root/gc/darwin_stop_world.c
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DEFINITIONS
This source file includes following definitions.
- StackFrame
- FindTopOfStack
- GC_push_all_stacks
- GC_push_all_stacks
- GC_stop_init
- GC_suspend_thread_list
- GC_stop_world
- GC_start_world
- GC_darwin_register_mach_handler_thread
1 #include "private/pthread_support.h"
2
3 # if defined(GC_DARWIN_THREADS)
4
5 /* From "Inside Mac OS X - Mach-O Runtime Architecture" published by Apple
6 Page 49:
7 "The space beneath the stack pointer, where a new stack frame would normally
8 be allocated, is called the red zone. This area as shown in Figure 3-2 may
9 be used for any purpose as long as a new stack frame does not need to be
10 added to the stack."
11
12 Page 50: "If a leaf procedure's red zone usage would exceed 224 bytes, then
13 it must set up a stack frame just like routines that call other routines."
14 */
15 #ifdef POWERPC
16 # if CPP_WORDSZ == 32
17 # define PPC_RED_ZONE_SIZE 224
18 # elif CPP_WORDSZ == 64
19 # define PPC_RED_ZONE_SIZE 320
20 # endif
21 #endif
22
23 typedef struct StackFrame {
24 unsigned long savedSP;
25 unsigned long savedCR;
26 unsigned long savedLR;
27 unsigned long reserved[2];
28 unsigned long savedRTOC;
29 } StackFrame;
30
31 unsigned long FindTopOfStack(unsigned int stack_start) {
32 StackFrame *frame;
33
34 if (stack_start == 0) {
35 # ifdef POWERPC
36 # if CPP_WORDSZ == 32
37 __asm__ volatile("lwz %0,0(r1)" : "=r" (frame));
38 # else
39 __asm__ volatile("ldz %0,0(r1)" : "=r" (frame));
40 # endif
41 # endif
42 } else {
43 frame = (StackFrame *)stack_start;
44 }
45
46 # ifdef DEBUG_THREADS
47 /* GC_printf1("FindTopOfStack start at sp = %p\n", frame); */
48 # endif
49 do {
50 if (frame->savedSP == 0) break;
51 /* if there are no more stack frames, stop */
52
53 frame = (StackFrame*)frame->savedSP;
54
55 /* we do these next two checks after going to the next frame
56 because the LR for the first stack frame in the loop
57 is not set up on purpose, so we shouldn't check it. */
58 if ((frame->savedLR & ~3) == 0) break; /* if the next LR is bogus, stop */
59 if ((~(frame->savedLR) & ~3) == 0) break; /* ditto */
60 } while (1);
61
62 # ifdef DEBUG_THREADS
63 /* GC_printf1("FindTopOfStack finish at sp = %p\n", frame); */
64 # endif
65
66 return (unsigned long)frame;
67 }
68
69 #ifdef DARWIN_DONT_PARSE_STACK
70 void GC_push_all_stacks() {
71 int i;
72 kern_return_t r;
73 GC_thread p;
74 pthread_t me;
75 ptr_t lo, hi;
76 ppc_thread_state_t state;
77 mach_msg_type_number_t thread_state_count = MACHINE_THREAD_STATE_COUNT;
78
79 me = pthread_self();
80 if (!GC_thr_initialized) GC_thr_init();
81
82 for(i=0;i<THREAD_TABLE_SZ;i++) {
83 for(p=GC_threads[i];p!=0;p=p->next) {
84 if(p -> flags & FINISHED) continue;
85 if(pthread_equal(p->id,me)) {
86 lo = GC_approx_sp();
87 } else {
88 /* Get the thread state (registers, etc) */
89 r = thread_get_state(
90 p->stop_info.mach_thread,
91 MACHINE_THREAD_STATE,
92 (natural_t*)&state,
93 &thread_state_count);
94 if(r != KERN_SUCCESS) ABORT("thread_get_state failed");
95
96 lo = (void*)(state.r1 - PPC_RED_ZONE_SIZE);
97
98 GC_push_one(state.r0);
99 GC_push_one(state.r2);
100 GC_push_one(state.r3);
101 GC_push_one(state.r4);
102 GC_push_one(state.r5);
103 GC_push_one(state.r6);
104 GC_push_one(state.r7);
105 GC_push_one(state.r8);
106 GC_push_one(state.r9);
107 GC_push_one(state.r10);
108 GC_push_one(state.r11);
109 GC_push_one(state.r12);
110 GC_push_one(state.r13);
111 GC_push_one(state.r14);
112 GC_push_one(state.r15);
113 GC_push_one(state.r16);
114 GC_push_one(state.r17);
115 GC_push_one(state.r18);
116 GC_push_one(state.r19);
117 GC_push_one(state.r20);
118 GC_push_one(state.r21);
119 GC_push_one(state.r22);
120 GC_push_one(state.r23);
121 GC_push_one(state.r24);
122 GC_push_one(state.r25);
123 GC_push_one(state.r26);
124 GC_push_one(state.r27);
125 GC_push_one(state.r28);
126 GC_push_one(state.r29);
127 GC_push_one(state.r30);
128 GC_push_one(state.r31);
129 } /* p != me */
130 if(p->flags & MAIN_THREAD)
131 hi = GC_stackbottom;
132 else
133 hi = p->stack_end;
134 #if DEBUG_THREADS
135 GC_printf3("Darwin: Stack for thread 0x%lx = [%lx,%lx)\n",
136 (unsigned long) p -> id,
137 (unsigned long) lo,
138 (unsigned long) hi
139 );
140 #endif
141 GC_push_all_stack(lo,hi);
142 } /* for(p=GC_threads[i]...) */
143 } /* for(i=0;i<THREAD_TABLE_SZ...) */
144 }
145
146 #else /* !DARWIN_DONT_PARSE_STACK; Use FindTopOfStack() */
147
148 void GC_push_all_stacks() {
149 int i;
150 kern_return_t r;
151 mach_port_t me;
152 ptr_t lo, hi;
153 thread_act_array_t act_list = 0;
154 mach_msg_type_number_t listcount = 0;
155
156 me = mach_thread_self();
157 if (!GC_thr_initialized) GC_thr_init();
158
159 r = task_threads(current_task(), &act_list, &listcount);
160 if(r != KERN_SUCCESS) ABORT("task_threads failed");
161 for(i = 0; i < listcount; i++) {
162 thread_act_t thread = act_list[i];
163 if (thread == me) {
164 lo = GC_approx_sp();
165 hi = (ptr_t)FindTopOfStack(0);
166 } else {
167 # if defined(POWERPC)
168 # if CPP_WORDSZ == 32
169 ppc_thread_state_t info;
170 # else
171 ppc_thread_state64_t info;
172 # endif
173 mach_msg_type_number_t outCount = THREAD_STATE_MAX;
174 r = thread_get_state(thread, MACHINE_THREAD_STATE,
175 (natural_t *)&info, &outCount);
176 if(r != KERN_SUCCESS) ABORT("task_get_state failed");
177
178 lo = (void*)(info.r1 - PPC_RED_ZONE_SIZE);
179 hi = (ptr_t)FindTopOfStack(info.r1);
180
181 GC_push_one(info.r0);
182 GC_push_one(info.r2);
183 GC_push_one(info.r3);
184 GC_push_one(info.r4);
185 GC_push_one(info.r5);
186 GC_push_one(info.r6);
187 GC_push_one(info.r7);
188 GC_push_one(info.r8);
189 GC_push_one(info.r9);
190 GC_push_one(info.r10);
191 GC_push_one(info.r11);
192 GC_push_one(info.r12);
193 GC_push_one(info.r13);
194 GC_push_one(info.r14);
195 GC_push_one(info.r15);
196 GC_push_one(info.r16);
197 GC_push_one(info.r17);
198 GC_push_one(info.r18);
199 GC_push_one(info.r19);
200 GC_push_one(info.r20);
201 GC_push_one(info.r21);
202 GC_push_one(info.r22);
203 GC_push_one(info.r23);
204 GC_push_one(info.r24);
205 GC_push_one(info.r25);
206 GC_push_one(info.r26);
207 GC_push_one(info.r27);
208 GC_push_one(info.r28);
209 GC_push_one(info.r29);
210 GC_push_one(info.r30);
211 GC_push_one(info.r31);
212 # else
213 /* FIXME: Remove after testing: */
214 WARN("This is completely untested and likely will not work\n", 0);
215 i386_thread_state_t info;
216 mach_msg_type_number_t outCount = THREAD_STATE_MAX;
217 r = thread_get_state(thread, MACHINE_THREAD_STATE,
218 (natural_t *)&info, &outCount);
219 if(r != KERN_SUCCESS) ABORT("task_get_state failed");
220
221 lo = (void*)info.esp;
222 hi = (ptr_t)FindTopOfStack(info.esp);
223
224 GC_push_one(info.eax);
225 GC_push_one(info.ebx);
226 GC_push_one(info.ecx);
227 GC_push_one(info.edx);
228 GC_push_one(info.edi);
229 GC_push_one(info.esi);
230 /* GC_push_one(info.ebp); */
231 /* GC_push_one(info.esp); */
232 GC_push_one(info.ss);
233 GC_push_one(info.eip);
234 GC_push_one(info.cs);
235 GC_push_one(info.ds);
236 GC_push_one(info.es);
237 GC_push_one(info.fs);
238 GC_push_one(info.gs);
239 # endif /* !POWERPC */
240 }
241 # if DEBUG_THREADS
242 GC_printf3("Darwin: Stack for thread 0x%lx = [%lx,%lx)\n",
243 (unsigned long) thread,
244 (unsigned long) lo,
245 (unsigned long) hi
246 );
247 # endif
248 GC_push_all_stack(lo, hi);
249 } /* for(p=GC_threads[i]...) */
250 }
251 #endif /* !DARWIN_DONT_PARSE_STACK */
252
253 static mach_port_t GC_mach_handler_thread;
254 static int GC_use_mach_handler_thread = 0;
255
256 static struct GC_mach_thread GC_mach_threads[THREAD_TABLE_SZ];
257 static int GC_mach_threads_count;
258
259 void GC_stop_init() {
260 int i;
261
262 for (i = 0; i < THREAD_TABLE_SZ; i++) {
263 GC_mach_threads[i].thread = 0;
264 GC_mach_threads[i].already_suspended = 0;
265 }
266 GC_mach_threads_count = 0;
267 }
268
269 /* returns true if there's a thread in act_list that wasn't in old_list */
270 int GC_suspend_thread_list(thread_act_array_t act_list, int count,
271 thread_act_array_t old_list, int old_count) {
272 mach_port_t my_thread = mach_thread_self();
273 int i, j;
274
275 int changed = 0;
276
277 for(i = 0; i < count; i++) {
278 thread_act_t thread = act_list[i];
279 # if DEBUG_THREADS
280 GC_printf1("Attempting to suspend thread %p\n", thread);
281 # endif
282 /* find the current thread in the old list */
283 int found = 0;
284 for(j = 0; j < old_count; j++) {
285 thread_act_t old_thread = old_list[j];
286 if (old_thread == thread) {
287 found = 1;
288 break;
289 }
290 }
291 if (!found) {
292 /* add it to the GC_mach_threads list */
293 GC_mach_threads[GC_mach_threads_count].thread = thread;
294 /* default is not suspended */
295 GC_mach_threads[GC_mach_threads_count].already_suspended = 0;
296 changed = 1;
297 }
298
299 if (thread != my_thread &&
300 (!GC_use_mach_handler_thread
301 || (GC_use_mach_handler_thread
302 && GC_mach_handler_thread != thread))) {
303 struct thread_basic_info info;
304 mach_msg_type_number_t outCount = THREAD_INFO_MAX;
305 kern_return_t kern_result = thread_info(thread, THREAD_BASIC_INFO,
306 (thread_info_t)&info, &outCount);
307 if(kern_result != KERN_SUCCESS) {
308 /* the thread may have quit since the thread_threads () call
309 * we mark already_suspended so it's not dealt with anymore later
310 */
311 if (!found) {
312 GC_mach_threads[GC_mach_threads_count].already_suspended = TRUE;
313 GC_mach_threads_count++;
314 }
315 continue;
316 }
317 # if DEBUG_THREADS
318 GC_printf2("Thread state for 0x%lx = %d\n", thread, info.run_state);
319 # endif
320 if (!found) {
321 GC_mach_threads[GC_mach_threads_count].already_suspended = info.suspend_count;
322 }
323 if (info.suspend_count) continue;
324
325 # if DEBUG_THREADS
326 GC_printf1("Suspending 0x%lx\n", thread);
327 # endif
328 /* Suspend the thread */
329 kern_result = thread_suspend(thread);
330 if(kern_result != KERN_SUCCESS) {
331 /* the thread may have quit since the thread_threads () call
332 * we mark already_suspended so it's not dealt with anymore later
333 */
334 if (!found) {
335 GC_mach_threads[GC_mach_threads_count].already_suspended = TRUE;
336 GC_mach_threads_count++;
337 }
338 continue;
339 }
340 }
341 if (!found) GC_mach_threads_count++;
342 }
343 return changed;
344 }
345
346
347 /* Caller holds allocation lock. */
348 void GC_stop_world()
349 {
350 int i, changes;
351 GC_thread p;
352 mach_port_t my_thread = mach_thread_self();
353 kern_return_t kern_result;
354 thread_act_array_t act_list, prev_list;
355 mach_msg_type_number_t listcount, prevcount;
356
357 # if DEBUG_THREADS
358 GC_printf1("Stopping the world from 0x%lx\n", mach_thread_self());
359 # endif
360
361 /* clear out the mach threads list table */
362 GC_stop_init();
363
364 /* Make sure all free list construction has stopped before we start. */
365 /* No new construction can start, since free list construction is */
366 /* required to acquire and release the GC lock before it starts, */
367 /* and we have the lock. */
368 # ifdef PARALLEL_MARK
369 GC_acquire_mark_lock();
370 GC_ASSERT(GC_fl_builder_count == 0);
371 /* We should have previously waited for it to become zero. */
372 # endif /* PARALLEL_MARK */
373
374 /* Loop stopping threads until you have gone over the whole list
375 twice without a new one appearing. thread_create() won't
376 return (and thus the thread stop) until the new thread
377 exists, so there is no window whereby you could stop a
378 thread, recognise it is stopped, but then have a new thread
379 it created before stopping show up later.
380 */
381
382 changes = 1;
383 prev_list = NULL;
384 prevcount = 0;
385 do {
386 int result;
387 kern_result = task_threads(current_task(), &act_list, &listcount);
388 result = GC_suspend_thread_list(act_list, listcount,
389 prev_list, prevcount);
390 changes = result;
391 prev_list = act_list;
392 prevcount = listcount;
393 } while (changes);
394
395
396 # ifdef MPROTECT_VDB
397 if(GC_incremental) {
398 extern void GC_mprotect_stop();
399 GC_mprotect_stop();
400 }
401 # endif
402
403 # ifdef PARALLEL_MARK
404 GC_release_mark_lock();
405 # endif
406 #if DEBUG_THREADS
407 GC_printf1("World stopped from 0x%lx\n", my_thread);
408 #endif
409 }
410
411 /* Caller holds allocation lock, and has held it continuously since */
412 /* the world stopped. */
413 void GC_start_world()
414 {
415 mach_port_t my_thread = mach_thread_self();
416 int i, j;
417 GC_thread p;
418 kern_return_t kern_result;
419 thread_act_array_t act_list;
420 mach_msg_type_number_t listcount;
421 struct thread_basic_info info;
422 mach_msg_type_number_t outCount = THREAD_INFO_MAX;
423
424 # if DEBUG_THREADS
425 GC_printf0("World starting\n");
426 # endif
427
428 # ifdef MPROTECT_VDB
429 if(GC_incremental) {
430 extern void GC_mprotect_resume();
431 GC_mprotect_resume();
432 }
433 # endif
434
435 kern_result = task_threads(current_task(), &act_list, &listcount);
436 for(i = 0; i < listcount; i++) {
437 thread_act_t thread = act_list[i];
438 if (thread != my_thread &&
439 (!GC_use_mach_handler_thread ||
440 (GC_use_mach_handler_thread && GC_mach_handler_thread != thread))) {
441 for(j = 0; j < GC_mach_threads_count; j++) {
442 if (thread == GC_mach_threads[j].thread) {
443 if (GC_mach_threads[j].already_suspended) {
444 # if DEBUG_THREADS
445 GC_printf1("Not resuming already suspended thread %p\n", thread);
446 # endif
447 continue;
448 }
449 kern_result = thread_info(thread, THREAD_BASIC_INFO,
450 (thread_info_t)&info, &outCount);
451 if(kern_result != KERN_SUCCESS) ABORT("thread_info failed");
452 # if DEBUG_THREADS
453 GC_printf2("Thread state for 0x%lx = %d\n", thread,
454 info.run_state);
455 GC_printf1("Resuming 0x%lx\n", thread);
456 # endif
457 /* Resume the thread */
458 kern_result = thread_resume(thread);
459 if(kern_result != KERN_SUCCESS) ABORT("thread_resume failed");
460 }
461 }
462 }
463 }
464 # if DEBUG_THREADS
465 GC_printf0("World started\n");
466 # endif
467 }
468
469 void GC_darwin_register_mach_handler_thread(mach_port_t thread) {
470 GC_mach_handler_thread = thread;
471 GC_use_mach_handler_thread = 1;
472 }
473
474 #endif