1.1 --- a/src/share/vm/memory/referenceProcessor.cpp Thu Nov 20 12:27:41 2008 -0800
1.2 +++ b/src/share/vm/memory/referenceProcessor.cpp Thu Nov 20 16:56:09 2008 -0800
1.3 @@ -25,6 +25,11 @@
1.4 # include "incls/_precompiled.incl"
1.5 # include "incls/_referenceProcessor.cpp.incl"
1.6
1.7 +ReferencePolicy* ReferenceProcessor::_always_clear_soft_ref_policy = NULL;
1.8 +ReferencePolicy* ReferenceProcessor::_default_soft_ref_policy = NULL;
1.9 +oop ReferenceProcessor::_sentinelRef = NULL;
1.10 +const int subclasses_of_ref = REF_PHANTOM - REF_OTHER;
1.11 +
1.12 // List of discovered references.
1.13 class DiscoveredList {
1.14 public:
1.15 @@ -58,10 +63,6 @@
1.16 size_t _len;
1.17 };
1.18
1.19 -oop ReferenceProcessor::_sentinelRef = NULL;
1.20 -
1.21 -const int subclasses_of_ref = REF_PHANTOM - REF_OTHER;
1.22 -
1.23 void referenceProcessor_init() {
1.24 ReferenceProcessor::init_statics();
1.25 }
1.26 @@ -82,6 +83,12 @@
1.27 }
1.28 assert(_sentinelRef != NULL && _sentinelRef->is_oop(),
1.29 "Just constructed it!");
1.30 + _always_clear_soft_ref_policy = new AlwaysClearPolicy();
1.31 + _default_soft_ref_policy = new COMPILER2_PRESENT(LRUMaxHeapPolicy())
1.32 + NOT_COMPILER2(LRUCurrentHeapPolicy());
1.33 + if (_always_clear_soft_ref_policy == NULL || _default_soft_ref_policy == NULL) {
1.34 + vm_exit_during_initialization("Could not allocate reference policy object");
1.35 + }
1.36 guarantee(RefDiscoveryPolicy == ReferenceBasedDiscovery ||
1.37 RefDiscoveryPolicy == ReferentBasedDiscovery,
1.38 "Unrecongnized RefDiscoveryPolicy");
1.39 @@ -108,6 +115,7 @@
1.40 vm_exit_during_initialization("Could not allocate ReferenceProcessor object");
1.41 }
1.42 rp->set_is_alive_non_header(is_alive_non_header);
1.43 + rp->snap_policy(false /* default soft ref policy */);
1.44 return rp;
1.45 }
1.46
1.47 @@ -194,7 +202,6 @@
1.48 }
1.49
1.50 void ReferenceProcessor::process_discovered_references(
1.51 - ReferencePolicy* policy,
1.52 BoolObjectClosure* is_alive,
1.53 OopClosure* keep_alive,
1.54 VoidClosure* complete_gc,
1.55 @@ -209,7 +216,7 @@
1.56 // Soft references
1.57 {
1.58 TraceTime tt("SoftReference", trace_time, false, gclog_or_tty);
1.59 - process_discovered_reflist(_discoveredSoftRefs, policy, true,
1.60 + process_discovered_reflist(_discoveredSoftRefs, _current_soft_ref_policy, true,
1.61 is_alive, keep_alive, complete_gc, task_executor);
1.62 }
1.63
1.64 @@ -1092,15 +1099,28 @@
1.65 // reachable.
1.66 if (is_alive_non_header() != NULL) {
1.67 oop referent = java_lang_ref_Reference::referent(obj);
1.68 - // We'd like to assert the following:
1.69 - // assert(referent != NULL, "Refs with null referents already filtered");
1.70 - // However, since this code may be executed concurrently with
1.71 - // mutators, which can clear() the referent, it is not
1.72 - // guaranteed that the referent is non-NULL.
1.73 + // In the case of non-concurrent discovery, the last
1.74 + // disjunct below should hold. It may not hold in the
1.75 + // case of concurrent discovery because mutators may
1.76 + // concurrently clear() a Reference.
1.77 + assert(UseConcMarkSweepGC || UseG1GC || referent != NULL,
1.78 + "Refs with null referents already filtered");
1.79 if (is_alive_non_header()->do_object_b(referent)) {
1.80 return false; // referent is reachable
1.81 }
1.82 }
1.83 + if (rt == REF_SOFT) {
1.84 + // For soft refs we can decide now if these are not
1.85 + // current candidates for clearing, in which case we
1.86 + // can mark through them now, rather than delaying that
1.87 + // to the reference-processing phase. Since all current
1.88 + // time-stamp policies advance the soft-ref clock only
1.89 + // at a major collection cycle, this is always currently
1.90 + // accurate.
1.91 + if (!_current_soft_ref_policy->should_clear_reference(obj)) {
1.92 + return false;
1.93 + }
1.94 + }
1.95
1.96 HeapWord* const discovered_addr = java_lang_ref_Reference::discovered_addr(obj);
1.97 const oop discovered = java_lang_ref_Reference::discovered(obj);
