1.1 --- a/src/share/vm/runtime/jniHandles.cpp Thu Sep 05 18:40:52 2019 +0800
1.2 +++ b/src/share/vm/runtime/jniHandles.cpp Thu Sep 05 18:52:27 2019 +0800
1.3 @@ -24,11 +24,15 @@
1.4
1.5 #include "precompiled.hpp"
1.6 #include "classfile/systemDictionary.hpp"
1.7 +#include "memory/iterator.hpp"
1.8 #include "oops/oop.inline.hpp"
1.9 #include "prims/jvmtiExport.hpp"
1.10 #include "runtime/jniHandles.hpp"
1.11 #include "runtime/mutexLocker.hpp"
1.12 #include "runtime/thread.inline.hpp"
1.13 +#if INCLUDE_ALL_GCS
1.14 +#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
1.15 +#endif
1.16
1.17 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
1.18
1.19 @@ -86,34 +90,52 @@
1.20 return res;
1.21 }
1.22
1.23 -
1.24 jobject JNIHandles::make_weak_global(Handle obj) {
1.25 assert(!Universe::heap()->is_gc_active(), "can't extend the root set during GC");
1.26 jobject res = NULL;
1.27 if (!obj.is_null()) {
1.28 // ignore null handles
1.29 - MutexLocker ml(JNIGlobalHandle_lock);
1.30 - assert(Universe::heap()->is_in_reserved(obj()), "sanity check");
1.31 - res = _weak_global_handles->allocate_handle(obj());
1.32 + {
1.33 + MutexLocker ml(JNIGlobalHandle_lock);
1.34 + assert(Universe::heap()->is_in_reserved(obj()), "sanity check");
1.35 + res = _weak_global_handles->allocate_handle(obj());
1.36 + }
1.37 + // Add weak tag.
1.38 + assert(is_ptr_aligned(res, weak_tag_alignment), "invariant");
1.39 + char* tptr = reinterpret_cast<char*>(res) + weak_tag_value;
1.40 + res = reinterpret_cast<jobject>(tptr);
1.41 } else {
1.42 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
1.43 }
1.44 return res;
1.45 }
1.46
1.47 +template<bool external_guard>
1.48 +oop JNIHandles::resolve_jweak(jweak handle) {
1.49 + assert(is_jweak(handle), "precondition");
1.50 + oop result = jweak_ref(handle);
1.51 + result = guard_value<external_guard>(result);
1.52 +#if INCLUDE_ALL_GCS
1.53 + if (result != NULL && UseG1GC) {
1.54 + G1SATBCardTableModRefBS::enqueue(result);
1.55 + }
1.56 +#endif // INCLUDE_ALL_GCS
1.57 + return result;
1.58 +}
1.59 +
1.60 +template oop JNIHandles::resolve_jweak<true>(jweak);
1.61 +template oop JNIHandles::resolve_jweak<false>(jweak);
1.62
1.63 void JNIHandles::destroy_global(jobject handle) {
1.64 if (handle != NULL) {
1.65 assert(is_global_handle(handle), "Invalid delete of global JNI handle");
1.66 - *((oop*)handle) = deleted_handle(); // Mark the handle as deleted, allocate will reuse it
1.67 + jobject_ref(handle) = deleted_handle();
1.68 }
1.69 }
1.70
1.71 -
1.72 void JNIHandles::destroy_weak_global(jobject handle) {
1.73 if (handle != NULL) {
1.74 - assert(!CheckJNICalls || is_weak_global_handle(handle), "Invalid delete of weak global JNI handle");
1.75 - *((oop*)handle) = deleted_handle(); // Mark the handle as deleted, allocate will reuse it
1.76 + jweak_ref(handle) = deleted_handle();
1.77 }
1.78 }
1.79
1.80 @@ -129,6 +151,12 @@
1.81 }
1.82
1.83
1.84 +void JNIHandles::weak_oops_do(OopClosure* f) {
1.85 + AlwaysTrueClosure always_true;
1.86 + weak_oops_do(&always_true, f);
1.87 +}
1.88 +
1.89 +
1.90 void JNIHandles::initialize() {
1.91 _global_handles = JNIHandleBlock::allocate_block();
1.92 _weak_global_handles = JNIHandleBlock::allocate_block();
1.93 @@ -186,11 +214,6 @@
1.94 }
1.95
1.96
1.97 -class AlwaysAliveClosure: public BoolObjectClosure {
1.98 -public:
1.99 - bool do_object_b(oop obj) { return true; }
1.100 -};
1.101 -
1.102 class CountHandleClosure: public OopClosure {
1.103 private:
1.104 int _count;
1.105 @@ -212,9 +235,8 @@
1.106 "JNIHandles not initialized");
1.107
1.108 CountHandleClosure global_handle_count;
1.109 - AlwaysAliveClosure always_alive;
1.110 oops_do(&global_handle_count);
1.111 - weak_oops_do(&always_alive, &global_handle_count);
1.112 + weak_oops_do(&global_handle_count);
1.113
1.114 st->print_cr("JNI global references: %d", global_handle_count.count());
1.115 st->cr();
1.116 @@ -231,10 +253,9 @@
1.117
1.118 void JNIHandles::verify() {
1.119 VerifyHandleClosure verify_handle;
1.120 - AlwaysAliveClosure always_alive;
1.121
1.122 oops_do(&verify_handle);
1.123 - weak_oops_do(&always_alive, &verify_handle);
1.124 + weak_oops_do(&verify_handle);
1.125 }
1.126
1.127
