14 *
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 "gc/shared/workgroup.hpp"
27 #include "memory/allocation.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "runtime/atomic.inline.hpp"
30 #include "runtime/os.hpp"
31
32 // Definitions of WorkGang methods.
33
34 AbstractWorkGang::AbstractWorkGang(const char* name,
35 bool are_GC_task_threads,
36 bool are_ConcurrentGC_threads) :
37 _name(name),
38 _are_GC_task_threads(are_GC_task_threads),
39 _are_ConcurrentGC_threads(are_ConcurrentGC_threads) {
40
41 assert(!(are_GC_task_threads && are_ConcurrentGC_threads),
42 "They cannot both be STW GC and Concurrent threads" );
43
44 // Other initialization.
45 _monitor = new Monitor(/* priority */ Mutex::leaf,
46 /* name */ "WorkGroup monitor",
47 /* allow_vm_block */ are_GC_task_threads,
48 Monitor::_safepoint_check_sometimes);
49 assert(monitor() != NULL, "Failed to allocate monitor");
50 _task = NULL;
51 _sequence_number = 0;
52 _started_workers = 0;
53 _finished_workers = 0;
54 }
55
56 WorkGang::WorkGang(const char* name,
57 uint workers,
58 bool are_GC_task_threads,
59 bool are_ConcurrentGC_threads) :
60 AbstractWorkGang(name, are_GC_task_threads, are_ConcurrentGC_threads) {
61 _total_workers = workers;
62 }
63
64 GangWorker* WorkGang::allocate_worker(uint which) {
65 GangWorker* new_worker = new GangWorker(this, which);
66 return new_worker;
67 }
68
69 // The current implementation will exit if the allocation
70 // of any worker fails. Still, return a boolean so that
71 // a future implementation can possibly do a partial
72 // initialization of the workers and report such to the
73 // caller.
74 bool WorkGang::initialize_workers() {
75
76 if (TraceWorkGang) {
77 tty->print_cr("Constructing work gang %s with %d threads",
78 name(),
79 total_workers());
80 }
81 _gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, total_workers(), mtInternal);
82 if (gang_workers() == NULL) {
83 vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, "Cannot create GangWorker array.");
84 return false;
85 }
86 os::ThreadType worker_type;
87 if (are_ConcurrentGC_threads()) {
88 worker_type = os::cgc_thread;
89 } else {
90 worker_type = os::pgc_thread;
91 }
92 for (uint worker = 0; worker < total_workers(); worker += 1) {
93 GangWorker* new_worker = allocate_worker(worker);
94 assert(new_worker != NULL, "Failed to allocate GangWorker");
95 _gang_workers[worker] = new_worker;
96 if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) {
97 vm_exit_out_of_memory(0, OOM_MALLOC_ERROR,
98 "Cannot create worker GC thread. Out of system resources.");
99 return false;
100 }
101 if (!DisableStartThread) {
102 os::start_thread(new_worker);
103 }
104 }
105 return true;
106 }
107
108 GangWorker* AbstractWorkGang::gang_worker(uint i) const {
109 // Array index bounds checking.
110 GangWorker* result = NULL;
111 assert(gang_workers() != NULL, "No workers for indexing");
112 assert(i < total_workers(), "Worker index out of bounds");
113 result = _gang_workers[i];
114 assert(result != NULL, "Indexing to null worker");
115 return result;
116 }
117
118 void WorkGang::run_task(AbstractGangTask* task) {
119 run_task(task, total_workers());
120 }
121
122 void WorkGang::run_task(AbstractGangTask* task, uint no_of_parallel_workers) {
123 // This thread is executed by the VM thread which does not block
124 // on ordinary MutexLocker's.
125 MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
126 if (TraceWorkGang) {
127 tty->print_cr("Running work gang %s task %s", name(), task->name());
128 }
129 // Tell all the workers to run a task.
130 assert(task != NULL, "Running a null task");
131 // Initialize.
132 _task = task;
133 _sequence_number += 1;
134 _started_workers = 0;
135 _finished_workers = 0;
136 // Tell the workers to get to work.
137 monitor()->notify_all();
138 // Wait for them to be finished
139 while (finished_workers() < no_of_parallel_workers) {
140 if (TraceWorkGang) {
141 tty->print_cr("Waiting in work gang %s: %u/%u finished sequence %d",
142 name(), finished_workers(), no_of_parallel_workers,
143 _sequence_number);
144 }
145 monitor()->wait(/* no_safepoint_check */ true);
146 }
147 _task = NULL;
148 if (TraceWorkGang) {
149 tty->print_cr("\nFinished work gang %s: %u/%u sequence %d",
150 name(), finished_workers(), no_of_parallel_workers,
151 _sequence_number);
152 Thread* me = Thread::current();
153 tty->print_cr(" T: " PTR_FORMAT " VM_thread: %d", p2i(me), me->is_VM_thread());
154 }
155 }
156
157 void FlexibleWorkGang::run_task(AbstractGangTask* task) {
158 // If active_workers() is passed, _finished_workers
159 // must only be incremented for workers that find non_null
160 // work (as opposed to all those that just check that the
161 // task is not null).
162 WorkGang::run_task(task, (uint) active_workers());
163 }
164
165 void AbstractWorkGang::internal_worker_poll(WorkData* data) const {
166 assert(monitor()->owned_by_self(), "worker_poll is an internal method");
167 assert(data != NULL, "worker data is null");
168 data->set_task(task());
169 data->set_sequence_number(sequence_number());
170 }
171
172 void AbstractWorkGang::internal_note_start() {
173 assert(monitor()->owned_by_self(), "note_finish is an internal method");
174 _started_workers += 1;
175 }
176
177 void AbstractWorkGang::internal_note_finish() {
178 assert(monitor()->owned_by_self(), "note_finish is an internal method");
179 _finished_workers += 1;
180 }
181
182 void AbstractWorkGang::print_worker_threads_on(outputStream* st) const {
183 uint num_thr = total_workers();
184 for (uint i = 0; i < num_thr; i++) {
185 gang_worker(i)->print_on(st);
186 st->cr();
187 }
188 }
189
190 void AbstractWorkGang::threads_do(ThreadClosure* tc) const {
191 assert(tc != NULL, "Null ThreadClosure");
192 uint num_thr = total_workers();
193 for (uint i = 0; i < num_thr; i++) {
194 tc->do_thread(gang_worker(i));
195 }
196 }
197
198 // GangWorker methods.
199
200 GangWorker::GangWorker(AbstractWorkGang* gang, uint id) {
201 _gang = gang;
202 set_id(id);
203 set_name("%s#%d", gang->name(), id);
204 }
205
206 void GangWorker::run() {
207 initialize();
208 loop();
209 }
210
211 void GangWorker::initialize() {
212 this->initialize_thread_local_storage();
213 this->record_stack_base_and_size();
214 this->initialize_named_thread();
215 assert(_gang != NULL, "No gang to run in");
216 os::set_priority(this, NearMaxPriority);
217 if (TraceWorkGang) {
218 tty->print_cr("Running gang worker for gang %s id %u",
219 gang()->name(), id());
220 }
221 // The VM thread should not execute here because MutexLocker's are used
222 // as (opposed to MutexLockerEx's).
223 assert(!Thread::current()->is_VM_thread(), "VM thread should not be part"
224 " of a work gang");
225 }
226
227 void GangWorker::loop() {
228 int previous_sequence_number = 0;
229 Monitor* gang_monitor = gang()->monitor();
230 for ( ; ; ) {
231 WorkData data;
232 int part; // Initialized below.
233 {
234 // Grab the gang mutex.
235 MutexLocker ml(gang_monitor);
236 // Wait for something to do.
237 // Polling outside the while { wait } avoids missed notifies
238 // in the outer loop.
239 gang()->internal_worker_poll(&data);
240 if (TraceWorkGang) {
241 tty->print("Polled outside for work in gang %s worker %u",
242 gang()->name(), id());
243 tty->print(" sequence: %d (prev: %d)",
244 data.sequence_number(), previous_sequence_number);
245 if (data.task() != NULL) {
246 tty->print(" task: %s", data.task()->name());
282 tty->print("Work for work gang %s id %u task %s part %d",
283 gang()->name(), id(), data.task()->name(), part);
284 }
285 assert(data.task() != NULL, "Got null task");
286 data.task()->work(part);
287 {
288 if (TraceWorkGang) {
289 tty->print("Finish for work gang %s id %u task %s part %d",
290 gang()->name(), id(), data.task()->name(), part);
291 }
292 // Grab the gang mutex.
293 MutexLocker ml(gang_monitor);
294 gang()->internal_note_finish();
295 // Tell the gang you are done.
296 gang_monitor->notify_all();
297 // Drop the gang mutex.
298 }
299 previous_sequence_number = data.sequence_number();
300 }
301 }
302
303 bool GangWorker::is_GC_task_thread() const {
304 return gang()->are_GC_task_threads();
305 }
306
307 bool GangWorker::is_ConcurrentGC_thread() const {
308 return gang()->are_ConcurrentGC_threads();
309 }
310
311 void GangWorker::print_on(outputStream* st) const {
312 st->print("\"%s\" ", name());
313 Thread::print_on(st);
314 st->cr();
315 }
316
317 // Printing methods
318
319 const char* AbstractWorkGang::name() const {
320 return _name;
321 }
322
323 #ifndef PRODUCT
324
325 const char* AbstractGangTask::name() const {
326 return _name;
327 }
328
329 #endif /* PRODUCT */
330
331 // FlexibleWorkGang
332
333
334 // *** WorkGangBarrierSync
335
336 WorkGangBarrierSync::WorkGangBarrierSync()
337 : _monitor(Mutex::safepoint, "work gang barrier sync", true,
338 Monitor::_safepoint_check_never),
339 _n_workers(0), _n_completed(0), _should_reset(false), _aborted(false) {
340 }
341
342 WorkGangBarrierSync::WorkGangBarrierSync(uint n_workers, const char* name)
343 : _monitor(Mutex::safepoint, name, true, Monitor::_safepoint_check_never),
344 _n_workers(n_workers), _n_completed(0), _should_reset(false), _aborted(false) {
345 }
346
347 void WorkGangBarrierSync::set_n_workers(uint n_workers) {
348 _n_workers = n_workers;
349 _n_completed = 0;
350 _should_reset = false;
351 _aborted = false;
352 }
|
14 *
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 "gc/shared/workgroup.hpp"
27 #include "memory/allocation.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "runtime/atomic.inline.hpp"
30 #include "runtime/os.hpp"
31
32 // Definitions of WorkGang methods.
33
34 // The current implementation will exit if the allocation
35 // of any worker fails. Still, return a boolean so that
36 // a future implementation can possibly do a partial
37 // initialization of the workers and report such to the
38 // caller.
39 bool AbstractWorkGang::initialize_workers() {
40
41 if (TraceWorkGang) {
42 tty->print_cr("Constructing work gang %s with %d threads",
43 name(),
44 total_workers());
45 }
46 _workers = NEW_C_HEAP_ARRAY(AbstractGangWorker*, total_workers(), mtInternal);
47 if (_workers == NULL) {
48 vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, "Cannot create GangWorker array.");
49 return false;
50 }
51 os::ThreadType worker_type;
52 if (are_ConcurrentGC_threads()) {
53 worker_type = os::cgc_thread;
54 } else {
55 worker_type = os::pgc_thread;
56 }
57 for (uint worker = 0; worker < total_workers(); worker += 1) {
58 AbstractGangWorker* new_worker = allocate_worker(worker);
59 assert(new_worker != NULL, "Failed to allocate GangWorker");
60 _workers[worker] = new_worker;
61 if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) {
62 vm_exit_out_of_memory(0, OOM_MALLOC_ERROR,
63 "Cannot create worker GC thread. Out of system resources.");
64 return false;
65 }
66 if (!DisableStartThread) {
67 os::start_thread(new_worker);
68 }
69 }
70 return true;
71 }
72
73 AbstractGangWorker* AbstractWorkGang::worker(uint i) const {
74 // Array index bounds checking.
75 AbstractGangWorker* result = NULL;
76 assert(_workers != NULL, "No workers for indexing");
77 assert(i < total_workers(), "Worker index out of bounds");
78 result = _workers[i];
79 assert(result != NULL, "Indexing to null worker");
80 return result;
81 }
82
83 void AbstractWorkGang::print_worker_threads_on(outputStream* st) const {
84 uint workers = total_workers();
85 for (uint i = 0; i < workers; i++) {
86 worker(i)->print_on(st);
87 st->cr();
88 }
89 }
90
91 void AbstractWorkGang::threads_do(ThreadClosure* tc) const {
92 assert(tc != NULL, "Null ThreadClosure");
93 uint workers = total_workers();
94 for (uint i = 0; i < workers; i++) {
95 tc->do_thread(worker(i));
96 }
97 }
98
99 WorkGang::WorkGang(const char* name,
100 uint workers,
101 bool are_GC_task_threads,
102 bool are_ConcurrentGC_threads) :
103 AbstractWorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads),
104 _started_workers(0),
105 _finished_workers(0),
106 _sequence_number(0),
107 _task(NULL) {
108
109 // Other initialization.
110 _monitor = new Monitor(/* priority */ Mutex::leaf,
111 /* name */ "WorkGroup monitor",
112 /* allow_vm_block */ are_GC_task_threads,
113 Monitor::_safepoint_check_sometimes);
114
115 assert(monitor() != NULL, "Failed to allocate monitor");
116 }
117
118 AbstractGangWorker* WorkGang::allocate_worker(uint worker_id) {
119 return new GangWorker(this, worker_id);
120 }
121
122 void WorkGang::run_task(AbstractGangTask* task) {
123 run_task(task, (uint)active_workers());
124 }
125
126 void WorkGang::run_task(AbstractGangTask* task, uint no_of_parallel_workers) {
127 // This thread is executed by the VM thread which does not block
128 // on ordinary MutexLocker's.
129 MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
130 if (TraceWorkGang) {
131 tty->print_cr("Running work gang %s task %s", name(), task->name());
132 }
133 // Tell all the workers to run a task.
134 assert(task != NULL, "Running a null task");
135 // Initialize.
136 _task = task;
137 _sequence_number += 1;
138 _started_workers = 0;
139 _finished_workers = 0;
140 // Tell the workers to get to work.
141 monitor()->notify_all();
142 // Wait for them to be finished
143 while (finished_workers() < no_of_parallel_workers) {
144 if (TraceWorkGang) {
145 tty->print_cr("Waiting in work gang %s: %u/%u finished sequence %d",
146 name(), finished_workers(), no_of_parallel_workers,
147 _sequence_number);
148 }
149 monitor()->wait(/* no_safepoint_check */ true);
150 }
151 _task = NULL;
152 if (TraceWorkGang) {
153 tty->print_cr("\nFinished work gang %s: %u/%u sequence %d",
154 name(), finished_workers(), no_of_parallel_workers,
155 _sequence_number);
156 Thread* me = Thread::current();
157 tty->print_cr(" T: " PTR_FORMAT " VM_thread: %d", p2i(me), me->is_VM_thread());
158 }
159 }
160
161 void WorkGang::internal_worker_poll(WorkData* data) const {
162 assert(monitor()->owned_by_self(), "worker_poll is an internal method");
163 assert(data != NULL, "worker data is null");
164 data->set_task(task());
165 data->set_sequence_number(sequence_number());
166 }
167
168 void WorkGang::internal_note_start() {
169 assert(monitor()->owned_by_self(), "note_finish is an internal method");
170 _started_workers += 1;
171 }
172
173 void WorkGang::internal_note_finish() {
174 assert(monitor()->owned_by_self(), "note_finish is an internal method");
175 _finished_workers += 1;
176 }
177
178 // GangWorker methods.
179
180 AbstractGangWorker::AbstractGangWorker(AbstractWorkGang* gang, uint id) {
181 _gang = gang;
182 set_id(id);
183 set_name("%s#%d", gang->name(), id);
184 }
185
186 void AbstractGangWorker::run() {
187 initialize();
188 loop();
189 }
190
191 void AbstractGangWorker::initialize() {
192 this->initialize_thread_local_storage();
193 this->record_stack_base_and_size();
194 this->initialize_named_thread();
195 assert(_gang != NULL, "No gang to run in");
196 os::set_priority(this, NearMaxPriority);
197 if (TraceWorkGang) {
198 tty->print_cr("Running gang worker for gang %s id %u",
199 gang()->name(), id());
200 }
201 // The VM thread should not execute here because MutexLocker's are used
202 // as (opposed to MutexLockerEx's).
203 assert(!Thread::current()->is_VM_thread(), "VM thread should not be part"
204 " of a work gang");
205 }
206
207 bool AbstractGangWorker::is_GC_task_thread() const {
208 return gang()->are_GC_task_threads();
209 }
210
211 bool AbstractGangWorker::is_ConcurrentGC_thread() const {
212 return gang()->are_ConcurrentGC_threads();
213 }
214
215 void AbstractGangWorker::print_on(outputStream* st) const {
216 st->print("\"%s\" ", name());
217 Thread::print_on(st);
218 st->cr();
219 }
220
221 void GangWorker::loop() {
222 int previous_sequence_number = 0;
223 Monitor* gang_monitor = gang()->monitor();
224 for ( ; ; ) {
225 WorkData data;
226 int part; // Initialized below.
227 {
228 // Grab the gang mutex.
229 MutexLocker ml(gang_monitor);
230 // Wait for something to do.
231 // Polling outside the while { wait } avoids missed notifies
232 // in the outer loop.
233 gang()->internal_worker_poll(&data);
234 if (TraceWorkGang) {
235 tty->print("Polled outside for work in gang %s worker %u",
236 gang()->name(), id());
237 tty->print(" sequence: %d (prev: %d)",
238 data.sequence_number(), previous_sequence_number);
239 if (data.task() != NULL) {
240 tty->print(" task: %s", data.task()->name());
276 tty->print("Work for work gang %s id %u task %s part %d",
277 gang()->name(), id(), data.task()->name(), part);
278 }
279 assert(data.task() != NULL, "Got null task");
280 data.task()->work(part);
281 {
282 if (TraceWorkGang) {
283 tty->print("Finish for work gang %s id %u task %s part %d",
284 gang()->name(), id(), data.task()->name(), part);
285 }
286 // Grab the gang mutex.
287 MutexLocker ml(gang_monitor);
288 gang()->internal_note_finish();
289 // Tell the gang you are done.
290 gang_monitor->notify_all();
291 // Drop the gang mutex.
292 }
293 previous_sequence_number = data.sequence_number();
294 }
295 }
296
297 // *** WorkGangBarrierSync
298
299 WorkGangBarrierSync::WorkGangBarrierSync()
300 : _monitor(Mutex::safepoint, "work gang barrier sync", true,
301 Monitor::_safepoint_check_never),
302 _n_workers(0), _n_completed(0), _should_reset(false), _aborted(false) {
303 }
304
305 WorkGangBarrierSync::WorkGangBarrierSync(uint n_workers, const char* name)
306 : _monitor(Mutex::safepoint, name, true, Monitor::_safepoint_check_never),
307 _n_workers(n_workers), _n_completed(0), _should_reset(false), _aborted(false) {
308 }
309
310 void WorkGangBarrierSync::set_n_workers(uint n_workers) {
311 _n_workers = n_workers;
312 _n_completed = 0;
313 _should_reset = false;
314 _aborted = false;
315 }
|