Mercurial > hg > graal-compiler
view src/share/vm/runtime/sweeper.cpp @ 616:4f360ec815ba
6720309: G1: don't synchronously update RSet during evacuation pauses
6720334: G1: don't update RSets of collection set regions during an evacuation pause
Summary: Introduced a deferred update mechanism for delaying the rset updates during the collection pause
Reviewed-by: apetrusenko, tonyp
author | iveresov |
---|---|
date | Fri, 06 Mar 2009 13:50:14 -0800 |
parents | a61af66fc99e |
children | 8b46c4d82093 148e5441d916 |
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/* * Copyright 1997-2005 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/_sweeper.cpp.incl" long NMethodSweeper::_traversals = 0; // No. of stack traversals performed CodeBlob* NMethodSweeper::_current = NULL; // Current nmethod int NMethodSweeper::_seen = 0 ; // No. of blobs we have currently processed in current pass of CodeCache int NMethodSweeper::_invocations = 0; // No. of invocations left until we are completed with this pass jint NMethodSweeper::_locked_seen = 0; jint NMethodSweeper::_not_entrant_seen_on_stack = 0; bool NMethodSweeper::_rescan = false; void NMethodSweeper::sweep() { assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint"); if (!MethodFlushing) return; // No need to synchronize access, since this is always executed at a // safepoint. If we aren't in the middle of scan and a rescan // hasn't been requested then just return. if (_current == NULL && !_rescan) return; // Make sure CompiledIC_lock in unlocked, since we might update some // inline caches. If it is, we just bail-out and try later. if (CompiledIC_lock->is_locked() || Patching_lock->is_locked()) return; // Check for restart assert(CodeCache::find_blob_unsafe(_current) == _current, "Sweeper nmethod cached state invalid"); if (_current == NULL) { _seen = 0; _invocations = NmethodSweepFraction; _current = CodeCache::first(); _traversals += 1; if (PrintMethodFlushing) { tty->print_cr("### Sweep: stack traversal %d", _traversals); } Threads::nmethods_do(); // reset the flags since we started a scan from the beginning. _rescan = false; _locked_seen = 0; _not_entrant_seen_on_stack = 0; } if (PrintMethodFlushing && Verbose) { tty->print_cr("### Sweep at %d out of %d. Invocations left: %d", _seen, CodeCache::nof_blobs(), _invocations); } // We want to visit all nmethods after NmethodSweepFraction invocations. // If invocation is 1 we do the rest int todo = CodeCache::nof_blobs(); if (_invocations != 1) { todo = (CodeCache::nof_blobs() - _seen) / _invocations; _invocations--; } for(int i = 0; i < todo && _current != NULL; i++) { CodeBlob* next = CodeCache::next(_current); // Read next before we potentially delete current if (_current->is_nmethod()) { process_nmethod((nmethod *)_current); } _seen++; _current = next; } // Because we could stop on a codeBlob other than an nmethod we skip forward // to the next nmethod (if any). codeBlobs other than nmethods can be freed // async to us and make _current invalid while we sleep. while (_current != NULL && !_current->is_nmethod()) { _current = CodeCache::next(_current); } if (_current == NULL && !_rescan && (_locked_seen || _not_entrant_seen_on_stack)) { // we've completed a scan without making progress but there were // nmethods we were unable to process either because they were // locked or were still on stack. We don't have to aggresively // clean them up so just stop scanning. We could scan once more // but that complicates the control logic and it's unlikely to // matter much. if (PrintMethodFlushing) { tty->print_cr("### Couldn't make progress on some nmethods so stopping sweep"); } } } void NMethodSweeper::process_nmethod(nmethod *nm) { // Skip methods that are currently referenced by the VM if (nm->is_locked_by_vm()) { // But still remember to clean-up inline caches for alive nmethods if (nm->is_alive()) { // Clean-up all inline caches that points to zombie/non-reentrant methods nm->cleanup_inline_caches(); } else { _locked_seen++; } return; } if (nm->is_zombie()) { // If it is first time, we see nmethod then we mark it. Otherwise, // we reclame it. When we have seen a zombie method twice, we know that // there are no inline caches that referes to it. if (nm->is_marked_for_reclamation()) { assert(!nm->is_locked_by_vm(), "must not flush locked nmethods"); nm->flush(); } else { nm->mark_for_reclamation(); _rescan = true; } } else if (nm->is_not_entrant()) { // If there is no current activations of this method on the // stack we can safely convert it to a zombie method if (nm->can_not_entrant_be_converted()) { nm->make_zombie(); _rescan = true; } else { // Still alive, clean up its inline caches nm->cleanup_inline_caches(); // we coudn't transition this nmethod so don't immediately // request a rescan. If this method stays on the stack for a // long time we don't want to keep rescanning at every safepoint. _not_entrant_seen_on_stack++; } } else if (nm->is_unloaded()) { // Unloaded code, just make it a zombie if (nm->is_osr_only_method()) { // No inline caches will ever point to osr methods, so we can just remove it nm->flush(); } else { nm->make_zombie(); _rescan = true; } } else { assert(nm->is_alive(), "should be alive"); // Clean-up all inline caches that points to zombie/non-reentrant methods nm->cleanup_inline_caches(); } }