diff options
Diffstat (limited to 'kit/threads.win32.c')
| -rw-r--r-- | kit/threads.win32.c | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/kit/threads.win32.c b/kit/threads.win32.c new file mode 100644 index 0000000..ac185f7 --- /dev/null +++ b/kit/threads.win32.c @@ -0,0 +1,342 @@ +#include "threads.h" + +#ifndef KIT_DISABLE_SYSTEM_THREADS +# include "allocator.h" + +# if defined(_WIN32) && !defined(__CYGWIN__) +# include <assert.h> +# include <errno.h> +# include <limits.h> +# include <process.h> +# include <stdlib.h> + +# ifndef WIN32_LEAN_AND_MEAN +# define WIN32_LEAN_AND_MEAN 1 +# endif +# ifndef NOMINMAX +# define NOMINMAX +# endif +# include <windows.h> + +/* +Configuration macro: + + EMULATED_THREADS_USE_NATIVE_CALL_ONCE + Use native WindowsAPI one-time initialization function. + (requires WinVista or later) + Otherwise emulate by mtx_trylock() + *busy loop* for WinXP. +*/ + +# if _WIN32_WINNT >= 0x0600 +/* Prefer native WindowsAPI on newer environment. */ +# if !defined(__MINGW32__) +# define EMULATED_THREADS_USE_NATIVE_CALL_ONCE +# endif +# endif + +/* check configuration */ +# if defined(EMULATED_THREADS_USE_NATIVE_CALL_ONCE) && \ + (_WIN32_WINNT < 0x0600) +# error EMULATED_THREADS_USE_NATIVE_CALL_ONCE requires _WIN32_WINNT>=0x0600 +# endif + +static_assert(sizeof(cnd_t) == sizeof(CONDITION_VARIABLE), + "The size of cnd_t must equal to CONDITION_VARIABLE"); +static_assert(sizeof(thrd_t) == sizeof(HANDLE), + "The size of thrd_t must equal to HANDLE"); +static_assert(sizeof(mtx_t) == sizeof(CRITICAL_SECTION), + "The size of mtx_t must equal to CRITICAL_SECTION"); +static_assert(sizeof(once_flag) == sizeof(INIT_ONCE), + "The size of once_flag must equal to INIT_ONCE"); + +/* +Implementation limits: + - Conditionally emulation for "Initialization functions" + (see EMULATED_THREADS_USE_NATIVE_CALL_ONCE macro) + - Emulated `mtx_timelock()' with mtx_trylock() + *busy loop* +*/ + +typedef struct { + thrd_start_t func; + void *arg; + thrd_t thrd; +} impl_thrd_param_t; + +struct thrd_state { + thrd_t thrd; + int handle_need_close; +}; + +static thread_local struct thrd_state impl_current_thread = { 0 }; + +static unsigned __stdcall impl_thrd_routine(void *p) { + impl_thrd_param_t *pack_p = (impl_thrd_param_t *) p; + impl_thrd_param_t pack; + int code; + impl_current_thread.thrd = pack_p->thrd; + impl_current_thread.handle_need_close = 0; + memcpy(&pack, pack_p, sizeof(impl_thrd_param_t)); + kit_alloc_dispatch(NULL, KIT_DEALLOCATE, 0, 0, p); + code = pack.func(pack.arg); + return (unsigned) code; +} + +static time_t impl_timespec2msec(const struct timespec *ts) { + return (ts->tv_sec * 1000U) + (ts->tv_nsec / 1000000L); +} + +static DWORD impl_abs2relmsec(const struct timespec *abs_time) { + const time_t abs_ms = impl_timespec2msec(abs_time); + struct timespec now; + timespec_get(&now, TIME_UTC); + const time_t now_ms = impl_timespec2msec(&now); + const DWORD rel_ms = (abs_ms > now_ms) ? (DWORD) (abs_ms - now_ms) + : 0; + return rel_ms; +} + +# ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE +struct impl_call_once_param { + void (*func)(void); +}; + +static BOOL CALLBACK impl_call_once_callback(PINIT_ONCE InitOnce, + PVOID Parameter, + PVOID *Context) { + struct impl_call_once_param *param = (struct impl_call_once_param *) + Parameter; + (param->func)(); + ((void) InitOnce); + ((void) Context); /* suppress warning */ + return TRUE; +} +# endif /* ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE */ + +void call_once(once_flag *flag, void (*func)(void)) { + assert(flag && func); +# ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE + { + struct impl_call_once_param param; + param.func = func; + InitOnceExecuteOnce((PINIT_ONCE) flag, impl_call_once_callback, + (PVOID) ¶m, NULL); + } +# else + if (InterlockedCompareExchangePointer( + (PVOID volatile *) &flag->status, (PVOID) 1, (PVOID) 0) == + 0) { + (func)(); + InterlockedExchangePointer((PVOID volatile *) &flag->status, + (PVOID) 2); + } else { + while (flag->status == 1) { + // busy loop! + thrd_yield(); + } + } +# endif +} + +int cnd_broadcast(cnd_t *cond) { + assert(cond != NULL); + WakeAllConditionVariable((PCONDITION_VARIABLE) cond); + return thrd_success; +} + +void cnd_destroy(cnd_t *cond) { + assert(cond != NULL); + /* do nothing */ + (void) cond; +} + +int cnd_init(cnd_t *cond) { + assert(cond != NULL); + InitializeConditionVariable((PCONDITION_VARIABLE) cond); + return thrd_success; +} + +int cnd_signal(cnd_t *cond) { + assert(cond != NULL); + WakeConditionVariable((PCONDITION_VARIABLE) cond); + return thrd_success; +} + +int cnd_timedwait(cnd_t *cond, mtx_t *mtx, + const struct timespec *abs_time) { + assert(cond != NULL); + assert(mtx != NULL); + assert(abs_time != NULL); + const DWORD timeout = impl_abs2relmsec(abs_time); + if (SleepConditionVariableCS((PCONDITION_VARIABLE) cond, + (PCRITICAL_SECTION) mtx, timeout)) + return thrd_success; + return (GetLastError() == ERROR_TIMEOUT) ? thrd_timedout + : thrd_error; +} + +int cnd_wait(cnd_t *cond, mtx_t *mtx) { + assert(cond != NULL); + assert(mtx != NULL); + SleepConditionVariableCS((PCONDITION_VARIABLE) cond, + (PCRITICAL_SECTION) mtx, INFINITE); + return thrd_success; +} + +void mtx_destroy(mtx_t *mtx) { + assert(mtx); + DeleteCriticalSection((PCRITICAL_SECTION) mtx); +} + +int mtx_init(mtx_t *mtx, int type) { + assert(mtx != NULL); + if (type != mtx_plain && type != mtx_timed && + type != (mtx_plain | mtx_recursive) && + type != (mtx_timed | mtx_recursive)) + return thrd_error; + InitializeCriticalSection((PCRITICAL_SECTION) mtx); + return thrd_success; +} + +int mtx_lock(mtx_t *mtx) { + assert(mtx != NULL); + EnterCriticalSection((PCRITICAL_SECTION) mtx); + return thrd_success; +} + +int mtx_timedlock(mtx_t *mtx, const struct timespec *ts) { + assert(mtx != NULL); + assert(ts != NULL); + while (mtx_trylock(mtx) != thrd_success) { + if (impl_abs2relmsec(ts) == 0) + return thrd_timedout; + /* busy loop! */ + thrd_yield(); + } + return thrd_success; +} + +int mtx_trylock(mtx_t *mtx) { + assert(mtx != NULL); + return TryEnterCriticalSection((PCRITICAL_SECTION) mtx) + ? thrd_success + : thrd_busy; +} + +int mtx_unlock(mtx_t *mtx) { + assert(mtx != NULL); + LeaveCriticalSection((PCRITICAL_SECTION) mtx); + return thrd_success; +} + +int thrd_create_with_stack(thrd_t *thr, thrd_start_t func, void *arg, + ptrdiff_t const stack_size) { + impl_thrd_param_t *pack; + uintptr_t handle; + assert(thr != NULL); + assert(stack_size >= 0 && stack_size < 0x100000000); + + pack = (impl_thrd_param_t *) kit_alloc_dispatch( + NULL, KIT_ALLOCATE, (sizeof(impl_thrd_param_t)), 0, NULL); + if (!pack) + return thrd_nomem; + pack->func = func; + pack->arg = arg; + handle = _beginthreadex(NULL, (unsigned) stack_size, + impl_thrd_routine, pack, CREATE_SUSPENDED, + NULL); + if (handle == 0) { + kit_alloc_dispatch(NULL, KIT_DEALLOCATE, 0, 0, pack); + if (errno == EAGAIN || errno == EACCES) + return thrd_nomem; + return thrd_error; + } + thr->handle = (void *) handle; + pack->thrd = *thr; + ResumeThread((HANDLE) handle); + return thrd_success; +} + +int thrd_create(thrd_t *thr, thrd_start_t func, void *arg) { + return thrd_create_with_stack(thr, func, arg, 0); +} + +thrd_t thrd_current(void) { + /* GetCurrentThread() returns a pseudo-handle, which we need + * to pass to DuplicateHandle(). Only the resulting handle can be + * used from other threads. + * + * Note that neither handle can be compared to the one by + * thread_create. Only the thread IDs - as returned by GetThreadId() + * and GetCurrentThreadId() can be compared directly. + * + * Other potential solutions would be: + * - define thrd_t as a thread Ids, but this would mean we'd need to + * OpenThread for many operations + * - use malloc'ed memory for thrd_t. This would imply using TLS for + * current thread. + * + * Neither is particularly nice. + * + * Life would be much easier if C11 threads had different + * abstractions for threads and thread IDs, just like C++11 threads + * does... + */ + struct thrd_state *state = &impl_current_thread; + if (state->thrd.handle == NULL) { + if (!DuplicateHandle(GetCurrentProcess(), GetCurrentThread(), + GetCurrentProcess(), &(state->thrd.handle), + 0, FALSE, DUPLICATE_SAME_ACCESS)) { + abort(); + } + state->handle_need_close = 1; + } + return state->thrd; +} + +int thrd_detach(thrd_t thr) { + CloseHandle(thr.handle); + return thrd_success; +} + +int thrd_equal(thrd_t thr0, thrd_t thr1) { + return GetThreadId(thr0.handle) == GetThreadId(thr1.handle); +} + +_Noreturn void thrd_exit(int res) { + _endthreadex((unsigned) res); +} + +int thrd_join(thrd_t thr, int *res) { + DWORD w, code; + if (thr.handle == NULL) { + return thrd_error; + } + w = WaitForSingleObject(thr.handle, INFINITE); + if (w != WAIT_OBJECT_0) + return thrd_error; + if (res) { + if (!GetExitCodeThread(thr.handle, &code)) { + CloseHandle(thr.handle); + return thrd_error; + } + *res = (int) code; + } + CloseHandle(thr.handle); + return thrd_success; +} + +int thrd_sleep(const struct timespec *time_point, + struct timespec *remaining) { + (void) remaining; + assert(time_point); + assert(!remaining); /* not implemented */ + Sleep((DWORD) impl_timespec2msec(time_point)); + return 0; +} + +void thrd_yield(void) { + SwitchToThread(); +} + +# endif +#endif |