diff options
Diffstat (limited to 'mysys/my_getsystime.c')
| -rw-r--r-- | mysys/my_getsystime.c | 140 |
1 files changed, 48 insertions, 92 deletions
diff --git a/mysys/my_getsystime.c b/mysys/my_getsystime.c index 614f49fc425..01b3b912aae 100644 --- a/mysys/my_getsystime.c +++ b/mysys/my_getsystime.c @@ -25,13 +25,25 @@ #include "mysys_priv.h" #include "my_static.h" +/** + Get high-resolution time. + + @remark For windows platforms we need the frequency value of + the CPU. This is initialized in my_init.c through + QueryPerformanceFrequency(). If the Windows platform + doesn't support QueryPerformanceFrequency(), zero is + returned. + + @retval current high-resolution time. +*/ + ulonglong my_getsystime() { #ifdef HAVE_CLOCK_GETTIME struct timespec tp; clock_gettime(CLOCK_REALTIME, &tp); return (ulonglong)tp.tv_sec*10000000+(ulonglong)tp.tv_nsec/100; -#elif defined(__WIN__) +#elif defined(_WIN32) LARGE_INTEGER t_cnt; if (query_performance_frequency) { @@ -50,22 +62,17 @@ ulonglong my_getsystime() } -/* - Return current time +/** + Return current time. - SYNOPSIS - my_time() - flags If MY_WME is set, write error if time call fails + @param flags If MY_WME is set, write error if time call fails. + @retval current time. */ -time_t my_time(myf flags __attribute__((unused))) +time_t my_time(myf flags) { 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) { @@ -73,39 +80,26 @@ time_t my_time(myf flags __attribute__((unused))) 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. +/** + Return time in microseconds. - For windows platforms we need the frequency value of the CUP. This is - initalized in my_init.c through QueryPerformanceFrequency(). + @remark 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. - 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 + @retval Value in microseconds from some undefined point in time. */ ulonglong my_micro_time() { -#if defined(__WIN__) +#ifdef _WIN32 ulonglong newtime; GetSystemTimeAsFileTime((FILETIME*)&newtime); return (newtime/10); -#elif defined(HAVE_GETHRTIME) - return gethrtime()/1000; #else ulonglong newtime; struct timeval t; @@ -116,69 +110,37 @@ ulonglong my_micro_time() {} newtime= (ulonglong)t.tv_sec * 1000000 + t.tv_usec; return newtime; -#endif /* defined(__WIN__) */ +#endif } -/* +/** 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) + @param time_arg Will be set to seconds since epoch. - 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) + @remark 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() + @remark The time source is the same as for my_micro_time(), meaning + that time values returned by both functions can be intermixed + in meaningful ways (i.e. for comparison purposes). - RETURN - Value in microseconds from some undefined point in time + @retval Value in microseconds from some undefined point in time. */ -#define DELTA_FOR_SECONDS 500000000LL /* Half a second */ - /* Difference between GetSystemTimeAsFileTime() and now() */ #define OFFSET_TO_EPOCH 116444736000000000ULL ulonglong my_micro_time_and_time(time_t *time_arg) { -#if defined(__WIN__) +#ifdef _WIN32 ulonglong newtime; GetSystemTimeAsFileTime((FILETIME*)&newtime); *time_arg= (time_t) ((newtime - OFFSET_TO_EPOCH) / 10000000); return (newtime/10); -#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; - - mysql_mutex_lock(&THR_LOCK_time); - cur_gethrtime= gethrtime(); - /* - Due to bugs in the Solaris (x86) implementation of gethrtime(), - the time returned by it might not be monotonic. Don't use the - cached time(2) value if this is a case. - */ - if ((prev_gethrtime > cur_gethrtime) || - ((cur_gethrtime - prev_gethrtime) > DELTA_FOR_SECONDS)) - { - cur_time= time(0); - prev_gethrtime= cur_gethrtime; - } - *time_arg= cur_time; - mysql_mutex_unlock(&THR_LOCK_time); - return cur_gethrtime/1000; #else ulonglong newtime; struct timeval t; @@ -190,37 +152,31 @@ ulonglong my_micro_time_and_time(time_t *time_arg) *time_arg= t.tv_sec; newtime= (ulonglong)t.tv_sec * 1000000 + t.tv_usec; return newtime; -#endif /* defined(__WIN__) */ +#endif } -/* - Returns current time +/** + Returns current time. - SYNOPSIS - my_time_possible_from_micro() - microtime Value from very recent my_micro_time() + @param 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. + @remark 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 + @retval current time. */ time_t my_time_possible_from_micro(ulonglong microtime __attribute__((unused))) { -#if defined(__WIN__) +#ifdef _WIN32 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__) */ +#endif } |