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sigsuspend(2) [osf1 man page]

sigsuspend(2)							System Calls Manual						     sigsuspend(2)

NAME
sigsuspend - Atomically changes the set of blocked signals and waits for a signal LIBRARY
Standard C Library (libc.so, libc.a) SYNOPSIS
#include <signal.h> int sigsuspend ( const sigset_t *signal_mask ); STANDARDS
Interfaces documented on this reference page conform to industry standards as follows: sigsuspend(): XPG4, XPG4-UNIX Refer to the standards(5) reference page for more information about industry standards and associated tags. PARAMETERS
Points to a set of signals. DESCRIPTION
The sigsuspend() function replaces the signal mask of the process (or thread) with the set of signals pointed to by the signal_mask parame- ter, and then suspends execution of the caller until delivery of a signal whose action is either to execute a signal-catching function or to terminate the process. The sigsuspend() function does not allow the SIGKILL or SIGSTOP signals to be blocked. If a program attempts to block one of these signals, the sigsuspend() function gives no indication of the error; the illegal request is simply ignored. If delivery of a signal causes the process to terminate, the sigsuspend() function does not return. If delivery of a signal causes a sig- nal-catching function to execute, the sigsuspend() function returns after the signal-catching function returns, with the signal mask restored to the set that existed prior to the call to the sigsuspend() function. The sigsuspend() function sets the signal mask and waits for an unblocked signal as one atomic operation. This means that signals cannot occur between the operations of setting the mask and waiting for a signal. If a program invokes sigprocmask(SIG_SETMASK) and sigpause() separately, a signal that occurs between these functions might not be noticed by sigpause(). In normal usage, a signal is blocked by using the sigprocmask(SIG_BLOCK,...) or pthread_sigmask(...) function at the beginning of a crit- ical section. The process then determines whether there is work for it to do. If no work is to be done, the process waits for work by call- ing the sigsuspend() function with the mask previously returned by the sigprocmask() function. NOTES
The sigpause() function is provided for compatibility with older UNIX systems; its function is a subset of the sigsuspend() function. RETURN VALUES
Since the sigsuspend() function suspends process execution indefinitely, there is no successful completion return value. If a return occurs, -1 is returned and errno is set to indicate the error. ERRORS
The sigsuspend() function sets errno to the specified values for the following conditions: A signal is caught by the calling process and control is returned from the signal-catching function. RELATED INFORMATION
Functions: pause(3), sigaction(2), sigblock(2), sigprocmask(2), sigvec(2) Standards: standards(5) delim off sigsuspend(2)

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SIGSUSPEND(2)						     Linux Programmer's Manual						     SIGSUSPEND(2)

NAME
sigsuspend - wait for a signal SYNOPSIS
#include <signal.h> int sigsuspend(const sigset_t *mask); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigsuspend(): _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE DESCRIPTION
sigsuspend() temporarily replaces the signal mask of the calling process with the mask given by mask and then suspends the process until delivery of a signal whose action is to invoke a signal handler or to terminate a process. If the signal terminates the process, then sigsuspend() does not return. If the signal is caught, then sigsuspend() returns after the sig- nal handler returns, and the signal mask is restored to the state before the call to sigsuspend(). It is not possible to block SIGKILL or SIGSTOP; specifying these signals in mask, has no effect on the process's signal mask. RETURN VALUE
sigsuspend() always returns -1, normally with the error EINTR. ERRORS
EFAULT mask points to memory which is not a valid part of the process address space. EINTR The call was interrupted by a signal. CONFORMING TO
POSIX.1-2001. NOTES
Normally, sigsuspend() is used in conjunction with sigprocmask(2) in order to prevent delivery of a signal during the execution of a criti- cal code section. The caller first blocks the signals with sigprocmask(2). When the critical code has completed, the caller then waits for the signals by calling sigsuspend() with the signal mask that was returned by sigprocmask(2) (in the oldset argument). See sigsetops(3) for details on manipulating signal sets. SEE ALSO
kill(2), pause(2), sigaction(2), signal(2), sigprocmask(2), sigwaitinfo(2), sigsetops(3), sigwait(3), signal(7) COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2008-08-29 SIGSUSPEND(2)
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