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Diffstat (limited to 'linuxthreads/man/pthread_sigmask.man')
| -rw-r--r-- | linuxthreads/man/pthread_sigmask.man | 123 |
1 files changed, 0 insertions, 123 deletions
diff --git a/linuxthreads/man/pthread_sigmask.man b/linuxthreads/man/pthread_sigmask.man deleted file mode 100644 index 784161da2b..0000000000 --- a/linuxthreads/man/pthread_sigmask.man +++ /dev/null @@ -1,123 +0,0 @@ -.TH PTHREAD_SIGNAL 3 LinuxThreads - -.XREF pthread_kill -.XREF sigwait - -.SH NAME -pthread_sigmask, pthread_kill, sigwait \- handling of signals in threads - -.SH SYNOPSIS -#include <pthread.h> -.br -#include <signal.h> - -int pthread_sigmask(int how, const sigset_t *newmask, sigset_t *oldmask); - -int pthread_kill(pthread_t thread, int signo); - -int sigwait(const sigset_t *set, int *sig); - -.SH DESCRIPTION - -!pthread_sigmask! changes the signal mask for the calling thread as -described by the |how| and |newmask| arguments. If |oldmask| is not -!NULL!, the previous signal mask is stored in the location pointed to -by |oldmask|. - -The meaning of the |how| and |newmask| arguments is the same as for -!sigprocmask!(2). If |how| is !SIG_SETMASK!, the signal mask is set to -|newmask|. If |how| is !SIG_BLOCK!, the signals specified to |newmask| -are added to the current signal mask. If |how| is !SIG_UNBLOCK!, the -signals specified to |newmask| are removed from the current signal -mask. - -Recall that signal masks are set on a per-thread basis, but signal -actions and signal handlers, as set with !sigaction!(2), are shared -between all threads. - -!pthread_kill! send signal number |signo| to the thread -|thread|. The signal is delivered and handled as described in -!kill!(2). - -!sigwait! suspends the calling thread until one of the signals -in |set| is delivered to the calling thread. It then stores the number -of the signal received in the location pointed to by |sig| and -returns. The signals in |set| must be blocked and not ignored on -entrance to !sigwait!. If the delivered signal has a signal handler -function attached, that function is |not| called. - -.SH CANCELLATION - -!sigwait! is a cancellation point. - -.SH "RETURN VALUE" - -On success, 0 is returned. On failure, a non-zero error code is returned. - -.SH ERRORS - -The !pthread_sigmask! function returns the following error codes -on error: -.RS -.TP -!EINVAL! -|how| is not one of !SIG_SETMASK!, !SIG_BLOCK!, or !SIG_UNBLOCK! - -.TP -!EFAULT! -|newmask| or |oldmask| point to invalid addresses -.RE - -The !pthread_kill! function returns the following error codes -on error: -.RS -.TP -!EINVAL! -|signo| is not a valid signal number - -.TP -!ESRCH! -the thread |thread| does not exist (e.g. it has already terminated) -.RE - -The !sigwait! function never returns an error. - -.SH AUTHOR -Xavier Leroy <Xavier.Leroy@inria.fr> - -.SH "SEE ALSO" -!sigprocmask!(2), -!kill!(2), -!sigaction!(2), -!sigsuspend!(2). - -.SH NOTES - -For !sigwait! to work reliably, the signals being waited for must be -blocked in all threads, not only in the calling thread, since -otherwise the POSIX semantics for signal delivery do not guarantee -that it's the thread doing the !sigwait! that will receive the signal. -The best way to achieve this is block those signals before any threads -are created, and never unblock them in the program other than by -calling !sigwait!. - -.SH BUGS - -Signal handling in LinuxThreads departs significantly from the POSIX -standard. According to the standard, ``asynchronous'' (external) -signals are addressed to the whole process (the collection of all -threads), which then delivers them to one particular thread. The -thread that actually receives the signal is any thread that does -not currently block the signal. - -In LinuxThreads, each thread is actually a kernel process with its own -PID, so external signals are always directed to one particular thread. -If, for instance, another thread is blocked in !sigwait! on that -signal, it will not be restarted. - -The LinuxThreads implementation of !sigwait! installs dummy signal -handlers for the signals in |set| for the duration of the wait. Since -signal handlers are shared between all threads, other threads must not -attach their own signal handlers to these signals, or alternatively -they should all block these signals (which is recommended anyway -- -see the Notes section). |