diff options
Diffstat (limited to 'mysys/my_getsystime.c')
| -rw-r--r-- | mysys/my_getsystime.c | 51 |
1 files changed, 32 insertions, 19 deletions
diff --git a/mysys/my_getsystime.c b/mysys/my_getsystime.c index 43bb6c08af9..4fdd979f4bb 100644 --- a/mysys/my_getsystime.c +++ b/mysys/my_getsystime.c @@ -17,6 +17,11 @@ /* thus to get the current time we should use the system function with the highest possible resolution */ +/* + TODO: in functions my_micro_time() and my_micro_time_and_time() there + exists some common code that should be merged into a function. +*/ + #include "mysys_priv.h" #include "my_static.h" @@ -35,9 +40,9 @@ ulonglong my_getsystime() if (query_performance_frequency) { QueryPerformanceCounter(&t_cnt); - return (t_cnt.QuadPart / query_performance_frequency * 10000000+ - t_cnt.QuadPart % query_performance_frequency * 10000000/ - query_performance_frequency+query_performance_offset); + return ((t_cnt.QuadPart / query_performance_frequency * 10000000) + + (t_cnt.QuadPart % query_performance_frequency * 10000000 / + query_performance_frequency) + query_performance_offset); } return 0; #elif defined(__NETWARE__) @@ -108,16 +113,20 @@ ulonglong my_micro_time() if (query_performance_frequency) { QueryPerformanceCounter((LARGE_INTEGER*) &newtime); - newtime/= (query_performance_frequency * 1000000); + return ((newtime / query_performance_frequency * 10000000) + + (newtime % query_performance_frequency * 10000000 / + query_performance_frequency)); } else - newtime= (GetTickCount() * 1000); /* GetTickCount only returns milliseconds */ + newtime= (GetTickCount() * 1000); /* GetTickCount only returns millisec */ 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 */ + /* + 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; @@ -131,18 +140,18 @@ ulonglong my_micro_time() SYNOPSIS my_micro_time_and_time() - time_arg Will be set to seconds since epoch (00:00:00 UTC, January 1, - 1970) + 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) + 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() + 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 @@ -157,16 +166,18 @@ ulonglong my_micro_time_and_time(time_t *time_arg) if (query_performance_frequency) { QueryPerformanceCounter((LARGE_INTEGER*) &newtime); - newtime/= (query_performance_frequency * 1000000); + return ((newtime / query_performance_frequency * 10000000) + + (newtime % query_performance_frequency * 10000000 / + query_performance_frequency)); } else - newtime= (GetTickCount() * 1000); /* GetTickCount only returns milliseconds */ + newtime= (GetTickCount() * 1000); /* GetTickCount only returns millisec. */ (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 + 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; @@ -184,7 +195,9 @@ ulonglong my_micro_time_and_time(time_t *time_arg) return cur_gethrtime/1000; #else struct timeval t; - /* The following loop is here because gettimeofday may fail on some systems */ + /* + The following loop is here because gettimeofday may fail on some systems + */ while (gettimeofday(&t, NULL) != 0) {} *time_arg= t.tv_sec; @@ -203,8 +216,8 @@ ulonglong my_micro_time_and_time(time_t *time_arg) 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. + if my_micro_time() uses a function that can safely be converted to the + current time. RETURN current time |