15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "code/codeCache.hpp"
29 #include "gc_interface/collectedHeap.inline.hpp"
30 #include "memory/sharedHeap.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "runtime/atomic.inline.hpp"
33 #include "runtime/fprofiler.hpp"
34 #include "runtime/java.hpp"
35 #include "services/management.hpp"
36 #include "utilities/copy.hpp"
37 #include "utilities/workgroup.hpp"
38
39 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
40
41 SharedHeap* SharedHeap::_sh;
42
43 // The set of potentially parallel tasks in root scanning.
44 enum SH_process_roots_tasks {
45 SH_PS_Universe_oops_do,
46 SH_PS_JNIHandles_oops_do,
47 SH_PS_ObjectSynchronizer_oops_do,
48 SH_PS_FlatProfiler_oops_do,
49 SH_PS_Management_oops_do,
50 SH_PS_SystemDictionary_oops_do,
51 SH_PS_ClassLoaderDataGraph_oops_do,
52 SH_PS_jvmti_oops_do,
53 SH_PS_CodeCache_oops_do,
54 // Leave this one last.
55 SH_PS_NumElements
56 };
57
58 SharedHeap::SharedHeap(CollectorPolicy* policy_) :
59 CollectedHeap(),
60 _collector_policy(policy_),
61 _rem_set(NULL),
62 _strong_roots_scope(NULL),
63 _strong_roots_parity(0),
64 _process_strong_tasks(new SubTasksDone(SH_PS_NumElements)),
65 _workers(NULL)
66 {
67 if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) {
68 vm_exit_during_initialization("Failed necessary allocation.");
69 }
70 _sh = this; // ch is static, should be set only once.
71 if ((UseParNewGC ||
72 (UseConcMarkSweepGC && (CMSParallelInitialMarkEnabled ||
73 CMSParallelRemarkEnabled)) ||
74 UseG1GC) &&
75 ParallelGCThreads > 0) {
76 _workers = new FlexibleWorkGang("Parallel GC Threads", ParallelGCThreads,
77 /* are_GC_task_threads */true,
78 /* are_ConcurrentGC_threads */false);
79 if (_workers == NULL) {
80 vm_exit_during_initialization("Failed necessary allocation.");
81 } else {
82 _workers->initialize_workers();
83 }
84 }
85 }
86
87 int SharedHeap::n_termination() {
88 return _process_strong_tasks->n_threads();
89 }
90
91 void SharedHeap::set_n_termination(int t) {
92 _process_strong_tasks->set_n_threads(t);
93 }
94
95 bool SharedHeap::heap_lock_held_for_gc() {
96 Thread* t = Thread::current();
97 return Heap_lock->owned_by_self()
98 || ( (t->is_GC_task_thread() || t->is_VM_thread())
99 && _thread_holds_heap_lock_for_gc);
100 }
101
102 void SharedHeap::set_par_threads(uint t) {
103 assert(t == 0 || !UseSerialGC, "Cannot have parallel threads");
104 _n_par_threads = t;
105 _process_strong_tasks->set_n_threads(t);
106 }
107
108 #ifdef ASSERT
109 class AssertNonScavengableClosure: public OopClosure {
110 public:
111 virtual void do_oop(oop* p) {
112 assert(!Universe::heap()->is_in_partial_collection(*p),
113 "Referent should not be scavengable."); }
114 virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
115 };
116 static AssertNonScavengableClosure assert_is_non_scavengable_closure;
117 #endif
118
119 SharedHeap::StrongRootsScope* SharedHeap::active_strong_roots_scope() const {
120 return _strong_roots_scope;
121 }
122 void SharedHeap::register_strong_roots_scope(SharedHeap::StrongRootsScope* scope) {
123 assert(_strong_roots_scope == NULL, "Should only have one StrongRootsScope active");
124 assert(scope != NULL, "Illegal argument");
125 _strong_roots_scope = scope;
126 }
127 void SharedHeap::unregister_strong_roots_scope(SharedHeap::StrongRootsScope* scope) {
128 assert(_strong_roots_scope == scope, "Wrong scope unregistered");
129 _strong_roots_scope = NULL;
130 }
131
132 void SharedHeap::change_strong_roots_parity() {
133 // Also set the new collection parity.
134 assert(_strong_roots_parity >= 0 && _strong_roots_parity <= 2,
135 "Not in range.");
136 _strong_roots_parity++;
137 if (_strong_roots_parity == 3) _strong_roots_parity = 1;
138 assert(_strong_roots_parity >= 1 && _strong_roots_parity <= 2,
139 "Not in range.");
140 }
141
142 SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* heap, bool activate)
143 : MarkScope(activate), _sh(heap), _n_workers_done_with_threads(0)
144 {
145 if (_active) {
146 _sh->register_strong_roots_scope(this);
147 _sh->change_strong_roots_parity();
148 // Zero the claimed high water mark in the StringTable
149 StringTable::clear_parallel_claimed_index();
150 }
151 }
152
153 SharedHeap::StrongRootsScope::~StrongRootsScope() {
154 if (_active) {
155 _sh->unregister_strong_roots_scope(this);
156 }
157 }
158
159 Monitor* SharedHeap::StrongRootsScope::_lock = new Monitor(Mutex::leaf, "StrongRootsScope lock", false);
160
161 void SharedHeap::StrongRootsScope::mark_worker_done_with_threads(uint n_workers) {
162 // The Thread work barrier is only needed by G1 Class Unloading.
163 // No need to use the barrier if this is single-threaded code.
164 if (UseG1GC && ClassUnloadingWithConcurrentMark && n_workers > 0) {
165 uint new_value = (uint)Atomic::add(1, &_n_workers_done_with_threads);
166 if (new_value == n_workers) {
167 // This thread is last. Notify the others.
168 MonitorLockerEx ml(_lock, Mutex::_no_safepoint_check_flag);
169 _lock->notify_all();
170 }
171 }
172 }
173
174 void SharedHeap::StrongRootsScope::wait_until_all_workers_done_with_threads(uint n_workers) {
175 assert(UseG1GC, "Currently only used by G1");
176 assert(ClassUnloadingWithConcurrentMark, "Currently only needed when doing G1 Class Unloading");
177
178 // No need to use the barrier if this is single-threaded code.
179 if (n_workers > 0 && (uint)_n_workers_done_with_threads != n_workers) {
180 MonitorLockerEx ml(_lock, Mutex::_no_safepoint_check_flag);
181 while ((uint)_n_workers_done_with_threads != n_workers) {
182 _lock->wait(Mutex::_no_safepoint_check_flag, 0, false);
183 }
184 }
185 }
186
187 void SharedHeap::process_roots(bool activate_scope,
188 ScanningOption so,
189 OopClosure* strong_roots,
190 OopClosure* weak_roots,
191 CLDClosure* strong_cld_closure,
192 CLDClosure* weak_cld_closure,
193 CodeBlobClosure* code_roots) {
194 StrongRootsScope srs(this, activate_scope);
195
196 // General roots.
197 assert(_strong_roots_parity != 0, "must have called prologue code");
198 assert(code_roots != NULL, "code root closure should always be set");
199 // _n_termination for _process_strong_tasks should be set up stream
200 // in a method not running in a GC worker. Otherwise the GC worker
201 // could be trying to change the termination condition while the task
202 // is executing in another GC worker.
203
204 // Iterating over the CLDG and the Threads are done early to allow G1 to
205 // first process the strong CLDs and nmethods and then, after a barrier,
206 // let the thread process the weak CLDs and nmethods.
207
208 if (!_process_strong_tasks->is_task_claimed(SH_PS_ClassLoaderDataGraph_oops_do)) {
209 ClassLoaderDataGraph::roots_cld_do(strong_cld_closure, weak_cld_closure);
210 }
211
212 // Some CLDs contained in the thread frames should be considered strong.
213 // Don't process them if they will be processed during the ClassLoaderDataGraph phase.
214 CLDClosure* roots_from_clds_p = (strong_cld_closure != weak_cld_closure) ? strong_cld_closure : NULL;
215 // Only process code roots from thread stacks if we aren't visiting the entire CodeCache anyway
216 CodeBlobClosure* roots_from_code_p = (so & SO_AllCodeCache) ? NULL : code_roots;
217
218 Threads::possibly_parallel_oops_do(strong_roots, roots_from_clds_p, roots_from_code_p);
219
220 // This is the point where this worker thread will not find more strong CLDs/nmethods.
221 // Report this so G1 can synchronize the strong and weak CLDs/nmethods processing.
222 active_strong_roots_scope()->mark_worker_done_with_threads(n_par_threads());
223
224 if (!_process_strong_tasks->is_task_claimed(SH_PS_Universe_oops_do)) {
225 Universe::oops_do(strong_roots);
226 }
227 // Global (strong) JNI handles
228 if (!_process_strong_tasks->is_task_claimed(SH_PS_JNIHandles_oops_do))
229 JNIHandles::oops_do(strong_roots);
230
231 if (!_process_strong_tasks-> is_task_claimed(SH_PS_ObjectSynchronizer_oops_do))
232 ObjectSynchronizer::oops_do(strong_roots);
233 if (!_process_strong_tasks->is_task_claimed(SH_PS_FlatProfiler_oops_do))
234 FlatProfiler::oops_do(strong_roots);
235 if (!_process_strong_tasks->is_task_claimed(SH_PS_Management_oops_do))
236 Management::oops_do(strong_roots);
237 if (!_process_strong_tasks->is_task_claimed(SH_PS_jvmti_oops_do))
238 JvmtiExport::oops_do(strong_roots);
239
240 if (!_process_strong_tasks->is_task_claimed(SH_PS_SystemDictionary_oops_do)) {
241 SystemDictionary::roots_oops_do(strong_roots, weak_roots);
242 }
243
244 // All threads execute the following. A specific chunk of buckets
245 // from the StringTable are the individual tasks.
246 if (weak_roots != NULL) {
247 if (CollectedHeap::use_parallel_gc_threads()) {
248 StringTable::possibly_parallel_oops_do(weak_roots);
249 } else {
250 StringTable::oops_do(weak_roots);
251 }
252 }
253
254 if (!_process_strong_tasks->is_task_claimed(SH_PS_CodeCache_oops_do)) {
255 if (so & SO_ScavengeCodeCache) {
256 assert(code_roots != NULL, "must supply closure for code cache");
257
258 // We only visit parts of the CodeCache when scavenging.
259 CodeCache::scavenge_root_nmethods_do(code_roots);
260 }
261 if (so & SO_AllCodeCache) {
262 assert(code_roots != NULL, "must supply closure for code cache");
263
264 // CMSCollector uses this to do intermediate-strength collections.
265 // We scan the entire code cache, since CodeCache::do_unloading is not called.
266 CodeCache::blobs_do(code_roots);
267 }
268 // Verify that the code cache contents are not subject to
269 // movement by a scavenging collection.
270 DEBUG_ONLY(CodeBlobToOopClosure assert_code_is_non_scavengable(&assert_is_non_scavengable_closure, !CodeBlobToOopClosure::FixRelocations));
271 DEBUG_ONLY(CodeCache::asserted_non_scavengable_nmethods_do(&assert_code_is_non_scavengable));
272 }
273
274 _process_strong_tasks->all_tasks_completed();
275 }
276
277 void SharedHeap::process_all_roots(bool activate_scope,
278 ScanningOption so,
279 OopClosure* roots,
280 CLDClosure* cld_closure,
281 CodeBlobClosure* code_closure) {
282 process_roots(activate_scope, so,
283 roots, roots,
284 cld_closure, cld_closure,
285 code_closure);
286 }
287
288 void SharedHeap::process_strong_roots(bool activate_scope,
289 ScanningOption so,
290 OopClosure* roots,
291 CLDClosure* cld_closure,
292 CodeBlobClosure* code_closure) {
293 process_roots(activate_scope, so,
294 roots, NULL,
295 cld_closure, NULL,
296 code_closure);
297 }
298
299
300 class AlwaysTrueClosure: public BoolObjectClosure {
301 public:
302 bool do_object_b(oop p) { return true; }
303 };
304 static AlwaysTrueClosure always_true;
305
306 void SharedHeap::process_weak_roots(OopClosure* root_closure) {
307 // Global (weak) JNI handles
308 JNIHandles::weak_oops_do(&always_true, root_closure);
309 }
310
311 void SharedHeap::set_barrier_set(BarrierSet* bs) {
312 _barrier_set = bs;
313 // Cached barrier set for fast access in oops
314 oopDesc::set_bs(bs);
315 }
316
317 void SharedHeap::post_initialize() {
318 CollectedHeap::post_initialize();
319 ref_processing_init();
320 }
321
322 void SharedHeap::ref_processing_init() {}
323
324 // Some utilities.
325 void SharedHeap::print_size_transition(outputStream* out,
326 size_t bytes_before,
327 size_t bytes_after,
328 size_t capacity) {
|
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "code/codeCache.hpp"
29 #include "gc_interface/collectedHeap.inline.hpp"
30 #include "memory/sharedHeap.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "runtime/atomic.inline.hpp"
33 #include "runtime/fprofiler.hpp"
34 #include "runtime/java.hpp"
35 #include "utilities/copy.hpp"
36 #include "utilities/workgroup.hpp"
37
38 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
39
40 SharedHeap* SharedHeap::_sh;
41
42 SharedHeap::SharedHeap(CollectorPolicy* policy_) :
43 CollectedHeap(),
44 _collector_policy(policy_),
45 _rem_set(NULL),
46 _strong_roots_parity(0),
47 _workers(NULL)
48 {
49 _sh = this; // ch is static, should be set only once.
50 if ((UseParNewGC ||
51 (UseConcMarkSweepGC && (CMSParallelInitialMarkEnabled ||
52 CMSParallelRemarkEnabled)) ||
53 UseG1GC) &&
54 ParallelGCThreads > 0) {
55 _workers = new FlexibleWorkGang("Parallel GC Threads", ParallelGCThreads,
56 /* are_GC_task_threads */true,
57 /* are_ConcurrentGC_threads */false);
58 if (_workers == NULL) {
59 vm_exit_during_initialization("Failed necessary allocation.");
60 } else {
61 _workers->initialize_workers();
62 }
63 }
64 }
65
66 bool SharedHeap::heap_lock_held_for_gc() {
67 Thread* t = Thread::current();
68 return Heap_lock->owned_by_self()
69 || ( (t->is_GC_task_thread() || t->is_VM_thread())
70 && _thread_holds_heap_lock_for_gc);
71 }
72
73 void SharedHeap::set_par_threads(uint t) {
74 assert(t == 0 || !UseSerialGC, "Cannot have parallel threads");
75 _n_par_threads = t;
76 }
77
78 void SharedHeap::change_strong_roots_parity() {
79 // Also set the new collection parity.
80 assert(_strong_roots_parity >= 0 && _strong_roots_parity <= 2,
81 "Not in range.");
82 _strong_roots_parity++;
83 if (_strong_roots_parity == 3) _strong_roots_parity = 1;
84 assert(_strong_roots_parity >= 1 && _strong_roots_parity <= 2,
85 "Not in range.");
86 }
87
88 SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* heap, bool activate)
89 : MarkScope(activate), _sh(heap)
90 {
91 if (_active) {
92 _sh->change_strong_roots_parity();
93 // Zero the claimed high water mark in the StringTable
94 StringTable::clear_parallel_claimed_index();
95 }
96 }
97
98 void SharedHeap::set_barrier_set(BarrierSet* bs) {
99 _barrier_set = bs;
100 // Cached barrier set for fast access in oops
101 oopDesc::set_bs(bs);
102 }
103
104 void SharedHeap::post_initialize() {
105 CollectedHeap::post_initialize();
106 ref_processing_init();
107 }
108
109 void SharedHeap::ref_processing_init() {}
110
111 // Some utilities.
112 void SharedHeap::print_size_transition(outputStream* out,
113 size_t bytes_before,
114 size_t bytes_after,
115 size_t capacity) {
|