/* * C11 emulation library * * (C) Copyright yohhoy 2012. * Distributed under the Boost Software License, Version 1.0. * * Permission is hereby granted, free of charge, to any person or organization * obtaining a copy of the software and accompanying documentation covered by * this license (the "Software") to use, reproduce, display, distribute, * execute, and transmit the Software, and to prepare [[derivative work]]s of the * Software, and to permit third-parties to whom the Software is furnished to * do so, all subject to the following: * * The copyright notices in the Software and this entire statement, including * the above license grant, this restriction and the following disclaimer, * must be included in all copies of the Software, in whole or in part, and * all derivative works of the Software, unless such copies or derivative * works are solely in the form of machine-executable object code generated by * a source language processor. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ #ifndef assert #include #endif #include #include #include // MSVCRT #include /* 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. EMULATED_THREADS_USE_NATIVE_CV Use native WindowsAPI condition variable object. (requires WinVista or later) Otherwise use emulated implementation for WinXP. EMULATED_THREADS_TSS_DTOR_SLOTNUM Max registerable TSS dtor number. */ // XXX: Retain XP compatability #if 0 #if _WIN32_WINNT >= 0x0600 // Prefer native WindowsAPI on newer environment. #if !defined(__MINGW32__) #define EMULATED_THREADS_USE_NATIVE_CALL_ONCE #endif #define EMULATED_THREADS_USE_NATIVE_CV #endif #endif #define EMULATED_THREADS_TSS_DTOR_SLOTNUM 64 // see TLS_MINIMUM_AVAILABLE #include // 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 #if defined(EMULATED_THREADS_USE_NATIVE_CV) && (_WIN32_WINNT < 0x0600) #error EMULATED_THREADS_USE_NATIVE_CV requires _WIN32_WINNT>=0x0600 #endif /* Visual Studio 2015 and later */ #if _MSC_VER >= 1900 #define HAVE_TIMESPEC #define HAVE_TIMESPEC_GET #elif defined(__MINGW32__) #define HAVE_TIMESPEC #endif #ifndef HAVE_TIMESPEC struct timespec { time_t tv_sec; long tv_nsec; }; #endif /*---------------------------- macros ----------------------------*/ #ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE #define ONCE_FLAG_INIT INIT_ONCE_STATIC_INIT #else #define ONCE_FLAG_INIT {0} #endif #define TSS_DTOR_ITERATIONS 1 // FIXME: temporary non-standard hack to ease transition #define _MTX_INITIALIZER_NP {(PCRITICAL_SECTION_DEBUG)-1, -1, 0, 0, 0, 0} /*---------------------------- types ----------------------------*/ typedef struct cnd_t { #ifdef EMULATED_THREADS_USE_NATIVE_CV CONDITION_VARIABLE condvar; #else int blocked; int gone; int to_unblock; HANDLE sem_queue; HANDLE sem_gate; CRITICAL_SECTION monitor; #endif } cnd_t; typedef HANDLE thrd_t; typedef DWORD tss_t; typedef CRITICAL_SECTION mtx_t; #ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE typedef INIT_ONCE once_flag; #else typedef struct once_flag_t { volatile LONG status; } once_flag; #endif static inline void * tss_get(tss_t key); static inline void thrd_yield(void); static inline int mtx_trylock(mtx_t *mtx); static inline int mtx_lock(mtx_t *mtx); static inline int mtx_unlock(mtx_t *mtx); /* Implementation limits: - Conditionally emulation for "Initialization functions" (see EMULATED_THREADS_USE_NATIVE_CALL_ONCE macro) - Emulated `mtx_timelock()' with mtx_trylock() + *busy loop* */ static void impl_tss_dtor_invoke(void); // forward decl. struct impl_thrd_param { thrd_start_t func; void *arg; }; static unsigned __stdcall impl_thrd_routine(void *p) { struct impl_thrd_param pack; int code; memcpy(&pack, p, sizeof(struct impl_thrd_param)); free(p); code = pack.func(pack.arg); impl_tss_dtor_invoke(); return (unsigned)code; } static DWORD impl_timespec2msec(const struct timespec *ts) { return (DWORD)((ts->tv_sec * 1000U) + (ts->tv_nsec / 1000000L)); } #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 #ifndef EMULATED_THREADS_USE_NATIVE_CV /* Note: The implementation of condition variable is ported from Boost.Interprocess See http://www.boost.org/boost/interprocess/sync/windows/condition.hpp */ static void impl_cond_do_signal(cnd_t *cond, int broadcast) { int nsignal = 0; EnterCriticalSection(&cond->monitor); if (cond->to_unblock != 0) { if (cond->blocked == 0) { LeaveCriticalSection(&cond->monitor); return; } if (broadcast) { cond->to_unblock += nsignal = cond->blocked; cond->blocked = 0; } else { nsignal = 1; cond->to_unblock++; cond->blocked--; } } else if (cond->blocked > cond->gone) { WaitForSingleObject(cond->sem_gate, INFINITE); if (cond->gone != 0) { cond->blocked -= cond->gone; cond->gone = 0; } if (broadcast) { nsignal = cond->to_unblock = cond->blocked; cond->blocked = 0; } else { nsignal = cond->to_unblock = 1; cond->blocked--; } } LeaveCriticalSection(&cond->monitor); if (0 < nsignal) ReleaseSemaphore(cond->sem_queue, nsignal, NULL); } static int impl_cond_do_wait(cnd_t *cond, mtx_t *mtx, const struct timespec *ts) { int nleft = 0; int ngone = 0; int timeout = 0; DWORD w; WaitForSingleObject(cond->sem_gate, INFINITE); cond->blocked++; ReleaseSemaphore(cond->sem_gate, 1, NULL); mtx_unlock(mtx); w = WaitForSingleObject(cond->sem_queue, ts ? impl_timespec2msec(ts) : INFINITE); timeout = (w == WAIT_TIMEOUT); EnterCriticalSection(&cond->monitor); if ((nleft = cond->to_unblock) != 0) { if (timeout) { if (cond->blocked != 0) { cond->blocked--; } else { cond->gone++; } } if (--cond->to_unblock == 0) { if (cond->blocked != 0) { ReleaseSemaphore(cond->sem_gate, 1, NULL); nleft = 0; } else if ((ngone = cond->gone) != 0) { cond->gone = 0; } } } else if (++cond->gone == INT_MAX/2) { WaitForSingleObject(cond->sem_gate, INFINITE); cond->blocked -= cond->gone; ReleaseSemaphore(cond->sem_gate, 1, NULL); cond->gone = 0; } LeaveCriticalSection(&cond->monitor); if (nleft == 1) { while (ngone--) WaitForSingleObject(cond->sem_queue, INFINITE); ReleaseSemaphore(cond->sem_gate, 1, NULL); } mtx_lock(mtx); return timeout ? thrd_busy : thrd_success; } #endif // ifndef EMULATED_THREADS_USE_NATIVE_CV static struct impl_tss_dtor_entry { tss_t key; tss_dtor_t dtor; } impl_tss_dtor_tbl[EMULATED_THREADS_TSS_DTOR_SLOTNUM]; static int impl_tss_dtor_register(tss_t key, tss_dtor_t dtor) { int i; for (i = 0; i < EMULATED_THREADS_TSS_DTOR_SLOTNUM; i++) { if (!impl_tss_dtor_tbl[i].dtor) break; } if (i == EMULATED_THREADS_TSS_DTOR_SLOTNUM) return 1; impl_tss_dtor_tbl[i].key = key; impl_tss_dtor_tbl[i].dtor = dtor; return 0; } static void impl_tss_dtor_invoke() { int i; for (i = 0; i < EMULATED_THREADS_TSS_DTOR_SLOTNUM; i++) { if (impl_tss_dtor_tbl[i].dtor) { void* val = tss_get(impl_tss_dtor_tbl[i].key); if (val) (impl_tss_dtor_tbl[i].dtor)(val); } } } /*--------------- 7.25.2 Initialization functions ---------------*/ // 7.25.2.1 static inline 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(flag, impl_call_once_callback, (PVOID)¶m, NULL); } #else if (InterlockedCompareExchange(&flag->status, 1, 0) == 0) { (func)(); InterlockedExchange(&flag->status, 2); } else { while (flag->status == 1) { // busy loop! thrd_yield(); } } #endif } /*------------- 7.25.3 Condition variable functions -------------*/ // 7.25.3.1 static inline int cnd_broadcast(cnd_t *cond) { if (!cond) return thrd_error; #ifdef EMULATED_THREADS_USE_NATIVE_CV WakeAllConditionVariable(&cond->condvar); #else impl_cond_do_signal(cond, 1); #endif return thrd_success; } // 7.25.3.2 static inline void cnd_destroy(cnd_t *cond) { assert(cond); #ifdef EMULATED_THREADS_USE_NATIVE_CV // do nothing #else CloseHandle(cond->sem_queue); CloseHandle(cond->sem_gate); DeleteCriticalSection(&cond->monitor); #endif } // 7.25.3.3 static inline int cnd_init(cnd_t *cond) { if (!cond) return thrd_error; #ifdef EMULATED_THREADS_USE_NATIVE_CV InitializeConditionVariable(&cond->condvar); #else cond->blocked = 0; cond->gone = 0; cond->to_unblock = 0; cond->sem_queue = CreateSemaphore(NULL, 0, LONG_MAX, NULL); cond->sem_gate = CreateSemaphore(NULL, 1, 1, NULL); InitializeCriticalSection(&cond->monitor); #endif return thrd_success; } // 7.25.3.4 static inline int cnd_signal(cnd_t *cond) { if (!cond) return thrd_error; #ifdef EMULATED_THREADS_USE_NATIVE_CV WakeConditionVariable(&cond->condvar); #else impl_cond_do_signal(cond, 0); #endif return thrd_success; } // 7.25.3.5 static inline int cnd_timedwait(cnd_t *cond, mtx_t *mtx, const struct timespec *abs_time) { if (!cond || !mtx || !abs_time) return thrd_error; #ifdef EMULATED_THREADS_USE_NATIVE_CV if (SleepConditionVariableCS(&cond->condvar, mtx, impl_timespec2msec(abs_time))) return thrd_success; return (GetLastError() == ERROR_TIMEOUT) ? thrd_busy : thrd_error; #else return impl_cond_do_wait(cond, mtx, abs_time); #endif } // 7.25.3.6 static inline int cnd_wait(cnd_t *cond, mtx_t *mtx) { if (!cond || !mtx) return thrd_error; #ifdef EMULATED_THREADS_USE_NATIVE_CV SleepConditionVariableCS(&cond->condvar, mtx, INFINITE); #else impl_cond_do_wait(cond, mtx, NULL); #endif return thrd_success; } /*-------------------- 7.25.4 Mutex functions --------------------*/ // 7.25.4.1 static inline void mtx_destroy(mtx_t *mtx) { assert(mtx); DeleteCriticalSection(mtx); } // 7.25.4.2 static inline int mtx_init(mtx_t *mtx, int type) { if (!mtx) return thrd_error; if (type != mtx_plain && type != mtx_timed && type != mtx_try && type != (mtx_plain|mtx_recursive) && type != (mtx_timed|mtx_recursive) && type != (mtx_try|mtx_recursive)) return thrd_error; InitializeCriticalSection(mtx); return thrd_success; } // 7.25.4.3 static inline int mtx_lock(mtx_t *mtx) { if (!mtx) return thrd_error; EnterCriticalSection(mtx); return thrd_success; } // 7.25.4.4 static inline int mtx_timedlock(mtx_t *mtx, const struct timespec *ts) { time_t expire, now; if (!mtx || !ts) return thrd_error; expire = time(NULL); expire += ts->tv_sec; while (mtx_trylock(mtx) != thrd_success) { now = time(NULL); if (expire < now) return thrd_busy; // busy loop! thrd_yield(); } return thrd_success; } // 7.25.4.5 static inline int mtx_trylock(mtx_t *mtx) { if (!mtx) return thrd_error; return TryEnterCriticalSection(mtx) ? thrd_success : thrd_busy; } // 7.25.4.6 static inline int mtx_unlock(mtx_t *mtx) { if (!mtx) return thrd_error; LeaveCriticalSection(mtx); return thrd_success; } /*------------------- 7.25.5 Thread functions -------------------*/ // 7.25.5.1 static inline int thrd_create(thrd_t *thr, thrd_start_t func, void *arg) { struct impl_thrd_param *pack; uintptr_t handle; if (!thr) return thrd_error; pack = (struct impl_thrd_param *)malloc(sizeof(struct impl_thrd_param)); if (!pack) return thrd_nomem; pack->func = func; pack->arg = arg; handle = _beginthreadex(NULL, 0, impl_thrd_routine, pack, 0, NULL); if (handle == 0) { if (errno == EAGAIN || errno == EACCES) return thrd_nomem; return thrd_error; } *thr = (thrd_t)handle; return thrd_success; } #if 0 // 7.25.5.2 static inline thrd_t thrd_current(void) { HANDLE hCurrentThread; BOOL bRet; /* 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... */ bRet = DuplicateHandle(GetCurrentProcess(), // source process (pseudo) handle GetCurrentThread(), // source (pseudo) handle GetCurrentProcess(), // target process &hCurrentThread, // target handle 0, FALSE, DUPLICATE_SAME_ACCESS); assert(bRet); if (!bRet) { hCurrentThread = GetCurrentThread(); } return hCurrentThread; } #endif // 7.25.5.3 static inline int thrd_detach(thrd_t thr) { CloseHandle(thr); return thrd_success; } // 7.25.5.4 static inline int thrd_equal(thrd_t thr0, thrd_t thr1) { return GetThreadId(thr0) == GetThreadId(thr1); } // 7.25.5.5 static inline void thrd_exit(int res) { impl_tss_dtor_invoke(); _endthreadex((unsigned)res); } // 7.25.5.6 static inline int thrd_join(thrd_t thr, int *res) { DWORD w, code; w = WaitForSingleObject(thr, INFINITE); if (w != WAIT_OBJECT_0) return thrd_error; if (res) { if (!GetExitCodeThread(thr, &code)) { CloseHandle(thr); return thrd_error; } *res = (int)code; } CloseHandle(thr); return thrd_success; } // 7.25.5.7 static inline void thrd_sleep(const struct timespec *time_point, struct timespec *remaining) { assert(time_point); assert(!remaining); /* not implemented */ Sleep(impl_timespec2msec(time_point)); } // 7.25.5.8 static inline void thrd_yield(void) { SwitchToThread(); } /*----------- 7.25.6 Thread-specific storage functions -----------*/ // 7.25.6.1 static inline int tss_create(tss_t *key, tss_dtor_t dtor) { if (!key) return thrd_error; *key = TlsAlloc(); if (dtor) { if (impl_tss_dtor_register(*key, dtor)) { TlsFree(*key); return thrd_error; } } return (*key != 0xFFFFFFFF) ? thrd_success : thrd_error; } // 7.25.6.2 static inline void tss_delete(tss_t key) { TlsFree(key); } // 7.25.6.3 static inline void * tss_get(tss_t key) { return TlsGetValue(key); } // 7.25.6.4 static inline int tss_set(tss_t key, void *val) { return TlsSetValue(key, val) ? thrd_success : thrd_error; } /*-------------------- 7.25.7 Time functions --------------------*/ // 7.25.6.1 #ifndef HAVE_TIMESPEC_GET static inline int timespec_get(struct timespec *ts, int base) { if (!ts) return 0; if (base == TIME_UTC) { ts->tv_sec = time(NULL); ts->tv_nsec = 0; return base; } return 0; } #endif