7110718: -XX:MarkSweepAlwaysCompactCount=0 crashes the JVM
Summary: Interpret MarkSweepAlwaysCompactCount < 1 as never do full compaction
Reviewed-by: ysr, tonyp, jmasa, johnc
/*
* Copyright (c) 1997, 2011, 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.
*
*/
#include "precompiled.hpp"
#include "memory/allocation.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/resourceArea.hpp"
#include "runtime/os.hpp"
#include "runtime/task.hpp"
#include "runtime/threadCritical.hpp"
#include "utilities/ostream.hpp"
#ifdef TARGET_OS_FAMILY_linux
# include "os_linux.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_solaris
# include "os_solaris.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_windows
# include "os_windows.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_bsd
# include "os_bsd.inline.hpp"
#endif
void* CHeapObj::operator new(size_t size){
return (void *) AllocateHeap(size, "CHeapObj-new");
}
void* CHeapObj::operator new (size_t size, const std::nothrow_t& nothrow_constant) {
char* p = (char*) os::malloc(size);
#ifdef ASSERT
if (PrintMallocFree) trace_heap_malloc(size, "CHeapObj-new", p);
#endif
return p;
}
void CHeapObj::operator delete(void* p){
FreeHeap(p);
}
void* StackObj::operator new(size_t size) { ShouldNotCallThis(); return 0; };
void StackObj::operator delete(void* p) { ShouldNotCallThis(); };
void* _ValueObj::operator new(size_t size) { ShouldNotCallThis(); return 0; };
void _ValueObj::operator delete(void* p) { ShouldNotCallThis(); };
void* ResourceObj::operator new(size_t size, allocation_type type) {
address res;
switch (type) {
case C_HEAP:
res = (address)AllocateHeap(size, "C_Heap: ResourceOBJ");
DEBUG_ONLY(set_allocation_type(res, C_HEAP);)
break;
case RESOURCE_AREA:
// new(size) sets allocation type RESOURCE_AREA.
res = (address)operator new(size);
break;
default:
ShouldNotReachHere();
}
return res;
}
void ResourceObj::operator delete(void* p) {
assert(((ResourceObj *)p)->allocated_on_C_heap(),
"delete only allowed for C_HEAP objects");
DEBUG_ONLY(((ResourceObj *)p)->_allocation_t[0] = (uintptr_t)badHeapOopVal;)
FreeHeap(p);
}
#ifdef ASSERT
void ResourceObj::set_allocation_type(address res, allocation_type type) {
// Set allocation type in the resource object
uintptr_t allocation = (uintptr_t)res;
assert((allocation & allocation_mask) == 0, "address should be aligned to 4 bytes at least");
assert(type <= allocation_mask, "incorrect allocation type");
ResourceObj* resobj = (ResourceObj *)res;
resobj->_allocation_t[0] = ~(allocation + type);
if (type != STACK_OR_EMBEDDED) {
// Called from operator new() and CollectionSetChooser(),
// set verification value.
resobj->_allocation_t[1] = (uintptr_t)&(resobj->_allocation_t[1]) + type;
}
}
ResourceObj::allocation_type ResourceObj::get_allocation_type() const {
assert(~(_allocation_t[0] | allocation_mask) == (uintptr_t)this, "lost resource object");
return (allocation_type)((~_allocation_t[0]) & allocation_mask);
}
bool ResourceObj::is_type_set() const {
allocation_type type = (allocation_type)(_allocation_t[1] & allocation_mask);
return get_allocation_type() == type &&
(_allocation_t[1] - type) == (uintptr_t)(&_allocation_t[1]);
}
ResourceObj::ResourceObj() { // default constructor
if (~(_allocation_t[0] | allocation_mask) != (uintptr_t)this) {
// Operator new() is not called for allocations
// on stack and for embedded objects.
set_allocation_type((address)this, STACK_OR_EMBEDDED);
} else if (allocated_on_stack()) { // STACK_OR_EMBEDDED
// For some reason we got a value which resembles
// an embedded or stack object (operator new() does not
// set such type). Keep it since it is valid value
// (even if it was garbage).
// Ignore garbage in other fields.
} else if (is_type_set()) {
// Operator new() was called and type was set.
assert(!allocated_on_stack(),
err_msg("not embedded or stack, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
this, get_allocation_type(), _allocation_t[0], _allocation_t[1]));
} else {
// Operator new() was not called.
// Assume that it is embedded or stack object.
set_allocation_type((address)this, STACK_OR_EMBEDDED);
}
_allocation_t[1] = 0; // Zap verification value
}
ResourceObj::ResourceObj(const ResourceObj& r) { // default copy constructor
// Used in ClassFileParser::parse_constant_pool_entries() for ClassFileStream.
// Note: garbage may resembles valid value.
assert(~(_allocation_t[0] | allocation_mask) != (uintptr_t)this || !is_type_set(),
err_msg("embedded or stack only, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
this, get_allocation_type(), _allocation_t[0], _allocation_t[1]));
set_allocation_type((address)this, STACK_OR_EMBEDDED);
_allocation_t[1] = 0; // Zap verification value
}
ResourceObj& ResourceObj::operator=(const ResourceObj& r) { // default copy assignment
// Used in InlineTree::ok_to_inline() for WarmCallInfo.
assert(allocated_on_stack(),
err_msg("copy only into local, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
this, get_allocation_type(), _allocation_t[0], _allocation_t[1]));
// Keep current _allocation_t value;
return *this;
}
ResourceObj::~ResourceObj() {
// allocated_on_C_heap() also checks that encoded (in _allocation) address == this.
if (!allocated_on_C_heap()) { // ResourceObj::delete() will zap _allocation for C_heap.
_allocation_t[0] = (uintptr_t)badHeapOopVal; // zap type
}
}
#endif // ASSERT
void trace_heap_malloc(size_t size, const char* name, void* p) {
// A lock is not needed here - tty uses a lock internally
tty->print_cr("Heap malloc " INTPTR_FORMAT " " SIZE_FORMAT " %s", p, size, name == NULL ? "" : name);
}
void trace_heap_free(void* p) {
// A lock is not needed here - tty uses a lock internally
tty->print_cr("Heap free " INTPTR_FORMAT, p);
}
bool warn_new_operator = false; // see vm_main
//--------------------------------------------------------------------------------------
// ChunkPool implementation
// MT-safe pool of chunks to reduce malloc/free thrashing
// NB: not using Mutex because pools are used before Threads are initialized
class ChunkPool {
Chunk* _first; // first cached Chunk; its first word points to next chunk
size_t _num_chunks; // number of unused chunks in pool
size_t _num_used; // number of chunks currently checked out
const size_t _size; // size of each chunk (must be uniform)
// Our three static pools
static ChunkPool* _large_pool;
static ChunkPool* _medium_pool;
static ChunkPool* _small_pool;
// return first element or null
void* get_first() {
Chunk* c = _first;
if (_first) {
_first = _first->next();
_num_chunks--;
}
return c;
}
public:
// All chunks in a ChunkPool has the same size
ChunkPool(size_t size) : _size(size) { _first = NULL; _num_chunks = _num_used = 0; }
// Allocate a new chunk from the pool (might expand the pool)
void* allocate(size_t bytes) {
assert(bytes == _size, "bad size");
void* p = NULL;
{ ThreadCritical tc;
_num_used++;
p = get_first();
if (p == NULL) p = os::malloc(bytes);
}
if (p == NULL)
vm_exit_out_of_memory(bytes, "ChunkPool::allocate");
return p;
}
// Return a chunk to the pool
void free(Chunk* chunk) {
assert(chunk->length() + Chunk::aligned_overhead_size() == _size, "bad size");
ThreadCritical tc;
_num_used--;
// Add chunk to list
chunk->set_next(_first);
_first = chunk;
_num_chunks++;
}
// Prune the pool
void free_all_but(size_t n) {
// if we have more than n chunks, free all of them
ThreadCritical tc;
if (_num_chunks > n) {
// free chunks at end of queue, for better locality
Chunk* cur = _first;
for (size_t i = 0; i < (n - 1) && cur != NULL; i++) cur = cur->next();
if (cur != NULL) {
Chunk* next = cur->next();
cur->set_next(NULL);
cur = next;
// Free all remaining chunks
while(cur != NULL) {
next = cur->next();
os::free(cur);
_num_chunks--;
cur = next;
}
}
}
}
// Accessors to preallocated pool's
static ChunkPool* large_pool() { assert(_large_pool != NULL, "must be initialized"); return _large_pool; }
static ChunkPool* medium_pool() { assert(_medium_pool != NULL, "must be initialized"); return _medium_pool; }
static ChunkPool* small_pool() { assert(_small_pool != NULL, "must be initialized"); return _small_pool; }
static void initialize() {
_large_pool = new ChunkPool(Chunk::size + Chunk::aligned_overhead_size());
_medium_pool = new ChunkPool(Chunk::medium_size + Chunk::aligned_overhead_size());
_small_pool = new ChunkPool(Chunk::init_size + Chunk::aligned_overhead_size());
}
static void clean() {
enum { BlocksToKeep = 5 };
_small_pool->free_all_but(BlocksToKeep);
_medium_pool->free_all_but(BlocksToKeep);
_large_pool->free_all_but(BlocksToKeep);
}
};
ChunkPool* ChunkPool::_large_pool = NULL;
ChunkPool* ChunkPool::_medium_pool = NULL;
ChunkPool* ChunkPool::_small_pool = NULL;
void chunkpool_init() {
ChunkPool::initialize();
}
void
Chunk::clean_chunk_pool() {
ChunkPool::clean();
}
//--------------------------------------------------------------------------------------
// ChunkPoolCleaner implementation
//
class ChunkPoolCleaner : public PeriodicTask {
enum { CleaningInterval = 5000 }; // cleaning interval in ms
public:
ChunkPoolCleaner() : PeriodicTask(CleaningInterval) {}
void task() {
ChunkPool::clean();
}
};
//--------------------------------------------------------------------------------------
// Chunk implementation
void* Chunk::operator new(size_t requested_size, size_t length) {
// requested_size is equal to sizeof(Chunk) but in order for the arena
// allocations to come out aligned as expected the size must be aligned
// to expected arean alignment.
// expect requested_size but if sizeof(Chunk) doesn't match isn't proper size we must align it.
assert(ARENA_ALIGN(requested_size) == aligned_overhead_size(), "Bad alignment");
size_t bytes = ARENA_ALIGN(requested_size) + length;
switch (length) {
case Chunk::size: return ChunkPool::large_pool()->allocate(bytes);
case Chunk::medium_size: return ChunkPool::medium_pool()->allocate(bytes);
case Chunk::init_size: return ChunkPool::small_pool()->allocate(bytes);
default: {
void *p = os::malloc(bytes);
if (p == NULL)
vm_exit_out_of_memory(bytes, "Chunk::new");
return p;
}
}
}
void Chunk::operator delete(void* p) {
Chunk* c = (Chunk*)p;
switch (c->length()) {
case Chunk::size: ChunkPool::large_pool()->free(c); break;
case Chunk::medium_size: ChunkPool::medium_pool()->free(c); break;
case Chunk::init_size: ChunkPool::small_pool()->free(c); break;
default: os::free(c);
}
}
Chunk::Chunk(size_t length) : _len(length) {
_next = NULL; // Chain on the linked list
}
void Chunk::chop() {
Chunk *k = this;
while( k ) {
Chunk *tmp = k->next();
// clear out this chunk (to detect allocation bugs)
if (ZapResourceArea) memset(k->bottom(), badResourceValue, k->length());
delete k; // Free chunk (was malloc'd)
k = tmp;
}
}
void Chunk::next_chop() {
_next->chop();
_next = NULL;
}
void Chunk::start_chunk_pool_cleaner_task() {
#ifdef ASSERT
static bool task_created = false;
assert(!task_created, "should not start chuck pool cleaner twice");
task_created = true;
#endif
ChunkPoolCleaner* cleaner = new ChunkPoolCleaner();
cleaner->enroll();
}
//------------------------------Arena------------------------------------------
Arena::Arena(size_t init_size) {
size_t round_size = (sizeof (char *)) - 1;
init_size = (init_size+round_size) & ~round_size;
_first = _chunk = new (init_size) Chunk(init_size);
_hwm = _chunk->bottom(); // Save the cached hwm, max
_max = _chunk->top();
set_size_in_bytes(init_size);
}
Arena::Arena() {
_first = _chunk = new (Chunk::init_size) Chunk(Chunk::init_size);
_hwm = _chunk->bottom(); // Save the cached hwm, max
_max = _chunk->top();
set_size_in_bytes(Chunk::init_size);
}
Arena::Arena(Arena *a) : _chunk(a->_chunk), _hwm(a->_hwm), _max(a->_max), _first(a->_first) {
set_size_in_bytes(a->size_in_bytes());
}
Arena *Arena::move_contents(Arena *copy) {
copy->destruct_contents();
copy->_chunk = _chunk;
copy->_hwm = _hwm;
copy->_max = _max;
copy->_first = _first;
copy->set_size_in_bytes(size_in_bytes());
// Destroy original arena
reset();
return copy; // Return Arena with contents
}
Arena::~Arena() {
destruct_contents();
}
// Destroy this arenas contents and reset to empty
void Arena::destruct_contents() {
if (UseMallocOnly && _first != NULL) {
char* end = _first->next() ? _first->top() : _hwm;
free_malloced_objects(_first, _first->bottom(), end, _hwm);
}
_first->chop();
reset();
}
// Total of all Chunks in arena
size_t Arena::used() const {
size_t sum = _chunk->length() - (_max-_hwm); // Size leftover in this Chunk
register Chunk *k = _first;
while( k != _chunk) { // Whilst have Chunks in a row
sum += k->length(); // Total size of this Chunk
k = k->next(); // Bump along to next Chunk
}
return sum; // Return total consumed space.
}
void Arena::signal_out_of_memory(size_t sz, const char* whence) const {
vm_exit_out_of_memory(sz, whence);
}
// Grow a new Chunk
void* Arena::grow( size_t x ) {
// Get minimal required size. Either real big, or even bigger for giant objs
size_t len = MAX2(x, (size_t) Chunk::size);
Chunk *k = _chunk; // Get filled-up chunk address
_chunk = new (len) Chunk(len);
if (_chunk == NULL) {
signal_out_of_memory(len * Chunk::aligned_overhead_size(), "Arena::grow");
}
if (k) k->set_next(_chunk); // Append new chunk to end of linked list
else _first = _chunk;
_hwm = _chunk->bottom(); // Save the cached hwm, max
_max = _chunk->top();
set_size_in_bytes(size_in_bytes() + len);
void* result = _hwm;
_hwm += x;
return result;
}
// Reallocate storage in Arena.
void *Arena::Arealloc(void* old_ptr, size_t old_size, size_t new_size) {
assert(new_size >= 0, "bad size");
if (new_size == 0) return NULL;
#ifdef ASSERT
if (UseMallocOnly) {
// always allocate a new object (otherwise we'll free this one twice)
char* copy = (char*)Amalloc(new_size);
size_t n = MIN2(old_size, new_size);
if (n > 0) memcpy(copy, old_ptr, n);
Afree(old_ptr,old_size); // Mostly done to keep stats accurate
return copy;
}
#endif
char *c_old = (char*)old_ptr; // Handy name
// Stupid fast special case
if( new_size <= old_size ) { // Shrink in-place
if( c_old+old_size == _hwm) // Attempt to free the excess bytes
_hwm = c_old+new_size; // Adjust hwm
return c_old;
}
// make sure that new_size is legal
size_t corrected_new_size = ARENA_ALIGN(new_size);
// See if we can resize in-place
if( (c_old+old_size == _hwm) && // Adjusting recent thing
(c_old+corrected_new_size <= _max) ) { // Still fits where it sits
_hwm = c_old+corrected_new_size; // Adjust hwm
return c_old; // Return old pointer
}
// Oops, got to relocate guts
void *new_ptr = Amalloc(new_size);
memcpy( new_ptr, c_old, old_size );
Afree(c_old,old_size); // Mostly done to keep stats accurate
return new_ptr;
}
// Determine if pointer belongs to this Arena or not.
bool Arena::contains( const void *ptr ) const {
#ifdef ASSERT
if (UseMallocOnly) {
// really slow, but not easy to make fast
if (_chunk == NULL) return false;
char** bottom = (char**)_chunk->bottom();
for (char** p = (char**)_hwm - 1; p >= bottom; p--) {
if (*p == ptr) return true;
}
for (Chunk *c = _first; c != NULL; c = c->next()) {
if (c == _chunk) continue; // current chunk has been processed
char** bottom = (char**)c->bottom();
for (char** p = (char**)c->top() - 1; p >= bottom; p--) {
if (*p == ptr) return true;
}
}
return false;
}
#endif
if( (void*)_chunk->bottom() <= ptr && ptr < (void*)_hwm )
return true; // Check for in this chunk
for (Chunk *c = _first; c; c = c->next()) {
if (c == _chunk) continue; // current chunk has been processed
if ((void*)c->bottom() <= ptr && ptr < (void*)c->top()) {
return true; // Check for every chunk in Arena
}
}
return false; // Not in any Chunk, so not in Arena
}
#ifdef ASSERT
void* Arena::malloc(size_t size) {
assert(UseMallocOnly, "shouldn't call");
// use malloc, but save pointer in res. area for later freeing
char** save = (char**)internal_malloc_4(sizeof(char*));
return (*save = (char*)os::malloc(size));
}
// for debugging with UseMallocOnly
void* Arena::internal_malloc_4(size_t x) {
assert( (x&(sizeof(char*)-1)) == 0, "misaligned size" );
check_for_overflow(x, "Arena::internal_malloc_4");
if (_hwm + x > _max) {
return grow(x);
} else {
char *old = _hwm;
_hwm += x;
return old;
}
}
#endif
//--------------------------------------------------------------------------------------
// Non-product code
#ifndef PRODUCT
// The global operator new should never be called since it will usually indicate
// a memory leak. Use CHeapObj as the base class of such objects to make it explicit
// that they're allocated on the C heap.
// Commented out in product version to avoid conflicts with third-party C++ native code.
// %% note this is causing a problem on solaris debug build. the global
// new is being called from jdk source and causing data corruption.
// src/share/native/sun/awt/font/fontmanager/textcache/hsMemory.cpp::hsSoftNew
// define CATCH_OPERATOR_NEW_USAGE if you want to use this.
#ifdef CATCH_OPERATOR_NEW_USAGE
void* operator new(size_t size){
static bool warned = false;
if (!warned && warn_new_operator)
warning("should not call global (default) operator new");
warned = true;
return (void *) AllocateHeap(size, "global operator new");
}
#endif
void AllocatedObj::print() const { print_on(tty); }
void AllocatedObj::print_value() const { print_value_on(tty); }
void AllocatedObj::print_on(outputStream* st) const {
st->print_cr("AllocatedObj(" INTPTR_FORMAT ")", this);
}
void AllocatedObj::print_value_on(outputStream* st) const {
st->print("AllocatedObj(" INTPTR_FORMAT ")", this);
}
julong Arena::_bytes_allocated = 0;
void Arena::inc_bytes_allocated(size_t x) { inc_stat_counter(&_bytes_allocated, x); }
AllocStats::AllocStats() {
start_mallocs = os::num_mallocs;
start_frees = os::num_frees;
start_malloc_bytes = os::alloc_bytes;
start_mfree_bytes = os::free_bytes;
start_res_bytes = Arena::_bytes_allocated;
}
julong AllocStats::num_mallocs() { return os::num_mallocs - start_mallocs; }
julong AllocStats::alloc_bytes() { return os::alloc_bytes - start_malloc_bytes; }
julong AllocStats::num_frees() { return os::num_frees - start_frees; }
julong AllocStats::free_bytes() { return os::free_bytes - start_mfree_bytes; }
julong AllocStats::resource_bytes() { return Arena::_bytes_allocated - start_res_bytes; }
void AllocStats::print() {
tty->print_cr(UINT64_FORMAT " mallocs (" UINT64_FORMAT "MB), "
UINT64_FORMAT" frees (" UINT64_FORMAT "MB), " UINT64_FORMAT "MB resrc",
num_mallocs(), alloc_bytes()/M, num_frees(), free_bytes()/M, resource_bytes()/M);
}
// debugging code
inline void Arena::free_all(char** start, char** end) {
for (char** p = start; p < end; p++) if (*p) os::free(*p);
}
void Arena::free_malloced_objects(Chunk* chunk, char* hwm, char* max, char* hwm2) {
assert(UseMallocOnly, "should not call");
// free all objects malloced since resource mark was created; resource area
// contains their addresses
if (chunk->next()) {
// this chunk is full, and some others too
for (Chunk* c = chunk->next(); c != NULL; c = c->next()) {
char* top = c->top();
if (c->next() == NULL) {
top = hwm2; // last junk is only used up to hwm2
assert(c->contains(hwm2), "bad hwm2");
}
free_all((char**)c->bottom(), (char**)top);
}
assert(chunk->contains(hwm), "bad hwm");
assert(chunk->contains(max), "bad max");
free_all((char**)hwm, (char**)max);
} else {
// this chunk was partially used
assert(chunk->contains(hwm), "bad hwm");
assert(chunk->contains(hwm2), "bad hwm2");
free_all((char**)hwm, (char**)hwm2);
}
}
ReallocMark::ReallocMark() {
#ifdef ASSERT
Thread *thread = ThreadLocalStorage::get_thread_slow();
_nesting = thread->resource_area()->nesting();
#endif
}
void ReallocMark::check() {
#ifdef ASSERT
if (_nesting != Thread::current()->resource_area()->nesting()) {
fatal("allocation bug: array could grow within nested ResourceMark");
}
#endif
}
#endif // Non-product