During this time, an interval timer runs, first for one second, then on an interval of 300 milliseconds.įor better understanding, save and compile the sample code with the name interval. The above code uses the sleep() function to wait for three seconds. Setitimer(ITIMER_REAL, &new_timer, &old_timer) Įrrorf("sleep error %s", strerror(errno))
Printf("Signal %d caught on %li.% 03li ", signum, now.tv_sec, now.tv_usec / 1000) Here is an example of defining the signal handler function with the debug header: # include which is not one of ITIMERREAL, ITIMERVIRTUAL, or ITIMERPROF or (since Linux 2.6.22) one of the tvusec fields in the structure pointed to by newvalue contains a value outside the range 0 to 999999. newvalue, oldvalue, or currvalue is not valid a pointer. All lwps executing in user mode when the timer expires are interrupted into system mode. On error, -1 is returned, and errno is set appropriately. The counter corresponds to the state of the lwp at the time of the timer tick. Although you can make a second check on the remaining time with gettimer(), it does not make sense to use them simultaneously. Each time the ITIMERREALPROF timer expires, one counter in a set of counters maintained by the system for each lightweight process (lwp) is incremented. It can be used to catch the most time-consuming functions in order to optimize the program. gprof is used to analyze the time-consuming of function calls. Using an interval timer and alarm() in the same application will be confusing. Linux performance optimization gprof usage. You can see from this table that the ITIMER_REAL type sends a SIGALRM signal, just like the alarm() function. subject='Re: y2038: move itimer reset into itimer.Independent of the time spent by the application, calculated over the total elapsed time.Ĭalculated over the time the application is running in user mode only.Ĭalculated over the sum of the time spent by the application in both user and system modes. for setting itimer / / Upon SIGALRM, call DoStuff().
* Reply using the -to, -cc, and -in-reply-to setitimer.c - simple use of the interval timer / include* Save the following mbox file, import it into your mail client,Īvoid top-posting and favor interleaved quoting: You may reply publicly to this message via plain-text email 21:12 ` y2038: allow disabling time32 system calls Arnd Bergmann 21:12 ` y2038: itimer: use ktime_t internally Arnd Bergmann
If oldvalue is non-NULL, the old value of the timer is stored there. The function setitimer () sets the specified timer to the value in newvalue. Similarly, itinterval is set to the reset value. 21:12 ` y2038: itimer: change implementation to timespec64 Arnd Bergmann The element itvalue is set to the amount of time remaining on the timer, or zero if the timer is disabled. 10:57 ` Arnd Bergmann 8:51 ` Ondrej Mosnacek 21:12 ` y2038: move itimer reset into itimer.c Arnd Bergmann > +static inline void clear_itimer(void) _itimer on alpha Arnd Bergmann The setitimer() function sets the timer specified by which to the value in the structure pointed to by value and stores the previous value of the timer in. > -extern int do_getitimer(int which, struct itimerval *value) > -extern int do_setitimer(int which, struct itimerval *value, > On Sat, at 2:43 PM Ondrej Mosnacek wrote: > On Sat, at 10:03 PM Arnd Bergmann wrote: > On Sun, at 12:07 AM Ondrej Mosnacek wrote: To understand whether we can do anything useful with this bug, we need to: Analyse what happens in itimerdelete to see whats being freed and how. Subject: Re: y2038: move itimer reset into itimer.cĭate: Thu, 09:51:52 +0100
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Re: y2038: move itimer reset into itimer.c - Ondrej Mosnacek LKML Archive on help / color / mirror / Atom feed From: Ondrej Mosnacek
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