1 #include "private/gc_priv.h"
2
3 #if defined(GC_WIN32_THREADS)
4
5 #include <windows.h>
6
7 #ifdef CYGWIN32
8 # include <errno.h>
9
10 /* Cygwin-specific forward decls */
11 # undef pthread_create
12 # undef pthread_sigmask
13 # undef pthread_join
14 # undef pthread_detach
15 # undef dlopen
16
17 # define DEBUG_CYGWIN_THREADS 0
18
19 void * GC_start_routine(void * arg);
20 void GC_thread_exit_proc(void *arg);
21
22 #endif
23
24 /* The type of the first argument to InterlockedExchange. */
25 /* Documented to be LONG volatile *, but at least gcc likes */
26 /* this better. */
27 typedef LONG * IE_t;
28
29 #ifndef MAX_THREADS
30 # define MAX_THREADS 256
31 /* FIXME: */
32 /* Things may get quite slow for large numbers of threads, */
33 /* since we look them up with sequential search. */
34 #endif
35
36 GC_bool GC_thr_initialized = FALSE;
37
38 DWORD GC_main_thread = 0;
39
40 struct GC_thread_Rep {
41 LONG in_use; /* Updated without lock. */
42 /* We assert that unused */
43 /* entries have invalid ids of */
44 /* zero and zero stack fields. */
45 DWORD id;
46 HANDLE handle;
47 ptr_t stack_base; /* The cold end of the stack. */
48 /* 0 ==> entry not valid. */
49 /* !in_use ==> stack_base == 0 */
50 GC_bool suspended;
51
52 # ifdef CYGWIN32
53 void *status; /* hold exit value until join in case it's a pointer */
54 pthread_t pthread_id;
55 short flags; /* Protected by GC lock. */
56 # define FINISHED 1 /* Thread has exited. */
57 # define DETACHED 2 /* Thread is intended to be detached. */
58 # endif
59 };
60
61 typedef volatile struct GC_thread_Rep * GC_thread;
62
63 /*
64 * We generally assume that volatile ==> memory ordering, at least among
65 * volatiles.
66 */
67
68 volatile GC_bool GC_please_stop = FALSE;
69
70 volatile struct GC_thread_Rep thread_table[MAX_THREADS];
71
72 volatile LONG GC_max_thread_index = 0; /* Largest index in thread_table */
73 /* that was ever used. */
74
75 extern LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info);
76
77 /*
78 * This may be called from DllMain, and hence operates under unusual
79 * constraints.
80 */
GC_new_thread(void)81 static GC_thread GC_new_thread(void) {
82 int i;
83 /* It appears to be unsafe to acquire a lock here, since this */
84 /* code is apparently not preeemptible on some systems. */
85 /* (This is based on complaints, not on Microsoft's official */
86 /* documentation, which says this should perform "only simple */
87 /* initialization tasks".) */
88 /* Hence we make do with nonblocking synchronization. */
89
90 /* The following should be a noop according to the win32 */
91 /* documentation. There is empirical evidence that it */
92 /* isn't. - HB */
93 # if defined(MPROTECT_VDB)
94 if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler);
95 # endif
96 /* cast away volatile qualifier */
97 for (i = 0; InterlockedExchange((IE_t)&thread_table[i].in_use,1) != 0; i++) {
98 /* Compare-and-swap would make this cleaner, but that's not */
99 /* supported before Windows 98 and NT 4.0. In Windows 2000, */
100 /* InterlockedExchange is supposed to be replaced by */
101 /* InterlockedExchangePointer, but that's not really what I */
102 /* want here. */
103 if (i == MAX_THREADS - 1)
104 ABORT("too many threads");
105 }
106 /* Update GC_max_thread_index if necessary. The following is safe, */
107 /* and unlike CompareExchange-based solutions seems to work on all */
108 /* Windows95 and later platforms. */
109 /* Unfortunately, GC_max_thread_index may be temporarily out of */
110 /* bounds, so readers have to compensate. */
111 while (i > GC_max_thread_index) {
112 InterlockedIncrement((IE_t)&GC_max_thread_index);
113 }
114 if (GC_max_thread_index >= MAX_THREADS) {
115 /* We overshot due to simultaneous increments. */
116 /* Setting it to MAX_THREADS-1 is always safe. */
117 GC_max_thread_index = MAX_THREADS - 1;
118 }
119
120 # ifdef CYGWIN32
121 thread_table[i].pthread_id = pthread_self();
122 # endif
123 if (!DuplicateHandle(GetCurrentProcess(),
124 GetCurrentThread(),
125 GetCurrentProcess(),
126 (HANDLE*)&thread_table[i].handle,
127 0,
128 0,
129 DUPLICATE_SAME_ACCESS)) {
130 DWORD last_error = GetLastError();
131 GC_printf1("Last error code: %lx\n", last_error);
132 ABORT("DuplicateHandle failed");
133 }
134 thread_table[i].stack_base = GC_get_stack_base();
135 /* Up until this point, GC_push_all_stacks considers this thread */
136 /* invalid. */
137 if (thread_table[i].stack_base == NULL)
138 ABORT("Failed to find stack base in GC_new_thread");
139 /* Up until this point, this entry is viewed as reserved but invalid */
140 /* by GC_delete_thread. */
141 thread_table[i].id = GetCurrentThreadId();
142 /* If this thread is being created while we are trying to stop */
143 /* the world, wait here. Hopefully this can't happen on any */
144 /* systems that don't allow us to block here. */
145 while (GC_please_stop) Sleep(20);
146 return thread_table + i;
147 }
148
149 /*
150 * GC_max_thread_index may temporarily be larger than MAX_THREADS.
151 * To avoid subscript errors, we check on access.
152 */
153 #ifdef __GNUC__
154 __inline__
155 #endif
GC_get_max_thread_index()156 LONG GC_get_max_thread_index()
157 {
158 LONG my_max = GC_max_thread_index;
159
160 if (my_max >= MAX_THREADS) return MAX_THREADS-1;
161 return my_max;
162 }
163
164 /* This is intended to be lock-free, though that */
165 /* assumes that the CloseHandle becomes visible before the */
166 /* in_use assignment. */
GC_delete_gc_thread(GC_thread thr)167 static void GC_delete_gc_thread(GC_thread thr)
168 {
169 CloseHandle(thr->handle);
170 /* cast away volatile qualifier */
171 thr->stack_base = 0;
172 thr->id = 0;
173 # ifdef CYGWIN32
174 thr->pthread_id = 0;
175 # endif /* CYGWIN32 */
176 thr->in_use = FALSE;
177 }
178
GC_delete_thread(DWORD thread_id)179 static void GC_delete_thread(DWORD thread_id) {
180 int i;
181 LONG my_max = GC_get_max_thread_index();
182
183 for (i = 0;
184 i <= my_max &&
185 (!thread_table[i].in_use || thread_table[i].id != thread_id);
186 /* Must still be in_use, since nobody else can store our thread_id. */
187 i++) {}
188 if (i > my_max) {
189 WARN("Removing nonexistent thread %ld\n", (GC_word)thread_id);
190 } else {
191 GC_delete_gc_thread(thread_table+i);
192 }
193 }
194
195
196 #ifdef CYGWIN32
197
198 /* Return a GC_thread corresponding to a given pthread_t. */
199 /* Returns 0 if it's not there. */
200 /* We assume that this is only called for pthread ids that */
201 /* have not yet terminated or are still joinable. */
GC_lookup_thread(pthread_t id)202 static GC_thread GC_lookup_thread(pthread_t id)
203 {
204 int i;
205 LONG my_max = GC_get_max_thread_index();
206
207 for (i = 0;
208 i <= my_max &&
209 (!thread_table[i].in_use || thread_table[i].pthread_id != id
210 || !thread_table[i].in_use);
211 /* Must still be in_use, since nobody else can store our thread_id. */
212 i++);
213 if (i > my_max) return 0;
214 return thread_table + i;
215 }
216
217 #endif /* CYGWIN32 */
218
GC_push_thread_structures(void)219 void GC_push_thread_structures GC_PROTO((void))
220 {
221 /* Unlike the other threads implementations, the thread table here */
222 /* contains no pointers to the collectable heap. Thus we have */
223 /* no private structures we need to preserve. */
224 # ifdef CYGWIN32
225 { int i; /* pthreads may keep a pointer in the thread exit value */
226 LONG my_max = GC_get_max_thread_index();
227
228 for (i = 0; i <= my_max; i++)
229 if (thread_table[i].in_use)
230 GC_push_all((ptr_t)&(thread_table[i].status),
231 (ptr_t)(&(thread_table[i].status)+1));
232 }
233 # endif
234 }
235
236 /* Defined in misc.c */
237 extern CRITICAL_SECTION GC_write_cs;
238
GC_stop_world()239 void GC_stop_world()
240 {
241 DWORD thread_id = GetCurrentThreadId();
242 int i;
243
244 if (!GC_thr_initialized) ABORT("GC_stop_world() called before GC_thr_init()");
245
246 GC_please_stop = TRUE;
247 # ifndef CYGWIN32
248 EnterCriticalSection(&GC_write_cs);
249 # endif /* !CYGWIN32 */
250 for (i = 0; i <= GC_get_max_thread_index(); i++)
251 if (thread_table[i].stack_base != 0
252 && thread_table[i].id != thread_id) {
253 # ifdef MSWINCE
254 /* SuspendThread will fail if thread is running kernel code */
255 while (SuspendThread(thread_table[i].handle) == (DWORD)-1)
256 Sleep(10);
257 # else
258 /* Apparently the Windows 95 GetOpenFileName call creates */
259 /* a thread that does not properly get cleaned up, and */
260 /* SuspendThread on its descriptor may provoke a crash. */
261 /* This reduces the probability of that event, though it still */
262 /* appears there's a race here. */
263 DWORD exitCode;
264 if (GetExitCodeThread(thread_table[i].handle,&exitCode) &&
265 exitCode != STILL_ACTIVE) {
266 thread_table[i].stack_base = 0; /* prevent stack from being pushed */
267 # ifndef CYGWIN32
268 /* this breaks pthread_join on Cygwin, which is guaranteed to */
269 /* only see user pthreads */
270 thread_table[i].in_use = FALSE;
271 CloseHandle(thread_table[i].handle);
272 # endif
273 continue;
274 }
275 if (SuspendThread(thread_table[i].handle) == (DWORD)-1)
276 ABORT("SuspendThread failed");
277 # endif
278 thread_table[i].suspended = TRUE;
279 }
280 # ifndef CYGWIN32
281 LeaveCriticalSection(&GC_write_cs);
282 # endif /* !CYGWIN32 */
283 }
284
GC_start_world()285 void GC_start_world()
286 {
287 DWORD thread_id = GetCurrentThreadId();
288 int i;
289 LONG my_max = GC_get_max_thread_index();
290
291 for (i = 0; i <= my_max; i++)
292 if (thread_table[i].stack_base != 0 && thread_table[i].suspended
293 && thread_table[i].id != thread_id) {
294 if (ResumeThread(thread_table[i].handle) == (DWORD)-1)
295 ABORT("ResumeThread failed");
296 thread_table[i].suspended = FALSE;
297 }
298 GC_please_stop = FALSE;
299 }
300
301 # ifdef _MSC_VER
302 # pragma warning(disable:4715)
303 # endif
GC_current_stackbottom()304 ptr_t GC_current_stackbottom()
305 {
306 DWORD thread_id = GetCurrentThreadId();
307 int i;
308 LONG my_max = GC_get_max_thread_index();
309
310 for (i = 0; i <= my_max; i++)
311 if (thread_table[i].stack_base && thread_table[i].id == thread_id)
312 return thread_table[i].stack_base;
313 ABORT("no thread table entry for current thread");
314 }
315 # ifdef _MSC_VER
316 # pragma warning(default:4715)
317 # endif
318
319 # ifdef MSWINCE
320 /* The VirtualQuery calls below won't work properly on WinCE, but */
321 /* since each stack is restricted to an aligned 64K region of */
322 /* virtual memory we can just take the next lowest multiple of 64K. */
323 # define GC_get_stack_min(s) \
324 ((ptr_t)(((DWORD)(s) - 1) & 0xFFFF0000))
325 # else
GC_get_stack_min(ptr_t s)326 static ptr_t GC_get_stack_min(ptr_t s)
327 {
328 ptr_t bottom;
329 MEMORY_BASIC_INFORMATION info;
330 VirtualQuery(s, &info, sizeof(info));
331 do {
332 bottom = info.BaseAddress;
333 VirtualQuery(bottom - 1, &info, sizeof(info));
334 } while ((info.Protect & PAGE_READWRITE)
335 && !(info.Protect & PAGE_GUARD));
336 return(bottom);
337 }
338 # endif
339
GC_push_all_stacks()340 void GC_push_all_stacks()
341 {
342 DWORD thread_id = GetCurrentThreadId();
343 GC_bool found_me = FALSE;
344 int i;
345 int dummy;
346 ptr_t sp, stack_min;
347 GC_thread thread;
348 LONG my_max = GC_get_max_thread_index();
349
350 for (i = 0; i <= my_max; i++) {
351 thread = thread_table + i;
352 if (thread -> in_use && thread -> stack_base) {
353 if (thread -> id == thread_id) {
354 sp = (ptr_t) &dummy;
355 found_me = TRUE;
356 } else {
357 CONTEXT context;
358 context.ContextFlags = CONTEXT_INTEGER|CONTEXT_CONTROL;
359 if (!GetThreadContext(thread_table[i].handle, &context))
360 ABORT("GetThreadContext failed");
361
362 /* Push all registers that might point into the heap. Frame */
363 /* pointer registers are included in case client code was */
364 /* compiled with the 'omit frame pointer' optimisation. */
365 # define PUSH1(reg) GC_push_one((word)context.reg)
366 # define PUSH2(r1,r2) PUSH1(r1), PUSH1(r2)
367 # define PUSH4(r1,r2,r3,r4) PUSH2(r1,r2), PUSH2(r3,r4)
368 # if defined(__x86_64__)
369 PUSH4(Rdi,Rsi,Rbx,Rdx), PUSH2(Rcx,Rax), PUSH1(Rbp);
370 PUSH4(R8,R9,R10,R11), PUSH4(R12,R13,R14,R15);
371 sp = (ptr_t)context.Rsp;
372 # elif defined(I386)
373 PUSH4(Edi,Esi,Ebx,Edx), PUSH2(Ecx,Eax), PUSH1(Ebp);
374 sp = (ptr_t)context.Esp;
375 # elif defined(ARM32)
376 PUSH4(R0,R1,R2,R3),PUSH4(R4,R5,R6,R7),PUSH4(R8,R9,R10,R11),PUSH1(R12);
377 sp = (ptr_t)context.Sp;
378 # elif defined(SHx)
379 PUSH4(R0,R1,R2,R3), PUSH4(R4,R5,R6,R7), PUSH4(R8,R9,R10,R11);
380 PUSH2(R12,R13), PUSH1(R14);
381 sp = (ptr_t)context.R15;
382 # elif defined(MIPS)
383 PUSH4(IntAt,IntV0,IntV1,IntA0), PUSH4(IntA1,IntA2,IntA3,IntT0);
384 PUSH4(IntT1,IntT2,IntT3,IntT4), PUSH4(IntT5,IntT6,IntT7,IntS0);
385 PUSH4(IntS1,IntS2,IntS3,IntS4), PUSH4(IntS5,IntS6,IntS7,IntT8);
386 PUSH4(IntT9,IntK0,IntK1,IntS8);
387 sp = (ptr_t)context.IntSp;
388 # elif defined(PPC)
389 PUSH4(Gpr0, Gpr3, Gpr4, Gpr5), PUSH4(Gpr6, Gpr7, Gpr8, Gpr9);
390 PUSH4(Gpr10,Gpr11,Gpr12,Gpr14), PUSH4(Gpr15,Gpr16,Gpr17,Gpr18);
391 PUSH4(Gpr19,Gpr20,Gpr21,Gpr22), PUSH4(Gpr23,Gpr24,Gpr25,Gpr26);
392 PUSH4(Gpr27,Gpr28,Gpr29,Gpr30), PUSH1(Gpr31);
393 sp = (ptr_t)context.Gpr1;
394 # elif defined(ALPHA)
395 PUSH4(IntV0,IntT0,IntT1,IntT2), PUSH4(IntT3,IntT4,IntT5,IntT6);
396 PUSH4(IntT7,IntS0,IntS1,IntS2), PUSH4(IntS3,IntS4,IntS5,IntFp);
397 PUSH4(IntA0,IntA1,IntA2,IntA3), PUSH4(IntA4,IntA5,IntT8,IntT9);
398 PUSH4(IntT10,IntT11,IntT12,IntAt);
399 sp = (ptr_t)context.IntSp;
400 # else
401 # error "architecture is not supported"
402 # endif
403 }
404
405 stack_min = GC_get_stack_min(thread->stack_base);
406
407 if (sp >= stack_min && sp < thread->stack_base)
408 GC_push_all_stack(sp, thread->stack_base);
409 else {
410 WARN("Thread stack pointer 0x%lx out of range, pushing everything\n",
411 (unsigned long)sp);
412 GC_push_all_stack(stack_min, thread->stack_base);
413 }
414 }
415 }
416 if (!found_me) ABORT("Collecting from unknown thread.");
417 }
418
GC_get_next_stack(char * start,char ** lo,char ** hi)419 void GC_get_next_stack(char *start, char **lo, char **hi)
420 {
421 int i;
422 # define ADDR_LIMIT (char *)(-1L)
423 char * current_min = ADDR_LIMIT;
424 LONG my_max = GC_get_max_thread_index();
425
426 for (i = 0; i <= my_max; i++) {
427 char * s = (char *)thread_table[i].stack_base;
428
429 if (0 != s && s > start && s < current_min) {
430 current_min = s;
431 }
432 }
433 *hi = current_min;
434 if (current_min == ADDR_LIMIT) {
435 *lo = ADDR_LIMIT;
436 return;
437 }
438 *lo = GC_get_stack_min(current_min);
439 if (*lo < start) *lo = start;
440 }
441
442 #if !defined(CYGWIN32)
443
444 #if !defined(MSWINCE) && defined(GC_DLL)
445
446 /* We register threads from DllMain */
447
GC_CreateThread(LPSECURITY_ATTRIBUTES lpThreadAttributes,DWORD dwStackSize,LPTHREAD_START_ROUTINE lpStartAddress,LPVOID lpParameter,DWORD dwCreationFlags,LPDWORD lpThreadId)448 GC_API HANDLE WINAPI GC_CreateThread(
449 LPSECURITY_ATTRIBUTES lpThreadAttributes,
450 DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
451 LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId )
452 {
453 return CreateThread(lpThreadAttributes, dwStackSize, lpStartAddress,
454 lpParameter, dwCreationFlags, lpThreadId);
455 }
456
457 #else /* defined(MSWINCE) || !defined(GC_DLL)) */
458
459 /* We have no DllMain to take care of new threads. Thus we */
460 /* must properly intercept thread creation. */
461
462 typedef struct {
463 LPTHREAD_START_ROUTINE start;
464 LPVOID param;
465 } thread_args;
466
467 static DWORD WINAPI thread_start(LPVOID arg);
468
GC_CreateThread(LPSECURITY_ATTRIBUTES lpThreadAttributes,DWORD dwStackSize,LPTHREAD_START_ROUTINE lpStartAddress,LPVOID lpParameter,DWORD dwCreationFlags,LPDWORD lpThreadId)469 GC_API HANDLE WINAPI GC_CreateThread(
470 LPSECURITY_ATTRIBUTES lpThreadAttributes,
471 DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
472 LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId )
473 {
474 HANDLE thread_h = NULL;
475
476 thread_args *args;
477
478 if (!GC_is_initialized) GC_init();
479 /* make sure GC is initialized (i.e. main thread is attached) */
480
481 args = GC_malloc_uncollectable(sizeof(thread_args));
482 /* Handed off to and deallocated by child thread. */
483 if (0 == args) {
484 SetLastError(ERROR_NOT_ENOUGH_MEMORY);
485 return NULL;
486 }
487
488 /* set up thread arguments */
489 args -> start = lpStartAddress;
490 args -> param = lpParameter;
491
492 thread_h = CreateThread(lpThreadAttributes,
493 dwStackSize, thread_start,
494 args, dwCreationFlags,
495 lpThreadId);
496
497 return thread_h;
498 }
499
thread_start(LPVOID arg)500 static DWORD WINAPI thread_start(LPVOID arg)
501 {
502 DWORD ret = 0;
503 thread_args *args = (thread_args *)arg;
504
505 GC_new_thread();
506
507 /* Clear the thread entry even if we exit with an exception. */
508 /* This is probably pointless, since an uncaught exception is */
509 /* supposed to result in the process being killed. */
510 #ifndef __GNUC__
511 __try {
512 #endif /* __GNUC__ */
513 ret = args->start (args->param);
514 #ifndef __GNUC__
515 } __finally {
516 #endif /* __GNUC__ */
517 GC_free(args);
518 GC_delete_thread(GetCurrentThreadId());
519 #ifndef __GNUC__
520 }
521 #endif /* __GNUC__ */
522
523 return ret;
524 }
525 #endif /* !defined(MSWINCE) && !(defined(__MINGW32__) && !defined(_DLL)) */
526
527 #endif /* !CYGWIN32 */
528
529 #ifdef MSWINCE
530
531 typedef struct {
532 HINSTANCE hInstance;
533 HINSTANCE hPrevInstance;
534 LPWSTR lpCmdLine;
535 int nShowCmd;
536 } main_thread_args;
537
538 DWORD WINAPI main_thread_start(LPVOID arg);
539
WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPWSTR lpCmdLine,int nShowCmd)540 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
541 LPWSTR lpCmdLine, int nShowCmd)
542 {
543 DWORD exit_code = 1;
544
545 main_thread_args args = {
546 hInstance, hPrevInstance, lpCmdLine, nShowCmd
547 };
548 HANDLE thread_h;
549 DWORD thread_id;
550
551 /* initialize everything */
552 GC_init();
553
554 /* start the main thread */
555 thread_h = GC_CreateThread(
556 NULL, 0, main_thread_start, &args, 0, &thread_id);
557
558 if (thread_h != NULL)
559 {
560 WaitForSingleObject (thread_h, INFINITE);
561 GetExitCodeThread (thread_h, &exit_code);
562 CloseHandle (thread_h);
563 }
564
565 GC_deinit();
566 DeleteCriticalSection(&GC_allocate_ml);
567
568 return (int) exit_code;
569 }
570
main_thread_start(LPVOID arg)571 DWORD WINAPI main_thread_start(LPVOID arg)
572 {
573 main_thread_args * args = (main_thread_args *) arg;
574
575 return (DWORD) GC_WinMain (args->hInstance, args->hPrevInstance,
576 args->lpCmdLine, args->nShowCmd);
577 }
578
579 # else /* !MSWINCE */
580
581 /* Called by GC_init() - we hold the allocation lock. */
GC_thr_init()582 void GC_thr_init() {
583 if (GC_thr_initialized) return;
584 GC_main_thread = GetCurrentThreadId();
585 GC_thr_initialized = TRUE;
586
587 /* Add the initial thread, so we can stop it. */
588 GC_new_thread();
589 }
590
591 #ifdef CYGWIN32
592
593 struct start_info {
594 void *(*start_routine)(void *);
595 void *arg;
596 GC_bool detached;
597 };
598
GC_pthread_join(pthread_t pthread_id,void ** retval)599 int GC_pthread_join(pthread_t pthread_id, void **retval) {
600 int result;
601 int i;
602 GC_thread me;
603
604 # if DEBUG_CYGWIN_THREADS
605 GC_printf3("thread 0x%x(0x%x) is joining thread 0x%x.\n",
606 (int)pthread_self(), GetCurrentThreadId(), (int)pthread_id);
607 # endif
608
609 /* Thread being joined might not have registered itself yet. */
610 /* After the join,thread id may have been recycled. */
611 /* FIXME: It would be better if this worked more like */
612 /* pthread_support.c. */
613
614 while ((me = GC_lookup_thread(pthread_id)) == 0) Sleep(10);
615
616 result = pthread_join(pthread_id, retval);
617
618 GC_delete_gc_thread(me);
619
620 # if DEBUG_CYGWIN_THREADS
621 GC_printf3("thread 0x%x(0x%x) completed join with thread 0x%x.\n",
622 (int)pthread_self(), GetCurrentThreadId(), (int)pthread_id);
623 # endif
624
625 return result;
626 }
627
628 /* Cygwin-pthreads calls CreateThread internally, but it's not
629 * easily interceptible by us..
630 * so intercept pthread_create instead
631 */
632 int
GC_pthread_create(pthread_t * new_thread,const pthread_attr_t * attr,void * (* start_routine)(void *),void * arg)633 GC_pthread_create(pthread_t *new_thread,
634 const pthread_attr_t *attr,
635 void *(*start_routine)(void *), void *arg) {
636 int result;
637 struct start_info * si;
638
639 if (!GC_is_initialized) GC_init();
640 /* make sure GC is initialized (i.e. main thread is attached) */
641
642 /* This is otherwise saved only in an area mmapped by the thread */
643 /* library, which isn't visible to the collector. */
644 si = GC_malloc_uncollectable(sizeof(struct start_info));
645 if (0 == si) return(EAGAIN);
646
647 si -> start_routine = start_routine;
648 si -> arg = arg;
649 if (attr != 0 &&
650 pthread_attr_getdetachstate(attr, &si->detached)
651 == PTHREAD_CREATE_DETACHED) {
652 si->detached = TRUE;
653 }
654
655 # if DEBUG_CYGWIN_THREADS
656 GC_printf2("About to create a thread from 0x%x(0x%x)\n",
657 (int)pthread_self(), GetCurrentThreadId);
658 # endif
659 result = pthread_create(new_thread, attr, GC_start_routine, si);
660
661 if (result) { /* failure */
662 GC_free(si);
663 }
664
665 return(result);
666 }
667
GC_start_routine(void * arg)668 void * GC_start_routine(void * arg)
669 {
670 struct start_info * si = arg;
671 void * result;
672 void *(*start)(void *);
673 void *start_arg;
674 pthread_t pthread_id;
675 GC_thread me;
676 GC_bool detached;
677 int i;
678
679 # if DEBUG_CYGWIN_THREADS
680 GC_printf2("thread 0x%x(0x%x) starting...\n",(int)pthread_self(),
681 GetCurrentThreadId());
682 # endif
683
684 /* If a GC occurs before the thread is registered, that GC will */
685 /* ignore this thread. That's fine, since it will block trying to */
686 /* acquire the allocation lock, and won't yet hold interesting */
687 /* pointers. */
688 LOCK();
689 /* We register the thread here instead of in the parent, so that */
690 /* we don't need to hold the allocation lock during pthread_create. */
691 me = GC_new_thread();
692 UNLOCK();
693
694 start = si -> start_routine;
695 start_arg = si -> arg;
696 if (si-> detached) me -> flags |= DETACHED;
697 me -> pthread_id = pthread_id = pthread_self();
698
699 GC_free(si); /* was allocated uncollectable */
700
701 pthread_cleanup_push(GC_thread_exit_proc, (void *)me);
702 result = (*start)(start_arg);
703 me -> status = result;
704 pthread_cleanup_pop(0);
705
706 # if DEBUG_CYGWIN_THREADS
707 GC_printf2("thread 0x%x(0x%x) returned from start routine.\n",
708 (int)pthread_self(),GetCurrentThreadId());
709 # endif
710
711 return(result);
712 }
713
GC_thread_exit_proc(void * arg)714 void GC_thread_exit_proc(void *arg)
715 {
716 GC_thread me = (GC_thread)arg;
717 int i;
718
719 # if DEBUG_CYGWIN_THREADS
720 GC_printf2("thread 0x%x(0x%x) called pthread_exit().\n",
721 (int)pthread_self(),GetCurrentThreadId());
722 # endif
723
724 LOCK();
725 if (me -> flags & DETACHED) {
726 GC_delete_thread(GetCurrentThreadId());
727 } else {
728 /* deallocate it as part of join */
729 me -> flags |= FINISHED;
730 }
731 UNLOCK();
732 }
733
734 /* nothing required here... */
GC_pthread_sigmask(int how,const sigset_t * set,sigset_t * oset)735 int GC_pthread_sigmask(int how, const sigset_t *set, sigset_t *oset) {
736 return pthread_sigmask(how, set, oset);
737 }
738
GC_pthread_detach(pthread_t thread)739 int GC_pthread_detach(pthread_t thread)
740 {
741 int result;
742 GC_thread thread_gc_id;
743
744 LOCK();
745 thread_gc_id = GC_lookup_thread(thread);
746 UNLOCK();
747 result = pthread_detach(thread);
748 if (result == 0) {
749 LOCK();
750 thread_gc_id -> flags |= DETACHED;
751 /* Here the pthread thread id may have been recycled. */
752 if (thread_gc_id -> flags & FINISHED) {
753 GC_delete_gc_thread(thread_gc_id);
754 }
755 UNLOCK();
756 }
757 return result;
758 }
759
GC_get_thread_stack_base()760 GC_PTR GC_get_thread_stack_base()
761 {
762 #ifdef __x86_64__
763 return ((NT_TIB*)NtCurrentTeb())->StackBase;
764 #else
765 extern GC_PTR _tlsbase __asm__ ("%fs:4");
766 return _tlsbase;
767 #endif
768 }
769
770 #else /* !CYGWIN32 */
771
772 /*
773 * We avoid acquiring locks here, since this doesn't seem to be preemptable.
774 * Pontus Rydin suggests wrapping the thread start routine instead.
775 */
776 #ifdef GC_DLL
DllMain(HINSTANCE inst,ULONG reason,LPVOID reserved)777 BOOL WINAPI DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved)
778 {
779 switch (reason) {
780 case DLL_PROCESS_ATTACH:
781 GC_init(); /* Force initialization before thread attach. */
782 /* fall through */
783 case DLL_THREAD_ATTACH:
784 GC_ASSERT(GC_thr_initialized);
785 if (GC_main_thread != GetCurrentThreadId()) {
786 GC_new_thread();
787 } /* o.w. we already did it during GC_thr_init(), called by GC_init() */
788 break;
789
790 case DLL_THREAD_DETACH:
791 GC_delete_thread(GetCurrentThreadId());
792 break;
793
794 case DLL_PROCESS_DETACH:
795 {
796 int i;
797
798 LOCK();
799 for (i = 0; i <= GC_get_max_thread_index(); ++i)
800 {
801 if (thread_table[i].in_use)
802 GC_delete_gc_thread(thread_table + i);
803 }
804 UNLOCK();
805
806 GC_deinit();
807 DeleteCriticalSection(&GC_allocate_ml);
808 }
809 break;
810
811 }
812 return TRUE;
813 }
814 #endif /* GC_DLL */
815 #endif /* !CYGWIN32 */
816
817 # endif /* !MSWINCE */
818
819 #endif /* GC_WIN32_THREADS */
820