diff options
Diffstat (limited to 'gc/win32_threads.c')
| -rwxr-xr-x | gc/win32_threads.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/gc/win32_threads.c b/gc/win32_threads.c new file mode 100755 index 0000000..f6f74bd --- /dev/null +++ b/gc/win32_threads.c @@ -0,0 +1,209 @@ +#ifdef WIN32_THREADS + +#include "gc_priv.h" + +#define STRICT +#include <windows.h> + +#define MAX_THREADS 64 + +struct thread_entry { + LONG in_use; + DWORD id; + HANDLE handle; + void *stack; /* The cold end of the stack. */ + /* 0 ==> entry not valid. */ + /* !in_use ==> stack == 0 */ + CONTEXT context; + GC_bool suspended; +}; + +volatile GC_bool GC_please_stop = FALSE; + +volatile struct thread_entry thread_table[MAX_THREADS]; + +void GC_stop_world() +{ + DWORD thread_id = GetCurrentThreadId(); + int i; + + GC_please_stop = TRUE; + for (i = 0; i < MAX_THREADS; i++) + if (thread_table[i].stack != 0 + && thread_table[i].id != thread_id) { + if (SuspendThread(thread_table[i].handle) == (DWORD)-1) + ABORT("SuspendThread failed"); + thread_table[i].suspended = TRUE; + } +} + +void GC_start_world() +{ + DWORD thread_id = GetCurrentThreadId(); + int i; + for (i = 0; i < MAX_THREADS; i++) + if (thread_table[i].stack != 0 && thread_table[i].suspended + && thread_table[i].id != thread_id) { + if (ResumeThread(thread_table[i].handle) == (DWORD)-1) + ABORT("ResumeThread failed"); + thread_table[i].suspended = FALSE; + } + GC_please_stop = FALSE; +} + +ptr_t GC_current_stackbottom() +{ + DWORD thread_id = GetCurrentThreadId(); + int i; + for (i = 0; i < MAX_THREADS; i++) + if (thread_table[i].stack && thread_table[i].id == thread_id) + return thread_table[i].stack; + ABORT("no thread table entry for current thread"); +} + +ptr_t GC_get_lo_stack_addr(ptr_t s) +{ + ptr_t bottom; + MEMORY_BASIC_INFORMATION info; + VirtualQuery(s, &info, sizeof(info)); + do { + bottom = info.BaseAddress; + VirtualQuery(bottom - 1, &info, sizeof(info)); + } while ((info.Protect & PAGE_READWRITE) && !(info.Protect & PAGE_GUARD)); + return(bottom); +} + +void GC_push_all_stacks() +{ + DWORD thread_id = GetCurrentThreadId(); + int i; + for (i = 0; i < MAX_THREADS; i++) + if (thread_table[i].stack) { + ptr_t bottom = GC_get_lo_stack_addr(thread_table[i].stack); + if (thread_table[i].id == thread_id) + GC_push_all(&i, thread_table[i].stack); + else { + thread_table[i].context.ContextFlags + = (CONTEXT_INTEGER|CONTEXT_CONTROL); + if (!GetThreadContext(thread_table[i].handle, + &thread_table[i].context)) + ABORT("GetThreadContext failed"); + if (thread_table[i].context.Esp >= (DWORD)thread_table[i].stack + || thread_table[i].context.Esp < (DWORD)bottom) + ABORT("Thread stack pointer out of range"); + GC_push_one ((word) thread_table[i].context.Edi); + GC_push_one ((word) thread_table[i].context.Esi); + GC_push_one ((word) thread_table[i].context.Ebx); + GC_push_one ((word) thread_table[i].context.Edx); + GC_push_one ((word) thread_table[i].context.Ecx); + GC_push_one ((word) thread_table[i].context.Eax); + GC_push_all_stack(thread_table[i].context.Esp, thread_table[i].stack); + } + } +} + +void GC_get_next_stack(char *start, char **lo, char **hi) +{ + int i; +# define ADDR_LIMIT (char *)(-1L) + char * current_min = ADDR_LIMIT; + + for (i = 0; i < MAX_THREADS; i++) { + char * s = (char *)thread_table[i].stack; + + if (0 != s && s > start && s < current_min) { + current_min = s; + } + } + *hi = current_min; + if (current_min == ADDR_LIMIT) { + *lo = ADDR_LIMIT; + return; + } + *lo = GC_get_lo_stack_addr(current_min); + if (*lo < start) *lo = start; +} + +LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info); + +/* + * This isn't generally safe, since DllMain is not premptible. + * If another thread holds the lock while this runs we're in trouble. + * Pontus Rydin suggests wrapping the thread start routine instead. + */ +BOOL WINAPI DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved) +{ + switch (reason) { + case DLL_PROCESS_ATTACH: + InitializeCriticalSection(&GC_allocate_ml); + GC_init(); /* Force initialization before thread attach. */ + /* fall through */ + case DLL_THREAD_ATTACH: + { + int i; + /* It appears to be unsafe to acquire a lock here, since this */ + /* code is apparently not preeemptible on some systems. */ + /* (This is based on complaints, not on Microsoft's official */ + /* documentation, which says this should perform "only simple */ + /* inititalization tasks".) */ + /* Hence we make do with nonblocking synchronization. */ + + /* The following should be a noop according to the win32 */ + /* documentation. There is empirical evidence that it */ + /* isn't. - HB */ +# ifndef SMALL_CONFIG + if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler); +# endif + + for (i = 0; InterlockedExchange(&thread_table[i].in_use,1) != 0; i++) { + /* Compare-and-swap would make this cleaner, but that's not */ + /* supported before Windows 98 and NT 4.0. In Windows 2000, */ + /* InterlockedExchange is supposed to be replaced by */ + /* InterlockedExchangePointer, but that's not really what I */ + /* want here. */ + if (i == MAX_THREADS - 1) + ABORT("too many threads"); + } + thread_table[i].id = GetCurrentThreadId(); + if (!DuplicateHandle(GetCurrentProcess(), + GetCurrentThread(), + GetCurrentProcess(), + &thread_table[i].handle, + 0, + 0, + DUPLICATE_SAME_ACCESS)) { + DWORD last_error = GetLastError(); + GC_printf1("Last error code: %lx\n", last_error); + ABORT("DuplicateHandle failed"); + } + thread_table[i].stack = GC_get_stack_base(); + /* If this thread is being created while we are trying to stop */ + /* the world, wait here. Hopefully this can't happen on any */ + /* systems that don't allow us to block here. */ + while (GC_please_stop) Sleep(20); + } + break; + case DLL_PROCESS_DETACH: + case DLL_THREAD_DETACH: + { + int i; + DWORD thread_id = GetCurrentThreadId(); + LOCK(); + for (i = 0; + thread_table[i].stack == 0 || thread_table[i].id != thread_id; + i++) { + if (i == MAX_THREADS - 1) + ABORT("thread not found on detach"); + } + thread_table[i].stack = 0; + thread_table[i].in_use = FALSE; + CloseHandle(thread_table[i].handle); + BZERO(&thread_table[i].context, sizeof(CONTEXT)); + UNLOCK(); + } + break; + } + return TRUE; +} + +#endif /* WIN32_THREADS */ |