sleep()

Suspend a thread for a given length of time

Synopsis:

#include <unistd.h>

unsigned int sleep( unsigned int seconds );

Arguments:

seconds
The number of realtime seconds that you want to suspend the thread for.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The sleep() function suspends the calling thread until the number of realtime seconds specified by the seconds argument have elapsed, or the thread receives a signal whose action is either to terminate the process or to call a signal handler.

This function can interfere with the kernel's efforts to manage power usage. The suspension time may be greater than the requested amount, due to the nature of time measurement (see the Tick, Tock: Understanding the Microkernel's Concept of Time chapter of the BlackBerry 10 OS Programmer's Guide), or due to the scheduling of other, higher priority threads by the system.

Returns:

0 if the full time specified was completed; otherwise, the number of seconds unslept if interrupted by a signal.

Examples:

/*
 * The following program sleeps for the
 * number of seconds specified in argv[1].
 */
#include <stdlib.h>
#include <unistd.h>

int main( int argc, char **argv )
{
    unsigned seconds;

    seconds = (unsigned) strtol( argv[1], NULL, 0 );
    sleep( seconds );
    
    return EXIT_SUCCESS;
}

Classification:

POSIX 1003.1

Safety:  
Cancellation point Yes
Interrupt handler No
Signal handler Yes
Thread Yes

Last modified: 2013-12-23

comments powered by Disqus