Timers

Timers — keep track of elapsed time

Synopsis


#include <glib.h>

                    GTimer;
GTimer*             g_timer_new                         (void);
void                g_timer_start                       (GTimer *timer);
void                g_timer_stop                        (GTimer *timer);
void                g_timer_continue                    (GTimer *timer);
gdouble             g_timer_elapsed                     (GTimer *timer,
                                                         gulong *microseconds);
void                g_timer_reset                       (GTimer *timer);
void                g_timer_destroy                     (GTimer *timer);

Description

GTimer records a start time, and counts microseconds elapsed since that time. This is done somewhat differently on different platforms, and can be tricky to get exactly right, so GTimer provides a portable/convenient interface.

Note

GTimer uses a higher-quality clock when thread support is available. Therefore, calling g_thread_init() while timers are running may lead to unreliable results. It is best to call g_thread_init() before starting any timers, if you are using threads at all.

Details

GTimer

typedef struct _GTimer GTimer;

Opaque datatype that records a start time.


g_timer_new ()

GTimer*             g_timer_new                         (void);

Creates a new timer, and starts timing (i.e. g_timer_start() is implicitly called for you).

Returns : a new GTimer.

g_timer_start ()

void                g_timer_start                       (GTimer *timer);

Marks a start time, so that future calls to g_timer_elapsed() will report the time since g_timer_start() was called. g_timer_new() automatically marks the start time, so no need to call g_timer_start() immediately after creating the timer.

timer : a GTimer.

g_timer_stop ()

void                g_timer_stop                        (GTimer *timer);

Marks an end time, so calls to g_timer_elapsed() will return the difference between this end time and the start time.

timer : a GTimer.

g_timer_continue ()

void                g_timer_continue                    (GTimer *timer);

Resumes a timer that has previously been stopped with g_timer_stop(). g_timer_stop() must be called before using this function.

timer : a GTimer.

Since 2.4


g_timer_elapsed ()

gdouble             g_timer_elapsed                     (GTimer *timer,
                                                         gulong *microseconds);

If timer has been started but not stopped, obtains the time since the timer was started. If timer has been stopped, obtains the elapsed time between the time it was started and the time it was stopped. The return value is the number of seconds elapsed, including any fractional part. The microseconds out parameter is essentially useless.

Warning

Calling initialization functions, in particular g_thread_init(), while a timer is running will cause invalid return values from this function.

timer : a GTimer.
microseconds : return location for the fractional part of seconds elapsed, in microseconds (that is, the total number of microseconds elapsed, modulo 1000000), or NULL
Returns : seconds elapsed as a floating point value, including any fractional part.

g_timer_reset ()

void                g_timer_reset                       (GTimer *timer);

This function is useless; it's fine to call g_timer_start() on an already-started timer to reset the start time, so g_timer_reset() serves no purpose.

timer : a GTimer.

g_timer_destroy ()

void                g_timer_destroy                     (GTimer *timer);

Destroys a timer, freeing associated resources.

timer : a GTimer to destroy.