Mercurial > hg > graal-jvmci-8
view src/share/vm/memory/permGen.cpp @ 3992:d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
Summary: There is a race between one thread successfully forwarding and copying the klass mirror for the SoftReference class (including the static master clock) and another thread attempting to use the master clock while attempting to discover a soft reference object. Maintain a shadow copy of the soft reference master clock and use the shadow during reference discovery and reference processing.
Reviewed-by: tonyp, brutisso, ysr
author | johnc |
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date | Wed, 12 Oct 2011 10:25:51 -0700 |
parents | f95d63e2154a |
children |
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/* * Copyright (c) 2000, 2010, 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_implementation/shared/cSpaceCounters.hpp" #include "gc_implementation/shared/vmGCOperations.hpp" #include "gc_interface/collectedHeap.inline.hpp" #include "memory/blockOffsetTable.inline.hpp" #include "memory/compactPermGen.hpp" #include "memory/gcLocker.hpp" #include "memory/gcLocker.inline.hpp" #include "memory/genCollectedHeap.hpp" #include "memory/generation.inline.hpp" #include "memory/permGen.hpp" #include "memory/universe.hpp" #include "oops/oop.inline.hpp" #include "runtime/java.hpp" #include "runtime/vmThread.hpp" HeapWord* PermGen::request_expand_and_allocate(Generation* gen, size_t size, GCCause::Cause prev_cause) { if (gen->capacity() < _capacity_expansion_limit || prev_cause != GCCause::_no_gc || UseG1GC) { // last disjunct is a temporary hack for G1 return gen->expand_and_allocate(size, false); } // We have reached the limit of capacity expansion where // we will not expand further until a GC is done; request denied. return NULL; } HeapWord* PermGen::mem_allocate_in_gen(size_t size, Generation* gen) { GCCause::Cause next_cause = GCCause::_permanent_generation_full; GCCause::Cause prev_cause = GCCause::_no_gc; unsigned int gc_count_before, full_gc_count_before; HeapWord* obj; for (;;) { { MutexLocker ml(Heap_lock); if ((obj = gen->allocate(size, false)) != NULL) { return obj; } // Attempt to expand and allocate the requested space: // specific subtypes may use specific policy to either expand // or not. The default policy (see above) is to expand until // _capacity_expansion_limit, and no further unless a GC is done. // Concurrent collectors may decide to kick off a concurrent // collection under appropriate conditions. obj = request_expand_and_allocate(gen, size, prev_cause); if (obj != NULL || prev_cause == GCCause::_last_ditch_collection) { return obj; } if (GC_locker::is_active_and_needs_gc()) { // 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 holding the Heap_lock gc_count_before = SharedHeap::heap()->total_collections(); full_gc_count_before = SharedHeap::heap()->total_full_collections(); } // Give up heap lock above, VMThread::execute below gets it back VM_GenCollectForPermanentAllocation op(size, gc_count_before, full_gc_count_before, next_cause); VMThread::execute(&op); if (!op.prologue_succeeded() || op.gc_locked()) { assert(op.result() == NULL, "must be NULL if gc_locked() is true"); continue; // retry and/or stall as necessary } obj = op.result(); assert(obj == NULL || SharedHeap::heap()->is_in_reserved(obj), "result not in heap"); if (obj != NULL) { return obj; } prev_cause = next_cause; next_cause = GCCause::_last_ditch_collection; } } CompactingPermGen::CompactingPermGen(ReservedSpace rs, ReservedSpace shared_rs, size_t initial_byte_size, GenRemSet* remset, PermanentGenerationSpec* perm_spec) { CompactingPermGenGen* g = new CompactingPermGenGen(rs, shared_rs, initial_byte_size, -1, remset, NULL, perm_spec); if (g == NULL) vm_exit_during_initialization("Could not allocate a CompactingPermGen"); _gen = g; g->initialize_performance_counters(); _capacity_expansion_limit = g->capacity() + MaxPermHeapExpansion; } HeapWord* CompactingPermGen::mem_allocate(size_t size) { return mem_allocate_in_gen(size, _gen); } void CompactingPermGen::compute_new_size() { size_t desired_capacity = align_size_up(_gen->used(), MinPermHeapExpansion); if (desired_capacity < PermSize) { desired_capacity = PermSize; } if (_gen->capacity() > desired_capacity) { _gen->shrink(_gen->capacity() - desired_capacity); } set_capacity_expansion_limit(_gen->capacity() + MaxPermHeapExpansion); }