truffle: src/share/vm/memory/collectorPolicy.cpp comparison

comparison src/share/vm/memory/collectorPolicy.cpp @ 0:a61af66fc99e jdk7-b24

Initial load

author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	183f41cf8bfe

comparison

equal deleted inserted replaced

--1:000000000000
+:a61af66fc99e
+/*
+* Copyright 2001-2007 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/_collectorPolicy.cpp.incl"
+// CollectorPolicy methods.
+void CollectorPolicy::initialize_flags() {
+if (PermSize > MaxPermSize) {
+MaxPermSize = PermSize;
+}
+PermSize = align_size_down(PermSize, min_alignment());
+MaxPermSize = align_size_up(MaxPermSize, max_alignment());
+MinPermHeapExpansion = align_size_down(MinPermHeapExpansion, min_alignment());
+MaxPermHeapExpansion = align_size_down(MaxPermHeapExpansion, min_alignment());
+MinHeapDeltaBytes = align_size_up(MinHeapDeltaBytes, min_alignment());
+SharedReadOnlySize = align_size_up(SharedReadOnlySize, max_alignment());
+SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment());
+SharedMiscDataSize = align_size_up(SharedMiscDataSize, max_alignment());
+assert(PermSize    % min_alignment() == 0, "permanent space alignment");
+assert(MaxPermSize % max_alignment() == 0, "maximum permanent space alignment");
+assert(SharedReadOnlySize % max_alignment() == 0, "read-only space alignment");
+assert(SharedReadWriteSize % max_alignment() == 0, "read-write space alignment");
+assert(SharedMiscDataSize % max_alignment() == 0, "misc-data space alignment");
+if (PermSize < M) {
+vm_exit_during_initialization("Too small initial permanent heap");
+}
+}
+void CollectorPolicy::initialize_size_info() {
+// User inputs from -mx and ms are aligned
+_initial_heap_byte_size = align_size_up(Arguments::initial_heap_size(),
+min_alignment());
+_min_heap_byte_size = align_size_up(Arguments::min_heap_size(),
+min_alignment());
+_max_heap_byte_size = align_size_up(MaxHeapSize, max_alignment());
+// Check validity of heap parameters from launcher
+if (_initial_heap_byte_size == 0) {
+_initial_heap_byte_size = NewSize + OldSize;
+} else {
+Universe::check_alignment(_initial_heap_byte_size, min_alignment(),
+"initial heap");
+}
+if (_min_heap_byte_size == 0) {
+_min_heap_byte_size = NewSize + OldSize;
+} else {
+Universe::check_alignment(_min_heap_byte_size, min_alignment(),
+"initial heap");
+}
+// Check heap parameter properties
+if (_initial_heap_byte_size < M) {
+vm_exit_during_initialization("Too small initial heap");
+}
+// Check heap parameter properties
+if (_min_heap_byte_size < M) {
+vm_exit_during_initialization("Too small minimum heap");
+}
+if (_initial_heap_byte_size <= NewSize) {
+// make sure there is at least some room in old space
+vm_exit_during_initialization("Too small initial heap for new size specified");
+}
+if (_max_heap_byte_size < _min_heap_byte_size) {
+vm_exit_during_initialization("Incompatible minimum and maximum heap sizes specified");
+}
+if (_initial_heap_byte_size < _min_heap_byte_size) {
+vm_exit_during_initialization("Incompatible minimum and initial heap sizes specified");
+}
+if (_max_heap_byte_size < _initial_heap_byte_size) {
+vm_exit_during_initialization("Incompatible initial and maximum heap sizes specified");
+}
+}
+void CollectorPolicy::initialize_perm_generation(PermGen::Name pgnm) {
+_permanent_generation =
+new PermanentGenerationSpec(pgnm, PermSize, MaxPermSize,
+SharedReadOnlySize,
+SharedReadWriteSize,
+SharedMiscDataSize,
+SharedMiscCodeSize);
+if (_permanent_generation == NULL) {
+vm_exit_during_initialization("Unable to allocate gen spec");
+}
+}
+GenRemSet* CollectorPolicy::create_rem_set(MemRegion whole_heap,
+int max_covered_regions) {
+switch (rem_set_name()) {
+case GenRemSet::CardTable: {
+if (barrier_set_name() != BarrierSet::CardTableModRef)
+vm_exit_during_initialization("Mismatch between RS and BS.");
+CardTableRS* res = new CardTableRS(whole_heap, max_covered_regions);
+return res;
+}
+default:
+guarantee(false, "unrecognized GenRemSet::Name");
+return NULL;
+}
+}
+// GenCollectorPolicy methods.
+void GenCollectorPolicy::initialize_size_policy(size_t init_eden_size,
+size_t init_promo_size,
+size_t init_survivor_size) {
+double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
+_size_policy = new AdaptiveSizePolicy(init_eden_size,
+init_promo_size,
+init_survivor_size,
+max_gc_minor_pause_sec,
+GCTimeRatio);
+}
+size_t GenCollectorPolicy::compute_max_alignment() {
+// The card marking array and the offset arrays for old generations are
+// committed in os pages as well. Make sure they are entirely full (to
+// avoid partial page problems), e.g. if 512 bytes heap corresponds to 1
+// byte entry and the os page size is 4096, the maximum heap size should
+// be 512*4096 = 2MB aligned.
+size_t alignment = GenRemSet::max_alignment_constraint(rem_set_name());
+// Parallel GC does its own alignment of the generations to avoid requiring a
+// large page (256M on some platforms) for the permanent generation.  The
+// other collectors should also be updated to do their own alignment and then
+// this use of lcm() should be removed.
+if (UseLargePages && !UseParallelGC) {
+// in presence of large pages we have to make sure that our
+// alignment is large page aware
+alignment = lcm(os::large_page_size(), alignment);
+}
+return alignment;
+}
+void GenCollectorPolicy::initialize_flags() {
+// All sizes must be multiples of the generation granularity.
+set_min_alignment((uintx) Generation::GenGrain);
+set_max_alignment(compute_max_alignment());
+assert(max_alignment() >= min_alignment() &&
+max_alignment() % min_alignment() == 0,
+"invalid alignment constraints");
+CollectorPolicy::initialize_flags();
+// All generational heaps have a youngest gen; handle those flags here.
+// Adjust max size parameters
+if (NewSize > MaxNewSize) {
+MaxNewSize = NewSize;
+}
+NewSize = align_size_down(NewSize, min_alignment());
+MaxNewSize = align_size_down(MaxNewSize, min_alignment());
+// Check validity of heap flags
+assert(NewSize     % min_alignment() == 0, "eden space alignment");
+assert(MaxNewSize  % min_alignment() == 0, "survivor space alignment");
+if (NewSize < 3*min_alignment()) {
+// make sure there room for eden and two survivor spaces
+vm_exit_during_initialization("Too small new size specified");
+}
+if (SurvivorRatio < 1 || NewRatio < 1) {
+vm_exit_during_initialization("Invalid heap ratio specified");
+}
+}
+void TwoGenerationCollectorPolicy::initialize_flags() {
+GenCollectorPolicy::initialize_flags();
+OldSize = align_size_down(OldSize, min_alignment());
+if (NewSize + OldSize > MaxHeapSize) {
+MaxHeapSize = NewSize + OldSize;
+}
+MaxHeapSize = align_size_up(MaxHeapSize, max_alignment());
+always_do_update_barrier = UseConcMarkSweepGC;
+BlockOffsetArrayUseUnallocatedBlock =
+BlockOffsetArrayUseUnallocatedBlock || ParallelGCThreads > 0;
+// Check validity of heap flags
+assert(OldSize     % min_alignment() == 0, "old space alignment");
+assert(MaxHeapSize % max_alignment() == 0, "maximum heap alignment");
+}
+void GenCollectorPolicy::initialize_size_info() {
+CollectorPolicy::initialize_size_info();
+// Minimum sizes of the generations may be different than
+// the initial sizes.
+if (!FLAG_IS_DEFAULT(NewSize)) {
+_min_gen0_size = NewSize;
+} else {
+_min_gen0_size = align_size_down(_min_heap_byte_size / (NewRatio+1),
+min_alignment());
+// We bound the minimum size by NewSize below (since it historically
+// would have been NewSize and because the NewRatio calculation could
+// yield a size that is too small) and bound it by MaxNewSize above.
+// This is not always best.  The NewSize calculated by CMS (which has
+// a fixed minimum of 16m) can sometimes be "too" large.  Consider
+// the case where -Xmx32m.  The CMS calculated NewSize would be about
+// half the entire heap which seems too large.  But the counter
+// example is seen when the client defaults for NewRatio are used.
+// An initial young generation size of 640k was observed
+// with -Xmx128m -XX:MaxNewSize=32m when NewSize was not used
+// as a lower bound as with
+// _min_gen0_size = MIN2(_min_gen0_size, MaxNewSize);
+// and 640k seemed too small a young generation.
+_min_gen0_size = MIN2(MAX2(_min_gen0_size, NewSize), MaxNewSize);
+}
+// Parameters are valid, compute area sizes.
+size_t max_new_size = align_size_down(_max_heap_byte_size / (NewRatio+1),
+min_alignment());
+max_new_size = MIN2(MAX2(max_new_size, _min_gen0_size), MaxNewSize);
+// desired_new_size is used to set the initial size.  The
+// initial size must be greater than the minimum size.
+size_t desired_new_size =
+align_size_down(_initial_heap_byte_size / (NewRatio+1),
+min_alignment());
+size_t new_size = MIN2(MAX2(desired_new_size, _min_gen0_size), max_new_size);
+_initial_gen0_size = new_size;
+_max_gen0_size = max_new_size;
+}
+void TwoGenerationCollectorPolicy::initialize_size_info() {
+GenCollectorPolicy::initialize_size_info();
+// Minimum sizes of the generations may be different than
+// the initial sizes.  An inconsistently is permitted here
+// in the total size that can be specified explicitly by
+// command line specification of OldSize and NewSize and
+// also a command line specification of -Xms.  Issue a warning
+// but allow the values to pass.
+if (!FLAG_IS_DEFAULT(OldSize)) {
+_min_gen1_size = OldSize;
+// The generation minimums and the overall heap mimimum should
+// be within one heap alignment.
+if ((_min_gen1_size + _min_gen0_size + max_alignment()) <
+_min_heap_byte_size) {
+warning("Inconsistency between minimum heap size and minimum "
+"generation sizes: using min heap = " SIZE_FORMAT,
+_min_heap_byte_size);
+}
+} else {
+_min_gen1_size = _min_heap_byte_size - _min_gen0_size;
+}
+_initial_gen1_size = _initial_heap_byte_size - _initial_gen0_size;
+_max_gen1_size = _max_heap_byte_size - _max_gen0_size;
+}
+HeapWord* GenCollectorPolicy::mem_allocate_work(size_t size,
+bool is_tlab,
+bool* gc_overhead_limit_was_exceeded) {
+GenCollectedHeap *gch = GenCollectedHeap::heap();
+debug_only(gch->check_for_valid_allocation_state());
+assert(gch->no_gc_in_progress(), "Allocation during gc not allowed");
+HeapWord* result = NULL;
+// Loop until the allocation is satisified,
+// or unsatisfied after GC.
+for (int try_count = 1; /* return or throw */; try_count += 1) {
+HandleMark hm; // discard any handles allocated in each iteration
+// First allocation attempt is lock-free.
+Generation *gen0 = gch->get_gen(0);
+assert(gen0->supports_inline_contig_alloc(),
+"Otherwise, must do alloc within heap lock");
+if (gen0->should_allocate(size, is_tlab)) {
+result = gen0->par_allocate(size, is_tlab);
+if (result != NULL) {
+assert(gch->is_in_reserved(result), "result not in heap");
+return result;
+}
+}
+unsigned int gc_count_before;  // read inside the Heap_lock locked region
+{
+MutexLocker ml(Heap_lock);
+if (PrintGC && Verbose) {
+gclog_or_tty->print_cr("TwoGenerationCollectorPolicy::mem_allocate_work:"
+" attempting locked slow path allocation");
+}
+// Note that only large objects get a shot at being
+// allocated in later generations.
+bool first_only = ! should_try_older_generation_allocation(size);
+result = gch->attempt_allocation(size, is_tlab, first_only);
+if (result != NULL) {
+assert(gch->is_in_reserved(result), "result not in heap");
+return result;
+}
+// There are NULL's returned for different circumstances below.
+// In general gc_overhead_limit_was_exceeded should be false so
+// set it so here and reset it to true only if the gc time
+// limit is being exceeded as checked below.
+*gc_overhead_limit_was_exceeded = false;
+if (GC_locker::is_active_and_needs_gc()) {
+if (is_tlab) {
+return NULL;  // Caller will retry allocating individual object
+}
+if (!gch->is_maximal_no_gc()) {
+// Try and expand heap to satisfy request
+result = expand_heap_and_allocate(size, is_tlab);
+// result could be null if we are out of space
+if (result != NULL) {
+return result;
+}
+}
+// If this thread is not in a jni critical section, we stall
+// the requestor until the critical section has cleared and
+// GC allowed. When the critical section clears, a GC is
+// initiated by the last thread exiting the critical section; so
+// we retry the allocation sequence from the beginning of the loop,
+// rather than causing more, now probably unnecessary, GC attempts.
+JavaThread* jthr = JavaThread::current();
+if (!jthr->in_critical()) {
+MutexUnlocker mul(Heap_lock);
+// Wait for JNI critical section to be exited
+GC_locker::stall_until_clear();
+continue;
+} else {
+if (CheckJNICalls) {
+fatal("Possible deadlock due to allocating while"
+" in jni critical section");
+}
+return NULL;
+}
+}
+// Read the gc count while the heap lock is held.
+gc_count_before = Universe::heap()->total_collections();
+}
+// Allocation has failed and a collection is about
+// to be done.  If the gc time limit was exceeded the
+// last time a collection was done, return NULL so
+// that an out-of-memory will be thrown.  Clear
+// gc_time_limit_exceeded so that subsequent attempts
+// at a collection will be made.
+if (size_policy()->gc_time_limit_exceeded()) {
+*gc_overhead_limit_was_exceeded = true;
+size_policy()->set_gc_time_limit_exceeded(false);
+return NULL;
+}
+VM_GenCollectForAllocation op(size,
+is_tlab,
+gc_count_before);
+VMThread::execute(&op);
+if (op.prologue_succeeded()) {
+result = op.result();
+if (op.gc_locked()) {
+assert(result == NULL, "must be NULL if gc_locked() is true");
+continue;  // retry and/or stall as necessary
+}
+assert(result == NULL || gch->is_in_reserved(result),
+"result not in heap");
+return result;
+}
+// Give a warning if we seem to be looping forever.
+if ((QueuedAllocationWarningCount > 0) &&
+(try_count % QueuedAllocationWarningCount == 0)) {
+warning("TwoGenerationCollectorPolicy::mem_allocate_work retries %d times \n\t"
+" size=%d %s", try_count, size, is_tlab ? "(TLAB)" : "");
+}
+}
+}
+HeapWord* GenCollectorPolicy::expand_heap_and_allocate(size_t size,
+bool   is_tlab) {
+GenCollectedHeap *gch = GenCollectedHeap::heap();
+HeapWord* result = NULL;
+for (int i = number_of_generations() - 1; i >= 0 && result == NULL; i--) {
+Generation *gen = gch->get_gen(i);
+if (gen->should_allocate(size, is_tlab)) {
+result = gen->expand_and_allocate(size, is_tlab);
+}
+}
+assert(result == NULL || gch->is_in_reserved(result), "result not in heap");
+return result;
+}
+HeapWord* GenCollectorPolicy::satisfy_failed_allocation(size_t size,
+bool   is_tlab) {
+GenCollectedHeap *gch = GenCollectedHeap::heap();
+GCCauseSetter x(gch, GCCause::_allocation_failure);
+HeapWord* result = NULL;
+assert(size != 0, "Precondition violated");
+if (GC_locker::is_active_and_needs_gc()) {
+// GC locker is active; instead of a collection we will attempt
+// to expand the heap, if there's room for expansion.
+if (!gch->is_maximal_no_gc()) {
+result = expand_heap_and_allocate(size, is_tlab);
+}
+return result;   // could be null if we are out of space
+} else if (!gch->incremental_collection_will_fail()) {
+// The gc_prologues have not executed yet.  The value
+// for incremental_collection_will_fail() is the remanent
+// of the last collection.
+// Do an incremental collection.
+gch->do_collection(false            /* full */,
+false            /* clear_all_soft_refs */,
+size             /* size */,
+is_tlab          /* is_tlab */,
+number_of_generations() - 1 /* max_level */);
+} else {
+// Try a full collection; see delta for bug id 6266275
+// for the original code and why this has been simplified
+// with from-space allocation criteria modified and
+// such allocation moved out of the safepoint path.
+gch->do_collection(true             /* full */,
+false            /* clear_all_soft_refs */,
+size             /* size */,
+is_tlab          /* is_tlab */,
+number_of_generations() - 1 /* max_level */);
+}
+result = gch->attempt_allocation(size, is_tlab, false /*first_only*/);
+if (result != NULL) {
+assert(gch->is_in_reserved(result), "result not in heap");
+return result;
+}
+// OK, collection failed, try expansion.
+result = expand_heap_and_allocate(size, is_tlab);
+if (result != NULL) {
+return result;
+}
+// If we reach this point, we're really out of memory. Try every trick
+// we can to reclaim memory. Force collection of soft references. Force
+// a complete compaction of the heap. Any additional methods for finding
+// free memory should be here, especially if they are expensive. If this
+// attempt fails, an OOM exception will be thrown.
+{
+IntFlagSetting flag_change(MarkSweepAlwaysCompactCount, 1); // Make sure the heap is fully compacted
+gch->do_collection(true             /* full */,
+true             /* clear_all_soft_refs */,
+size             /* size */,
+is_tlab          /* is_tlab */,
+number_of_generations() - 1 /* max_level */);
+}
+result = gch->attempt_allocation(size, is_tlab, false /* first_only */);
+if (result != NULL) {
+assert(gch->is_in_reserved(result), "result not in heap");
+return result;
+}
+// What else?  We might try synchronous finalization later.  If the total
+// space available is large enough for the allocation, then a more
+// complete compaction phase than we've tried so far might be
+// appropriate.
+return NULL;
+}
+size_t GenCollectorPolicy::large_typearray_limit() {
+return FastAllocateSizeLimit;
+}
+// Return true if any of the following is true:
+// . the allocation won't fit into the current young gen heap
+// . gc locker is occupied (jni critical section)
+// . heap memory is tight -- the most recent previous collection
+//   was a full collection because a partial collection (would
+//   have) failed and is likely to fail again
+bool GenCollectorPolicy::should_try_older_generation_allocation(
+size_t word_size) const {
+GenCollectedHeap* gch = GenCollectedHeap::heap();
+size_t gen0_capacity = gch->get_gen(0)->capacity_before_gc();
+return    (word_size > heap_word_size(gen0_capacity))
+|| (GC_locker::is_active_and_needs_gc())
+|| (   gch->last_incremental_collection_failed()
+&& gch->incremental_collection_will_fail());
+}
+//
+// MarkSweepPolicy methods
+//
+MarkSweepPolicy::MarkSweepPolicy() {
+initialize_all();
+}
+void MarkSweepPolicy::initialize_generations() {
+initialize_perm_generation(PermGen::MarkSweepCompact);
+_generations = new GenerationSpecPtr[number_of_generations()];
+if (_generations == NULL)
+vm_exit_during_initialization("Unable to allocate gen spec");
+if (UseParNewGC && ParallelGCThreads > 0) {
+_generations[0] = new GenerationSpec(Generation::ParNew, _initial_gen0_size, _max_gen0_size);
+} else {
+_generations[0] = new GenerationSpec(Generation::DefNew, _initial_gen0_size, _max_gen0_size);
+}
+_generations[1] = new GenerationSpec(Generation::MarkSweepCompact, _initial_gen1_size, _max_gen1_size);
+if (_generations[0] == NULL || _generations[1] == NULL)
+vm_exit_during_initialization("Unable to allocate gen spec");
+}
+void MarkSweepPolicy::initialize_gc_policy_counters() {
+// initialize the policy counters - 2 collectors, 3 generations
+if (UseParNewGC && ParallelGCThreads > 0) {
+_gc_policy_counters = new GCPolicyCounters("ParNew:MSC", 2, 3);
+}
+else {
+_gc_policy_counters = new GCPolicyCounters("Copy:MSC", 2, 3);
+}
+}

Mercurial > hg > truffle

comparison src/share/vm/memory/collectorPolicy.cpp @ 0:a61af66fc99e jdk7-b24