diff options
Diffstat (limited to 'dep/mysqllite/mysys/my_wincond.c')
| -rw-r--r-- | dep/mysqllite/mysys/my_wincond.c | 242 |
1 files changed, 191 insertions, 51 deletions
diff --git a/dep/mysqllite/mysys/my_wincond.c b/dep/mysqllite/mysys/my_wincond.c index 1134d40229a..58c09e332d6 100644 --- a/dep/mysqllite/mysys/my_wincond.c +++ b/dep/mysqllite/mysys/my_wincond.c @@ -16,16 +16,116 @@ /***************************************************************************** ** The following is a simple implementation of posix conditions *****************************************************************************/ +#if defined(_WIN32) #undef SAFE_MUTEX /* Avoid safe_mutex redefinitions */ #include "mysys_priv.h" -#if defined(THREAD) && defined(__WIN__) #include <m_string.h> -#undef getpid #include <process.h> #include <sys/timeb.h> -int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr) + +/* + Windows native condition variables. We use runtime loading / function + pointers, because they are not available on XP +*/ + +/* Prototypes and function pointers for condition variable functions */ +typedef VOID (WINAPI * InitializeConditionVariableProc) + (PCONDITION_VARIABLE ConditionVariable); + +typedef BOOL (WINAPI * SleepConditionVariableCSProc) + (PCONDITION_VARIABLE ConditionVariable, + PCRITICAL_SECTION CriticalSection, + DWORD dwMilliseconds); + +typedef VOID (WINAPI * WakeAllConditionVariableProc) + (PCONDITION_VARIABLE ConditionVariable); + +typedef VOID (WINAPI * WakeConditionVariableProc) + (PCONDITION_VARIABLE ConditionVariable); + +static InitializeConditionVariableProc my_InitializeConditionVariable; +static SleepConditionVariableCSProc my_SleepConditionVariableCS; +static WakeAllConditionVariableProc my_WakeAllConditionVariable; +static WakeConditionVariableProc my_WakeConditionVariable; + + +/** + Indicates if we have native condition variables, + initialized first time pthread_cond_init is called. +*/ + +static BOOL have_native_conditions= FALSE; + + +/** + Check if native conditions can be used, load function pointers +*/ + +static void check_native_cond_availability(void) +{ + HMODULE module= GetModuleHandle("kernel32"); + + my_InitializeConditionVariable= (InitializeConditionVariableProc) + GetProcAddress(module, "InitializeConditionVariable"); + my_SleepConditionVariableCS= (SleepConditionVariableCSProc) + GetProcAddress(module, "SleepConditionVariableCS"); + my_WakeAllConditionVariable= (WakeAllConditionVariableProc) + GetProcAddress(module, "WakeAllConditionVariable"); + my_WakeConditionVariable= (WakeConditionVariableProc) + GetProcAddress(module, "WakeConditionVariable"); + + if (my_InitializeConditionVariable) + have_native_conditions= TRUE; +} + + + +/** + Convert abstime to milliseconds +*/ + +static DWORD get_milliseconds(const struct timespec *abstime) +{ + long long millis; + union ft64 now; + + if (abstime == NULL) + return INFINITE; + + GetSystemTimeAsFileTime(&now.ft); + + /* + Calculate time left to abstime + - subtract start time from current time(values are in 100ns units) + - convert to millisec by dividing with 10000 + */ + millis= (abstime->tv.i64 - now.i64) / 10000; + + /* Don't allow the timeout to be negative */ + if (millis < 0) + return 0; + + /* + Make sure the calculated timeout does not exceed original timeout + value which could cause "wait for ever" if system time changes + */ + if (millis > abstime->max_timeout_msec) + millis= abstime->max_timeout_msec; + + if (millis > UINT_MAX) + millis= UINT_MAX; + + return (DWORD)millis; +} + + +/* + Old (pre-vista) implementation using events +*/ + +static int legacy_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr) { cond->waiting= 0; InitializeCriticalSection(&cond->lock_waiting); @@ -54,7 +154,8 @@ int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr) return 0; } -int pthread_cond_destroy(pthread_cond_t *cond) + +static int legacy_cond_destroy(pthread_cond_t *cond) { DeleteCriticalSection(&cond->lock_waiting); @@ -66,48 +167,13 @@ int pthread_cond_destroy(pthread_cond_t *cond) } -int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex) -{ - return pthread_cond_timedwait(cond,mutex,NULL); -} - - -int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, +static int legacy_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, struct timespec *abstime) { int result; - long timeout; - union ft64 now; - - if( abstime != NULL ) - { - GetSystemTimeAsFileTime(&now.ft); - - /* - Calculate time left to abstime - - subtract start time from current time(values are in 100ns units) - - convert to millisec by dividing with 10000 - */ - timeout= (long)((abstime->tv.i64 - now.i64) / 10000); - - /* Don't allow the timeout to be negative */ - if (timeout < 0) - timeout= 0L; - - /* - Make sure the calucated timeout does not exceed original timeout - value which could cause "wait for ever" if system time changes - */ - if (timeout > abstime->max_timeout_msec) - timeout= abstime->max_timeout_msec; - - } - else - { - /* No time specified; don't expire */ - timeout= INFINITE; - } + DWORD timeout; + timeout= get_milliseconds(abstime); /* Block access if previous broadcast hasn't finished. This is just for safety and should normally not @@ -143,7 +209,7 @@ int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, return result == WAIT_TIMEOUT ? ETIMEDOUT : 0; } -int pthread_cond_signal(pthread_cond_t *cond) +static int legacy_cond_signal(pthread_cond_t *cond) { EnterCriticalSection(&cond->lock_waiting); @@ -156,7 +222,7 @@ int pthread_cond_signal(pthread_cond_t *cond) } -int pthread_cond_broadcast(pthread_cond_t *cond) +static int legacy_cond_broadcast(pthread_cond_t *cond) { EnterCriticalSection(&cond->lock_waiting); /* @@ -178,11 +244,91 @@ int pthread_cond_broadcast(pthread_cond_t *cond) } +/* + Posix API functions. Just choose between native and legacy implementation. +*/ + +int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr) +{ + /* + Once initialization is used here rather than in my_init(), to + 1) avoid my_init() pitfalls- undefined order in which initialization should + run + 2) be potentially useful C++ (in static constructors that run before main()) + 3) just to simplify the API. + Also, the overhead of my_pthread_once is very small. + */ + static my_pthread_once_t once_control= MY_PTHREAD_ONCE_INIT; + my_pthread_once(&once_control, check_native_cond_availability); + + if (have_native_conditions) + { + my_InitializeConditionVariable(&cond->native_cond); + return 0; + } + else + return legacy_cond_init(cond, attr); +} + + +int pthread_cond_destroy(pthread_cond_t *cond) +{ + if (have_native_conditions) + return 0; /* no destroy function */ + else + return legacy_cond_destroy(cond); +} + + +int pthread_cond_broadcast(pthread_cond_t *cond) +{ + if (have_native_conditions) + { + my_WakeAllConditionVariable(&cond->native_cond); + return 0; + } + else + return legacy_cond_broadcast(cond); +} + + +int pthread_cond_signal(pthread_cond_t *cond) +{ + if (have_native_conditions) + { + my_WakeConditionVariable(&cond->native_cond); + return 0; + } + else + return legacy_cond_signal(cond); +} + + +int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, + struct timespec *abstime) +{ + if (have_native_conditions) + { + DWORD timeout= get_milliseconds(abstime); + if (!my_SleepConditionVariableCS(&cond->native_cond, mutex, timeout)) + return ETIMEDOUT; + return 0; + } + else + return legacy_cond_timedwait(cond, mutex, abstime); +} + + +int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex) +{ + return pthread_cond_timedwait(cond, mutex, NULL); +} + + int pthread_attr_init(pthread_attr_t *connect_att) { connect_att->dwStackSize = 0; connect_att->dwCreatingFlag = 0; - connect_att->priority = 0; return 0; } @@ -192,12 +338,6 @@ int pthread_attr_setstacksize(pthread_attr_t *connect_att,DWORD stack) return 0; } -int pthread_attr_setprio(pthread_attr_t *connect_att,int priority) -{ - connect_att->priority=priority; - return 0; -} - int pthread_attr_destroy(pthread_attr_t *connect_att) { bzero((uchar*) connect_att,sizeof(*connect_att)); |