Mercurial > hg > graal-jvmci-8
diff src/share/vm/memory/defNewGeneration.cpp @ 356:1ee8caae33af
Merge
author | tonyp |
---|---|
date | Thu, 21 Aug 2008 23:36:31 -0400 |
parents | 60fb9c4db4e6 850fdf70db2b |
children | c96030fff130 |
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--- a/src/share/vm/memory/defNewGeneration.cpp Wed Aug 06 11:57:31 2008 -0400 +++ b/src/share/vm/memory/defNewGeneration.cpp Thu Aug 21 23:36:31 2008 -0400 @@ -1,5 +1,5 @@ /* - * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. + * Copyright 2001-2008 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 @@ -172,15 +172,25 @@ _to_counters = new CSpaceCounters("s1", 2, _max_survivor_size, _to_space, _gen_counters); - compute_space_boundaries(0); + compute_space_boundaries(0, SpaceDecorator::Clear, SpaceDecorator::Mangle); update_counters(); _next_gen = NULL; _tenuring_threshold = MaxTenuringThreshold; _pretenure_size_threshold_words = PretenureSizeThreshold >> LogHeapWordSize; } -void DefNewGeneration::compute_space_boundaries(uintx minimum_eden_size) { - uintx alignment = GenCollectedHeap::heap()->collector_policy()->min_alignment(); +void DefNewGeneration::compute_space_boundaries(uintx minimum_eden_size, + bool clear_space, + bool mangle_space) { + uintx alignment = + GenCollectedHeap::heap()->collector_policy()->min_alignment(); + + // If the spaces are being cleared (only done at heap initialization + // currently), the survivor spaces need not be empty. + // Otherwise, no care is taken for used areas in the survivor spaces + // so check. + assert(clear_space || (to()->is_empty() && from()->is_empty()), + "Initialization of the survivor spaces assumes these are empty"); // Compute sizes uintx size = _virtual_space.committed_size(); @@ -214,26 +224,45 @@ MemRegion fromMR((HeapWord*)from_start, (HeapWord*)to_start); MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end); - eden()->set_bounds(edenMR); - if (minimum_eden_size == 0) { - // The "minimum_eden_size" is really the amount of eden occupied by - // allocated objects -- if this is zero, then we can clear the space. - eden()->clear(); - } else { - // Otherwise, we will not have cleared eden. This can cause newly - // expanded space not to be mangled if using ZapUnusedHeapArea. - // We explicitly do such mangling here. + // A minimum eden size implies that there is a part of eden that + // is being used and that affects the initialization of any + // newly formed eden. + bool live_in_eden = minimum_eden_size > 0; + + // If not clearing the spaces, do some checking to verify that + // the space are already mangled. + if (!clear_space) { + // Must check mangling before the spaces are reshaped. Otherwise, + // the bottom or end of one space may have moved into another + // a failure of the check may not correctly indicate which space + // is not properly mangled. if (ZapUnusedHeapArea) { - eden()->mangle_unused_area(); + HeapWord* limit = (HeapWord*) _virtual_space.high(); + eden()->check_mangled_unused_area(limit); + from()->check_mangled_unused_area(limit); + to()->check_mangled_unused_area(limit); } } - from()->initialize(fromMR, true /* clear */); - to()->initialize( toMR, true /* clear */); - // Make sure we compact eden, then from. + + // Reset the spaces for their new regions. + eden()->initialize(edenMR, + clear_space && !live_in_eden, + SpaceDecorator::Mangle); + // If clear_space and live_in_eden, we will not have cleared any + // portion of eden above its top. This can cause newly + // expanded space not to be mangled if using ZapUnusedHeapArea. + // We explicitly do such mangling here. + if (ZapUnusedHeapArea && clear_space && live_in_eden && mangle_space) { + eden()->mangle_unused_area(); + } + from()->initialize(fromMR, clear_space, mangle_space); + to()->initialize(toMR, clear_space, mangle_space); + + // Set next compaction spaces. + eden()->set_next_compaction_space(from()); // The to-space is normally empty before a compaction so need // not be considered. The exception is during promotion // failure handling when to-space can contain live objects. - eden()->set_next_compaction_space(from()); from()->set_next_compaction_space(NULL); } @@ -256,7 +285,16 @@ bool DefNewGeneration::expand(size_t bytes) { MutexLocker x(ExpandHeap_lock); + HeapWord* prev_high = (HeapWord*) _virtual_space.high(); bool success = _virtual_space.expand_by(bytes); + if (success && ZapUnusedHeapArea) { + // Mangle newly committed space immediately because it + // can be done here more simply that after the new + // spaces have been computed. + HeapWord* new_high = (HeapWord*) _virtual_space.high(); + MemRegion mangle_region(prev_high, new_high); + SpaceMangler::mangle_region(mangle_region); + } // Do not attempt an expand-to-the reserve size. The // request should properly observe the maximum size of @@ -268,7 +306,8 @@ // value. if (GC_locker::is_active()) { if (PrintGC && Verbose) { - gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead"); + gclog_or_tty->print_cr("Garbage collection disabled, " + "expanded heap instead"); } } @@ -332,16 +371,24 @@ changed = true; } if (changed) { - compute_space_boundaries(eden()->used()); - MemRegion cmr((HeapWord*)_virtual_space.low(), (HeapWord*)_virtual_space.high()); + // The spaces have already been mangled at this point but + // may not have been cleared (set top = bottom) and should be. + // Mangling was done when the heap was being expanded. + compute_space_boundaries(eden()->used(), + SpaceDecorator::Clear, + SpaceDecorator::DontMangle); + MemRegion cmr((HeapWord*)_virtual_space.low(), + (HeapWord*)_virtual_space.high()); Universe::heap()->barrier_set()->resize_covered_region(cmr); if (Verbose && PrintGC) { size_t new_size_after = _virtual_space.committed_size(); size_t eden_size_after = eden()->capacity(); size_t survivor_size_after = from()->capacity(); - gclog_or_tty->print("New generation size " SIZE_FORMAT "K->" SIZE_FORMAT "K [eden=" + gclog_or_tty->print("New generation size " SIZE_FORMAT "K->" + SIZE_FORMAT "K [eden=" SIZE_FORMAT "K,survivor=" SIZE_FORMAT "K]", - new_size_before/K, new_size_after/K, eden_size_after/K, survivor_size_after/K); + new_size_before/K, new_size_after/K, + eden_size_after/K, survivor_size_after/K); if (WizardMode) { gclog_or_tty->print("[allowed " SIZE_FORMAT "K extra for %d threads]", thread_increase_size/K, threads_count); @@ -486,7 +533,7 @@ ScanWeakRefClosure scan_weak_ref(this); age_table()->clear(); - to()->clear(); + to()->clear(SpaceDecorator::Mangle); gch->rem_set()->prepare_for_younger_refs_iterate(false); @@ -531,8 +578,18 @@ soft_ref_policy, &is_alive, &keep_alive, &evacuate_followers, NULL); if (!promotion_failed()) { // Swap the survivor spaces. - eden()->clear(); - from()->clear(); + eden()->clear(SpaceDecorator::Mangle); + from()->clear(SpaceDecorator::Mangle); + if (ZapUnusedHeapArea) { + // This is now done here because of the piece-meal mangling which + // can check for valid mangling at intermediate points in the + // collection(s). When a minor collection fails to collect + // sufficient space resizing of the young generation can occur + // an redistribute the spaces in the young generation. Mangle + // here so that unzapped regions don't get distributed to + // other spaces. + to()->mangle_unused_area(); + } swap_spaces(); assert(to()->is_empty(), "to space should be empty now"); @@ -759,6 +816,15 @@ } } +void DefNewGeneration::reset_scratch() { + // If contributing scratch in to_space, mangle all of + // to_space if ZapUnusedHeapArea. This is needed because + // top is not maintained while using to-space as scratch. + if (ZapUnusedHeapArea) { + to()->mangle_unused_area_complete(); + } +} + bool DefNewGeneration::collection_attempt_is_safe() { if (!to()->is_empty()) { return false; @@ -812,11 +878,25 @@ } } + if (ZapUnusedHeapArea) { + eden()->check_mangled_unused_area_complete(); + from()->check_mangled_unused_area_complete(); + to()->check_mangled_unused_area_complete(); + } + // update the generation and space performance counters update_counters(); gch->collector_policy()->counters()->update_counters(); } +void DefNewGeneration::record_spaces_top() { + assert(ZapUnusedHeapArea, "Not mangling unused space"); + eden()->set_top_for_allocations(); + to()->set_top_for_allocations(); + from()->set_top_for_allocations(); +} + + void DefNewGeneration::update_counters() { if (UsePerfData) { _eden_counters->update_all();