Write a c program to catch the sigalrm signal

Thanks a lot for any information. Please reply to my e-mail address also in addition to posting to the newsgroup. Thanks, Rajesh Dasari, University of Florida. There is no signal handling in Win There is no way to create a periodic interval. What you can do is create a separate thread which will act as a timer by invoking callbacks. Please don't crosspost these kinds of platform-specific questions to comp. Forget signals - they are basically present on Unix to compensate for the fact that most Unix systems aren't multi-threaded.

What you'd do with signals under Unix, do with threads under NT. Simply create a thread which "sleeps" for the required interval and then calls the appropriate function.

Where have we heard this before? The textbook WinNT examples of multithreading are lame. Use MT when you need to drive your car with one hand and eat a sandwich with the other; the two processes "should" not interfere with each other, except for contention over a single resource, your face.

But the textbook examples show simple things, like reading two files at the same time, or multiplexing blocking IO from a serial port and the mouse at the same time. Prerequisite : Fork system call , Wait system call A signal is a software generated interrupt that is sent to a process by the OS because of when user press ctrl-c or another process tell something to this process.

There are fix set of signals that can be sent to a process. Signal number have symbolic names. The two integers keep track of: pending signals and blocked signals With 32 bit integers, up to 32 different signals can be represented.

A signal is sent to a process setting the corresponding bit in the pending signals integer for the process. Each time the OS selects a process to be run on a processor, the pending and blocked integers are checked.

If no signals are pending, the process is restarted normally and continues executing at its next instruction. If 1 or more signals are pending, but each one is blocked, the process is also restarted normally but with the signals still marked as pending. Default Signal Handlers There are several default signal handler routines. Each signal is associated with one of these default handler routine. The different default handler routines typically have one of the following actions: Ign: Ignore the signal; i.

If user presses ctrl-c to terminate the process because of SIGINT signal sent and its default handler to terminate the process. A signal handler function can have any name, but must have return type void and have one int parameter. Hi, Thanks a lot, very nice article.. Thanks again.. Nima March 10, , am. Himanshu March 10, , pm. Nima March 10, , pm.

Himanshu Arora March 12, , am. Ganesh April 27, , am. Thanks a lot for this article, it really helped me to understand my course and to do my practical work.

Regards from france! Chomp January 9, , am. Vlad January 15, , am. Arjun Pakrashi December 4, , pm. Radu March 15, , am. Mixing sleep with alarm is a bad idea, according to the Linux manual because they both share the same timer: calls to one will interfere with use of other Anyway, I like your stuff! Nick H. September 17, , am. Rahul April 30, , am. Andro Nooh February 6, , pm. I will be posting instruction guides, how-to, troubleshooting tips and tricks on Linux, database, hardware, security and web.

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