diff options
Diffstat (limited to 'mysys/my_getsystime.c')
| -rw-r--r-- | mysys/my_getsystime.c | 200 |
1 files changed, 181 insertions, 19 deletions
diff --git a/mysys/my_getsystime.c b/mysys/my_getsystime.c index 2fd7eed7778..43bb6c08af9 100644 --- a/mysys/my_getsystime.c +++ b/mysys/my_getsystime.c @@ -17,11 +17,13 @@ /* thus to get the current time we should use the system function with the highest possible resolution */ +#include "mysys_priv.h" +#include "my_static.h" + #ifdef __NETWARE__ #include <nks/time.h> #endif -#include "mysys_priv.h" ulonglong my_getsystime() { #ifdef HAVE_CLOCK_GETTIME @@ -29,28 +31,15 @@ ulonglong my_getsystime() clock_gettime(CLOCK_REALTIME, &tp); return (ulonglong)tp.tv_sec*10000000+(ulonglong)tp.tv_nsec/100; #elif defined(__WIN__) -#define OFFSET_TO_EPOC ((__int64) 134774 * 24 * 60 * 60 * 1000 * 1000 * 10) - static __int64 offset=0, freq; LARGE_INTEGER t_cnt; - if (!offset) + if (query_performance_frequency) { - /* strictly speaking there should be a mutex to protect - initialization section. But my_getsystime() is called from - UUID() code, and UUID() calls are serialized with a mutex anyway - */ - LARGE_INTEGER li; - FILETIME ft; - GetSystemTimeAsFileTime(&ft); - li.LowPart=ft.dwLowDateTime; - li.HighPart=ft.dwHighDateTime; - offset=li.QuadPart-OFFSET_TO_EPOC; - QueryPerformanceFrequency(&li); - freq=li.QuadPart; QueryPerformanceCounter(&t_cnt); - offset-=t_cnt.QuadPart/freq*10000000+t_cnt.QuadPart%freq*10000000/freq; + return (t_cnt.QuadPart / query_performance_frequency * 10000000+ + t_cnt.QuadPart % query_performance_frequency * 10000000/ + query_performance_frequency+query_performance_offset); } - QueryPerformanceCounter(&t_cnt); - return t_cnt.QuadPart/freq*10000000+t_cnt.QuadPart%freq*10000000/freq+offset; + return 0; #elif defined(__NETWARE__) NXTime_t tm; NXGetTime(NX_SINCE_1970, NX_NSECONDS, &tm); @@ -62,3 +51,176 @@ ulonglong my_getsystime() return (ulonglong)tv.tv_sec*10000000+(ulonglong)tv.tv_usec*10; #endif } + + +/* + Return current time + + SYNOPSIS + my_time() + flags If MY_WME is set, write error if time call fails + +*/ + +time_t my_time(myf flags __attribute__((unused))) +{ + time_t t; +#ifdef HAVE_GETHRTIME + (void) my_micro_time_and_time(&t); + return t; +#else + /* The following loop is here beacuse time() may fail on some systems */ + while ((t= time(0)) == (time_t) -1) + { + if (flags & MY_WME) + fprintf(stderr, "%s: Warning: time() call failed\n", my_progname); + } + return t; +#endif +} + + +/* + Return time in micro seconds + + SYNOPSIS + my_micro_time() + + NOTES + This function is to be used to measure performance in micro seconds. + As it's not defined whats the start time for the clock, this function + us only useful to measure time between two moments. + + For windows platforms we need the frequency value of the CUP. This is + initalized in my_init.c through QueryPerformanceFrequency(). + + If Windows platform doesn't support QueryPerformanceFrequency() we will + obtain the time via GetClockCount, which only supports milliseconds. + + RETURN + Value in microseconds from some undefined point in time +*/ + +ulonglong my_micro_time() +{ + ulonglong newtime; +#if defined(__WIN__) + if (query_performance_frequency) + { + QueryPerformanceCounter((LARGE_INTEGER*) &newtime); + newtime/= (query_performance_frequency * 1000000); + } + else + newtime= (GetTickCount() * 1000); /* GetTickCount only returns milliseconds */ + return newtime; +#elif defined(HAVE_GETHRTIME) + return gethrtime()/1000; +#else + struct timeval t; + /* The following loop is here because gettimeofday may fail on some systems */ + while (gettimeofday(&t, NULL) != 0) + {} + newtime= (ulonglong)t.tv_sec * 1000000 + t.tv_usec; + return newtime; +#endif /* defined(__WIN__) */ +} + + +/* + Return time in seconds and timer in microseconds (not different start!) + + SYNOPSIS + my_micro_time_and_time() + time_arg Will be set to seconds since epoch (00:00:00 UTC, January 1, + 1970) + + NOTES + This function is to be useful when we need both the time and microtime. + For example in MySQL this is used to get the query time start of a query and + to measure the time of a query (for the slow query log) + + IMPLEMENTATION + Value of time is as in time() call. + Value of microtime is same as my_micro_time(), which may be totally unrealated + to time() + + RETURN + Value in microseconds from some undefined point in time +*/ + +#define DELTA_FOR_SECONDS LL(500000000) /* Half a second */ + +ulonglong my_micro_time_and_time(time_t *time_arg) +{ + ulonglong newtime; +#if defined(__WIN__) + if (query_performance_frequency) + { + QueryPerformanceCounter((LARGE_INTEGER*) &newtime); + newtime/= (query_performance_frequency * 1000000); + } + else + newtime= (GetTickCount() * 1000); /* GetTickCount only returns milliseconds */ + (void) time(time_arg); + return newtime; +#elif defined(HAVE_GETHRTIME) + /* + Solaris has a very slow time() call. We optimize this by using the very fast + gethrtime() call and only calling time() every 1/2 second + */ + static hrtime_t prev_gethrtime= 0; + static time_t cur_time= 0; + hrtime_t cur_gethrtime; + + pthread_mutex_lock(&THR_LOCK_time); + cur_gethrtime= gethrtime(); + if ((cur_gethrtime - prev_gethrtime) > DELTA_FOR_SECONDS) + { + cur_time= time(0); + prev_gethrtime= cur_gethrtime; + } + *time_arg= cur_time; + pthread_mutex_unlock(&THR_LOCK_time); + return cur_gethrtime/1000; +#else + struct timeval t; + /* The following loop is here because gettimeofday may fail on some systems */ + while (gettimeofday(&t, NULL) != 0) + {} + *time_arg= t.tv_sec; + newtime= (ulonglong)t.tv_sec * 1000000 + t.tv_usec; + return newtime; +#endif /* defined(__WIN__) */ +} + + +/* + Returns current time + + SYNOPSIS + my_time_possible_from_micro() + microtime Value from very recent my_micro_time() + + NOTES + This function returns the current time. The microtime argument is only used + if my_micro_time() uses a function that can safely be converted to the current + time. + + RETURN + current time +*/ + +time_t my_time_possible_from_micro(ulonglong microtime __attribute__((unused))) +{ +#if defined(__WIN__) + time_t t; + while ((t= time(0)) == (time_t) -1) + {} + return t; +#elif defined(HAVE_GETHRTIME) + return my_time(0); /* Cached time */ +#else + return (time_t) (microtime / 1000000); +#endif /* defined(__WIN__) */ +} + |