Annotation of OpenXM_contrib2/asir2000/gc5.3/win32_threads.c, Revision 1.1
1.1 ! noro 1: #ifdef WIN32_THREADS
! 2:
! 3: #include "gc_priv.h"
! 4:
! 5: #if 0
! 6: #define STRICT
! 7: #include <windows.h>
! 8: #endif
! 9:
! 10: #define MAX_THREADS 64
! 11:
! 12: struct thread_entry {
! 13: LONG in_use;
! 14: DWORD id;
! 15: HANDLE handle;
! 16: void *stack; /* The cold end of the stack. */
! 17: /* 0 ==> entry not valid. */
! 18: /* !in_use ==> stack == 0 */
! 19: CONTEXT context;
! 20: GC_bool suspended;
! 21: };
! 22:
! 23: volatile GC_bool GC_please_stop = FALSE;
! 24:
! 25: volatile struct thread_entry thread_table[MAX_THREADS];
! 26:
! 27: void GC_stop_world()
! 28: {
! 29: DWORD thread_id = GetCurrentThreadId();
! 30: int i;
! 31:
! 32: GC_please_stop = TRUE;
! 33: for (i = 0; i < MAX_THREADS; i++)
! 34: if (thread_table[i].stack != 0
! 35: && thread_table[i].id != thread_id) {
! 36: /* Apparently the Windows 95 GetOpenFileName call creates */
! 37: /* a thread that does not properly get cleaned up, and */
! 38: /* SuspendThread on its descriptor may provoke a crash. */
! 39: /* This reduces the probability of that event, though it still */
! 40: /* appears there's a race here. */
! 41: DWORD exitCode;
! 42: if (GetExitCodeThread(thread_table[i].handle,&exitCode) &&
! 43: exitCode != STILL_ACTIVE) {
! 44: thread_table[i].stack = 0;
! 45: thread_table[i].in_use = FALSE;
! 46: CloseHandle(thread_table[i].handle);
! 47: BZERO(&thread_table[i].context, sizeof(CONTEXT));
! 48: continue;
! 49: }
! 50: if (SuspendThread(thread_table[i].handle) == (DWORD)-1)
! 51: ABORT("SuspendThread failed");
! 52: thread_table[i].suspended = TRUE;
! 53: }
! 54: }
! 55:
! 56: void GC_start_world()
! 57: {
! 58: DWORD thread_id = GetCurrentThreadId();
! 59: int i;
! 60: for (i = 0; i < MAX_THREADS; i++)
! 61: if (thread_table[i].stack != 0 && thread_table[i].suspended
! 62: && thread_table[i].id != thread_id) {
! 63: if (ResumeThread(thread_table[i].handle) == (DWORD)-1)
! 64: ABORT("ResumeThread failed");
! 65: thread_table[i].suspended = FALSE;
! 66: }
! 67: GC_please_stop = FALSE;
! 68: }
! 69:
! 70: ptr_t GC_current_stackbottom()
! 71: {
! 72: DWORD thread_id = GetCurrentThreadId();
! 73: int i;
! 74: for (i = 0; i < MAX_THREADS; i++)
! 75: if (thread_table[i].stack && thread_table[i].id == thread_id)
! 76: return thread_table[i].stack;
! 77: ABORT("no thread table entry for current thread");
! 78: }
! 79:
! 80: static ptr_t GC_get_lo_stack_addr(ptr_t s)
! 81: {
! 82: ptr_t bottom;
! 83: MEMORY_BASIC_INFORMATION info;
! 84: VirtualQuery(s, &info, sizeof(info));
! 85: do {
! 86: bottom = info.BaseAddress;
! 87: VirtualQuery(bottom - 1, &info, sizeof(info));
! 88: } while ((info.Protect & PAGE_READWRITE) && !(info.Protect & PAGE_GUARD));
! 89: return(bottom);
! 90: }
! 91:
! 92: void GC_push_all_stacks()
! 93: {
! 94: DWORD thread_id = GetCurrentThreadId();
! 95: int i;
! 96: for (i = 0; i < MAX_THREADS; i++)
! 97: if (thread_table[i].stack) {
! 98: ptr_t bottom = GC_get_lo_stack_addr(thread_table[i].stack);
! 99: if (thread_table[i].id == thread_id)
! 100: GC_push_all_stack(&i, thread_table[i].stack);
! 101: else {
! 102: thread_table[i].context.ContextFlags
! 103: = (CONTEXT_INTEGER|CONTEXT_CONTROL);
! 104: if (!GetThreadContext(thread_table[i].handle,
! 105: &thread_table[i].context))
! 106: ABORT("GetThreadContext failed");
! 107: if (thread_table[i].context.Esp >= (DWORD)thread_table[i].stack
! 108: || thread_table[i].context.Esp < (DWORD)bottom)
! 109: ABORT("Thread stack pointer out of range");
! 110: GC_push_one ((word) thread_table[i].context.Edi);
! 111: GC_push_one ((word) thread_table[i].context.Esi);
! 112: GC_push_one ((word) thread_table[i].context.Ebx);
! 113: GC_push_one ((word) thread_table[i].context.Edx);
! 114: GC_push_one ((word) thread_table[i].context.Ecx);
! 115: GC_push_one ((word) thread_table[i].context.Eax);
! 116: GC_push_all_stack(thread_table[i].context.Esp, thread_table[i].stack);
! 117: }
! 118: }
! 119: }
! 120:
! 121: void GC_get_next_stack(char *start, char **lo, char **hi)
! 122: {
! 123: int i;
! 124: # define ADDR_LIMIT (char *)(-1L)
! 125: char * current_min = ADDR_LIMIT;
! 126:
! 127: for (i = 0; i < MAX_THREADS; i++) {
! 128: char * s = (char *)thread_table[i].stack;
! 129:
! 130: if (0 != s && s > start && s < current_min) {
! 131: current_min = s;
! 132: }
! 133: }
! 134: *hi = current_min;
! 135: if (current_min == ADDR_LIMIT) {
! 136: *lo = ADDR_LIMIT;
! 137: return;
! 138: }
! 139: *lo = GC_get_lo_stack_addr(current_min);
! 140: if (*lo < start) *lo = start;
! 141: }
! 142:
! 143: LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info);
! 144:
! 145: /*
! 146: * This isn't generally safe, since DllMain is not premptible.
! 147: * If another thread holds the lock while this runs we're in trouble.
! 148: * Pontus Rydin suggests wrapping the thread start routine instead.
! 149: */
! 150: BOOL WINAPI DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved)
! 151: {
! 152: switch (reason) {
! 153: case DLL_PROCESS_ATTACH:
! 154: InitializeCriticalSection(&GC_allocate_ml);
! 155: GC_init(); /* Force initialization before thread attach. */
! 156: /* fall through */
! 157: case DLL_THREAD_ATTACH:
! 158: {
! 159: int i;
! 160: /* It appears to be unsafe to acquire a lock here, since this */
! 161: /* code is apparently not preeemptible on some systems. */
! 162: /* (This is based on complaints, not on Microsoft's official */
! 163: /* documentation, which says this should perform "only simple */
! 164: /* inititalization tasks".) */
! 165: /* Hence we make do with nonblocking synchronization. */
! 166:
! 167: /* The following should be a noop according to the win32 */
! 168: /* documentation. There is empirical evidence that it */
! 169: /* isn't. - HB */
! 170: # ifndef SMALL_CONFIG
! 171: if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler);
! 172: # endif
! 173:
! 174: for (i = 0; InterlockedExchange(&thread_table[i].in_use,1) != 0; i++) {
! 175: /* Compare-and-swap would make this cleaner, but that's not */
! 176: /* supported before Windows 98 and NT 4.0. In Windows 2000, */
! 177: /* InterlockedExchange is supposed to be replaced by */
! 178: /* InterlockedExchangePointer, but that's not really what I */
! 179: /* want here. */
! 180: if (i == MAX_THREADS - 1)
! 181: ABORT("too many threads");
! 182: }
! 183: thread_table[i].id = GetCurrentThreadId();
! 184: if (!DuplicateHandle(GetCurrentProcess(),
! 185: GetCurrentThread(),
! 186: GetCurrentProcess(),
! 187: &thread_table[i].handle,
! 188: 0,
! 189: 0,
! 190: DUPLICATE_SAME_ACCESS)) {
! 191: DWORD last_error = GetLastError();
! 192: GC_printf1("Last error code: %lx\n", last_error);
! 193: ABORT("DuplicateHandle failed");
! 194: }
! 195: thread_table[i].stack = GC_get_stack_base();
! 196: /* If this thread is being created while we are trying to stop */
! 197: /* the world, wait here. Hopefully this can't happen on any */
! 198: /* systems that don't allow us to block here. */
! 199: while (GC_please_stop) Sleep(20);
! 200: }
! 201: break;
! 202: case DLL_PROCESS_DETACH:
! 203: case DLL_THREAD_DETACH:
! 204: {
! 205: int i;
! 206: DWORD thread_id = GetCurrentThreadId();
! 207: LOCK();
! 208: for (i = 0;
! 209: thread_table[i].stack == 0 || thread_table[i].id != thread_id;
! 210: i++) {
! 211: if (i == MAX_THREADS - 1)
! 212: ABORT("thread not found on detach");
! 213: }
! 214: thread_table[i].stack = 0;
! 215: thread_table[i].in_use = FALSE;
! 216: CloseHandle(thread_table[i].handle);
! 217: BZERO(&thread_table[i].context, sizeof(CONTEXT));
! 218: UNLOCK();
! 219: }
! 220: break;
! 221: }
! 222: return TRUE;
! 223: }
! 224:
! 225: #endif /* WIN32_THREADS */
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