--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/arena.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,526 @@
+/*
+ * Copyright (c) 2017, 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 "gc/shared/genCollectedHeap.hpp"
+#include "memory/allocation.hpp"
+#include "memory/allocation.inline.hpp"
+#include "memory/metaspaceShared.hpp"
+#include "memory/resourceArea.hpp"
+#include "memory/universe.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/os.hpp"
+#include "runtime/task.hpp"
+#include "runtime/threadCritical.hpp"
+#include "services/memTracker.hpp"
+#include "utilities/ostream.hpp"
+
+//--------------------------------------------------------------------------------------
+// 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: public CHeapObj<mtInternal> {
+ 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 four static pools
+ static ChunkPool* _large_pool;
+ static ChunkPool* _medium_pool;
+ static ChunkPool* _small_pool;
+ static ChunkPool* _tiny_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)
+ NOINLINE void* allocate(size_t bytes, AllocFailType alloc_failmode) {
+ assert(bytes == _size, "bad size");
+ void* p = NULL;
+ // No VM lock can be taken inside ThreadCritical lock, so os::malloc
+ // should be done outside ThreadCritical lock due to NMT
+ { ThreadCritical tc;
+ _num_used++;
+ p = get_first();
+ }
+ if (p == NULL) p = os::malloc(bytes, mtChunk, CURRENT_PC);
+ if (p == NULL && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
+ vm_exit_out_of_memory(bytes, OOM_MALLOC_ERROR, "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) {
+ Chunk* cur = NULL;
+ Chunk* next;
+ {
+ // 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
+ cur = _first;
+ for (size_t i = 0; i < (n - 1) && cur != NULL; i++) cur = cur->next();
+
+ if (cur != NULL) {
+ next = cur->next();
+ cur->set_next(NULL);
+ cur = next;
+
+ // Free all remaining chunks while in ThreadCritical lock
+ // so NMT adjustment is stable.
+ 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 ChunkPool* tiny_pool() { assert(_tiny_pool != NULL, "must be initialized"); return _tiny_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());
+ _tiny_pool = new ChunkPool(Chunk::tiny_size + Chunk::aligned_overhead_size());
+ }
+
+ static void clean() {
+ enum { BlocksToKeep = 5 };
+ _tiny_pool->free_all_but(BlocksToKeep);
+ _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;
+ChunkPool* ChunkPool::_tiny_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, AllocFailType alloc_failmode, size_t length) throw() {
+ // 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 arena 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, alloc_failmode);
+ case Chunk::medium_size: return ChunkPool::medium_pool()->allocate(bytes, alloc_failmode);
+ case Chunk::init_size: return ChunkPool::small_pool()->allocate(bytes, alloc_failmode);
+ case Chunk::tiny_size: return ChunkPool::tiny_pool()->allocate(bytes, alloc_failmode);
+ default: {
+ void* p = os::malloc(bytes, mtChunk, CALLER_PC);
+ if (p == NULL && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
+ vm_exit_out_of_memory(bytes, OOM_MALLOC_ERROR, "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;
+ case Chunk::tiny_size: ChunkPool::tiny_pool()->free(c); break;
+ default:
+ ThreadCritical tc; // Free chunks under TC lock so that NMT adjustment is stable.
+ 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(MEMFLAGS flag, size_t init_size) : _flags(flag), _size_in_bytes(0) {
+ size_t round_size = (sizeof (char *)) - 1;
+ init_size = (init_size+round_size) & ~round_size;
+ _first = _chunk = new (AllocFailStrategy::EXIT_OOM, init_size) Chunk(init_size);
+ _hwm = _chunk->bottom(); // Save the cached hwm, max
+ _max = _chunk->top();
+ MemTracker::record_new_arena(flag);
+ set_size_in_bytes(init_size);
+}
+
+Arena::Arena(MEMFLAGS flag) : _flags(flag), _size_in_bytes(0) {
+ _first = _chunk = new (AllocFailStrategy::EXIT_OOM, Chunk::init_size) Chunk(Chunk::init_size);
+ _hwm = _chunk->bottom(); // Save the cached hwm, max
+ _max = _chunk->top();
+ MemTracker::record_new_arena(flag);
+ set_size_in_bytes(Chunk::init_size);
+}
+
+Arena *Arena::move_contents(Arena *copy) {
+ copy->destruct_contents();
+ copy->_chunk = _chunk;
+ copy->_hwm = _hwm;
+ copy->_max = _max;
+ copy->_first = _first;
+
+ // workaround rare racing condition, which could double count
+ // the arena size by native memory tracking
+ size_t size = size_in_bytes();
+ set_size_in_bytes(0);
+ copy->set_size_in_bytes(size);
+ // Destroy original arena
+ reset();
+ return copy; // Return Arena with contents
+}
+
+Arena::~Arena() {
+ destruct_contents();
+ MemTracker::record_arena_free(_flags);
+}
+
+void* Arena::operator new(size_t size) throw() {
+ assert(false, "Use dynamic memory type binding");
+ return NULL;
+}
+
+void* Arena::operator new (size_t size, const std::nothrow_t& nothrow_constant) throw() {
+ assert(false, "Use dynamic memory type binding");
+ return NULL;
+}
+
+ // dynamic memory type binding
+void* Arena::operator new(size_t size, MEMFLAGS flags) throw() {
+#ifdef ASSERT
+ void* p = (void*)AllocateHeap(size, flags, CALLER_PC);
+ if (PrintMallocFree) trace_heap_malloc(size, "Arena-new", p);
+ return p;
+#else
+ return (void *) AllocateHeap(size, flags, CALLER_PC);
+#endif
+}
+
+void* Arena::operator new(size_t size, const std::nothrow_t& nothrow_constant, MEMFLAGS flags) throw() {
+#ifdef ASSERT
+ void* p = os::malloc(size, flags, CALLER_PC);
+ if (PrintMallocFree) trace_heap_malloc(size, "Arena-new", p);
+ return p;
+#else
+ return os::malloc(size, flags, CALLER_PC);
+#endif
+}
+
+void Arena::operator delete(void* p) {
+ FreeHeap(p);
+}
+
+// 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);
+ }
+ // reset size before chop to avoid a rare racing condition
+ // that can have total arena memory exceed total chunk memory
+ set_size_in_bytes(0);
+ _first->chop();
+ reset();
+}
+
+// This is high traffic method, but many calls actually don't
+// change the size
+void Arena::set_size_in_bytes(size_t size) {
+ if (_size_in_bytes != size) {
+ long delta = (long)(size - size_in_bytes());
+ _size_in_bytes = size;
+ MemTracker::record_arena_size_change(delta, _flags);
+ }
+}
+
+// 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, OOM_MALLOC_ERROR, "%s", whence);
+}
+
+// Grow a new Chunk
+void* Arena::grow(size_t x, AllocFailType alloc_failmode) {
+ // 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 (alloc_failmode, len) Chunk(len);
+
+ if (_chunk == NULL) {
+ _chunk = k; // restore the previous value of _chunk
+ return NULL;
+ }
+ 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, AllocFailType alloc_failmode) {
+ 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, alloc_failmode);
+ if (copy == NULL) {
+ return NULL;
+ }
+ 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, alloc_failmode);
+ if (new_ptr == NULL) {
+ return NULL;
+ }
+ 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, mtChunk));
+}
+
+// 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
+
+julong Arena::_bytes_allocated = 0;
+
+void Arena::inc_bytes_allocated(size_t x) { inc_stat_counter(&_bytes_allocated, x); }
+
+// 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);
+ }
+}
+
+#endif // Non-product