Annotation of OpenXM_contrib2/asir2000/gc/win32_threads.c, Revision 1.2
1.1 noro 1: #ifdef WIN32_THREADS
2:
3: #include "gc_priv.h"
4:
1.2 ! noro 5: #if 0
1.1 noro 6: #define STRICT
7: #include <windows.h>
1.2 ! noro 8: #endif
1.1 noro 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) {
1.2 ! noro 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: }
1.1 noro 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:
1.2 ! noro 80: static ptr_t GC_get_lo_stack_addr(ptr_t s)
1.1 noro 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)
1.2 ! noro 100: GC_push_all_stack(&i, thread_table[i].stack);
1.1 noro 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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