From d17de811757c09c89b64631d442884bb14791c57 Mon Sep 17 00:00:00 2001 From: Lucas De Marchi Date: Mon, 27 Sep 2010 22:35:35 +0000 Subject: [PATCH] Make ecore_time_get and friends use monotonic clock Instead of relying on unix time, use a monotonic clock provided by clock_gettime(). If a monotonic clock is not available, it will fallback to CLOCK_REALTIME or unix time if neither is available. The impact is that now it only makes sense to call ecore_time_get() or ecore_time_loop_get() if the value retrieved is intended to be used as relative to previous/posterior measurements. If an absolute value is needed, the right function to call now is ecore_time_unix_get() which will give the number of seconds since Jan 1st, 1970, 12:00AM. SVN revision: 52824 --- legacy/ecore/configure.ac | 12 ++ legacy/ecore/src/lib/ecore/Ecore.h | 1 + legacy/ecore/src/lib/ecore/Makefile.am | 2 +- legacy/ecore/src/lib/ecore/ecore.c | 2 +- legacy/ecore/src/lib/ecore/ecore_private.h | 2 + legacy/ecore/src/lib/ecore/ecore_time.c | 121 ++++++++++++++++++--- 6 files changed, 122 insertions(+), 18 deletions(-) diff --git a/legacy/ecore/configure.ac b/legacy/ecore/configure.ac index 9df3cdd1b4..ba4b7fbef3 100644 --- a/legacy/ecore/configure.ac +++ b/legacy/ecore/configure.ac @@ -404,17 +404,29 @@ case "$host_os" in mingw32ce* | cegcc*) WIN32_LIBS="-lws2" dlopen_libs="-ldl" + rt_libs="-lrt" ;; mingw*) WIN32_LIBS="-lws2_32" dlopen_libs="-ldl" + rt_libs="-lrt" ;; *) AC_CHECK_LIB(dl, dlopen, dlopen_libs=-ldl) + AC_CHECK_LIB(rt, clock_gettime, rt_libs=-lrt) ;; esac AC_SUBST(WIN32_LIBS) AC_SUBST(dlopen_libs) +AC_SUBST(rt_libs) + +if test -n "$rt_libs"; then + _bkp_LDFLAGS="$LDFLAGS" + LDFLAGS="$LDFLAGS $rt_libs" + AC_CHECK_FUNCS(clock_gettime) + LDFLAGS="$_bkp_LDFLAGS" + unset "$_bkp_LDFLAGS" +fi # Eina library diff --git a/legacy/ecore/src/lib/ecore/Ecore.h b/legacy/ecore/src/lib/ecore/Ecore.h index d3645e9c15..f547f5e47e 100644 --- a/legacy/ecore/src/lib/ecore/Ecore.h +++ b/legacy/ecore/src/lib/ecore/Ecore.h @@ -445,6 +445,7 @@ extern "C" { EAPI double ecore_time_get(void); + EAPI double ecore_time_unix_get(void); EAPI double ecore_loop_time_get(void); EAPI Ecore_Timer *ecore_timer_add(double in, Ecore_Task_Cb func, const void *data); diff --git a/legacy/ecore/src/lib/ecore/Makefile.am b/legacy/ecore/src/lib/ecore/Makefile.am index 960e9dc816..37e7bda5b2 100644 --- a/legacy/ecore/src/lib/ecore/Makefile.am +++ b/legacy/ecore/src/lib/ecore/Makefile.am @@ -45,7 +45,7 @@ endif endif -libecore_la_LIBADD = @dlopen_libs@ @EINA_LIBS@ @EVIL_LIBS@ @GLIB_LIBS@ @WIN32_LIBS@ @LTLIBINTL@ @EFL_PTHREAD_LIBS@ -lm +libecore_la_LIBADD = @dlopen_libs@ @EINA_LIBS@ @EVIL_LIBS@ @GLIB_LIBS@ @WIN32_LIBS@ @LTLIBINTL@ @EFL_PTHREAD_LIBS@ @rt_libs@ -lm libecore_la_LDFLAGS = -no-undefined @lt_enable_auto_import@ -version-info @version_info@ @release_info@ EXTRA_DIST = ecore_private.h diff --git a/legacy/ecore/src/lib/ecore/ecore.c b/legacy/ecore/src/lib/ecore/ecore.c index 5bf12bc10d..8f2a045f72 100644 --- a/legacy/ecore/src/lib/ecore/ecore.c +++ b/legacy/ecore/src/lib/ecore/ecore.c @@ -117,7 +117,7 @@ ecore_init(void) _ecore_thread_init(); _ecore_glib_init(); _ecore_job_init(); - _ecore_loop_time = ecore_time_get(); + _ecore_time_init(); #if HAVE_MALLINFO if (getenv("ECORE_MEM_STAT")) diff --git a/legacy/ecore/src/lib/ecore/ecore_private.h b/legacy/ecore/src/lib/ecore/ecore_private.h index 170845941b..5ff4ab27d3 100644 --- a/legacy/ecore/src/lib/ecore/ecore_private.h +++ b/legacy/ecore/src/lib/ecore/ecore_private.h @@ -117,6 +117,8 @@ typedef unsigned int Ecore_Magic; EAPI void _ecore_magic_fail(const void *d, Ecore_Magic m, Ecore_Magic req_m, const char *fname); +void _ecore_time_init(void); + void _ecore_timer_shutdown(void); void _ecore_timer_cleanup(void); void _ecore_timer_enable_new(void); diff --git a/legacy/ecore/src/lib/ecore/ecore_time.c b/legacy/ecore/src/lib/ecore/ecore_time.c index 9e51df6abf..b26a390eee 100644 --- a/legacy/ecore/src/lib/ecore/ecore_time.c +++ b/legacy/ecore/src/lib/ecore/ecore_time.c @@ -15,20 +15,62 @@ #include "Ecore.h" #include "ecore_private.h" +#include - -/* FIXME: clock_gettime() is an option... */ +#if HAVE_CLOCK_GETTIME +static clockid_t _ecore_time_clock_id = -1; +#endif +double _ecore_loop_time = -1.0; /** * Retrieves the current system time as a floating point value in seconds. * - * Also see ecore_loop_time_get(). + * This uses a monotonic clock and thus never goes back in time while + * machine is live (even if user changes time or timezone changes, + * however it may be reset whenever the machine is restarted). + * + * @see ecore_loop_time_get(). + * @see ecore_time_unix_get(). + * + * @return The number of seconds. Start time is not defined (it may be + * when the machine was booted, unix time, etc), all it is + * defined is that it never goes backwards (unless you got big critical + * messages when the application started). + * @ingroup Ecore_Time_Group + */ +EAPI double +ecore_time_get(void) +{ +#if !HAVE_CLOCK_GETTIME + return ecore_time_unix_get(); +#else + struct timespec t; + + if (EINA_UNLIKELY(_ecore_time_clock_id < 0)) + return ecore_time_unix_get(); + + if (EINA_UNLIKELY(clock_gettime(_ecore_time_clock_id, &t))) + { + CRIT("Cannot get current time."); + /* Try to at least return the latest value retrieved*/ + return _ecore_loop_time; + } + + return (double)t.tv_sec + (((double)t.tv_nsec) / 1000000000.0); +#endif +} + +/** + * Retrieves the current UNIX time as a floating point value in seconds. + * + * @see ecore_time_get(). + * @see ecore_loop_time_get(). * * @return The number of seconds since 12.00AM 1st January 1970. * @ingroup Ecore_Time_Group */ EAPI double -ecore_time_get(void) +ecore_time_unix_get(void) { #ifdef HAVE_EVIL return evil_time_get(); @@ -44,21 +86,26 @@ ecore_time_get(void) #endif } -double _ecore_loop_time = -1.0; - /** - * Retrieves the time at which the last loop stopped waiting for timeouts or events + * Retrieves the time at which the last loop stopped waiting for timeouts or + * events. * - * This gets the time (since Jan 1st, 1970, 12:00AM) that the main loop ceased - * waiting for timouts and/or events to come in or for signals or any other - * interrupt source. This should be considered a reference point for all - * time based activity that should calculate its timepoint from the return - * of ecore_loop_time_get(). use this UNLESS you absolutely must get the - * current actual timepoint - then use ecore_time_get(). If this is called - * before any loop has ever been run, then it will call ecore_time_get() for - * you the first time and thus have an initial time reference. + * This gets the time that the main loop ceased waiting for timouts and/or + * events to come in or for signals or any other interrupt source. This should + * be considered a reference point for all time based activity that should + * calculate its timepoint from the return of ecore_loop_time_get(). Use this + * UNLESS you absolutely must get the current actual timepoint - then use + * ecore_time_get(). Note that this time is meant to be used as relative to + * other times obtained on this run. If you need absolute time references, use + * ecore_time_unix_get() instead. * - * @return The number of seconds since 12.00AM 1st January 1970. + * This function can be called before any loop has ever been run, but either + * ecore_init() or ecore_time_get() must have been called once. + * + * @return The number of seconds. Start time is not defined (it may be + * when the machine was booted, unix time, etc), all it is + * defined is that it never goes backwards (unless you got big critical + * messages when the application started). * @ingroup Ecore_Time_Group */ EAPI double @@ -66,3 +113,45 @@ ecore_loop_time_get(void) { return _ecore_loop_time; } + + +/********************** Internal methods ********************************/ + +/* TODO: Documentation says "All implementations support the system-wide + * real-time clock, which is identified by CLOCK_REALTIME. Check if the fallback + * to unix time (without specifying the resolution) might be removed + */ +void +_ecore_time_init(void) +{ +#if HAVE_CLOCK_GETTIME + struct timespec t; + + if (_ecore_time_clock_id != -1) return; + + if (!clock_gettime(CLOCK_MONOTONIC, &t)) + { + _ecore_time_clock_id = CLOCK_MONOTONIC; + DBG("using CLOCK_MONOTONIC."); + } + else if (!clock_gettime(CLOCK_REALTIME, &t)) + { + /* may go backwards */ + _ecore_time_clock_id = CLOCK_REALTIME; + WRN("CLOCK_MONOTONIC not available. Fallback to CLOCK_REALTIME."); + } + else + { + _ecore_time_clock_id = -2; + CRIT("Cannot get a valid clock_gettime() clock id! " + "Fallback to unix time."); + } +#else +# warning "Your platform isn't supported yet" + _ecore_time_clock_it = -2; + CRIT("Platform does not support clock_gettime. " + "Fallback to unix time."); +#endif + + _ecore_loop_time = ecore_time_get(); +}