--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.cpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,469 @@
+/*
+ * Copyright 2003-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_asPSYoungGen.cpp.incl"
+
+ASPSYoungGen::ASPSYoungGen(size_t init_byte_size,
+ size_t minimum_byte_size,
+ size_t byte_size_limit) :
+ PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit),
+ _gen_size_limit(byte_size_limit) {
+}
+
+
+ASPSYoungGen::ASPSYoungGen(PSVirtualSpace* vs,
+ size_t init_byte_size,
+ size_t minimum_byte_size,
+ size_t byte_size_limit) :
+ //PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit),
+ PSYoungGen(vs->committed_size(), minimum_byte_size, byte_size_limit),
+ _gen_size_limit(byte_size_limit) {
+
+ assert(vs->committed_size() == init_byte_size, "Cannot replace with");
+
+ _virtual_space = vs;
+}
+
+void ASPSYoungGen::initialize_virtual_space(ReservedSpace rs,
+ size_t alignment) {
+ assert(_init_gen_size != 0, "Should have a finite size");
+ _virtual_space = new PSVirtualSpaceHighToLow(rs, alignment);
+ if (!_virtual_space->expand_by(_init_gen_size)) {
+ vm_exit_during_initialization("Could not reserve enough space for "
+ "object heap");
+ }
+}
+
+void ASPSYoungGen::initialize(ReservedSpace rs, size_t alignment) {
+ initialize_virtual_space(rs, alignment);
+ initialize_work();
+}
+
+size_t ASPSYoungGen::available_for_expansion() {
+
+ size_t current_committed_size = virtual_space()->committed_size();
+ assert((gen_size_limit() >= current_committed_size),
+ "generation size limit is wrong");
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ size_t result = gen_size_limit() - current_committed_size;
+ size_t result_aligned = align_size_down(result, heap->young_gen_alignment());
+ return result_aligned;
+}
+
+// Return the number of bytes the young gen is willing give up.
+//
+// Future implementations could check the survivors and if to_space is in the
+// right place (below from_space), take a chunk from to_space.
+size_t ASPSYoungGen::available_for_contraction() {
+
+ size_t uncommitted_bytes = virtual_space()->uncommitted_size();
+ if (uncommitted_bytes != 0) {
+ return uncommitted_bytes;
+ }
+
+ if (eden_space()->is_empty()) {
+ // Respect the minimum size for eden and for the young gen as a whole.
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ const size_t eden_alignment = heap->intra_generation_alignment();
+ const size_t gen_alignment = heap->young_gen_alignment();
+
+ assert(eden_space()->capacity_in_bytes() >= eden_alignment,
+ "Alignment is wrong");
+ size_t eden_avail = eden_space()->capacity_in_bytes() - eden_alignment;
+ eden_avail = align_size_down(eden_avail, gen_alignment);
+
+ assert(virtual_space()->committed_size() >= min_gen_size(),
+ "minimum gen size is wrong");
+ size_t gen_avail = virtual_space()->committed_size() - min_gen_size();
+ assert(virtual_space()->is_aligned(gen_avail), "not aligned");
+
+ const size_t max_contraction = MIN2(eden_avail, gen_avail);
+ // See comment for ASPSOldGen::available_for_contraction()
+ // for reasons the "increment" fraction is used.
+ PSAdaptiveSizePolicy* policy = heap->size_policy();
+ size_t result = policy->eden_increment_aligned_down(max_contraction);
+ size_t result_aligned = align_size_down(result, gen_alignment);
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr("ASPSYoungGen::available_for_contraction: %d K",
+ result_aligned/K);
+ gclog_or_tty->print_cr(" max_contraction %d K", max_contraction/K);
+ gclog_or_tty->print_cr(" eden_avail %d K", eden_avail/K);
+ gclog_or_tty->print_cr(" gen_avail %d K", gen_avail/K);
+ }
+ return result_aligned;
+
+ }
+
+ return 0;
+}
+
+// The current implementation only considers to the end of eden.
+// If to_space is below from_space, to_space is not considered.
+// to_space can be.
+size_t ASPSYoungGen::available_to_live() {
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ const size_t alignment = heap->intra_generation_alignment();
+
+ // Include any space that is committed but is not in eden.
+ size_t available = pointer_delta(eden_space()->bottom(),
+ virtual_space()->low(),
+ sizeof(char));
+
+ const size_t eden_capacity = eden_space()->capacity_in_bytes();
+ if (eden_space()->is_empty() && eden_capacity > alignment) {
+ available += eden_capacity - alignment;
+ }
+ return available;
+}
+
+// Similar to PSYoungGen::resize_generation() but
+// allows sum of eden_size and 2 * survivor_size to exceed _max_gen_size
+// expands at the low end of the virtual space
+// moves the boundary between the generations in order to expand
+// some additional diagnostics
+// If no additional changes are required, this can be deleted
+// and the changes factored back into PSYoungGen::resize_generation().
+bool ASPSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
+ const size_t alignment = virtual_space()->alignment();
+ size_t orig_size = virtual_space()->committed_size();
+ bool size_changed = false;
+
+ // There used to be a guarantee here that
+ // (eden_size + 2*survivor_size) <= _max_gen_size
+ // This requirement is enforced by the calculation of desired_size
+ // below. It may not be true on entry since the size of the
+ // eden_size is no bounded by the generation size.
+
+ assert(max_size() == reserved().byte_size(), "max gen size problem?");
+ assert(min_gen_size() <= orig_size && orig_size <= max_size(),
+ "just checking");
+
+ // Adjust new generation size
+ const size_t eden_plus_survivors =
+ align_size_up(eden_size + 2 * survivor_size, alignment);
+ size_t desired_size = MAX2(MIN2(eden_plus_survivors, gen_size_limit()),
+ min_gen_size());
+ assert(desired_size <= gen_size_limit(), "just checking");
+
+ if (desired_size > orig_size) {
+ // Grow the generation
+ size_t change = desired_size - orig_size;
+ if (!virtual_space()->expand_by(change)) {
+ return false;
+ }
+ size_changed = true;
+ } else if (desired_size < orig_size) {
+ size_t desired_change = orig_size - desired_size;
+
+ // How much is available for shrinking.
+ size_t available_bytes = limit_gen_shrink(desired_change);
+ size_t change = MIN2(desired_change, available_bytes);
+ virtual_space()->shrink_by(change);
+ size_changed = true;
+ } else {
+ if (Verbose && PrintGC) {
+ if (orig_size == gen_size_limit()) {
+ gclog_or_tty->print_cr("ASPSYoung generation size at maximum: "
+ SIZE_FORMAT "K", orig_size/K);
+ } else if (orig_size == min_gen_size()) {
+ gclog_or_tty->print_cr("ASPSYoung generation size at minium: "
+ SIZE_FORMAT "K", orig_size/K);
+ }
+ }
+ }
+
+ if (size_changed) {
+ reset_after_change();
+ if (Verbose && PrintGC) {
+ size_t current_size = virtual_space()->committed_size();
+ gclog_or_tty->print_cr("ASPSYoung generation size changed: "
+ SIZE_FORMAT "K->" SIZE_FORMAT "K",
+ orig_size/K, current_size/K);
+ }
+ }
+
+ guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
+ virtual_space()->committed_size() == max_size(), "Sanity");
+
+ return true;
+}
+
+// Similar to PSYoungGen::resize_spaces() but
+// eden always starts at the low end of the committed virtual space
+// current implementation does not allow holes between the spaces
+// _young_generation_boundary has to be reset because it changes.
+// so additional verification
+void ASPSYoungGen::resize_spaces(size_t requested_eden_size,
+ size_t requested_survivor_size) {
+ assert(requested_eden_size > 0 && requested_survivor_size > 0,
+ "just checking");
+
+ space_invariants();
+
+ // We require eden and to space to be empty
+ if ((!eden_space()->is_empty()) || (!to_space()->is_empty())) {
+ return;
+ }
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr("PSYoungGen::resize_spaces(requested_eden_size: "
+ SIZE_FORMAT
+ ", requested_survivor_size: " SIZE_FORMAT ")",
+ requested_eden_size, requested_survivor_size);
+ gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
+ SIZE_FORMAT,
+ eden_space()->bottom(),
+ eden_space()->end(),
+ pointer_delta(eden_space()->end(),
+ eden_space()->bottom(),
+ sizeof(char)));
+ gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") "
+ SIZE_FORMAT,
+ from_space()->bottom(),
+ from_space()->end(),
+ pointer_delta(from_space()->end(),
+ from_space()->bottom(),
+ sizeof(char)));
+ gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") "
+ SIZE_FORMAT,
+ to_space()->bottom(),
+ to_space()->end(),
+ pointer_delta( to_space()->end(),
+ to_space()->bottom(),
+ sizeof(char)));
+ }
+
+ // There's nothing to do if the new sizes are the same as the current
+ if (requested_survivor_size == to_space()->capacity_in_bytes() &&
+ requested_survivor_size == from_space()->capacity_in_bytes() &&
+ requested_eden_size == eden_space()->capacity_in_bytes()) {
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(" capacities are the right sizes, returning");
+ }
+ return;
+ }
+
+ char* eden_start = (char*)virtual_space()->low();
+ char* eden_end = (char*)eden_space()->end();
+ char* from_start = (char*)from_space()->bottom();
+ char* from_end = (char*)from_space()->end();
+ char* to_start = (char*)to_space()->bottom();
+ char* to_end = (char*)to_space()->end();
+
+ assert(eden_start < from_start, "Cannot push into from_space");
+
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ const size_t alignment = heap->intra_generation_alignment();
+
+ // Check whether from space is below to space
+ if (from_start < to_start) {
+ // Eden, from, to
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(" Eden, from, to:");
+ }
+
+ // Set eden
+ // Compute how big eden can be, then adjust end.
+ // See comment in PSYoungGen::resize_spaces() on
+ // calculating eden_end.
+ const size_t eden_size = MIN2(requested_eden_size,
+ pointer_delta(from_start,
+ eden_start,
+ sizeof(char)));
+ eden_end = eden_start + eden_size;
+ assert(eden_end >= eden_start, "addition overflowed")
+
+ // To may resize into from space as long as it is clear of live data.
+ // From space must remain page aligned, though, so we need to do some
+ // extra calculations.
+
+ // First calculate an optimal to-space
+ to_end = (char*)virtual_space()->high();
+ to_start = (char*)pointer_delta(to_end,
+ (char*)requested_survivor_size,
+ sizeof(char));
+
+ // Does the optimal to-space overlap from-space?
+ if (to_start < (char*)from_space()->end()) {
+ assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+ // Calculate the minimum offset possible for from_end
+ size_t from_size =
+ pointer_delta(from_space()->top(), from_start, sizeof(char));
+
+ // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
+ if (from_size == 0) {
+ from_size = alignment;
+ } else {
+ from_size = align_size_up(from_size, alignment);
+ }
+
+ from_end = from_start + from_size;
+ assert(from_end > from_start, "addition overflow or from_size problem");
+
+ guarantee(from_end <= (char*)from_space()->end(),
+ "from_end moved to the right");
+
+ // Now update to_start with the new from_end
+ to_start = MAX2(from_end, to_start);
+ }
+
+ guarantee(to_start != to_end, "to space is zero sized");
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(" [eden_start .. eden_end): "
+ "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+ eden_start,
+ eden_end,
+ pointer_delta(eden_end, eden_start, sizeof(char)));
+ gclog_or_tty->print_cr(" [from_start .. from_end): "
+ "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+ from_start,
+ from_end,
+ pointer_delta(from_end, from_start, sizeof(char)));
+ gclog_or_tty->print_cr(" [ to_start .. to_end): "
+ "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+ to_start,
+ to_end,
+ pointer_delta( to_end, to_start, sizeof(char)));
+ }
+ } else {
+ // Eden, to, from
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(" Eden, to, from:");
+ }
+
+ // To space gets priority over eden resizing. Note that we position
+ // to space as if we were able to resize from space, even though from
+ // space is not modified.
+ // Giving eden priority was tried and gave poorer performance.
+ to_end = (char*)pointer_delta(virtual_space()->high(),
+ (char*)requested_survivor_size,
+ sizeof(char));
+ to_end = MIN2(to_end, from_start);
+ to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
+ sizeof(char));
+ // if the space sizes are to be increased by several times then
+ // 'to_start' will point beyond the young generation. In this case
+ // 'to_start' should be adjusted.
+ to_start = MAX2(to_start, eden_start + alignment);
+
+ // Compute how big eden can be, then adjust end.
+ // See comment in PSYoungGen::resize_spaces() on
+ // calculating eden_end.
+ const size_t eden_size = MIN2(requested_eden_size,
+ pointer_delta(to_start,
+ eden_start,
+ sizeof(char)));
+ eden_end = eden_start + eden_size;
+ assert(eden_end >= eden_start, "addition overflowed")
+
+ // Don't let eden shrink down to 0 or less.
+ eden_end = MAX2(eden_end, eden_start + alignment);
+ to_start = MAX2(to_start, eden_end);
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(" [eden_start .. eden_end): "
+ "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+ eden_start,
+ eden_end,
+ pointer_delta(eden_end, eden_start, sizeof(char)));
+ gclog_or_tty->print_cr(" [ to_start .. to_end): "
+ "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+ to_start,
+ to_end,
+ pointer_delta( to_end, to_start, sizeof(char)));
+ gclog_or_tty->print_cr(" [from_start .. from_end): "
+ "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+ from_start,
+ from_end,
+ pointer_delta(from_end, from_start, sizeof(char)));
+ }
+ }
+
+
+ guarantee((HeapWord*)from_start <= from_space()->bottom(),
+ "from start moved to the right");
+ guarantee((HeapWord*)from_end >= from_space()->top(),
+ "from end moved into live data");
+ assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
+ assert(is_object_aligned((intptr_t)from_start), "checking alignment");
+ assert(is_object_aligned((intptr_t)to_start), "checking alignment");
+
+ MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
+ MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end);
+ MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
+
+ // Let's make sure the call to initialize doesn't reset "top"!
+ DEBUG_ONLY(HeapWord* old_from_top = from_space()->top();)
+
+ // For PrintAdaptiveSizePolicy block below
+ size_t old_from = from_space()->capacity_in_bytes();
+ size_t old_to = to_space()->capacity_in_bytes();
+
+ eden_space()->initialize(edenMR, true);
+ to_space()->initialize(toMR , true);
+ from_space()->initialize(fromMR, false); // Note, not cleared!
+ PSScavenge::set_young_generation_boundary(eden_space()->bottom());
+
+ assert(from_space()->top() == old_from_top, "from top changed!");
+
+ if (PrintAdaptiveSizePolicy) {
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+ gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
+ "collection: %d "
+ "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
+ "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
+ heap->total_collections(),
+ old_from, old_to,
+ from_space()->capacity_in_bytes(),
+ to_space()->capacity_in_bytes());
+ gclog_or_tty->cr();
+ }
+ space_invariants();
+}
+
+void ASPSYoungGen::reset_after_change() {
+ assert_locked_or_safepoint(Heap_lock);
+
+ _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
+ (HeapWord*)virtual_space()->high_boundary());
+ PSScavenge::reference_processor()->set_span(_reserved);
+
+ HeapWord* new_eden_bottom = (HeapWord*)virtual_space()->low();
+ HeapWord* eden_bottom = eden_space()->bottom();
+ if (new_eden_bottom != eden_bottom) {
+ MemRegion eden_mr(new_eden_bottom, eden_space()->end());
+ eden_space()->initialize(eden_mr, true);
+ PSScavenge::set_young_generation_boundary(eden_space()->bottom());
+ }
+ MemRegion cmr((HeapWord*)virtual_space()->low(),
+ (HeapWord*)virtual_space()->high());
+ Universe::heap()->barrier_set()->resize_covered_region(cmr);
+
+ space_invariants();
+}