diff options
Diffstat (limited to 'boehm-gc/win32_threads.c')
-rw-r--r-- | boehm-gc/win32_threads.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/boehm-gc/win32_threads.c b/boehm-gc/win32_threads.c new file mode 100644 index 0000000..eb485bd --- /dev/null +++ b/boehm-gc/win32_threads.c @@ -0,0 +1,168 @@ +#ifdef WIN32_THREADS + +#include "gc_priv.h" + +#define STRICT +#include <windows.h> + +#define MAX_THREADS 64 + +struct thread_entry { + DWORD id; + HANDLE handle; + void *stack; /* The cold end of the stack. */ + CONTEXT context; +}; + +struct thread_entry thread_table[MAX_THREADS]; + +void GC_stop_world() +{ + DWORD thread_id = GetCurrentThreadId(); + int i; + 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"); + } +} + +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].id != thread_id) { + if (ResumeThread(thread_table[i].handle) == (DWORD)-1) + ABORT("ResumeThread failed"); + } +} + +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_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); + /* fall through */ + case DLL_THREAD_ATTACH: + { + int i; + LOCK(); + /* The following should be a noop according to the win32 */ + /* documentation. There is empirical evidence that it */ + /* isn't. - HB */ + if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler); + for (i = 0; thread_table[i].stack != 0; i++) { + if (i == MAX_THREADS - 1) + ABORT("too many threads"); + } + thread_table[i].stack = GC_get_stack_base(); + 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"); + } + UNLOCK(); + } + 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; + CloseHandle(thread_table[i].handle); + BZERO(&thread_table[i].context, sizeof(CONTEXT)); + UNLOCK(); + } + break; + } + return TRUE; +} + +#endif /* WIN32_THREADS */ |