Annotation of OpenXM_contrib/gc/win32_threads.c, Revision 1.1.1.1
1.1 maekawa 1: #ifdef WIN32_THREADS
2:
3: #include "gc_priv.h"
4:
5: #define STRICT
6: #include <windows.h>
7:
8: #define MAX_THREADS 64
9:
10: struct thread_entry {
11: LONG in_use;
12: DWORD id;
13: HANDLE handle;
14: void *stack; /* The cold end of the stack. */
15: /* 0 ==> entry not valid. */
16: /* !in_use ==> stack == 0 */
17: CONTEXT context;
18: GC_bool suspended;
19: };
20:
21: volatile GC_bool GC_please_stop = FALSE;
22:
23: volatile struct thread_entry thread_table[MAX_THREADS];
24:
25: void GC_stop_world()
26: {
27: DWORD thread_id = GetCurrentThreadId();
28: int i;
29:
30: GC_please_stop = TRUE;
31: for (i = 0; i < MAX_THREADS; i++)
32: if (thread_table[i].stack != 0
33: && thread_table[i].id != thread_id) {
34: if (SuspendThread(thread_table[i].handle) == (DWORD)-1)
35: ABORT("SuspendThread failed");
36: thread_table[i].suspended = TRUE;
37: }
38: }
39:
40: void GC_start_world()
41: {
42: DWORD thread_id = GetCurrentThreadId();
43: int i;
44: for (i = 0; i < MAX_THREADS; i++)
45: if (thread_table[i].stack != 0 && thread_table[i].suspended
46: && thread_table[i].id != thread_id) {
47: if (ResumeThread(thread_table[i].handle) == (DWORD)-1)
48: ABORT("ResumeThread failed");
49: thread_table[i].suspended = FALSE;
50: }
51: GC_please_stop = FALSE;
52: }
53:
54: ptr_t GC_current_stackbottom()
55: {
56: DWORD thread_id = GetCurrentThreadId();
57: int i;
58: for (i = 0; i < MAX_THREADS; i++)
59: if (thread_table[i].stack && thread_table[i].id == thread_id)
60: return thread_table[i].stack;
61: ABORT("no thread table entry for current thread");
62: }
63:
64: ptr_t GC_get_lo_stack_addr(ptr_t s)
65: {
66: ptr_t bottom;
67: MEMORY_BASIC_INFORMATION info;
68: VirtualQuery(s, &info, sizeof(info));
69: do {
70: bottom = info.BaseAddress;
71: VirtualQuery(bottom - 1, &info, sizeof(info));
72: } while ((info.Protect & PAGE_READWRITE) && !(info.Protect & PAGE_GUARD));
73: return(bottom);
74: }
75:
76: void GC_push_all_stacks()
77: {
78: DWORD thread_id = GetCurrentThreadId();
79: int i;
80: for (i = 0; i < MAX_THREADS; i++)
81: if (thread_table[i].stack) {
82: ptr_t bottom = GC_get_lo_stack_addr(thread_table[i].stack);
83: if (thread_table[i].id == thread_id)
84: GC_push_all(&i, thread_table[i].stack);
85: else {
86: thread_table[i].context.ContextFlags
87: = (CONTEXT_INTEGER|CONTEXT_CONTROL);
88: if (!GetThreadContext(thread_table[i].handle,
89: &thread_table[i].context))
90: ABORT("GetThreadContext failed");
91: if (thread_table[i].context.Esp >= (DWORD)thread_table[i].stack
92: || thread_table[i].context.Esp < (DWORD)bottom)
93: ABORT("Thread stack pointer out of range");
94: GC_push_one ((word) thread_table[i].context.Edi);
95: GC_push_one ((word) thread_table[i].context.Esi);
96: GC_push_one ((word) thread_table[i].context.Ebx);
97: GC_push_one ((word) thread_table[i].context.Edx);
98: GC_push_one ((word) thread_table[i].context.Ecx);
99: GC_push_one ((word) thread_table[i].context.Eax);
100: GC_push_all_stack(thread_table[i].context.Esp, thread_table[i].stack);
101: }
102: }
103: }
104:
105: void GC_get_next_stack(char *start, char **lo, char **hi)
106: {
107: int i;
108: # define ADDR_LIMIT (char *)(-1L)
109: char * current_min = ADDR_LIMIT;
110:
111: for (i = 0; i < MAX_THREADS; i++) {
112: char * s = (char *)thread_table[i].stack;
113:
114: if (0 != s && s > start && s < current_min) {
115: current_min = s;
116: }
117: }
118: *hi = current_min;
119: if (current_min == ADDR_LIMIT) {
120: *lo = ADDR_LIMIT;
121: return;
122: }
123: *lo = GC_get_lo_stack_addr(current_min);
124: if (*lo < start) *lo = start;
125: }
126:
127: LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info);
128:
129: /*
130: * This isn't generally safe, since DllMain is not premptible.
131: * If another thread holds the lock while this runs we're in trouble.
132: * Pontus Rydin suggests wrapping the thread start routine instead.
133: */
134: BOOL WINAPI DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved)
135: {
136: switch (reason) {
137: case DLL_PROCESS_ATTACH:
138: InitializeCriticalSection(&GC_allocate_ml);
139: GC_init(); /* Force initialization before thread attach. */
140: /* fall through */
141: case DLL_THREAD_ATTACH:
142: {
143: int i;
144: /* It appears to be unsafe to acquire a lock here, since this */
145: /* code is apparently not preeemptible on some systems. */
146: /* (This is based on complaints, not on Microsoft's official */
147: /* documentation, which says this should perform "only simple */
148: /* inititalization tasks".) */
149: /* Hence we make do with nonblocking synchronization. */
150:
151: /* The following should be a noop according to the win32 */
152: /* documentation. There is empirical evidence that it */
153: /* isn't. - HB */
154: # ifndef SMALL_CONFIG
155: if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler);
156: # endif
157:
158: for (i = 0; InterlockedExchange(&thread_table[i].in_use,1) != 0; i++) {
159: /* Compare-and-swap would make this cleaner, but that's not */
160: /* supported before Windows 98 and NT 4.0. In Windows 2000, */
161: /* InterlockedExchange is supposed to be replaced by */
162: /* InterlockedExchangePointer, but that's not really what I */
163: /* want here. */
164: if (i == MAX_THREADS - 1)
165: ABORT("too many threads");
166: }
167: thread_table[i].id = GetCurrentThreadId();
168: if (!DuplicateHandle(GetCurrentProcess(),
169: GetCurrentThread(),
170: GetCurrentProcess(),
171: &thread_table[i].handle,
172: 0,
173: 0,
174: DUPLICATE_SAME_ACCESS)) {
175: DWORD last_error = GetLastError();
176: GC_printf1("Last error code: %lx\n", last_error);
177: ABORT("DuplicateHandle failed");
178: }
179: thread_table[i].stack = GC_get_stack_base();
180: /* If this thread is being created while we are trying to stop */
181: /* the world, wait here. Hopefully this can't happen on any */
182: /* systems that don't allow us to block here. */
183: while (GC_please_stop) Sleep(20);
184: }
185: break;
186: case DLL_PROCESS_DETACH:
187: case DLL_THREAD_DETACH:
188: {
189: int i;
190: DWORD thread_id = GetCurrentThreadId();
191: LOCK();
192: for (i = 0;
193: thread_table[i].stack == 0 || thread_table[i].id != thread_id;
194: i++) {
195: if (i == MAX_THREADS - 1)
196: ABORT("thread not found on detach");
197: }
198: thread_table[i].stack = 0;
199: thread_table[i].in_use = FALSE;
200: CloseHandle(thread_table[i].handle);
201: BZERO(&thread_table[i].context, sizeof(CONTEXT));
202: UNLOCK();
203: }
204: break;
205: }
206: return TRUE;
207: }
208:
209: #endif /* WIN32_THREADS */
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