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author | Graydon, Tracy <tracy.graydon@intel.com> | 2013-01-31 17:08:15 -0800 |
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committer | Graydon, Tracy <tracy.graydon@intel.com> | 2013-01-31 17:08:15 -0800 |
commit | 699fc9f67a9a62df492d1cd049e4978953640de9 (patch) | |
tree | f0c16f1494bd71922e7bf5258037427cac4a350b /compat/win32 | |
download | git-2.0alpha.tar.gz git-2.0alpha.tar.bz2 git-2.0alpha.zip |
Initial commit for TizenHEADsubmit/2.0alpha/20130201.014617accepted/2.0alpha/20130201.0121062.0alpha
Diffstat (limited to 'compat/win32')
-rw-r--r-- | compat/win32/pthread.c | 196 | ||||
-rw-r--r-- | compat/win32/pthread.h | 99 |
2 files changed, 295 insertions, 0 deletions
diff --git a/compat/win32/pthread.c b/compat/win32/pthread.c new file mode 100644 index 0000000..010e875 --- /dev/null +++ b/compat/win32/pthread.c @@ -0,0 +1,196 @@ +/* + * Copyright (C) 2009 Andrzej K. Haczewski <ahaczewski@gmail.com> + * + * DISCLAIMER: The implementation is Git-specific, it is subset of original + * Pthreads API, without lots of other features that Git doesn't use. + * Git also makes sure that the passed arguments are valid, so there's + * no need for double-checking. + */ + +#include "../../git-compat-util.h" +#include "pthread.h" + +#include <errno.h> +#include <limits.h> + +static unsigned __stdcall win32_start_routine(void *arg) +{ + pthread_t *thread = arg; + thread->tid = GetCurrentThreadId(); + thread->arg = thread->start_routine(thread->arg); + return 0; +} + +int pthread_create(pthread_t *thread, const void *unused, + void *(*start_routine)(void*), void *arg) +{ + thread->arg = arg; + thread->start_routine = start_routine; + thread->handle = (HANDLE) + _beginthreadex(NULL, 0, win32_start_routine, thread, 0, NULL); + + if (!thread->handle) + return errno; + else + return 0; +} + +int win32_pthread_join(pthread_t *thread, void **value_ptr) +{ + DWORD result = WaitForSingleObject(thread->handle, INFINITE); + switch (result) { + case WAIT_OBJECT_0: + if (value_ptr) + *value_ptr = thread->arg; + return 0; + case WAIT_ABANDONED: + return EINVAL; + default: + return err_win_to_posix(GetLastError()); + } +} + +pthread_t pthread_self(void) +{ + pthread_t t = { 0 }; + t.tid = GetCurrentThreadId(); + return t; +} + +int pthread_cond_init(pthread_cond_t *cond, const void *unused) +{ + cond->waiters = 0; + cond->was_broadcast = 0; + InitializeCriticalSection(&cond->waiters_lock); + + cond->sema = CreateSemaphore(NULL, 0, LONG_MAX, NULL); + if (!cond->sema) + die("CreateSemaphore() failed"); + + cond->continue_broadcast = CreateEvent(NULL, /* security */ + FALSE, /* auto-reset */ + FALSE, /* not signaled */ + NULL); /* name */ + if (!cond->continue_broadcast) + die("CreateEvent() failed"); + + return 0; +} + +int pthread_cond_destroy(pthread_cond_t *cond) +{ + CloseHandle(cond->sema); + CloseHandle(cond->continue_broadcast); + DeleteCriticalSection(&cond->waiters_lock); + return 0; +} + +int pthread_cond_wait(pthread_cond_t *cond, CRITICAL_SECTION *mutex) +{ + int last_waiter; + + EnterCriticalSection(&cond->waiters_lock); + cond->waiters++; + LeaveCriticalSection(&cond->waiters_lock); + + /* + * Unlock external mutex and wait for signal. + * NOTE: we've held mutex locked long enough to increment + * waiters count above, so there's no problem with + * leaving mutex unlocked before we wait on semaphore. + */ + LeaveCriticalSection(mutex); + + /* let's wait - ignore return value */ + WaitForSingleObject(cond->sema, INFINITE); + + /* + * Decrease waiters count. If we are the last waiter, then we must + * notify the broadcasting thread that it can continue. + * But if we continued due to cond_signal, we do not have to do that + * because the signaling thread knows that only one waiter continued. + */ + EnterCriticalSection(&cond->waiters_lock); + cond->waiters--; + last_waiter = cond->was_broadcast && cond->waiters == 0; + LeaveCriticalSection(&cond->waiters_lock); + + if (last_waiter) { + /* + * cond_broadcast was issued while mutex was held. This means + * that all other waiters have continued, but are contending + * for the mutex at the end of this function because the + * broadcasting thread did not leave cond_broadcast, yet. + * (This is so that it can be sure that each waiter has + * consumed exactly one slice of the semaphor.) + * The last waiter must tell the broadcasting thread that it + * can go on. + */ + SetEvent(cond->continue_broadcast); + /* + * Now we go on to contend with all other waiters for + * the mutex. Auf in den Kampf! + */ + } + /* lock external mutex again */ + EnterCriticalSection(mutex); + + return 0; +} + +/* + * IMPORTANT: This implementation requires that pthread_cond_signal + * is called while the mutex is held that is used in the corresponding + * pthread_cond_wait calls! + */ +int pthread_cond_signal(pthread_cond_t *cond) +{ + int have_waiters; + + EnterCriticalSection(&cond->waiters_lock); + have_waiters = cond->waiters > 0; + LeaveCriticalSection(&cond->waiters_lock); + + /* + * Signal only when there are waiters + */ + if (have_waiters) + return ReleaseSemaphore(cond->sema, 1, NULL) ? + 0 : err_win_to_posix(GetLastError()); + else + return 0; +} + +/* + * DOUBLY IMPORTANT: This implementation requires that pthread_cond_broadcast + * is called while the mutex is held that is used in the corresponding + * pthread_cond_wait calls! + */ +int pthread_cond_broadcast(pthread_cond_t *cond) +{ + EnterCriticalSection(&cond->waiters_lock); + + if ((cond->was_broadcast = cond->waiters > 0)) { + /* wake up all waiters */ + ReleaseSemaphore(cond->sema, cond->waiters, NULL); + LeaveCriticalSection(&cond->waiters_lock); + /* + * At this point all waiters continue. Each one takes its + * slice of the semaphor. Now it's our turn to wait: Since + * the external mutex is held, no thread can leave cond_wait, + * yet. For this reason, we can be sure that no thread gets + * a chance to eat *more* than one slice. OTOH, it means + * that the last waiter must send us a wake-up. + */ + WaitForSingleObject(cond->continue_broadcast, INFINITE); + /* + * Since the external mutex is held, no thread can enter + * cond_wait, and, hence, it is safe to reset this flag + * without cond->waiters_lock held. + */ + cond->was_broadcast = 0; + } else { + LeaveCriticalSection(&cond->waiters_lock); + } + return 0; +} diff --git a/compat/win32/pthread.h b/compat/win32/pthread.h new file mode 100644 index 0000000..2e20548 --- /dev/null +++ b/compat/win32/pthread.h @@ -0,0 +1,99 @@ +/* + * Header used to adapt pthread-based POSIX code to Windows API threads. + * + * Copyright (C) 2009 Andrzej K. Haczewski <ahaczewski@gmail.com> + */ + +#ifndef PTHREAD_H +#define PTHREAD_H + +#ifndef WIN32_LEAN_AND_MEAN +#define WIN32_LEAN_AND_MEAN +#endif + +#include <windows.h> + +/* + * Defines that adapt Windows API threads to pthreads API + */ +#define pthread_mutex_t CRITICAL_SECTION + +#define pthread_mutex_init(a,b) (InitializeCriticalSection((a)), 0) +#define pthread_mutex_destroy(a) DeleteCriticalSection((a)) +#define pthread_mutex_lock EnterCriticalSection +#define pthread_mutex_unlock LeaveCriticalSection + +typedef int pthread_mutexattr_t; +#define pthread_mutexattr_init(a) (*(a) = 0) +#define pthread_mutexattr_destroy(a) do {} while (0) +#define pthread_mutexattr_settype(a, t) 0 +#define PTHREAD_MUTEX_RECURSIVE 0 + +/* + * Implement simple condition variable for Windows threads, based on ACE + * implementation. + * + * See original implementation: http://bit.ly/1vkDjo + * ACE homepage: http://www.cse.wustl.edu/~schmidt/ACE.html + * See also: http://www.cse.wustl.edu/~schmidt/win32-cv-1.html + */ +typedef struct { + LONG waiters; + int was_broadcast; + CRITICAL_SECTION waiters_lock; + HANDLE sema; + HANDLE continue_broadcast; +} pthread_cond_t; + +extern int pthread_cond_init(pthread_cond_t *cond, const void *unused); +extern int pthread_cond_destroy(pthread_cond_t *cond); +extern int pthread_cond_wait(pthread_cond_t *cond, CRITICAL_SECTION *mutex); +extern int pthread_cond_signal(pthread_cond_t *cond); +extern int pthread_cond_broadcast(pthread_cond_t *cond); + +/* + * Simple thread creation implementation using pthread API + */ +typedef struct { + HANDLE handle; + void *(*start_routine)(void*); + void *arg; + DWORD tid; +} pthread_t; + +extern int pthread_create(pthread_t *thread, const void *unused, + void *(*start_routine)(void*), void *arg); + +/* + * To avoid the need of copying a struct, we use small macro wrapper to pass + * pointer to win32_pthread_join instead. + */ +#define pthread_join(a, b) win32_pthread_join(&(a), (b)) + +extern int win32_pthread_join(pthread_t *thread, void **value_ptr); + +#define pthread_equal(t1, t2) ((t1).tid == (t2).tid) +extern pthread_t pthread_self(void); + +static inline int pthread_exit(void *ret) +{ + ExitThread((DWORD)ret); +} + +typedef DWORD pthread_key_t; +static inline int pthread_key_create(pthread_key_t *keyp, void (*destructor)(void *value)) +{ + return (*keyp = TlsAlloc()) == TLS_OUT_OF_INDEXES ? EAGAIN : 0; +} + +static inline int pthread_setspecific(pthread_key_t key, const void *value) +{ + return TlsSetValue(key, (void *)value) ? 0 : EINVAL; +} + +static inline void *pthread_getspecific(pthread_key_t key) +{ + return TlsGetValue(key); +} + +#endif /* PTHREAD_H */ |