1.1 --- a/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp Tue Jul 01 09:03:55 2014 +0200
1.2 +++ b/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.cpp Mon Jul 07 10:12:40 2014 +0200
1.3 @@ -30,23 +30,52 @@
1.4
1.5 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
1.6
1.7 -G1CodeRootChunk::G1CodeRootChunk() : _top(NULL), _next(NULL), _prev(NULL) {
1.8 +G1CodeRootChunk::G1CodeRootChunk() : _top(NULL), _next(NULL), _prev(NULL), _free(NULL) {
1.9 _top = bottom();
1.10 }
1.11
1.12 void G1CodeRootChunk::reset() {
1.13 _next = _prev = NULL;
1.14 + _free = NULL;
1.15 _top = bottom();
1.16 }
1.17
1.18 void G1CodeRootChunk::nmethods_do(CodeBlobClosure* cl) {
1.19 - nmethod** cur = bottom();
1.20 + NmethodOrLink* cur = bottom();
1.21 while (cur != _top) {
1.22 - cl->do_code_blob(*cur);
1.23 + if (is_nmethod(cur)) {
1.24 + cl->do_code_blob(cur->_nmethod);
1.25 + }
1.26 cur++;
1.27 }
1.28 }
1.29
1.30 +bool G1CodeRootChunk::remove_lock_free(nmethod* method) {
1.31 + NmethodOrLink* cur = bottom();
1.32 +
1.33 + for (NmethodOrLink* cur = bottom(); cur != _top; cur++) {
1.34 + if (cur->_nmethod == method) {
1.35 + bool result = Atomic::cmpxchg_ptr(NULL, &cur->_nmethod, method) == method;
1.36 +
1.37 + if (!result) {
1.38 + // Someone else cleared out this entry.
1.39 + return false;
1.40 + }
1.41 +
1.42 + // The method was cleared. Time to link it into the free list.
1.43 + NmethodOrLink* prev_free;
1.44 + do {
1.45 + prev_free = (NmethodOrLink*)_free;
1.46 + cur->_link = prev_free;
1.47 + } while (Atomic::cmpxchg_ptr(cur, &_free, prev_free) != prev_free);
1.48 +
1.49 + return true;
1.50 + }
1.51 + }
1.52 +
1.53 + return false;
1.54 +}
1.55 +
1.56 G1CodeRootChunkManager::G1CodeRootChunkManager() : _free_list(), _num_chunks_handed_out(0) {
1.57 _free_list.initialize();
1.58 _free_list.set_size(G1CodeRootChunk::word_size());
1.59 @@ -140,34 +169,43 @@
1.60
1.61 void G1CodeRootSet::add(nmethod* method) {
1.62 if (!contains(method)) {
1.63 - // Try to add the nmethod. If there is not enough space, get a new chunk.
1.64 - if (_list.head() == NULL || _list.head()->is_full()) {
1.65 - G1CodeRootChunk* cur = new_chunk();
1.66 + // Find the first chunk thatisn't full.
1.67 + G1CodeRootChunk* cur = _list.head();
1.68 + while (cur != NULL) {
1.69 + if (!cur->is_full()) {
1.70 + break;
1.71 + }
1.72 + cur = cur->next();
1.73 + }
1.74 +
1.75 + // All chunks are full, get a new chunk.
1.76 + if (cur == NULL) {
1.77 + cur = new_chunk();
1.78 _list.return_chunk_at_head(cur);
1.79 }
1.80 - bool result = _list.head()->add(method);
1.81 +
1.82 + // Add the nmethod.
1.83 + bool result = cur->add(method);
1.84 +
1.85 guarantee(result, err_msg("Not able to add nmethod "PTR_FORMAT" to newly allocated chunk.", method));
1.86 +
1.87 _length++;
1.88 }
1.89 }
1.90
1.91 -void G1CodeRootSet::remove(nmethod* method) {
1.92 +void G1CodeRootSet::remove_lock_free(nmethod* method) {
1.93 G1CodeRootChunk* found = find(method);
1.94 if (found != NULL) {
1.95 - bool result = found->remove(method);
1.96 - guarantee(result, err_msg("could not find nmethod "PTR_FORMAT" during removal although we previously found it", method));
1.97 - // eventually free completely emptied chunk
1.98 - if (found->is_empty()) {
1.99 - _list.remove_chunk(found);
1.100 - free(found);
1.101 + bool result = found->remove_lock_free(method);
1.102 + if (result) {
1.103 + Atomic::dec_ptr((volatile intptr_t*)&_length);
1.104 }
1.105 - _length--;
1.106 }
1.107 assert(!contains(method), err_msg(PTR_FORMAT" still contains nmethod "PTR_FORMAT, this, method));
1.108 }
1.109
1.110 nmethod* G1CodeRootSet::pop() {
1.111 - do {
1.112 + while (true) {
1.113 G1CodeRootChunk* cur = _list.head();
1.114 if (cur == NULL) {
1.115 assert(_length == 0, "when there are no chunks, there should be no elements");
1.116 @@ -180,7 +218,7 @@
1.117 } else {
1.118 free(_list.get_chunk_at_head());
1.119 }
1.120 - } while (true);
1.121 + }
1.122 }
1.123
1.124 G1CodeRootChunk* G1CodeRootSet::find(nmethod* method) {
