NAME
pause - suspend the thread until a signal is received
SYNOPSIS
#include <unistd.h>
int pause(void);
DESCRIPTION
The pause() function shall suspend the calling thread until delivery of
a signal whose action is either to execute a signal-catching function
or to terminate the process.
If the action is to terminate the process, pause() shall not return.
If the action is to execute a signal-catching function, pause() shall
return after the signal-catching function returns.
RETURN VALUE
Since pause() suspends thread execution indefinitely unless interrupted
by a signal, there is no successful completion return value. A value of
-1 shall be returned and errno set to indicate the error.
ERRORS
The pause() function shall fail if:
EINTR A signal is caught by the calling process and control is
returned from the signal-catching function.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
Many common uses of pause() have timing windows. The scenario involves
checking a condition related to a signal and, if the signal has not
occurred, calling pause(). When the signal occurs between the check and
the call to pause(), the process often blocks indefinitely. The
sigprocmask() and sigsuspend() functions can be used to avoid this type
of problem.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
sigsuspend() , the Base Definitions volume of IEEE Std 1003.1-2001,
<unistd.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .