"Go" Linux Posix timer use

Original URL: http://blog.csdn.net/hongszh/article/details/8608781

The most powerful timer interface from the POSIX clock series, its creation, initialization, and removal of a timer action is divided into three different functions: Timer_create () (Create timer), Timer_settime () (initialization timer), and Timer_delete (Destroy it).

Man Timer_create/timer_settime, you can see the detailed documentation for man help:

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2. Timer_create (2) Linux Programmer ' s Manual
6. NAME
8. Timer_create-create a POSIX per-process timer
12. Synopsis
14. #include <signal.h>
16. #include <time.h>
20. int timer_create (clockid_t clockid, struct sigevent *sevp,
22. timer_t *timerid);
24. int Timer_settime (timer_t timerid, int flags,
26. const struct itimerspec *new_value,
28. struct Itimerspec * old_value);
30. int Timer_gettime (timer_t timerid, struct itimerspec *curr_value);

My implementation is as follows:

1. Define the function pointer type for timer timeout:

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1. typedef VOID (*timertimeout) (Union sigval SIG);

2. Define a two timer ID for our Gstplayer:

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1. timer_t Mseektimer;
2. timer_t Mprepareasynctimer;

3. Define the Createtimer function, create a timer, set the timeout function
Timerid: input and output parameters
Func:timer Timeout function

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2. void Createtimer (timer_t *timerid, timertimeout func)
4. {
6. struct sigevent sev;
10. Sev.sigev_notify = Sigev_thread;
12. Sev.sigev_signo = Sigrtmin;
14. Sev.sigev_value.sival_ptr = GPlayer;
16. Sev.sigev_notify_function = func;
18. Sev.sigev_notify_attributes = NULL;
22. / * Create timer * /
24. if (timer_create (Clock_realtime, &sev, timerid) = =-1)
26. {
28. ERR ("timer_create, error");
30. return;
32. }
36. if (*timerid = =-1)
38. ERR ("timer_create error, ID is-1");
40. return;
42. }

4. SetTimer function, call the Linux timer_settime, if not to time out, reset the previous timer

If it is already time out, you have to call Createtimer to generate a valid timer ID before calling SetTimer to start the timer.

-Here, set the interval parameter to 0 and specify that my timer does not work in loop mode.
-TIMEMSEC is the input parameter that specifies the time of day out in milliseconds.

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2. void SetTimer (timer_t *timerid, int timemsec)
4. {
6. struct Itimerspec its;
10. / * Start the timer * /
12. Its.it_value.tv_sec = timemsec/1000;
14. its.it_value.tv_nsec = (timemsec% 1000) * 1000000;
18. its.it_interval.tv_sec = 0;
20. its.it_interval.tv_nsec = 0;
24. if (timer_settime (*timerid, 0, &its, NULL) = =-1)
26. {
28. ERR ("Timer_settime error");
30. }
32. DEBUG ("Call Timer_settime reset timer is done.");
34. return;
36. }

The Seektimertimeout function, after time out, destroys the timer created before the Createtimer is destroyed and the work to do after time is completed

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2. void Seektimertimeout (Union sigval SIG)
4. {
6. Gstplayer *player = (gstplayerplayer*) sig.sival_ptr;
8. if (player->mseektimer! =-1)
10. {
12. DEBUG ("timeout, delete Timer:id =%d",
14. Player->mseektimer);
16. Timer_delete (Player->mseektimer);
18. Player->mseektimer =-1;
20. }
22. // ... Work to do after time is completed
24. }

The time out function of the prepareasynctimeout:

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2. void Prepareasynctimeout (Union sigval SIG)
4. {
6. Gststatechangereturn State_return;
8. Gstplayer *player = (gstplayerplayer*) sig.sival_ptr;
12. if (player->mprepareasynctimer! =-1)
14. {
16. DEBUG ("timeout, delete Timer:id =%d",
18. Player->mprepareasynctimer);
20. Timer_delete (Player->mprepareasynctimer);
22. Player->mprepareasynctimer =-1;
24. }
28. // ... Work to do after time is completed
30. }

Call One:

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1. Create timer, set Prepareasynctimeout
2. Start Timer,timeout time is 500ms
4. Createtimer (&mprepareasynctimer, prepareasynctimeout);
5. SetTimer (&mprepareasynctimer,/*ms*/);

Call Two:

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2. Create a timer and set the timeout callback function.
4. //Create timer
6. if (Mseektimer = =-1)
8. {
10. Createtimer (&mseektimer, seektimertimeout);
12. }
16. Determine if the Mseektimer is valid, valid, and calculate the remaining time to timeout, if not to timeout, reset timer,
18. Start a new timing.
20. //If timer exist and not expire, reset timer.
22. if (mseektimer! =-1)
24. {
26. Gulong remaining = 0; //us
28. struct Itimerspec its;
32. Timer_gettime (Mseektimer, &its);
34. Remaining = Its.it_value.tv_sec * 1000000
36. its.it_value.tv_nsec/1000;
38. DEBUG ("--remaining time =%lu us", remaining);
40. if ((/*ms*/* 1000-remaining) > 0)
42. {
44. SetTimer (&mseektimer,/*ms*/);
46. DEBUG ("The new seek interval < 100ms, return");
48. Mseekcount = 1;
50. return TRUE;
52. }
54. }

Reference:

http://blog.163.com/zheng_he_xiang/blog/static/18650532620116311020390/
http://blog.csdn.net/leo9150285/article/details/8271910

"Go" Linux Posix timer use