diff -r 00b023ae2d78 -r c96030fff130 src/share/vm/memory/referenceProcessor.cpp --- a/src/share/vm/memory/referenceProcessor.cpp Thu Nov 20 12:27:41 2008 -0800 +++ b/src/share/vm/memory/referenceProcessor.cpp Thu Nov 20 16:56:09 2008 -0800 @@ -25,6 +25,11 @@ # include "incls/_precompiled.incl" # include "incls/_referenceProcessor.cpp.incl" +ReferencePolicy* ReferenceProcessor::_always_clear_soft_ref_policy = NULL; +ReferencePolicy* ReferenceProcessor::_default_soft_ref_policy = NULL; +oop ReferenceProcessor::_sentinelRef = NULL; +const int subclasses_of_ref = REF_PHANTOM - REF_OTHER; + // List of discovered references. class DiscoveredList { public: @@ -58,10 +63,6 @@ size_t _len; }; -oop ReferenceProcessor::_sentinelRef = NULL; - -const int subclasses_of_ref = REF_PHANTOM - REF_OTHER; - void referenceProcessor_init() { ReferenceProcessor::init_statics(); } @@ -82,6 +83,12 @@ } assert(_sentinelRef != NULL && _sentinelRef->is_oop(), "Just constructed it!"); + _always_clear_soft_ref_policy = new AlwaysClearPolicy(); + _default_soft_ref_policy = new COMPILER2_PRESENT(LRUMaxHeapPolicy()) + NOT_COMPILER2(LRUCurrentHeapPolicy()); + if (_always_clear_soft_ref_policy == NULL || _default_soft_ref_policy == NULL) { + vm_exit_during_initialization("Could not allocate reference policy object"); + } guarantee(RefDiscoveryPolicy == ReferenceBasedDiscovery || RefDiscoveryPolicy == ReferentBasedDiscovery, "Unrecongnized RefDiscoveryPolicy"); @@ -108,6 +115,7 @@ vm_exit_during_initialization("Could not allocate ReferenceProcessor object"); } rp->set_is_alive_non_header(is_alive_non_header); + rp->snap_policy(false /* default soft ref policy */); return rp; } @@ -194,7 +202,6 @@ } void ReferenceProcessor::process_discovered_references( - ReferencePolicy* policy, BoolObjectClosure* is_alive, OopClosure* keep_alive, VoidClosure* complete_gc, @@ -209,7 +216,7 @@ // Soft references { TraceTime tt("SoftReference", trace_time, false, gclog_or_tty); - process_discovered_reflist(_discoveredSoftRefs, policy, true, + process_discovered_reflist(_discoveredSoftRefs, _current_soft_ref_policy, true, is_alive, keep_alive, complete_gc, task_executor); } @@ -1092,15 +1099,28 @@ // reachable. if (is_alive_non_header() != NULL) { oop referent = java_lang_ref_Reference::referent(obj); - // We'd like to assert the following: - // assert(referent != NULL, "Refs with null referents already filtered"); - // However, since this code may be executed concurrently with - // mutators, which can clear() the referent, it is not - // guaranteed that the referent is non-NULL. + // In the case of non-concurrent discovery, the last + // disjunct below should hold. It may not hold in the + // case of concurrent discovery because mutators may + // concurrently clear() a Reference. + assert(UseConcMarkSweepGC || UseG1GC || referent != NULL, + "Refs with null referents already filtered"); if (is_alive_non_header()->do_object_b(referent)) { return false; // referent is reachable } } + if (rt == REF_SOFT) { + // For soft refs we can decide now if these are not + // current candidates for clearing, in which case we + // can mark through them now, rather than delaying that + // to the reference-processing phase. Since all current + // time-stamp policies advance the soft-ref clock only + // at a major collection cycle, this is always currently + // accurate. + if (!_current_soft_ref_policy->should_clear_reference(obj)) { + return false; + } + } HeapWord* const discovered_addr = java_lang_ref_Reference::discovered_addr(obj); const oop discovered = java_lang_ref_Reference::discovered(obj);