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Diffstat (limited to '')
-rw-r--r-- | mysys/my_getsystime.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/mysys/my_getsystime.c b/mysys/my_getsystime.c new file mode 100644 index 00000000..09360078 --- /dev/null +++ b/mysys/my_getsystime.c @@ -0,0 +1,146 @@ +/* Copyright (c) 2004, 2011, Oracle and/or its affiliates. + Copyright (c) 2009-2011 Monty Program Ab + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */ + + +#include "mysys_priv.h" +#include "my_static.h" + +#ifdef _WIN32 +#define OFFSET_TO_EPOC 116444736000000000LL +static ulonglong query_performance_frequency=1; +#endif + +#ifdef HAVE_LINUX_UNISTD_H +#include <linux/unistd.h> +#endif + +/* For CYGWIN */ +#if !defined(CLOCK_THREAD_CPUTIME_ID) && defined(CLOCK_THREAD_CPUTIME) +#define CLOCK_THREAD_CPUTIME_ID CLOCK_THREAD_CPUTIME +#endif + +/* + return number of nanoseconds since unspecified (but always the same) + point in the past + + NOTE: + Thus to get the current time we should use the system function + with the highest possible resolution + + The value is not anchored to any specific point in time (e.g. epoch) nor + is it subject to resetting or drifting by way of adjtime() or settimeofday(), + and thus it is *NOT* appropriate for getting the current timestamp. It can be + used for calculating time intervals, though. +*/ + +ulonglong my_interval_timer() +{ +#ifdef HAVE_CLOCK_GETTIME + struct timespec tp; + clock_gettime(CLOCK_MONOTONIC, &tp); + return tp.tv_sec*1000000000ULL+tp.tv_nsec; +#elif defined(HAVE_GETHRTIME) + return gethrtime(); +#elif defined(_WIN32) + DBUG_ASSERT(query_performance_frequency); + LARGE_INTEGER t_cnt; + QueryPerformanceCounter(&t_cnt); + return (t_cnt.QuadPart / query_performance_frequency * 1000000000ULL) + + ((t_cnt.QuadPart % query_performance_frequency) * 1000000000ULL / + query_performance_frequency); +#else + /* TODO: check for other possibilities for hi-res timestamping */ + struct timeval tv; + gettimeofday(&tv,NULL); + return tv.tv_sec*1000000000ULL+tv.tv_usec*1000ULL; +#endif +} + + +/* Return current time in HRTIME_RESOLUTION (microseconds) since epoch */ + +my_hrtime_t my_hrtime() +{ + my_hrtime_t hrtime; +#if defined(_WIN32) + ulonglong newtime; + GetSystemTimePreciseAsFileTime((FILETIME*)&newtime); + hrtime.val= (newtime - OFFSET_TO_EPOC)/10; +#elif defined(HAVE_CLOCK_GETTIME) + struct timespec tp; + clock_gettime(CLOCK_REALTIME, &tp); + hrtime.val= tp.tv_sec*1000000ULL+tp.tv_nsec/1000ULL; +#else + struct timeval t; + /* The following loop is here because gettimeofday may fail */ + while (gettimeofday(&t, NULL) != 0) {} + hrtime.val= t.tv_sec*1000000ULL + t.tv_usec; +#endif + DBUG_EXECUTE_IF("system_time_plus_one_hour", hrtime.val += 3600*1000000ULL;); + DBUG_EXECUTE_IF("system_time_minus_one_hour", hrtime.val -= 3600*1000000ULL;); + return hrtime; +} + +#ifdef _WIN32 + +/* + Low accuracy, "coarse" timer. + Has lower latency than my_hrtime(). Used in situations, where microsecond + precision is not needed, e.g in Windows pthread_cond_timedwait, where POSIX + interface needs nanoseconds, yet the underlying Windows function only + accepts millisecons. +*/ +my_hrtime_t my_hrtime_coarse() +{ + my_hrtime_t hrtime; + ulonglong t; + GetSystemTimeAsFileTime((FILETIME*)&t); + hrtime.val= (t - OFFSET_TO_EPOC)/10; + return hrtime; +} + +#endif + +void my_time_init() +{ +#ifdef _WIN32 + compile_time_assert(sizeof(LARGE_INTEGER) == + sizeof(query_performance_frequency)); + QueryPerformanceFrequency((LARGE_INTEGER *)&query_performance_frequency); + DBUG_ASSERT(query_performance_frequency); +#endif +} + + +/* + Return cpu time in 1/10th on a microsecond (1e-7 s) +*/ + +ulonglong my_getcputime() +{ +#ifdef CLOCK_THREAD_CPUTIME_ID + struct timespec tp; + if (clock_gettime(CLOCK_THREAD_CPUTIME_ID, &tp)) + return 0; + return (ulonglong)tp.tv_sec*10000000+(ulonglong)tp.tv_nsec/100; +#elif defined(__NR_clock_gettime) + struct timespec tp; + if (syscall(__NR_clock_gettime, CLOCK_THREAD_CPUTIME_ID, &tp)) + return 0; + return (ulonglong)tp.tv_sec*10000000+(ulonglong)tp.tv_nsec/100; +#endif /* CLOCK_THREAD_CPUTIME_ID */ + return 0; +} |