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handling signals without race conditions
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RAISE_DEFAULT_SIGNAL(3) BSD Library Functions Manual RAISE_DEFAULT_SIGNAL(3) NAME
raise_default_signal -- raise the default signal handler LIBRARY
System Utilities Library (libutil, -lutil) SYNOPSIS
#include <util.h> int raise_default_signal(int sig); DESCRIPTION
The raise_default_signal() function raises the default signal handler for the signal sig. This function may be used by a user-defined signal handler router to ensure that a parent process receives the correct notification of a process termination by a signal. This can be used to avoid a common programming mistake when terminating a process from a custom SIGINT or SIGQUIT signal handler. The operations performed are: 1. Block all signals, using sigprocmask(2). 2. Set the signal handler for signal sig to the default signal handler (SIG_DFL). 3. raise(3) signal sig. 4. Unblock signal sig to deliver it. 5. Restore the original signal mask and handler, even if there was a failure. See signal(7) for a table of signals and default actions. The raise_default_signal() function should be async-signal-safe. RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and the global variable errno is set to indicate the error. ERRORS
The raise_default_signal() function may fail and set errno for any of the errors specified for the functions sigemptyset(3), sigfillset(3), sigaddset(3), sigprocmask(2), sigaction(2), or raise(3). SEE ALSO
sigaction(2), sigprocmask(2), raise(3), signal(7) HISTORY
The raise_default_signal() function first appeared in NetBSD 5.0. BSD
September 25, 2007 BSD
