_cycle;
-}
-
#ifndef PRODUCT
void CMSStats::print_on(outputStream *st) const {
st->print(" gc0_alpha=%d,cms_alpha=%d", _gc0_alpha, _cms_alpha);
st->print(",gc0_dur=%g,gc0_per=%g,gc0_promo=" SIZE_FORMAT,
gc0_duration(), gc0_period(), gc0_promoted());
- st->print(",cms_dur=%g,cms_dur_per_mb=%g,cms_per=%g,cms_alloc=" SIZE_FORMAT,
- cms_duration(), cms_duration_per_mb(),
- cms_period(), cms_allocated());
+ st->print(",cms_dur=%g,cms_per=%g,cms_alloc=" SIZE_FORMAT,
+ cms_duration(), cms_period(), cms_allocated());
st->print(",cms_since_beg=%g,cms_since_end=%g",
cms_time_since_begin(), cms_time_since_end());
st->print(",cms_used_beg=" SIZE_FORMAT ",cms_used_end=" SIZE_FORMAT,
_cms_used_at_gc0_begin, _cms_used_at_gc0_end);
- if (CMSIncrementalMode) {
- st->print(",dc=%d", icms_duty_cycle());
- }
if (valid()) {
st->print(",promo_rate=%g,cms_alloc_rate=%g",
@@ -579,8 +499,6 @@
#endif
_collection_count_start(0),
_verifying(false),
- _icms_start_limit(NULL),
- _icms_stop_limit(NULL),
_verification_mark_bm(0, Mutex::leaf + 1, "CMS_verification_mark_bm_lock"),
_completed_initialization(false),
_collector_policy(cp),
@@ -1116,137 +1034,6 @@
}
}
-static inline size_t percent_of_space(Space* space, HeapWord* addr)
-{
- size_t delta = pointer_delta(addr, space->bottom());
- return (size_t)(delta * 100.0 / (space->capacity() / HeapWordSize));
-}
-
-void CMSCollector::icms_update_allocation_limits()
-{
- Generation* young = GenCollectedHeap::heap()->get_gen(0);
- EdenSpace* eden = young->as_DefNewGeneration()->eden();
-
- const unsigned int duty_cycle = stats().icms_update_duty_cycle();
- if (CMSTraceIncrementalPacing) {
- stats().print();
- }
-
- assert(duty_cycle <= 100, "invalid duty cycle");
- if (duty_cycle != 0) {
- // The duty_cycle is a percentage between 0 and 100; convert to words and
- // then compute the offset from the endpoints of the space.
- size_t free_words = eden->free() / HeapWordSize;
- double free_words_dbl = (double)free_words;
- size_t duty_cycle_words = (size_t)(free_words_dbl * duty_cycle / 100.0);
- size_t offset_words = (free_words - duty_cycle_words) / 2;
-
- _icms_start_limit = eden->top() + offset_words;
- _icms_stop_limit = eden->end() - offset_words;
-
- // The limits may be adjusted (shifted to the right) by
- // CMSIncrementalOffset, to allow the application more mutator time after a
- // young gen gc (when all mutators were stopped) and before CMS starts and
- // takes away one or more cpus.
- if (CMSIncrementalOffset != 0) {
- double adjustment_dbl = free_words_dbl * CMSIncrementalOffset / 100.0;
- size_t adjustment = (size_t)adjustment_dbl;
- HeapWord* tmp_stop = _icms_stop_limit + adjustment;
- if (tmp_stop > _icms_stop_limit && tmp_stop < eden->end()) {
- _icms_start_limit += adjustment;
- _icms_stop_limit = tmp_stop;
- }
- }
- }
- if (duty_cycle == 0 || (_icms_start_limit == _icms_stop_limit)) {
- _icms_start_limit = _icms_stop_limit = eden->end();
- }
-
- // Install the new start limit.
- eden->set_soft_end(_icms_start_limit);
-
- if (CMSTraceIncrementalMode) {
- gclog_or_tty->print(" icms alloc limits: "
- PTR_FORMAT "," PTR_FORMAT
- " (" SIZE_FORMAT "%%," SIZE_FORMAT "%%) ",
- p2i(_icms_start_limit), p2i(_icms_stop_limit),
- percent_of_space(eden, _icms_start_limit),
- percent_of_space(eden, _icms_stop_limit));
- if (Verbose) {
- gclog_or_tty->print("eden: ");
- eden->print_on(gclog_or_tty);
- }
- }
-}
-
-// Any changes here should try to maintain the invariant
-// that if this method is called with _icms_start_limit
-// and _icms_stop_limit both NULL, then it should return NULL
-// and not notify the icms thread.
-HeapWord*
-CMSCollector::allocation_limit_reached(Space* space, HeapWord* top,
- size_t word_size)
-{
- // A start_limit equal to end() means the duty cycle is 0, so treat that as a
- // nop.
- if (CMSIncrementalMode && _icms_start_limit != space->end()) {
- if (top <= _icms_start_limit) {
- if (CMSTraceIncrementalMode) {
- space->print_on(gclog_or_tty);
- gclog_or_tty->stamp();
- gclog_or_tty->print_cr(" start limit top=" PTR_FORMAT
- ", new limit=" PTR_FORMAT
- " (" SIZE_FORMAT "%%)",
- p2i(top), p2i(_icms_stop_limit),
- percent_of_space(space, _icms_stop_limit));
- }
- ConcurrentMarkSweepThread::start_icms();
- assert(top < _icms_stop_limit, "Tautology");
- if (word_size < pointer_delta(_icms_stop_limit, top)) {
- return _icms_stop_limit;
- }
-
- // The allocation will cross both the _start and _stop limits, so do the
- // stop notification also and return end().
- if (CMSTraceIncrementalMode) {
- space->print_on(gclog_or_tty);
- gclog_or_tty->stamp();
- gclog_or_tty->print_cr(" +stop limit top=" PTR_FORMAT
- ", new limit=" PTR_FORMAT
- " (" SIZE_FORMAT "%%)",
- p2i(top), p2i(space->end()),
- percent_of_space(space, space->end()));
- }
- ConcurrentMarkSweepThread::stop_icms();
- return space->end();
- }
-
- if (top <= _icms_stop_limit) {
- if (CMSTraceIncrementalMode) {
- space->print_on(gclog_or_tty);
- gclog_or_tty->stamp();
- gclog_or_tty->print_cr(" stop limit top=" PTR_FORMAT
- ", new limit=" PTR_FORMAT
- " (" SIZE_FORMAT "%%)",
- top, space->end(),
- percent_of_space(space, space->end()));
- }
- ConcurrentMarkSweepThread::stop_icms();
- return space->end();
- }
-
- if (CMSTraceIncrementalMode) {
- space->print_on(gclog_or_tty);
- gclog_or_tty->stamp();
- gclog_or_tty->print_cr(" end limit top=" PTR_FORMAT
- ", new limit=" PTR_FORMAT,
- top, NULL);
- }
- }
-
- return NULL;
-}
-
oop ConcurrentMarkSweepGeneration::promote(oop obj, size_t obj_size) {
assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
// allocate, copy and if necessary update promoinfo --
@@ -1289,14 +1076,6 @@
}
-HeapWord*
-ConcurrentMarkSweepGeneration::allocation_limit_reached(Space* space,
- HeapWord* top,
- size_t word_sz)
-{
- return collector()->allocation_limit_reached(space, top, word_sz);
-}
-
// IMPORTANT: Notes on object size recognition in CMS.
// ---------------------------------------------------
// A block of storage in the CMS generation is always in
@@ -1809,9 +1588,6 @@
// we want to do a foreground collection.
_foregroundGCIsActive = true;
- // Disable incremental mode during a foreground collection.
- ICMSDisabler icms_disabler;
-
// release locks and wait for a notify from the background collector
// releasing the locks in only necessary for phases which
// do yields to improve the granularity of the collection.
@@ -2135,7 +1911,7 @@
void CMSCollector::print_eden_and_survivor_chunk_arrays() {
DefNewGeneration* dng = _young_gen->as_DefNewGeneration();
- EdenSpace* eden_space = dng->eden();
+ ContiguousSpace* eden_space = dng->eden();
ContiguousSpace* from_space = dng->from();
ContiguousSpace* to_space = dng->to();
// Eden
@@ -2783,10 +2559,6 @@
//
_cmsGen->update_counters(cms_used);
- if (CMSIncrementalMode) {
- icms_update_allocation_limits();
- }
-
bitMapLock()->unlock();
releaseFreelistLocks();
@@ -4272,12 +4044,10 @@
assert_lock_strong(_bit_map_lock);
_bit_map_lock->unlock();
ConcurrentMarkSweepThread::desynchronize(true);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
_collector->stopTimer();
if (PrintCMSStatistics != 0) {
_collector->incrementYields();
}
- _collector->icms_wait();
// It is possible for whichever thread initiated the yield request
// not to get a chance to wake up and take the bitmap lock between
@@ -4307,7 +4077,6 @@
ConcurrentMarkSweepThread::should_yield() &&
!CMSCollector::foregroundGCIsActive(); ++i) {
os::sleep(Thread::current(), 1, false);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
}
ConcurrentMarkSweepThread::synchronize(true);
@@ -5238,7 +5007,7 @@
void CMSParMarkTask::work_on_young_gen_roots(uint worker_id, OopsInGenClosure* cl) {
DefNewGeneration* dng = _collector->_young_gen->as_DefNewGeneration();
- EdenSpace* eden_space = dng->eden();
+ ContiguousSpace* eden_space = dng->eden();
ContiguousSpace* from_space = dng->from();
ContiguousSpace* to_space = dng->to();
@@ -5410,7 +5179,7 @@
while (!pst->is_task_claimed(/* reference */ nth_task)) {
// We claimed task # nth_task; compute its boundaries.
if (chunk_top == 0) { // no samples were taken
- assert(nth_task == 0 && n_tasks == 1, "Can have only 1 EdenSpace task");
+ assert(nth_task == 0 && n_tasks == 1, "Can have only 1 eden task");
start = space->bottom();
end = space->top();
} else if (nth_task == 0) {
@@ -5788,7 +5557,7 @@
// process_roots (which currently doesn't know how to
// parallelize such a scan), but rather will be broken up into
// a set of parallel tasks (via the sampling that the [abortable]
- // preclean phase did of EdenSpace, plus the [two] tasks of
+ // preclean phase did of eden, plus the [two] tasks of
// scanning the [two] survivor spaces. Further fine-grain
// parallelization of the scanning of the survivor spaces
// themselves, and of precleaning of the younger gen itself
@@ -6474,19 +6243,16 @@
assert_lock_strong(bitMapLock());
bitMapLock()->unlock();
ConcurrentMarkSweepThread::desynchronize(true);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
stopTimer();
if (PrintCMSStatistics != 0) {
incrementYields();
}
- icms_wait();
// See the comment in coordinator_yield()
for (unsigned i = 0; i < CMSYieldSleepCount &&
ConcurrentMarkSweepThread::should_yield() &&
!CMSCollector::foregroundGCIsActive(); ++i) {
os::sleep(Thread::current(), 1, false);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
}
ConcurrentMarkSweepThread::synchronize(true);
@@ -6509,10 +6275,6 @@
_collectorState = Idling;
}
- // Stop incremental mode after a cycle completes, so that any future cycles
- // are triggered by allocation.
- stop_icms();
-
NOT_PRODUCT(
if (RotateCMSCollectionTypes) {
_cmsGen->rotate_debug_collection_type();
@@ -6964,12 +6726,10 @@
_bit_map->lock()->unlock();
_freelistLock->unlock();
ConcurrentMarkSweepThread::desynchronize(true);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
_collector->stopTimer();
if (PrintCMSStatistics != 0) {
_collector->incrementYields();
}
- _collector->icms_wait();
// See the comment in coordinator_yield()
for (unsigned i = 0;
@@ -6978,7 +6738,6 @@
!CMSCollector::foregroundGCIsActive();
++i) {
os::sleep(Thread::current(), 1, false);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
}
ConcurrentMarkSweepThread::synchronize(true);
@@ -7124,19 +6883,16 @@
_bitMap->lock()->unlock();
_freelistLock->unlock();
ConcurrentMarkSweepThread::desynchronize(true);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
_collector->stopTimer();
if (PrintCMSStatistics != 0) {
_collector->incrementYields();
}
- _collector->icms_wait();
// See the comment in coordinator_yield()
for (unsigned i = 0; i < CMSYieldSleepCount &&
ConcurrentMarkSweepThread::should_yield() &&
!CMSCollector::foregroundGCIsActive(); ++i) {
os::sleep(Thread::current(), 1, false);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
}
ConcurrentMarkSweepThread::synchronize(true);
@@ -7196,19 +6952,16 @@
// Relinquish the bit map lock
_bit_map->lock()->unlock();
ConcurrentMarkSweepThread::desynchronize(true);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
_collector->stopTimer();
if (PrintCMSStatistics != 0) {
_collector->incrementYields();
}
- _collector->icms_wait();
// See the comment in coordinator_yield()
for (unsigned i = 0; i < CMSYieldSleepCount &&
ConcurrentMarkSweepThread::should_yield() &&
!CMSCollector::foregroundGCIsActive(); ++i) {
os::sleep(Thread::current(), 1, false);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
}
ConcurrentMarkSweepThread::synchronize(true);
@@ -7354,19 +7107,16 @@
assert_lock_strong(_bitMap->lock());
_bitMap->lock()->unlock();
ConcurrentMarkSweepThread::desynchronize(true);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
_collector->stopTimer();
if (PrintCMSStatistics != 0) {
_collector->incrementYields();
}
- _collector->icms_wait();
// See the comment in coordinator_yield()
for (unsigned i = 0; i < CMSYieldSleepCount &&
ConcurrentMarkSweepThread::should_yield() &&
!CMSCollector::foregroundGCIsActive(); ++i) {
os::sleep(Thread::current(), 1, false);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
}
ConcurrentMarkSweepThread::synchronize(true);
@@ -7388,7 +7138,7 @@
_finger = ptr + obj->size();
assert(_finger > ptr, "we just incremented it above");
// On large heaps, it may take us some time to get through
- // the marking phase (especially if running iCMS). During
+ // the marking phase. During
// this time it's possible that a lot of mutations have
// accumulated in the card table and the mod union table --
// these mutation records are redundant until we have
@@ -7505,7 +7255,7 @@
_finger = ptr + obj->size();
assert(_finger > ptr, "we just incremented it above");
// On large heaps, it may take us some time to get through
- // the marking phase (especially if running iCMS). During
+ // the marking phase. During
// this time it's possible that a lot of mutations have
// accumulated in the card table and the mod union table --
// these mutation records are redundant until we have
@@ -7994,20 +7744,16 @@
bml->unlock();
ConcurrentMarkSweepThread::desynchronize(true);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
-
_collector->stopTimer();
if (PrintCMSStatistics != 0) {
_collector->incrementYields();
}
- _collector->icms_wait();
// See the comment in coordinator_yield()
for (unsigned i = 0; i < CMSYieldSleepCount &&
ConcurrentMarkSweepThread::should_yield() &&
!CMSCollector::foregroundGCIsActive(); ++i) {
os::sleep(Thread::current(), 1, false);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
}
ConcurrentMarkSweepThread::synchronize(true);
@@ -8675,19 +8421,16 @@
_bitMap->lock()->unlock();
_freelistLock->unlock();
ConcurrentMarkSweepThread::desynchronize(true);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
_collector->stopTimer();
if (PrintCMSStatistics != 0) {
_collector->incrementYields();
}
- _collector->icms_wait();
// See the comment in coordinator_yield()
for (unsigned i = 0; i < CMSYieldSleepCount &&
ConcurrentMarkSweepThread::should_yield() &&
!CMSCollector::foregroundGCIsActive(); ++i) {
os::sleep(Thread::current(), 1, false);
- ConcurrentMarkSweepThread::acknowledge_yield_request();
}
ConcurrentMarkSweepThread::synchronize(true);
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -356,7 +356,6 @@
size_t _gc0_promoted; // bytes promoted per gc0
double _cms_duration;
double _cms_duration_pre_sweep; // time from initiation to start of sweep
- double _cms_duration_per_mb;
double _cms_period;
size_t _cms_allocated; // bytes of direct allocation per gc0 period
@@ -383,17 +382,7 @@
unsigned int _valid_bits;
- unsigned int _icms_duty_cycle; // icms duty cycle (0-100).
-
protected:
-
- // Return a duty cycle that avoids wild oscillations, by limiting the amount
- // of change between old_duty_cycle and new_duty_cycle (the latter is treated
- // as a recommended value).
- static unsigned int icms_damped_duty_cycle(unsigned int old_duty_cycle,
- unsigned int new_duty_cycle);
- unsigned int icms_update_duty_cycle_impl();
-
// In support of adjusting of cms trigger ratios based on history
// of concurrent mode failure.
double cms_free_adjustment_factor(size_t free) const;
@@ -426,7 +415,6 @@
size_t gc0_promoted() const { return _gc0_promoted; }
double cms_period() const { return _cms_period; }
double cms_duration() const { return _cms_duration; }
- double cms_duration_per_mb() const { return _cms_duration_per_mb; }
size_t cms_allocated() const { return _cms_allocated; }
size_t cms_used_at_gc0_end() const { return _cms_used_at_gc0_end;}
@@ -458,12 +446,6 @@
// End of higher level statistics.
- // Returns the cms incremental mode duty cycle, as a percentage (0-100).
- unsigned int icms_duty_cycle() const { return _icms_duty_cycle; }
-
- // Update the duty cycle and return the new value.
- unsigned int icms_update_duty_cycle();
-
// Debugging.
void print_on(outputStream* st) const PRODUCT_RETURN;
void print() const { print_on(gclog_or_tty); }
@@ -725,13 +707,6 @@
// Timing, allocation and promotion statistics, used for scheduling.
CMSStats _stats;
- // Allocation limits installed in the young gen, used only in
- // CMSIncrementalMode. When an allocation in the young gen would cross one of
- // these limits, the cms generation is notified and the cms thread is started
- // or stopped, respectively.
- HeapWord* _icms_start_limit;
- HeapWord* _icms_stop_limit;
-
enum CMS_op_type {
CMS_op_checkpointRootsInitial,
CMS_op_checkpointRootsFinal
@@ -867,10 +842,6 @@
// collector.
bool waitForForegroundGC();
- // Incremental mode triggering: recompute the icms duty cycle and set the
- // allocation limits in the young gen.
- void icms_update_allocation_limits();
-
size_t block_size_using_printezis_bits(HeapWord* addr) const;
size_t block_size_if_printezis_bits(HeapWord* addr) const;
HeapWord* next_card_start_after_block(HeapWord* addr) const;
@@ -928,9 +899,6 @@
void promoted(bool par, HeapWord* start,
bool is_obj_array, size_t obj_size);
- HeapWord* allocation_limit_reached(Space* space, HeapWord* top,
- size_t word_size);
-
void getFreelistLocks() const;
void releaseFreelistLocks() const;
bool haveFreelistLocks() const;
@@ -1001,14 +969,6 @@
// Timers/stats for gc scheduling and incremental mode pacing.
CMSStats& stats() { return _stats; }
- // Convenience methods that check whether CMSIncrementalMode is enabled and
- // forward to the corresponding methods in ConcurrentMarkSweepThread.
- static void start_icms();
- static void stop_icms(); // Called at the end of the cms cycle.
- static void disable_icms(); // Called before a foreground collection.
- static void enable_icms(); // Called after a foreground collection.
- void icms_wait(); // Called at yield points.
-
// Adaptive size policy
AdaptiveSizePolicy* size_policy();
@@ -1211,9 +1171,6 @@
return allocate(size, tlab);
}
- // Incremental mode triggering.
- HeapWord* allocation_limit_reached(Space* space, HeapWord* top,
- size_t word_size);
// Used by CMSStats to track direct allocation. The value is sampled and
// reset after each young gen collection.
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.inline.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.inline.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -234,36 +234,6 @@
}
}
-inline void CMSCollector::start_icms() {
- if (CMSIncrementalMode) {
- ConcurrentMarkSweepThread::start_icms();
- }
-}
-
-inline void CMSCollector::stop_icms() {
- if (CMSIncrementalMode) {
- ConcurrentMarkSweepThread::stop_icms();
- }
-}
-
-inline void CMSCollector::disable_icms() {
- if (CMSIncrementalMode) {
- ConcurrentMarkSweepThread::disable_icms();
- }
-}
-
-inline void CMSCollector::enable_icms() {
- if (CMSIncrementalMode) {
- ConcurrentMarkSweepThread::enable_icms();
- }
-}
-
-inline void CMSCollector::icms_wait() {
- if (CMSIncrementalMode) {
- cmsThread()->icms_wait();
- }
-}
-
inline void CMSCollector::save_sweep_limits() {
_cmsGen->save_sweep_limit();
}
@@ -363,12 +333,6 @@
_cms_duration = AdaptiveWeightedAverage::exp_avg(_cms_duration,
cur_duration, _cms_alpha);
- // Avoid division by 0.
- const size_t cms_used_mb = MAX2(_cms_used_at_cms_begin / M, (size_t)1);
- _cms_duration_per_mb = AdaptiveWeightedAverage::exp_avg(_cms_duration_per_mb,
- cur_duration / cms_used_mb,
- _cms_alpha);
-
_cms_end_time.update();
_cms_alpha = _saved_alpha;
_allow_duty_cycle_reduction = true;
@@ -400,15 +364,6 @@
return (gc0_promoted() + cms_allocated()) / gc0_period();
}
-inline unsigned int CMSStats::icms_update_duty_cycle() {
- // Update the duty cycle only if pacing is enabled and the stats are valid
- // (after at least one young gen gc and one cms cycle have completed).
- if (CMSIncrementalPacing && valid()) {
- return icms_update_duty_cycle_impl();
- }
- return _icms_duty_cycle;
-}
-
inline void ConcurrentMarkSweepGeneration::save_sweep_limit() {
cmsSpace()->save_sweep_limit();
}
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -49,13 +49,6 @@
int ConcurrentMarkSweepThread::_CMS_flag = CMS_nil;
volatile jint ConcurrentMarkSweepThread::_pending_yields = 0;
-volatile jint ConcurrentMarkSweepThread::_pending_decrements = 0;
-
-volatile jint ConcurrentMarkSweepThread::_icms_disabled = 0;
-volatile bool ConcurrentMarkSweepThread::_should_run = false;
-// When icms is enabled, the icms thread is stopped until explicitly
-// started.
-volatile bool ConcurrentMarkSweepThread::_should_stop = true;
SurrogateLockerThread*
ConcurrentMarkSweepThread::_slt = NULL;
@@ -99,7 +92,6 @@
}
}
_sltMonitor = SLT_lock;
- assert(!CMSIncrementalMode || icms_is_enabled(), "Error");
}
void ConcurrentMarkSweepThread::run() {
@@ -184,11 +176,6 @@
}
void ConcurrentMarkSweepThread::stop() {
- if (CMSIncrementalMode) {
- // Disable incremental mode and wake up the thread so it notices the change.
- disable_icms();
- start_icms();
- }
// it is ok to take late safepoints here, if needed
{
MutexLockerEx x(Terminator_lock);
@@ -387,23 +374,13 @@
void ConcurrentMarkSweepThread::sleepBeforeNextCycle() {
while (!_should_terminate) {
- if (CMSIncrementalMode) {
- icms_wait();
- if(CMSWaitDuration >= 0) {
- // Wait until the next synchronous GC, a concurrent full gc
- // request or a timeout, whichever is earlier.
- wait_on_cms_lock_for_scavenge(CMSWaitDuration);
- }
- return;
+ if(CMSWaitDuration >= 0) {
+ // Wait until the next synchronous GC, a concurrent full gc
+ // request or a timeout, whichever is earlier.
+ wait_on_cms_lock_for_scavenge(CMSWaitDuration);
} else {
- if(CMSWaitDuration >= 0) {
- // Wait until the next synchronous GC, a concurrent full gc
- // request or a timeout, whichever is earlier.
- wait_on_cms_lock_for_scavenge(CMSWaitDuration);
- } else {
- // Wait until any cms_lock event or check interval not to call shouldConcurrentCollect permanently
- wait_on_cms_lock(CMSCheckInterval);
- }
+ // Wait until any cms_lock event or check interval not to call shouldConcurrentCollect permanently
+ wait_on_cms_lock(CMSCheckInterval);
}
// Check if we should start a CMS collection cycle
if (_collector->shouldConcurrentCollect()) {
@@ -414,42 +391,6 @@
}
}
-// Incremental CMS
-void ConcurrentMarkSweepThread::start_icms() {
- assert(UseConcMarkSweepGC && CMSIncrementalMode, "just checking");
- MutexLockerEx x(iCMS_lock, Mutex::_no_safepoint_check_flag);
- trace_state("start_icms");
- _should_run = true;
- iCMS_lock->notify_all();
-}
-
-void ConcurrentMarkSweepThread::stop_icms() {
- assert(UseConcMarkSweepGC && CMSIncrementalMode, "just checking");
- MutexLockerEx x(iCMS_lock, Mutex::_no_safepoint_check_flag);
- if (!_should_stop) {
- trace_state("stop_icms");
- _should_stop = true;
- _should_run = false;
- asynchronous_yield_request();
- iCMS_lock->notify_all();
- }
-}
-
-void ConcurrentMarkSweepThread::icms_wait() {
- assert(UseConcMarkSweepGC && CMSIncrementalMode, "just checking");
- if (_should_stop && icms_is_enabled()) {
- MutexLockerEx x(iCMS_lock, Mutex::_no_safepoint_check_flag);
- trace_state("pause_icms");
- _collector->stats().stop_cms_timer();
- while(!_should_run && icms_is_enabled()) {
- iCMS_lock->wait(Mutex::_no_safepoint_check_flag);
- }
- _collector->stats().start_cms_timer();
- _should_stop = false;
- trace_state("pause_icms end");
- }
-}
-
// Note: this method, although exported by the ConcurrentMarkSweepThread,
// which is a non-JavaThread, can only be called by a JavaThread.
// Currently this is done at vm creation time (post-vm-init) by the
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -64,20 +64,11 @@
static bool clear_CMS_flag(int b) { return (_CMS_flag &= ~b) != 0; }
void sleepBeforeNextCycle();
- // CMS thread should yield for a young gen collection, direct allocation,
- // and iCMS activity.
+ // CMS thread should yield for a young gen collection and direct allocations
static char _pad_1[64 - sizeof(jint)]; // prevent cache-line sharing
static volatile jint _pending_yields;
- static volatile jint _pending_decrements; // decrements to _pending_yields
static char _pad_2[64 - sizeof(jint)]; // prevent cache-line sharing
- // Tracing messages, enabled by CMSTraceThreadState.
- static inline void trace_state(const char* desc);
-
- static volatile int _icms_disabled; // a counter to track #iCMS disable & enable
- static volatile bool _should_run; // iCMS may run
- static volatile bool _should_stop; // iCMS should stop
-
// debugging
void verify_ok_to_terminate() const PRODUCT_RETURN;
@@ -135,44 +126,13 @@
void wait_on_cms_lock_for_scavenge(long t_millis);
// The CMS thread will yield during the work portion of its cycle
- // only when requested to. Both synchronous and asychronous requests
- // are provided:
- // (1) A synchronous request is used for young gen collections and
- // for direct allocations. The requesting thread increments
- // _pending_yields at the beginning of an operation, and decrements
- // _pending_yields when that operation is completed.
- // In turn, the CMS thread yields when _pending_yields is positive,
- // and continues to yield until the value reverts to 0.
- // (2) An asynchronous request, on the other hand, is used by iCMS
- // for the stop_icms() operation. A single yield satisfies all of
- // the outstanding asynch yield requests, of which there may
- // occasionally be several in close succession. To accomplish
- // this, an asynch-requesting thread atomically increments both
- // _pending_yields and _pending_decrements. An asynchr requesting
- // thread does not wait and "acknowledge" completion of an operation
- // and deregister the request, like the synchronous version described
- // above does. In turn, after yielding, the CMS thread decrements both
- // _pending_yields and _pending_decrements by the value seen in
- // _pending_decrements before the decrement.
- // NOTE: The above scheme is isomorphic to having two request counters,
- // one for async requests and one for sync requests, and for the CMS thread
- // to check the sum of the two counters to decide whether it should yield
- // and to clear only the async counter when it yields. However, it turns out
- // to be more efficient for CMS code to just check a single counter
- // _pending_yields that holds the sum (of both sync and async requests), and
- // a second counter _pending_decrements that only holds the async requests,
- // for greater efficiency, since in a typical CMS run, there are many more
- // potential (i.e. static) yield points than there are actual
- // (i.e. dynamic) yields because of requests, which are few and far between.
- //
- // Note that, while "_pending_yields >= _pending_decrements" is an invariant,
- // we cannot easily test that invariant, since the counters are manipulated via
- // atomic instructions without explicit locking and we cannot read
- // the two counters atomically together: one suggestion is to
- // use (for example) 16-bit counters so as to be able to read the
- // two counters atomically even on 32-bit platforms. Notice that
- // the second assert in acknowledge_yield_request() below does indeed
- // check a form of the above invariant, albeit indirectly.
+ // only when requested to.
+ // A synchronous request is used for young gen collections and
+ // for direct allocations. The requesting thread increments
+ // _pending_yields at the beginning of an operation, and decrements
+ // _pending_yields when that operation is completed.
+ // In turn, the CMS thread yields when _pending_yields is positive,
+ // and continues to yield until the value reverts to 0.
static void increment_pending_yields() {
Atomic::inc(&_pending_yields);
@@ -182,67 +142,9 @@
Atomic::dec(&_pending_yields);
assert(_pending_yields >= 0, "can't be negative");
}
- static void asynchronous_yield_request() {
- assert(CMSIncrementalMode, "Currently only used w/iCMS");
- increment_pending_yields();
- Atomic::inc(&_pending_decrements);
- assert(_pending_decrements >= 0, "can't be negative");
- }
- static void acknowledge_yield_request() {
- jint decrement = _pending_decrements;
- if (decrement > 0) {
- assert(CMSIncrementalMode, "Currently only used w/iCMS");
- // Order important to preserve: _pending_yields >= _pending_decrements
- Atomic::add(-decrement, &_pending_decrements);
- Atomic::add(-decrement, &_pending_yields);
- assert(_pending_decrements >= 0, "can't be negative");
- assert(_pending_yields >= 0, "can't be negative");
- }
- }
static bool should_yield() { return _pending_yields > 0; }
-
- // CMS incremental mode.
- static void start_icms(); // notify thread to start a quantum of work
- static void stop_icms(); // request thread to stop working
- void icms_wait(); // if asked to stop, wait until notified to start
-
- // Incremental mode is enabled globally by the flag CMSIncrementalMode. It
- // must also be enabled/disabled dynamically to allow foreground collections.
-#define ICMS_ENABLING_ASSERT \
- assert((CMSIncrementalMode && _icms_disabled >= 0) || \
- (!CMSIncrementalMode && _icms_disabled <= 0), "Error")
-
- static inline void enable_icms() {
- ICMS_ENABLING_ASSERT;
- Atomic::dec(&_icms_disabled);
- }
- static inline void disable_icms() {
- ICMS_ENABLING_ASSERT;
- Atomic::inc(&_icms_disabled);
- }
- static inline bool icms_is_disabled() {
- ICMS_ENABLING_ASSERT;
- return _icms_disabled > 0;
- }
- static inline bool icms_is_enabled() {
- return !icms_is_disabled();
- }
};
-inline void ConcurrentMarkSweepThread::trace_state(const char* desc) {
- if (CMSTraceThreadState) {
- char buf[128];
- TimeStamp& ts = gclog_or_tty->time_stamp();
- if (!ts.is_updated()) {
- ts.update();
- }
- jio_snprintf(buf, sizeof(buf), " [%.3f: CMSThread %s] ",
- ts.seconds(), desc);
- buf[sizeof(buf) - 1] = '\0';
- gclog_or_tty->print("%s", buf);
- }
-}
-
// For scoped increment/decrement of (synchronous) yield requests
class CMSSynchronousYieldRequest: public StackObj {
public:
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -207,12 +207,6 @@
MutexLockerEx x(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
assert(_full_gc_count_before <= gch->total_full_collections(), "Error");
if (gch->total_full_collections() == _full_gc_count_before) {
- // Disable iCMS until the full collection is done, and
- // remember that we did so.
- CMSCollector::disable_icms();
- _disabled_icms = true;
- // In case CMS thread was in icms_wait(), wake it up.
- CMSCollector::start_icms();
// Nudge the CMS thread to start a concurrent collection.
CMSCollector::request_full_gc(_full_gc_count_before, _gc_cause);
} else {
@@ -276,8 +270,4 @@
FullGCCount_lock->wait(Mutex::_no_safepoint_check_flag);
}
}
- // Enable iCMS back if we disabled it earlier.
- if (_disabled_icms) {
- CMSCollector::enable_icms();
- }
}
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -128,13 +128,11 @@
// VM operation to invoke a concurrent collection of the heap as a
// GenCollectedHeap heap.
class VM_GenCollectFullConcurrent: public VM_GC_Operation {
- bool _disabled_icms;
public:
VM_GenCollectFullConcurrent(unsigned int gc_count_before,
unsigned int full_gc_count_before,
GCCause::Cause gc_cause)
- : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true /* full */),
- _disabled_icms(false)
+ : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true /* full */)
{
assert(FullGCCount_lock != NULL, "Error");
assert(UseAsyncConcMarkSweepGC, "Else will hang caller");
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -180,9 +180,32 @@
}
};
+class ParClearNextMarkBitmapTask : public AbstractGangTask {
+ ClearBitmapHRClosure* _cl;
+ HeapRegionClaimer _hrclaimer;
+ bool _suspendible; // If the task is suspendible, workers must join the STS.
+
+public:
+ ParClearNextMarkBitmapTask(ClearBitmapHRClosure *cl, uint n_workers, bool suspendible) :
+ _cl(cl), _suspendible(suspendible), AbstractGangTask("Parallel Clear Bitmap Task"), _hrclaimer(n_workers) {}
+
+ void work(uint worker_id) {
+ if (_suspendible) {
+ SuspendibleThreadSet::join();
+ }
+ G1CollectedHeap::heap()->heap_region_par_iterate(_cl, worker_id, &_hrclaimer);
+ if (_suspendible) {
+ SuspendibleThreadSet::leave();
+ }
+ }
+};
+
void CMBitMap::clearAll() {
+ G1CollectedHeap* g1h = G1CollectedHeap::heap();
ClearBitmapHRClosure cl(NULL, this, false /* may_yield */);
- G1CollectedHeap::heap()->heap_region_iterate(&cl);
+ uint n_workers = g1h->workers()->active_workers();
+ ParClearNextMarkBitmapTask task(&cl, n_workers, false);
+ g1h->workers()->run_task(&task);
guarantee(cl.complete(), "Must have completed iteration.");
return;
}
@@ -861,7 +884,8 @@
guarantee(!g1h->mark_in_progress(), "invariant");
ClearBitmapHRClosure cl(this, _nextMarkBitMap, true /* may_yield */);
- g1h->heap_region_iterate(&cl);
+ ParClearNextMarkBitmapTask task(&cl, parallel_marking_threads(), true);
+ _parallel_workers->run_task(&task);
// Clear the liveness counting data. If the marking has been aborted, the abort()
// call already did that.
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMarkThread.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMarkThread.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -280,7 +280,6 @@
// We may have aborted just before the remark. Do not bother clearing the
// bitmap then, as it has been done during mark abort.
if (!cm()->has_aborted()) {
- SuspendibleThreadSetJoiner sts;
_cm->clearNextBitmap();
} else {
assert(!G1VerifyBitmaps || _cm->nextMarkBitmapIsClear(), "Next mark bitmap must be clear");
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -1248,7 +1248,7 @@
// The same as above but assume that the caller holds the Heap_lock.
void collect_locked(GCCause::Cause cause);
- virtual void copy_allocation_context_stats(const jint* contexts,
+ virtual bool copy_allocation_context_stats(const jint* contexts,
jlong* totals,
jbyte* accuracy,
jint len);
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap_ext.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap_ext.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -25,8 +25,9 @@
#include "precompiled.hpp"
#include "gc_implementation/g1/g1CollectedHeap.hpp"
-void G1CollectedHeap::copy_allocation_context_stats(const jint* contexts,
+bool G1CollectedHeap::copy_allocation_context_stats(const jint* contexts,
jlong* totals,
jbyte* accuracy,
jint len) {
+ return false;
}
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -1585,34 +1585,22 @@
}
};
+uint G1CollectorPolicy::calculate_parallel_work_chunk_size(uint n_workers, uint n_regions) {
+ assert(n_workers > 0, "Active gc workers should be greater than 0");
+ const uint overpartition_factor = 4;
+ const uint min_chunk_size = MAX2(n_regions / n_workers, 1U);
+ return MAX2(n_regions / (n_workers * overpartition_factor), min_chunk_size);
+}
+
void
-G1CollectorPolicy::record_concurrent_mark_cleanup_end(int no_of_gc_threads) {
+G1CollectorPolicy::record_concurrent_mark_cleanup_end(uint n_workers) {
_collectionSetChooser->clear();
- uint region_num = _g1->num_regions();
- const uint OverpartitionFactor = 4;
- uint WorkUnit;
- // The use of MinChunkSize = 8 in the original code
- // causes some assertion failures when the total number of
- // region is less than 8. The code here tries to fix that.
- // Should the original code also be fixed?
- if (no_of_gc_threads > 0) {
- const uint MinWorkUnit = MAX2(region_num / no_of_gc_threads, 1U);
- WorkUnit = MAX2(region_num / (no_of_gc_threads * OverpartitionFactor),
- MinWorkUnit);
- } else {
- assert(no_of_gc_threads > 0,
- "The active gc workers should be greater than 0");
- // In a product build do something reasonable to avoid a crash.
- const uint MinWorkUnit = MAX2(region_num / (uint) ParallelGCThreads, 1U);
- WorkUnit =
- MAX2(region_num / (uint) (ParallelGCThreads * OverpartitionFactor),
- MinWorkUnit);
- }
- _collectionSetChooser->prepare_for_par_region_addition(_g1->num_regions(),
- WorkUnit);
- ParKnownGarbageTask parKnownGarbageTask(_collectionSetChooser, WorkUnit, (uint) no_of_gc_threads);
- _g1->workers()->run_task(&parKnownGarbageTask);
+ uint n_regions = _g1->num_regions();
+ uint chunk_size = calculate_parallel_work_chunk_size(n_workers, n_regions);
+ _collectionSetChooser->prepare_for_par_region_addition(n_regions, chunk_size);
+ ParKnownGarbageTask par_known_garbage_task(_collectionSetChooser, chunk_size, n_workers);
+ _g1->workers()->run_task(&par_known_garbage_task);
_collectionSetChooser->sort_regions();
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -612,6 +612,10 @@
uint desired_min_length,
uint desired_max_length);
+ // Calculate and return chunk size (in number of regions) for parallel
+ // concurrent mark cleanup.
+ uint calculate_parallel_work_chunk_size(uint n_workers, uint n_regions);
+
// Check whether a given young length (young_length) fits into the
// given target pause time and whether the prediction for the amount
// of objects to be copied for the given length will fit into the
@@ -687,7 +691,7 @@
// Record start, end, and completion of cleanup.
void record_concurrent_mark_cleanup_start();
- void record_concurrent_mark_cleanup_end(int no_of_gc_threads);
+ void record_concurrent_mark_cleanup_end(uint n_workers);
void record_concurrent_mark_cleanup_completed();
// Records the information about the heap size for reporting in
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -960,6 +960,10 @@
verify(VerifyOption_G1UsePrevMarking, /* failures */ &dummy);
}
+void HeapRegion::prepare_for_compaction(CompactPoint* cp) {
+ scan_and_forward(this, cp);
+}
+
// G1OffsetTableContigSpace code; copied from space.cpp. Hope this can go
// away eventually.
@@ -1043,12 +1047,6 @@
}
}
-#define block_is_always_obj(q) true
-void G1OffsetTableContigSpace::prepare_for_compaction(CompactPoint* cp) {
- SCAN_AND_FORWARD(cp, top, block_is_always_obj, block_size);
-}
-#undef block_is_always_obj
-
G1OffsetTableContigSpace::
G1OffsetTableContigSpace(G1BlockOffsetSharedArray* sharedOffsetArray,
MemRegion mr) :
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -187,8 +187,6 @@
HeapWord* block_start(const void* p);
HeapWord* block_start_const(const void* p) const;
- void prepare_for_compaction(CompactPoint* cp);
-
// Add offset table update.
virtual HeapWord* allocate(size_t word_size);
HeapWord* par_allocate(size_t word_size);
@@ -210,6 +208,9 @@
class HeapRegion: public G1OffsetTableContigSpace {
friend class VMStructs;
+ // Allow scan_and_forward to call (private) overrides for auxiliary functions on this class
+ template <typename SpaceType>
+ friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp);
private:
// The remembered set for this region.
@@ -219,6 +220,20 @@
G1BlockOffsetArrayContigSpace* offsets() { return &_offsets; }
+ // Auxiliary functions for scan_and_forward support.
+ // See comments for CompactibleSpace for more information.
+ inline HeapWord* scan_limit() const {
+ return top();
+ }
+
+ inline bool scanned_block_is_obj(const HeapWord* addr) const {
+ return true; // Always true, since scan_limit is top
+ }
+
+ inline size_t scanned_block_size(const HeapWord* addr) const {
+ return HeapRegion::block_size(addr); // Avoid virtual call
+ }
+
protected:
// The index of this region in the heap region sequence.
uint _hrm_index;
@@ -340,6 +355,9 @@
// and the amount of unallocated words if called on top()
size_t block_size(const HeapWord* p) const;
+ // Override for scan_and_forward support.
+ void prepare_for_compaction(CompactPoint* cp);
+
inline HeapWord* par_allocate_no_bot_updates(size_t word_size);
inline HeapWord* allocate_no_bot_updates(size_t word_size);
--- a/hotspot/src/share/vm/gc_implementation/shared/markSweep.inline.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_implementation/shared/markSweep.inline.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -27,6 +27,7 @@
#include "gc_implementation/shared/markSweep.hpp"
#include "gc_interface/collectedHeap.hpp"
+#include "oops/markOop.inline.hpp"
#include "utilities/stack.inline.hpp"
#include "utilities/macros.hpp"
#if INCLUDE_ALL_GCS
--- a/hotspot/src/share/vm/gc_interface/collectedHeap.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/gc_interface/collectedHeap.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -644,10 +644,13 @@
// For each context in contexts, set the corresponding entries in the totals
// and accuracy arrays to the current values held by the statistics. Each
// array should be of length len.
- virtual void copy_allocation_context_stats(const jint* contexts,
+ // Returns true if there are more stats available.
+ virtual bool copy_allocation_context_stats(const jint* contexts,
jlong* totals,
jbyte* accuracy,
- jint len) { }
+ jint len) {
+ return false;
+ }
/////////////// Unit tests ///////////////
--- a/hotspot/src/share/vm/memory/collectorPolicy.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/memory/collectorPolicy.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -189,11 +189,6 @@
return CollectorPolicy::CollectorPolicyKind;
}
- // Returns true if a collector has eden space with soft end.
- virtual bool has_soft_ended_eden() {
- return false;
- }
-
// Do any updates required to global flags that are due to heap initialization
// changes
virtual void post_heap_initialize() = 0;
--- a/hotspot/src/share/vm/memory/defNewGeneration.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/memory/defNewGeneration.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -194,11 +194,7 @@
(HeapWord*)_virtual_space.high());
Universe::heap()->barrier_set()->resize_covered_region(cmr);
- if (GenCollectedHeap::heap()->collector_policy()->has_soft_ended_eden()) {
- _eden_space = new ConcEdenSpace(this);
- } else {
- _eden_space = new EdenSpace(this);
- }
+ _eden_space = new ContiguousSpace();
_from_space = new ContiguousSpace();
_to_space = new ContiguousSpace();
@@ -1038,38 +1034,12 @@
if (CMSEdenChunksRecordAlways && _next_gen != NULL) {
_next_gen->sample_eden_chunk();
}
- return result;
- }
- do {
- HeapWord* old_limit = eden()->soft_end();
- if (old_limit < eden()->end()) {
- // Tell the next generation we reached a limit.
- HeapWord* new_limit =
- next_gen()->allocation_limit_reached(eden(), eden()->top(), word_size);
- if (new_limit != NULL) {
- Atomic::cmpxchg_ptr(new_limit, eden()->soft_end_addr(), old_limit);
- } else {
- assert(eden()->soft_end() == eden()->end(),
- "invalid state after allocation_limit_reached returned null");
- }
- } else {
- // The allocation failed and the soft limit is equal to the hard limit,
- // there are no reasons to do an attempt to allocate
- assert(old_limit == eden()->end(), "sanity check");
- break;
- }
- // Try to allocate until succeeded or the soft limit can't be adjusted
- result = eden()->par_allocate(word_size);
- } while (result == NULL);
-
- // If the eden is full and the last collection bailed out, we are running
- // out of heap space, and we try to allocate the from-space, too.
- // allocate_from_space can't be inlined because that would introduce a
- // circular dependency at compile time.
- if (result == NULL) {
+ } else {
+ // If the eden is full and the last collection bailed out, we are running
+ // out of heap space, and we try to allocate the from-space, too.
+ // allocate_from_space can't be inlined because that would introduce a
+ // circular dependency at compile time.
result = allocate_from_space(word_size);
- } else if (CMSEdenChunksRecordAlways && _next_gen != NULL) {
- _next_gen->sample_eden_chunk();
}
return result;
}
@@ -1083,11 +1053,6 @@
return res;
}
-void DefNewGeneration::gc_prologue(bool full) {
- // Ensure that _end and _soft_end are the same in eden space.
- eden()->set_soft_end(eden()->end());
-}
-
size_t DefNewGeneration::tlab_capacity() const {
return eden()->capacity();
}
--- a/hotspot/src/share/vm/memory/defNewGeneration.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/memory/defNewGeneration.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -32,7 +32,6 @@
#include "memory/generation.inline.hpp"
#include "utilities/stack.hpp"
-class EdenSpace;
class ContiguousSpace;
class ScanClosure;
class STWGCTimer;
@@ -132,7 +131,7 @@
void adjust_desired_tenuring_threshold();
// Spaces
- EdenSpace* _eden_space;
+ ContiguousSpace* _eden_space;
ContiguousSpace* _from_space;
ContiguousSpace* _to_space;
@@ -214,9 +213,9 @@
virtual Generation::Name kind() { return Generation::DefNew; }
// Accessing spaces
- EdenSpace* eden() const { return _eden_space; }
- ContiguousSpace* from() const { return _from_space; }
- ContiguousSpace* to() const { return _to_space; }
+ ContiguousSpace* eden() const { return _eden_space; }
+ ContiguousSpace* from() const { return _from_space; }
+ ContiguousSpace* to() const { return _to_space; }
virtual CompactibleSpace* first_compaction_space() const;
@@ -282,8 +281,6 @@
HeapWord* par_allocate(size_t word_size, bool is_tlab);
- // Prologue & Epilogue
- virtual void gc_prologue(bool full);
virtual void gc_epilogue(bool full);
// Save the tops for eden, from, and to
--- a/hotspot/src/share/vm/memory/generation.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/memory/generation.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -265,14 +265,6 @@
// Like "allocate", but performs any necessary locking internally.
virtual HeapWord* par_allocate(size_t word_size, bool is_tlab) = 0;
- // A 'younger' gen has reached an allocation limit, and uses this to notify
- // the next older gen. The return value is a new limit, or NULL if none. The
- // caller must do the necessary locking.
- virtual HeapWord* allocation_limit_reached(Space* space, HeapWord* top,
- size_t word_size) {
- return NULL;
- }
-
// Some generation may offer a region for shared, contiguous allocation,
// via inlined code (by exporting the address of the top and end fields
// defining the extent of the contiguous allocation region.)
--- a/hotspot/src/share/vm/memory/space.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/memory/space.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -438,52 +438,8 @@
}
}
-#define block_is_always_obj(q) true
-#define obj_size(q) oop(q)->size()
-#define adjust_obj_size(s) s
-
-void CompactibleSpace::prepare_for_compaction(CompactPoint* cp) {
- SCAN_AND_FORWARD(cp, end, block_is_obj, block_size);
-}
-
-// Faster object search.
void ContiguousSpace::prepare_for_compaction(CompactPoint* cp) {
- SCAN_AND_FORWARD(cp, top, block_is_always_obj, obj_size);
-}
-
-void Space::adjust_pointers() {
- // adjust all the interior pointers to point at the new locations of objects
- // Used by MarkSweep::mark_sweep_phase3()
-
- // First check to see if there is any work to be done.
- if (used() == 0) {
- return; // Nothing to do.
- }
-
- // Otherwise...
- HeapWord* q = bottom();
- HeapWord* t = end();
-
- debug_only(HeapWord* prev_q = NULL);
- while (q < t) {
- if (oop(q)->is_gc_marked()) {
- // q is alive
-
- // point all the oops to the new location
- size_t size = oop(q)->adjust_pointers();
-
- debug_only(prev_q = q);
-
- q += size;
- } else {
- // q is not a live object. But we're not in a compactible space,
- // So we don't have live ranges.
- debug_only(prev_q = q);
- q += block_size(q);
- assert(q > prev_q, "we should be moving forward through memory");
- }
- }
- assert(q == t, "just checking");
+ scan_and_forward(this, cp);
}
void CompactibleSpace::adjust_pointers() {
@@ -492,11 +448,11 @@
return; // Nothing to do.
}
- SCAN_AND_ADJUST_POINTERS(adjust_obj_size);
+ scan_and_adjust_pointers(this);
}
void CompactibleSpace::compact() {
- SCAN_AND_COMPACT(obj_size);
+ scan_and_compact(this);
}
void Space::print_short() const { print_short_on(tty); }
@@ -684,13 +640,12 @@
}
// This version requires locking.
-inline HeapWord* ContiguousSpace::allocate_impl(size_t size,
- HeapWord* const end_value) {
+inline HeapWord* ContiguousSpace::allocate_impl(size_t size) {
assert(Heap_lock->owned_by_self() ||
(SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread()),
"not locked");
HeapWord* obj = top();
- if (pointer_delta(end_value, obj) >= size) {
+ if (pointer_delta(end(), obj) >= size) {
HeapWord* new_top = obj + size;
set_top(new_top);
assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
@@ -701,11 +656,10 @@
}
// This version is lock-free.
-inline HeapWord* ContiguousSpace::par_allocate_impl(size_t size,
- HeapWord* const end_value) {
+inline HeapWord* ContiguousSpace::par_allocate_impl(size_t size) {
do {
HeapWord* obj = top();
- if (pointer_delta(end_value, obj) >= size) {
+ if (pointer_delta(end(), obj) >= size) {
HeapWord* new_top = obj + size;
HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
// result can be one of two:
@@ -744,12 +698,12 @@
// Requires locking.
HeapWord* ContiguousSpace::allocate(size_t size) {
- return allocate_impl(size, end());
+ return allocate_impl(size);
}
// Lock-free.
HeapWord* ContiguousSpace::par_allocate(size_t size) {
- return par_allocate_impl(size, end());
+ return par_allocate_impl(size);
}
void ContiguousSpace::allocate_temporary_filler(int factor) {
@@ -784,49 +738,6 @@
}
}
-void EdenSpace::clear(bool mangle_space) {
- ContiguousSpace::clear(mangle_space);
- set_soft_end(end());
-}
-
-// Requires locking.
-HeapWord* EdenSpace::allocate(size_t size) {
- return allocate_impl(size, soft_end());
-}
-
-// Lock-free.
-HeapWord* EdenSpace::par_allocate(size_t size) {
- return par_allocate_impl(size, soft_end());
-}
-
-HeapWord* ConcEdenSpace::par_allocate(size_t size)
-{
- do {
- // The invariant is top() should be read before end() because
- // top() can't be greater than end(), so if an update of _soft_end
- // occurs between 'end_val = end();' and 'top_val = top();' top()
- // also can grow up to the new end() and the condition
- // 'top_val > end_val' is true. To ensure the loading order
- // OrderAccess::loadload() is required after top() read.
- HeapWord* obj = top();
- OrderAccess::loadload();
- if (pointer_delta(*soft_end_addr(), obj) >= size) {
- HeapWord* new_top = obj + size;
- HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
- // result can be one of two:
- // the old top value: the exchange succeeded
- // otherwise: the new value of the top is returned.
- if (result == obj) {
- assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
- return obj;
- }
- } else {
- return NULL;
- }
- } while (true);
-}
-
-
HeapWord* OffsetTableContigSpace::initialize_threshold() {
return _offsets.initialize_threshold();
}
--- a/hotspot/src/share/vm/memory/space.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/memory/space.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -41,19 +41,6 @@
// implementations for keeping track of free and used space,
// for iterating over objects and free blocks, etc.
-// Here's the Space hierarchy:
-//
-// - Space -- an abstract base class describing a heap area
-// - CompactibleSpace -- a space supporting compaction
-// - CompactibleFreeListSpace -- (used for CMS generation)
-// - ContiguousSpace -- a compactible space in which all free space
-// is contiguous
-// - EdenSpace -- contiguous space used as nursery
-// - ConcEdenSpace -- contiguous space with a 'soft end safe' allocation
-// - OffsetTableContigSpace -- contiguous space with a block offset array
-// that allows "fast" block_start calls
-// - TenuredSpace -- (used for TenuredGeneration)
-
// Forward decls.
class Space;
class BlockOffsetArray;
@@ -238,7 +225,7 @@
// Mark-sweep-compact support: all spaces can update pointers to objects
// moving as a part of compaction.
- virtual void adjust_pointers();
+ virtual void adjust_pointers() = 0;
// PrintHeapAtGC support
virtual void print() const;
@@ -339,7 +326,36 @@
// necessarily, a space that is normally contiguous. But, for example, a
// free-list-based space whose normal collection is a mark-sweep without
// compaction could still support compaction in full GC's.
-
+//
+// The compaction operations are implemented by the
+// scan_and_{adjust_pointers,compact,forward} function templates.
+// The following are, non-virtual, auxiliary functions used by these function templates:
+// - scan_limit()
+// - scanned_block_is_obj()
+// - scanned_block_size()
+// - adjust_obj_size()
+// - obj_size()
+// These functions are to be used exclusively by the scan_and_* function templates,
+// and must be defined for all (non-abstract) subclasses of CompactibleSpace.
+//
+// NOTE: Any subclasses to CompactibleSpace wanting to change/define the behavior
+// in any of the auxiliary functions must also override the corresponding
+// prepare_for_compaction/adjust_pointers/compact functions using them.
+// If not, such changes will not be used or have no effect on the compaction operations.
+//
+// This translates to the following dependencies:
+// Overrides/definitions of
+// - scan_limit
+// - scanned_block_is_obj
+// - scanned_block_size
+// require override/definition of prepare_for_compaction().
+// Similar dependencies exist between
+// - adjust_obj_size and adjust_pointers()
+// - obj_size and compact().
+//
+// Additionally, this also means that changes to block_size() or block_is_obj() that
+// should be effective during the compaction operations must provide a corresponding
+// definition of scanned_block_size/scanned_block_is_obj respectively.
class CompactibleSpace: public Space {
friend class VMStructs;
friend class CompactibleFreeListSpace;
@@ -347,6 +363,15 @@
HeapWord* _compaction_top;
CompactibleSpace* _next_compaction_space;
+ // Auxiliary functions for scan_and_{forward,adjust_pointers,compact} support.
+ inline size_t adjust_obj_size(size_t size) const {
+ return size;
+ }
+
+ inline size_t obj_size(const HeapWord* addr) const {
+ return oop(addr)->size();
+ }
+
public:
CompactibleSpace() :
_compaction_top(NULL), _next_compaction_space(NULL) {}
@@ -390,7 +415,7 @@
// "cp->compaction_space" up-to-date. Offset tables may be updated in
// this phase as if the final copy had occurred; if so, "cp->threshold"
// indicates when the next such action should be taken.
- virtual void prepare_for_compaction(CompactPoint* cp);
+ virtual void prepare_for_compaction(CompactPoint* cp) = 0;
// MarkSweep support phase3
virtual void adjust_pointers();
// MarkSweep support phase4
@@ -449,6 +474,25 @@
// words remaining after this operation.
bool insert_deadspace(size_t& allowed_deadspace_words, HeapWord* q,
size_t word_len);
+
+ // Below are template functions for scan_and_* algorithms (avoiding virtual calls).
+ // The space argument should be a subclass of CompactibleSpace, implementing
+ // scan_limit(), scanned_block_is_obj(), and scanned_block_size(),
+ // and possibly also overriding obj_size(), and adjust_obj_size().
+ // These functions should avoid virtual calls whenever possible.
+
+ // Frequently calls adjust_obj_size().
+ template <class SpaceType>
+ static inline void scan_and_adjust_pointers(SpaceType* space);
+
+ // Frequently calls obj_size().
+ template <class SpaceType>
+ static inline void scan_and_compact(SpaceType* space);
+
+ // Frequently calls scanned_block_is_obj() and scanned_block_size().
+ // Requires the scan_limit() function.
+ template <class SpaceType>
+ static inline void scan_and_forward(SpaceType* space, CompactPoint* cp);
};
class GenSpaceMangler;
@@ -458,6 +502,25 @@
class ContiguousSpace: public CompactibleSpace {
friend class OneContigSpaceCardGeneration;
friend class VMStructs;
+ // Allow scan_and_forward function to call (private) overrides for auxiliary functions on this class
+ template <typename SpaceType>
+ friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp);
+
+ private:
+ // Auxiliary functions for scan_and_forward support.
+ // See comments for CompactibleSpace for more information.
+ inline HeapWord* scan_limit() const {
+ return top();
+ }
+
+ inline bool scanned_block_is_obj(const HeapWord* addr) const {
+ return true; // Always true, since scan_limit is top
+ }
+
+ inline size_t scanned_block_size(const HeapWord* addr) const {
+ return oop(addr)->size();
+ }
+
protected:
HeapWord* _top;
HeapWord* _concurrent_iteration_safe_limit;
@@ -467,8 +530,8 @@
GenSpaceMangler* mangler() { return _mangler; }
// Allocation helpers (return NULL if full).
- inline HeapWord* allocate_impl(size_t word_size, HeapWord* end_value);
- inline HeapWord* par_allocate_impl(size_t word_size, HeapWord* end_value);
+ inline HeapWord* allocate_impl(size_t word_size);
+ inline HeapWord* par_allocate_impl(size_t word_size);
public:
ContiguousSpace();
@@ -622,7 +685,6 @@
// Used to increase collection frequency. "factor" of 0 means entire
// space.
void allocate_temporary_filler(int factor);
-
};
@@ -685,56 +747,6 @@
{}
};
-
-// Class EdenSpace describes eden-space in new generation.
-
-class DefNewGeneration;
-
-class EdenSpace : public ContiguousSpace {
- friend class VMStructs;
- private:
- DefNewGeneration* _gen;
-
- // _soft_end is used as a soft limit on allocation. As soft limits are
- // reached, the slow-path allocation code can invoke other actions and then
- // adjust _soft_end up to a new soft limit or to end().
- HeapWord* _soft_end;
-
- public:
- EdenSpace(DefNewGeneration* gen) :
- _gen(gen), _soft_end(NULL) {}
-
- // Get/set just the 'soft' limit.
- HeapWord* soft_end() { return _soft_end; }
- HeapWord** soft_end_addr() { return &_soft_end; }
- void set_soft_end(HeapWord* value) { _soft_end = value; }
-
- // Override.
- void clear(bool mangle_space);
-
- // Set both the 'hard' and 'soft' limits (_end and _soft_end).
- void set_end(HeapWord* value) {
- set_soft_end(value);
- ContiguousSpace::set_end(value);
- }
-
- // Allocation (return NULL if full)
- HeapWord* allocate(size_t word_size);
- HeapWord* par_allocate(size_t word_size);
-};
-
-// Class ConcEdenSpace extends EdenSpace for the sake of safe
-// allocation while soft-end is being modified concurrently
-
-class ConcEdenSpace : public EdenSpace {
- public:
- ConcEdenSpace(DefNewGeneration* gen) : EdenSpace(gen) { }
-
- // Allocation (return NULL if full)
- HeapWord* par_allocate(size_t word_size);
-};
-
-
// A ContigSpace that Supports an efficient "block_start" operation via
// a BlockOffsetArray (whose BlockOffsetSharedArray may be shared with
// other spaces.) This is the abstract base class for old generation
--- a/hotspot/src/share/vm/memory/space.inline.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/memory/space.inline.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -25,6 +25,9 @@
#ifndef SHARE_VM_MEMORY_SPACE_INLINE_HPP
#define SHARE_VM_MEMORY_SPACE_INLINE_HPP
+#include "gc_implementation/shared/liveRange.hpp"
+#include "gc_implementation/shared/markSweep.inline.hpp"
+#include "gc_implementation/shared/spaceDecorator.hpp"
#include "gc_interface/collectedHeap.hpp"
#include "memory/space.hpp"
#include "memory/universe.hpp"
@@ -35,272 +38,6 @@
return block_start_const(p);
}
-#define SCAN_AND_FORWARD(cp,scan_limit,block_is_obj,block_size) { \
- /* Compute the new addresses for the live objects and store it in the mark \
- * Used by universe::mark_sweep_phase2() \
- */ \
- HeapWord* compact_top; /* This is where we are currently compacting to. */ \
- \
- /* We're sure to be here before any objects are compacted into this \
- * space, so this is a good time to initialize this: \
- */ \
- set_compaction_top(bottom()); \
- \
- if (cp->space == NULL) { \
- assert(cp->gen != NULL, "need a generation"); \
- assert(cp->threshold == NULL, "just checking"); \
- assert(cp->gen->first_compaction_space() == this, "just checking"); \
- cp->space = cp->gen->first_compaction_space(); \
- compact_top = cp->space->bottom(); \
- cp->space->set_compaction_top(compact_top); \
- cp->threshold = cp->space->initialize_threshold(); \
- } else { \
- compact_top = cp->space->compaction_top(); \
- } \
- \
- /* We allow some amount of garbage towards the bottom of the space, so \
- * we don't start compacting before there is a significant gain to be made.\
- * Occasionally, we want to ensure a full compaction, which is determined \
- * by the MarkSweepAlwaysCompactCount parameter. \
- */ \
- uint invocations = MarkSweep::total_invocations(); \
- bool skip_dead = ((invocations % MarkSweepAlwaysCompactCount) != 0); \
- \
- size_t allowed_deadspace = 0; \
- if (skip_dead) { \
- const size_t ratio = allowed_dead_ratio(); \
- allowed_deadspace = (capacity() * ratio / 100) / HeapWordSize; \
- } \
- \
- HeapWord* q = bottom(); \
- HeapWord* t = scan_limit(); \
- \
- HeapWord* end_of_live= q; /* One byte beyond the last byte of the last \
- live object. */ \
- HeapWord* first_dead = end();/* The first dead object. */ \
- LiveRange* liveRange = NULL; /* The current live range, recorded in the \
- first header of preceding free area. */ \
- _first_dead = first_dead; \
- \
- const intx interval = PrefetchScanIntervalInBytes; \
- \
- while (q < t) { \
- assert(!block_is_obj(q) || \
- oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() || \
- oop(q)->mark()->has_bias_pattern(), \
- "these are the only valid states during a mark sweep"); \
- if (block_is_obj(q) && oop(q)->is_gc_marked()) { \
- /* prefetch beyond q */ \
- Prefetch::write(q, interval); \
- size_t size = block_size(q); \
- compact_top = cp->space->forward(oop(q), size, cp, compact_top); \
- q += size; \
- end_of_live = q; \
- } else { \
- /* run over all the contiguous dead objects */ \
- HeapWord* end = q; \
- do { \
- /* prefetch beyond end */ \
- Prefetch::write(end, interval); \
- end += block_size(end); \
- } while (end < t && (!block_is_obj(end) || !oop(end)->is_gc_marked()));\
- \
- /* see if we might want to pretend this object is alive so that \
- * we don't have to compact quite as often. \
- */ \
- if (allowed_deadspace > 0 && q == compact_top) { \
- size_t sz = pointer_delta(end, q); \
- if (insert_deadspace(allowed_deadspace, q, sz)) { \
- compact_top = cp->space->forward(oop(q), sz, cp, compact_top); \
- q = end; \
- end_of_live = end; \
- continue; \
- } \
- } \
- \
- /* otherwise, it really is a free region. */ \
- \
- /* for the previous LiveRange, record the end of the live objects. */ \
- if (liveRange) { \
- liveRange->set_end(q); \
- } \
- \
- /* record the current LiveRange object. \
- * liveRange->start() is overlaid on the mark word. \
- */ \
- liveRange = (LiveRange*)q; \
- liveRange->set_start(end); \
- liveRange->set_end(end); \
- \
- /* see if this is the first dead region. */ \
- if (q < first_dead) { \
- first_dead = q; \
- } \
- \
- /* move on to the next object */ \
- q = end; \
- } \
- } \
- \
- assert(q == t, "just checking"); \
- if (liveRange != NULL) { \
- liveRange->set_end(q); \
- } \
- _end_of_live = end_of_live; \
- if (end_of_live < first_dead) { \
- first_dead = end_of_live; \
- } \
- _first_dead = first_dead; \
- \
- /* save the compaction_top of the compaction space. */ \
- cp->space->set_compaction_top(compact_top); \
-}
-
-#define SCAN_AND_ADJUST_POINTERS(adjust_obj_size) { \
- /* adjust all the interior pointers to point at the new locations of objects \
- * Used by MarkSweep::mark_sweep_phase3() */ \
- \
- HeapWord* q = bottom(); \
- HeapWord* t = _end_of_live; /* Established by "prepare_for_compaction". */ \
- \
- assert(_first_dead <= _end_of_live, "Stands to reason, no?"); \
- \
- if (q < t && _first_dead > q && \
- !oop(q)->is_gc_marked()) { \
- /* we have a chunk of the space which hasn't moved and we've \
- * reinitialized the mark word during the previous pass, so we can't \
- * use is_gc_marked for the traversal. */ \
- HeapWord* end = _first_dead; \
- \
- while (q < end) { \
- /* I originally tried to conjoin "block_start(q) == q" to the \
- * assertion below, but that doesn't work, because you can't \
- * accurately traverse previous objects to get to the current one \
- * after their pointers have been \
- * updated, until the actual compaction is done. dld, 4/00 */ \
- assert(block_is_obj(q), \
- "should be at block boundaries, and should be looking at objs"); \
- \
- /* point all the oops to the new location */ \
- size_t size = oop(q)->adjust_pointers(); \
- size = adjust_obj_size(size); \
- \
- q += size; \
- } \
- \
- if (_first_dead == t) { \
- q = t; \
- } else { \
- /* $$$ This is funky. Using this to read the previously written \
- * LiveRange. See also use below. */ \
- q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer(); \
- } \
- } \
- \
- const intx interval = PrefetchScanIntervalInBytes; \
- \
- debug_only(HeapWord* prev_q = NULL); \
- while (q < t) { \
- /* prefetch beyond q */ \
- Prefetch::write(q, interval); \
- if (oop(q)->is_gc_marked()) { \
- /* q is alive */ \
- /* point all the oops to the new location */ \
- size_t size = oop(q)->adjust_pointers(); \
- size = adjust_obj_size(size); \
- debug_only(prev_q = q); \
- q += size; \
- } else { \
- /* q is not a live object, so its mark should point at the next \
- * live object */ \
- debug_only(prev_q = q); \
- q = (HeapWord*) oop(q)->mark()->decode_pointer(); \
- assert(q > prev_q, "we should be moving forward through memory"); \
- } \
- } \
- \
- assert(q == t, "just checking"); \
-}
-
-#define SCAN_AND_COMPACT(obj_size) { \
- /* Copy all live objects to their new location \
- * Used by MarkSweep::mark_sweep_phase4() */ \
- \
- HeapWord* q = bottom(); \
- HeapWord* const t = _end_of_live; \
- debug_only(HeapWord* prev_q = NULL); \
- \
- if (q < t && _first_dead > q && \
- !oop(q)->is_gc_marked()) { \
- debug_only( \
- /* we have a chunk of the space which hasn't moved and we've reinitialized \
- * the mark word during the previous pass, so we can't use is_gc_marked for \
- * the traversal. */ \
- HeapWord* const end = _first_dead; \
- \
- while (q < end) { \
- size_t size = obj_size(q); \
- assert(!oop(q)->is_gc_marked(), \
- "should be unmarked (special dense prefix handling)"); \
- debug_only(prev_q = q); \
- q += size; \
- } \
- ) /* debug_only */ \
- \
- if (_first_dead == t) { \
- q = t; \
- } else { \
- /* $$$ Funky */ \
- q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer(); \
- } \
- } \
- \
- const intx scan_interval = PrefetchScanIntervalInBytes; \
- const intx copy_interval = PrefetchCopyIntervalInBytes; \
- while (q < t) { \
- if (!oop(q)->is_gc_marked()) { \
- /* mark is pointer to next marked oop */ \
- debug_only(prev_q = q); \
- q = (HeapWord*) oop(q)->mark()->decode_pointer(); \
- assert(q > prev_q, "we should be moving forward through memory"); \
- } else { \
- /* prefetch beyond q */ \
- Prefetch::read(q, scan_interval); \
- \
- /* size and destination */ \
- size_t size = obj_size(q); \
- HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); \
- \
- /* prefetch beyond compaction_top */ \
- Prefetch::write(compaction_top, copy_interval); \
- \
- /* copy object and reinit its mark */ \
- assert(q != compaction_top, "everything in this pass should be moving"); \
- Copy::aligned_conjoint_words(q, compaction_top, size); \
- oop(compaction_top)->init_mark(); \
- assert(oop(compaction_top)->klass() != NULL, "should have a class"); \
- \
- debug_only(prev_q = q); \
- q += size; \
- } \
- } \
- \
- /* Let's remember if we were empty before we did the compaction. */ \
- bool was_empty = used_region().is_empty(); \
- /* Reset space after compaction is complete */ \
- reset_after_compaction(); \
- /* We do this clear, below, since it has overloaded meanings for some */ \
- /* space subtypes. For example, OffsetTableContigSpace's that were */ \
- /* compacted into will have had their offset table thresholds updated */ \
- /* continuously, but those that weren't need to have their thresholds */ \
- /* re-initialized. Also mangles unused area for debugging. */ \
- if (used_region().is_empty()) { \
- if (!was_empty) clear(SpaceDecorator::Mangle); \
- } else { \
- if (ZapUnusedHeapArea) mangle_unused_area(); \
- } \
-}
-
inline HeapWord* OffsetTableContigSpace::allocate(size_t size) {
HeapWord* res = ContiguousSpace::allocate(size);
if (res != NULL) {
@@ -334,4 +71,263 @@
return _offsets.block_start(p);
}
+template <class SpaceType>
+inline void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp) {
+ // Compute the new addresses for the live objects and store it in the mark
+ // Used by universe::mark_sweep_phase2()
+ HeapWord* compact_top; // This is where we are currently compacting to.
+
+ // We're sure to be here before any objects are compacted into this
+ // space, so this is a good time to initialize this:
+ space->set_compaction_top(space->bottom());
+
+ if (cp->space == NULL) {
+ assert(cp->gen != NULL, "need a generation");
+ assert(cp->threshold == NULL, "just checking");
+ assert(cp->gen->first_compaction_space() == space, "just checking");
+ cp->space = cp->gen->first_compaction_space();
+ compact_top = cp->space->bottom();
+ cp->space->set_compaction_top(compact_top);
+ cp->threshold = cp->space->initialize_threshold();
+ } else {
+ compact_top = cp->space->compaction_top();
+ }
+
+ // We allow some amount of garbage towards the bottom of the space, so
+ // we don't start compacting before there is a significant gain to be made.
+ // Occasionally, we want to ensure a full compaction, which is determined
+ // by the MarkSweepAlwaysCompactCount parameter.
+ uint invocations = MarkSweep::total_invocations();
+ bool skip_dead = ((invocations % MarkSweepAlwaysCompactCount) != 0);
+
+ size_t allowed_deadspace = 0;
+ if (skip_dead) {
+ const size_t ratio = space->allowed_dead_ratio();
+ allowed_deadspace = (space->capacity() * ratio / 100) / HeapWordSize;
+ }
+
+ HeapWord* q = space->bottom();
+ HeapWord* t = space->scan_limit();
+
+ HeapWord* end_of_live= q; // One byte beyond the last byte of the last
+ // live object.
+ HeapWord* first_dead = space->end(); // The first dead object.
+ LiveRange* liveRange = NULL; // The current live range, recorded in the
+ // first header of preceding free area.
+ space->_first_dead = first_dead;
+
+ const intx interval = PrefetchScanIntervalInBytes;
+
+ while (q < t) {
+ assert(!space->scanned_block_is_obj(q) ||
+ oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() ||
+ oop(q)->mark()->has_bias_pattern(),
+ "these are the only valid states during a mark sweep");
+ if (space->scanned_block_is_obj(q) && oop(q)->is_gc_marked()) {
+ // prefetch beyond q
+ Prefetch::write(q, interval);
+ size_t size = space->scanned_block_size(q);
+ compact_top = cp->space->forward(oop(q), size, cp, compact_top);
+ q += size;
+ end_of_live = q;
+ } else {
+ // run over all the contiguous dead objects
+ HeapWord* end = q;
+ do {
+ // prefetch beyond end
+ Prefetch::write(end, interval);
+ end += space->scanned_block_size(end);
+ } while (end < t && (!space->scanned_block_is_obj(end) || !oop(end)->is_gc_marked()));
+
+ // see if we might want to pretend this object is alive so that
+ // we don't have to compact quite as often.
+ if (allowed_deadspace > 0 && q == compact_top) {
+ size_t sz = pointer_delta(end, q);
+ if (space->insert_deadspace(allowed_deadspace, q, sz)) {
+ compact_top = cp->space->forward(oop(q), sz, cp, compact_top);
+ q = end;
+ end_of_live = end;
+ continue;
+ }
+ }
+
+ // otherwise, it really is a free region.
+
+ // for the previous LiveRange, record the end of the live objects.
+ if (liveRange) {
+ liveRange->set_end(q);
+ }
+
+ // record the current LiveRange object.
+ // liveRange->start() is overlaid on the mark word.
+ liveRange = (LiveRange*)q;
+ liveRange->set_start(end);
+ liveRange->set_end(end);
+
+ // see if this is the first dead region.
+ if (q < first_dead) {
+ first_dead = q;
+ }
+
+ // move on to the next object
+ q = end;
+ }
+ }
+
+ assert(q == t, "just checking");
+ if (liveRange != NULL) {
+ liveRange->set_end(q);
+ }
+ space->_end_of_live = end_of_live;
+ if (end_of_live < first_dead) {
+ first_dead = end_of_live;
+ }
+ space->_first_dead = first_dead;
+
+ // save the compaction_top of the compaction space.
+ cp->space->set_compaction_top(compact_top);
+}
+
+template <class SpaceType>
+inline void CompactibleSpace::scan_and_adjust_pointers(SpaceType* space) {
+ // adjust all the interior pointers to point at the new locations of objects
+ // Used by MarkSweep::mark_sweep_phase3()
+
+ HeapWord* q = space->bottom();
+ HeapWord* t = space->_end_of_live; // Established by "prepare_for_compaction".
+
+ assert(space->_first_dead <= space->_end_of_live, "Stands to reason, no?");
+
+ if (q < t && space->_first_dead > q && !oop(q)->is_gc_marked()) {
+ // we have a chunk of the space which hasn't moved and we've
+ // reinitialized the mark word during the previous pass, so we can't
+ // use is_gc_marked for the traversal.
+ HeapWord* end = space->_first_dead;
+
+ while (q < end) {
+ // I originally tried to conjoin "block_start(q) == q" to the
+ // assertion below, but that doesn't work, because you can't
+ // accurately traverse previous objects to get to the current one
+ // after their pointers have been
+ // updated, until the actual compaction is done. dld, 4/00
+ assert(space->block_is_obj(q), "should be at block boundaries, and should be looking at objs");
+
+ // point all the oops to the new location
+ size_t size = oop(q)->adjust_pointers();
+ size = space->adjust_obj_size(size);
+
+ q += size;
+ }
+
+ if (space->_first_dead == t) {
+ q = t;
+ } else {
+ // $$$ This is funky. Using this to read the previously written
+ // LiveRange. See also use below.
+ q = (HeapWord*)oop(space->_first_dead)->mark()->decode_pointer();
+ }
+ }
+
+ const intx interval = PrefetchScanIntervalInBytes;
+
+ debug_only(HeapWord* prev_q = NULL);
+ while (q < t) {
+ // prefetch beyond q
+ Prefetch::write(q, interval);
+ if (oop(q)->is_gc_marked()) {
+ // q is alive
+ // point all the oops to the new location
+ size_t size = oop(q)->adjust_pointers();
+ size = space->adjust_obj_size(size);
+ debug_only(prev_q = q);
+ q += size;
+ } else {
+ // q is not a live object, so its mark should point at the next
+ // live object
+ debug_only(prev_q = q);
+ q = (HeapWord*) oop(q)->mark()->decode_pointer();
+ assert(q > prev_q, "we should be moving forward through memory");
+ }
+ }
+
+ assert(q == t, "just checking");
+}
+
+template <class SpaceType>
+inline void CompactibleSpace::scan_and_compact(SpaceType* space) {
+ // Copy all live objects to their new location
+ // Used by MarkSweep::mark_sweep_phase4()
+
+ HeapWord* q = space->bottom();
+ HeapWord* const t = space->_end_of_live;
+ debug_only(HeapWord* prev_q = NULL);
+
+ if (q < t && space->_first_dead > q && !oop(q)->is_gc_marked()) {
+ #ifdef ASSERT // Debug only
+ // we have a chunk of the space which hasn't moved and we've reinitialized
+ // the mark word during the previous pass, so we can't use is_gc_marked for
+ // the traversal.
+ HeapWord* const end = space->_first_dead;
+
+ while (q < end) {
+ size_t size = space->obj_size(q);
+ assert(!oop(q)->is_gc_marked(), "should be unmarked (special dense prefix handling)");
+ prev_q = q;
+ q += size;
+ }
+ #endif
+
+ if (space->_first_dead == t) {
+ q = t;
+ } else {
+ // $$$ Funky
+ q = (HeapWord*) oop(space->_first_dead)->mark()->decode_pointer();
+ }
+ }
+
+ const intx scan_interval = PrefetchScanIntervalInBytes;
+ const intx copy_interval = PrefetchCopyIntervalInBytes;
+ while (q < t) {
+ if (!oop(q)->is_gc_marked()) {
+ // mark is pointer to next marked oop
+ debug_only(prev_q = q);
+ q = (HeapWord*) oop(q)->mark()->decode_pointer();
+ assert(q > prev_q, "we should be moving forward through memory");
+ } else {
+ // prefetch beyond q
+ Prefetch::read(q, scan_interval);
+
+ // size and destination
+ size_t size = space->obj_size(q);
+ HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee();
+
+ // prefetch beyond compaction_top
+ Prefetch::write(compaction_top, copy_interval);
+
+ // copy object and reinit its mark
+ assert(q != compaction_top, "everything in this pass should be moving");
+ Copy::aligned_conjoint_words(q, compaction_top, size);
+ oop(compaction_top)->init_mark();
+ assert(oop(compaction_top)->klass() != NULL, "should have a class");
+
+ debug_only(prev_q = q);
+ q += size;
+ }
+ }
+
+ // Let's remember if we were empty before we did the compaction.
+ bool was_empty = space->used_region().is_empty();
+ // Reset space after compaction is complete
+ space->reset_after_compaction();
+ // We do this clear, below, since it has overloaded meanings for some
+ // space subtypes. For example, OffsetTableContigSpace's that were
+ // compacted into will have had their offset table thresholds updated
+ // continuously, but those that weren't need to have their thresholds
+ // re-initialized. Also mangles unused area for debugging.
+ if (space->used_region().is_empty()) {
+ if (!was_empty) space->clear(SpaceDecorator::Mangle);
+ } else {
+ if (ZapUnusedHeapArea) space->mangle_unused_area();
+ }
+}
#endif // SHARE_VM_MEMORY_SPACE_INLINE_HPP
--- a/hotspot/src/share/vm/opto/macro.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/opto/macro.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -1197,8 +1197,7 @@
}
if (C->env()->dtrace_alloc_probes() ||
- !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
- (UseConcMarkSweepGC && CMSIncrementalMode))) {
+ !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc())) {
// Force slow-path allocation
always_slow = true;
initial_slow_test = NULL;
--- a/hotspot/src/share/vm/runtime/arguments.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/runtime/arguments.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -1777,7 +1777,7 @@
#ifdef ASSERT
static bool verify_serial_gc_flags() {
return (UseSerialGC &&
- !(UseParNewGC || (UseConcMarkSweepGC || CMSIncrementalMode) || UseG1GC ||
+ !(UseParNewGC || (UseConcMarkSweepGC) || UseG1GC ||
UseParallelGC || UseParallelOldGC));
}
#endif // ASSERT
@@ -2191,10 +2191,6 @@
warning("Using the ParNew young collector with the Serial old collector is deprecated "
"and will likely be removed in a future release");
}
-
- if (CMSIncrementalMode) {
- warning("Using incremental CMS is deprecated and will likely be removed in a future release");
- }
}
void Arguments::check_deprecated_gc_flags() {
@@ -2316,31 +2312,8 @@
status = status && ArgumentsExt::check_gc_consistency_user();
status = status && check_stack_pages();
- if (CMSIncrementalMode) {
- if (!UseConcMarkSweepGC) {
- jio_fprintf(defaultStream::error_stream(),
- "error: invalid argument combination.\n"
- "The CMS collector (-XX:+UseConcMarkSweepGC) must be "
- "selected in order\nto use CMSIncrementalMode.\n");
- status = false;
- } else {
- status = status && verify_percentage(CMSIncrementalDutyCycle,
- "CMSIncrementalDutyCycle");
- status = status && verify_percentage(CMSIncrementalDutyCycleMin,
- "CMSIncrementalDutyCycleMin");
- status = status && verify_percentage(CMSIncrementalSafetyFactor,
- "CMSIncrementalSafetyFactor");
- status = status && verify_percentage(CMSIncrementalOffset,
- "CMSIncrementalOffset");
- status = status && verify_percentage(CMSExpAvgFactor,
- "CMSExpAvgFactor");
- // If it was not set on the command line, set
- // CMSInitiatingOccupancyFraction to 1 so icms can initiate cycles early.
- if (CMSInitiatingOccupancyFraction < 0) {
- FLAG_SET_DEFAULT(CMSInitiatingOccupancyFraction, 1);
- }
- }
- }
+ status = status && verify_percentage(CMSIncrementalSafetyFactor,
+ "CMSIncrementalSafetyFactor");
// CMS space iteration, which FLSVerifyAllHeapreferences entails,
// insists that we hold the requisite locks so that the iteration is
@@ -2874,14 +2847,6 @@
// -Xnoclassgc
} else if (match_option(option, "-Xnoclassgc", &tail)) {
FLAG_SET_CMDLINE(bool, ClassUnloading, false);
- // -Xincgc: i-CMS
- } else if (match_option(option, "-Xincgc", &tail)) {
- FLAG_SET_CMDLINE(bool, UseConcMarkSweepGC, true);
- FLAG_SET_CMDLINE(bool, CMSIncrementalMode, true);
- // -Xnoincgc: no i-CMS
- } else if (match_option(option, "-Xnoincgc", &tail)) {
- FLAG_SET_CMDLINE(bool, UseConcMarkSweepGC, false);
- FLAG_SET_CMDLINE(bool, CMSIncrementalMode, false);
// -Xconcgc
} else if (match_option(option, "-Xconcgc", &tail)) {
FLAG_SET_CMDLINE(bool, UseConcMarkSweepGC, true);
@@ -3711,7 +3676,6 @@
#if !INCLUDE_ALL_GCS
static void force_serial_gc() {
FLAG_SET_DEFAULT(UseSerialGC, true);
- FLAG_SET_DEFAULT(CMSIncrementalMode, false); // special CMS suboption
UNSUPPORTED_GC_OPTION(UseG1GC);
UNSUPPORTED_GC_OPTION(UseParallelGC);
UNSUPPORTED_GC_OPTION(UseParallelOldGC);
--- a/hotspot/src/share/vm/runtime/globals.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/runtime/globals.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -1638,30 +1638,10 @@
"The maximum size of young gen chosen by default per GC worker " \
"thread available") \
\
- product(bool, CMSIncrementalMode, false, \
- "Whether CMS GC should operate in \"incremental\" mode") \
- \
- product(uintx, CMSIncrementalDutyCycle, 10, \
- "Percentage (0-100) of CMS incremental mode duty cycle. If " \
- "CMSIncrementalPacing is enabled, then this is just the initial " \
- "value.") \
- \
- product(bool, CMSIncrementalPacing, true, \
- "Whether the CMS incremental mode duty cycle should be " \
- "automatically adjusted") \
- \
- product(uintx, CMSIncrementalDutyCycleMin, 0, \
- "Minimum percentage (0-100) of the CMS incremental duty cycle " \
- "used when CMSIncrementalPacing is enabled") \
- \
product(uintx, CMSIncrementalSafetyFactor, 10, \
"Percentage (0-100) used to add conservatism when computing the " \
"duty cycle") \
\
- product(uintx, CMSIncrementalOffset, 0, \
- "Percentage (0-100) by which the CMS incremental mode duty cycle "\
- "is shifted to the right within the period between young GCs") \
- \
product(uintx, CMSExpAvgFactor, 50, \
"Percentage (0-100) used to weight the current sample when " \
"computing exponential averages for CMS statistics") \
@@ -1720,15 +1700,6 @@
"Skip block flux-rate sampling for an epoch unless inter-sweep " \
"duration exceeds this threshold in milliseconds") \
\
- develop(bool, CMSTraceIncrementalMode, false, \
- "Trace CMS incremental mode") \
- \
- develop(bool, CMSTraceIncrementalPacing, false, \
- "Trace CMS incremental mode pacing computation") \
- \
- develop(bool, CMSTraceThreadState, false, \
- "Trace the CMS thread state (enable the trace_state() method)") \
- \
product(bool, CMSClassUnloadingEnabled, true, \
"Whether class unloading enabled when using CMS GC") \
\
--- a/hotspot/src/share/vm/runtime/mutexLocker.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/runtime/mutexLocker.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -72,7 +72,6 @@
Monitor* CGC_lock = NULL;
Monitor* STS_lock = NULL;
Monitor* SLT_lock = NULL;
-Monitor* iCMS_lock = NULL;
Monitor* FullGCCount_lock = NULL;
Monitor* CMark_lock = NULL;
Mutex* CMRegionStack_lock = NULL;
@@ -175,9 +174,6 @@
def(CGC_lock , Monitor, special, true ); // coordinate between fore- and background GC
def(STS_lock , Monitor, leaf, true );
- if (UseConcMarkSweepGC) {
- def(iCMS_lock , Monitor, special, true ); // CMS incremental mode start/stop notification
- }
if (UseConcMarkSweepGC || UseG1GC) {
def(FullGCCount_lock , Monitor, leaf, true ); // in support of ExplicitGCInvokesConcurrent
}
--- a/hotspot/src/share/vm/runtime/mutexLocker.hpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/runtime/mutexLocker.hpp Mon Nov 03 15:53:48 2014 +0100
@@ -66,7 +66,6 @@
// fore- & background GC threads.
extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
extern Monitor* SLT_lock; // used in CMS GC for acquiring PLL
-extern Monitor* iCMS_lock; // CMS incremental mode start/stop notification
extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc
extern Monitor* CMark_lock; // used for concurrent mark thread coordination
extern Mutex* CMRegionStack_lock; // used for protecting accesses to the CM region stack
--- a/hotspot/src/share/vm/runtime/vmStructs.cpp Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/src/share/vm/runtime/vmStructs.cpp Mon Nov 03 15:53:48 2014 +0100
@@ -527,12 +527,10 @@
nonstatic_field(DefNewGeneration, _next_gen, Generation*) \
nonstatic_field(DefNewGeneration, _tenuring_threshold, uint) \
nonstatic_field(DefNewGeneration, _age_table, ageTable) \
- nonstatic_field(DefNewGeneration, _eden_space, EdenSpace*) \
+ nonstatic_field(DefNewGeneration, _eden_space, ContiguousSpace*) \
nonstatic_field(DefNewGeneration, _from_space, ContiguousSpace*) \
nonstatic_field(DefNewGeneration, _to_space, ContiguousSpace*) \
\
- nonstatic_field(EdenSpace, _gen, DefNewGeneration*) \
- \
nonstatic_field(Generation, _reserved, MemRegion) \
nonstatic_field(Generation, _virtual_space, VirtualSpace) \
nonstatic_field(Generation, _level, int) \
@@ -1490,7 +1488,6 @@
declare_toplevel_type(BitMap) \
declare_type(CompactibleSpace, Space) \
declare_type(ContiguousSpace, CompactibleSpace) \
- declare_type(EdenSpace, ContiguousSpace) \
declare_type(OffsetTableContigSpace, ContiguousSpace) \
declare_type(TenuredSpace, OffsetTableContigSpace) \
declare_toplevel_type(BarrierSet) \
@@ -1532,7 +1529,6 @@
declare_toplevel_type(CollectedHeap*) \
declare_toplevel_type(ContiguousSpace*) \
declare_toplevel_type(DefNewGeneration*) \
- declare_toplevel_type(EdenSpace*) \
declare_toplevel_type(GenCollectedHeap*) \
declare_toplevel_type(Generation*) \
declare_toplevel_type(GenerationSpec**) \
--- a/hotspot/test/TEST.groups Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/test/TEST.groups Mon Nov 03 15:53:48 2014 +0100
@@ -175,11 +175,8 @@
gc/g1/TestShrinkToOneRegion.java \
gc/metaspace/G1AddMetaspaceDependency.java \
gc/startup_warnings/TestCMS.java \
- gc/startup_warnings/TestCMSIncrementalMode.java \
- gc/startup_warnings/TestCMSNoIncrementalMode.java \
gc/startup_warnings/TestDefaultMaxRAMFraction.java \
gc/startup_warnings/TestDefNewCMS.java \
- gc/startup_warnings/TestIncGC.java \
gc/startup_warnings/TestParallelGC.java \
gc/startup_warnings/TestParallelScavengeSerialOld.java \
gc/startup_warnings/TestParNewCMS.java \
@@ -274,8 +271,6 @@
gc/class_unloading/TestCMSClassUnloadingEnabledHWM.java \
gc/concurrentMarkSweep/ \
gc/startup_warnings/TestCMS.java \
- gc/startup_warnings/TestCMSIncrementalMode.java \
- gc/startup_warnings/TestCMSNoIncrementalMode.java \
gc/startup_warnings/TestDefNewCMS.java \
gc/startup_warnings/TestParNewCMS.java
--- a/hotspot/test/gc/g1/TestShrinkAuxiliaryData.java Fri Oct 31 08:00:09 2014 +0000
+++ b/hotspot/test/gc/g1/TestShrinkAuxiliaryData.java Mon Nov 03 15:53:48 2014 +0100
@@ -279,8 +279,7 @@
"-XX:\\+UseConcMarkSweepGC",
"-XX:\\+UseParallelOldGC",
"-XX:\\+UseParNewGC",
- "-Xconcgc",
- "-Xincgc"
+ "-Xconcgc"
};
}
}
--- a/hotspot/test/gc/startup_warnings/TestCMSIncrementalMode.java Fri Oct 31 08:00:09 2014 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,46 +0,0 @@
-
-/*
-* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
-* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
-*
-* This code is free software; you can redistribute it and/or modify it
-* under the terms of the GNU General Public License version 2 only, as
-* published by the Free Software Foundation.
-*
-* This code is distributed in the hope that it will be useful, but WITHOUT
-* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-* version 2 for more details (a copy is included in the LICENSE file that
-* accompanied this code).
-*
-* You should have received a copy of the GNU General Public License version
-* 2 along with this work; if not, write to the Free Software Foundation,
-* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
-*
-* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
-* or visit www.oracle.com if you need additional information or have any
-* questions.
-*/
-
-/*
-* @test TestCMSIncrementalMode
-* @key gc
-* @bug 8006398
-* @summary Test that the deprecated CMSIncrementalMode print a warning message
-* @library /testlibrary
-*/
-
-import com.oracle.java.testlibrary.OutputAnalyzer;
-import com.oracle.java.testlibrary.ProcessTools;
-
-public class TestCMSIncrementalMode {
-
- public static void main(String args[]) throws Exception {
- ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-XX:+UseConcMarkSweepGC", "-XX:+CMSIncrementalMode", "-version");
- OutputAnalyzer output = new OutputAnalyzer(pb.start());
- output.shouldContain("warning: Using incremental CMS is deprecated and will likely be removed in a future release");
- output.shouldNotContain("error");
- output.shouldHaveExitValue(0);
- }
-
-}
--- a/hotspot/test/gc/startup_warnings/TestCMSNoIncrementalMode.java Fri Oct 31 08:00:09 2014 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,45 +0,0 @@
-/*
-* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
-* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
-*
-* This code is free software; you can redistribute it and/or modify it
-* under the terms of the GNU General Public License version 2 only, as
-* published by the Free Software Foundation.
-*
-* This code is distributed in the hope that it will be useful, but WITHOUT
-* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-* version 2 for more details (a copy is included in the LICENSE file that
-* accompanied this code).
-*
-* You should have received a copy of the GNU General Public License version
-* 2 along with this work; if not, write to the Free Software Foundation,
-* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
-*
-* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
-* or visit www.oracle.com if you need additional information or have any
-* questions.
-*/
-
-/*
-* @test TestCMSNoIncrementalMode
-* @key gc
-* @bug 8006398
-* @summary Test that CMS with incremental mode turned off does not print a warning message
-* @library /testlibrary
-*/
-
-import com.oracle.java.testlibrary.OutputAnalyzer;
-import com.oracle.java.testlibrary.ProcessTools;
-
-public class TestCMSNoIncrementalMode {
-
- public static void main(String args[]) throws Exception {
- ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-XX:+UseConcMarkSweepGC", "-XX:-CMSIncrementalMode", "-version");
- OutputAnalyzer output = new OutputAnalyzer(pb.start());
- output.shouldNotContain("deprecated");
- output.shouldNotContain("error");
- output.shouldHaveExitValue(0);
- }
-
-}
--- a/hotspot/test/gc/startup_warnings/TestIncGC.java Fri Oct 31 08:00:09 2014 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,46 +0,0 @@
-/*
-* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
-* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
-*
-* This code is free software; you can redistribute it and/or modify it
-* under the terms of the GNU General Public License version 2 only, as
-* published by the Free Software Foundation.
-*
-* This code is distributed in the hope that it will be useful, but WITHOUT
-* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-* version 2 for more details (a copy is included in the LICENSE file that
-* accompanied this code).
-*
-* You should have received a copy of the GNU General Public License version
-* 2 along with this work; if not, write to the Free Software Foundation,
-* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
-*
-* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
-* or visit www.oracle.com if you need additional information or have any
-* questions.
-*/
-
-/*
-* @test TestIncGC
-* @key gc
-* @bug 8006398
-* @summary Test that the deprecated -Xincgc print a warning message
-* @library /testlibrary
-*/
-
-import com.oracle.java.testlibrary.OutputAnalyzer;
-import com.oracle.java.testlibrary.ProcessTools;
-
-
-public class TestIncGC {
-
- public static void main(String args[]) throws Exception {
- ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-Xincgc", "-version");
- OutputAnalyzer output = new OutputAnalyzer(pb.start());
- output.shouldContain("warning: Using incremental CMS is deprecated and will likely be removed in a future release");
- output.shouldNotContain("error");
- output.shouldHaveExitValue(0);
- }
-
-}