2161 } |
2161 } |
2162 |
2162 |
2163 void ConcurrentMark::weakRefsWork(bool clear_all_soft_refs) { |
2163 void ConcurrentMark::weakRefsWork(bool clear_all_soft_refs) { |
2164 ResourceMark rm; |
2164 ResourceMark rm; |
2165 HandleMark hm; |
2165 HandleMark hm; |
2166 G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
2166 |
2167 ReferenceProcessor* rp = g1h->ref_processor(); |
2167 G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
2168 |
2168 |
2169 // See the comment in G1CollectedHeap::ref_processing_init() |
2169 // Is alive closure. |
2170 // about how reference processing currently works in G1. |
2170 G1CMIsAliveClosure g1_is_alive(g1h); |
2171 |
2171 |
2172 // Process weak references. |
2172 // Inner scope to exclude the cleaning of the string and symbol |
2173 rp->setup_policy(clear_all_soft_refs); |
2173 // tables from the displayed time. |
2174 assert(_markStack.isEmpty(), "mark stack should be empty"); |
2174 { |
2175 |
2175 bool verbose = PrintGC && PrintGCDetails; |
2176 G1CMIsAliveClosure g1_is_alive(g1h); |
2176 if (verbose) { |
2177 G1CMKeepAliveClosure g1_keep_alive(g1h, this, nextMarkBitMap()); |
2177 gclog_or_tty->put(' '); |
2178 G1CMDrainMarkingStackClosure |
2178 } |
2179 g1_drain_mark_stack(nextMarkBitMap(), &_markStack, &g1_keep_alive); |
2179 TraceTime t("GC ref-proc", verbose, false, gclog_or_tty); |
2180 // We use the work gang from the G1CollectedHeap and we utilize all |
2180 |
2181 // the worker threads. |
2181 ReferenceProcessor* rp = g1h->ref_processor(); |
2182 int active_workers = g1h->workers() ? g1h->workers()->total_workers() : 1; |
2182 |
2183 active_workers = MAX2(MIN2(active_workers, (int)_max_task_num), 1); |
2183 // See the comment in G1CollectedHeap::ref_processing_init() |
2184 |
2184 // about how reference processing currently works in G1. |
2185 G1RefProcTaskExecutor par_task_executor(g1h, this, nextMarkBitMap(), |
2185 |
2186 g1h->workers(), active_workers); |
2186 // Process weak references. |
2187 |
2187 rp->setup_policy(clear_all_soft_refs); |
2188 |
2188 assert(_markStack.isEmpty(), "mark stack should be empty"); |
2189 if (rp->processing_is_mt()) { |
2189 |
2190 // Set the degree of MT here. If the discovery is done MT, there |
2190 G1CMKeepAliveClosure g1_keep_alive(g1h, this, nextMarkBitMap()); |
2191 // may have been a different number of threads doing the discovery |
2191 G1CMDrainMarkingStackClosure |
2192 // and a different number of discovered lists may have Ref objects. |
2192 g1_drain_mark_stack(nextMarkBitMap(), &_markStack, &g1_keep_alive); |
2193 // That is OK as long as the Reference lists are balanced (see |
2193 |
2194 // balance_all_queues() and balance_queues()). |
2194 // We use the work gang from the G1CollectedHeap and we utilize all |
2195 rp->set_active_mt_degree(active_workers); |
2195 // the worker threads. |
2196 |
2196 int active_workers = g1h->workers() ? g1h->workers()->total_workers() : 1; |
2197 rp->process_discovered_references(&g1_is_alive, |
2197 active_workers = MAX2(MIN2(active_workers, (int)_max_task_num), 1); |
|
2198 |
|
2199 G1RefProcTaskExecutor par_task_executor(g1h, this, nextMarkBitMap(), |
|
2200 g1h->workers(), active_workers); |
|
2201 |
|
2202 if (rp->processing_is_mt()) { |
|
2203 // Set the degree of MT here. If the discovery is done MT, there |
|
2204 // may have been a different number of threads doing the discovery |
|
2205 // and a different number of discovered lists may have Ref objects. |
|
2206 // That is OK as long as the Reference lists are balanced (see |
|
2207 // balance_all_queues() and balance_queues()). |
|
2208 rp->set_active_mt_degree(active_workers); |
|
2209 |
|
2210 rp->process_discovered_references(&g1_is_alive, |
2198 &g1_keep_alive, |
2211 &g1_keep_alive, |
2199 &g1_drain_mark_stack, |
2212 &g1_drain_mark_stack, |
2200 &par_task_executor); |
2213 &par_task_executor); |
2201 |
2214 |
2202 // The work routines of the parallel keep_alive and drain_marking_stack |
2215 // The work routines of the parallel keep_alive and drain_marking_stack |
2203 // will set the has_overflown flag if we overflow the global marking |
2216 // will set the has_overflown flag if we overflow the global marking |
2204 // stack. |
2217 // stack. |
2205 } else { |
2218 } else { |
2206 rp->process_discovered_references(&g1_is_alive, |
2219 rp->process_discovered_references(&g1_is_alive, |
2207 &g1_keep_alive, |
2220 &g1_keep_alive, |
2208 &g1_drain_mark_stack, |
2221 &g1_drain_mark_stack, |
2209 NULL); |
2222 NULL); |
2210 |
2223 } |
2211 } |
2224 |
2212 |
2225 assert(_markStack.overflow() || _markStack.isEmpty(), |
2213 assert(_markStack.overflow() || _markStack.isEmpty(), |
2226 "mark stack should be empty (unless it overflowed)"); |
2214 "mark stack should be empty (unless it overflowed)"); |
2227 if (_markStack.overflow()) { |
2215 if (_markStack.overflow()) { |
2228 // Should have been done already when we tried to push an |
2216 // Should have been done already when we tried to push an |
2229 // entry on to the global mark stack. But let's do it again. |
2217 // entry on to the global mark stack. But let's do it again. |
2230 set_has_overflown(); |
2218 set_has_overflown(); |
2231 } |
2219 } |
2232 |
2220 |
2233 if (rp->processing_is_mt()) { |
2221 if (rp->processing_is_mt()) { |
2234 assert(rp->num_q() == active_workers, "why not"); |
2222 assert(rp->num_q() == active_workers, "why not"); |
2235 rp->enqueue_discovered_references(&par_task_executor); |
2223 rp->enqueue_discovered_references(&par_task_executor); |
2236 } else { |
2224 } else { |
2237 rp->enqueue_discovered_references(); |
2225 rp->enqueue_discovered_references(); |
2238 } |
2226 } |
2239 |
2227 |
2240 rp->verify_no_references_recorded(); |
2228 rp->verify_no_references_recorded(); |
2241 assert(!rp->discovery_enabled(), "should have been disabled"); |
2229 assert(!rp->discovery_enabled(), "should have been disabled"); |
2242 } |
2230 |
2243 |
2231 // Now clean up stale oops in StringTable |
2244 // Now clean up stale oops in StringTable |
2232 StringTable::unlink(&g1_is_alive); |
2245 StringTable::unlink(&g1_is_alive); |
2233 // Clean up unreferenced symbols in symbol table. |
2246 // Clean up unreferenced symbols in symbol table. |
2234 SymbolTable::unlink(); |
2247 SymbolTable::unlink(); |