glibc/linuxthreads/man/pthread_sigmask.man
Ulrich Drepper 5afdca0087 LinuxThreads library.
1998-03-11 00:42  Wolfram Gloger  <wmglo@dent.med.uni-muenchen.de>
	* linuxthreads/manager.c: Enable resetting of the thread
	scheduling policy to SCHED_OTHER when the parent thread
	has a different one.
1998-02-01 13:51  Ulrich Drepper  <drepper@cygnus.com>
	* sysdeps/unix/sysv/linux/bits/posix_opt.h: Define
	_POSIX_ASYNCHRONOUS_IO.
	* sysdeps/pthread/pthread.h: Define bits for Unix98 variants of
	mutexes.
	* mutex.c: Implement new mutex types.
	* internals.h: Include <signal.h>.
	* libpthread.map: Add __erno_location and __h_errno_location.
	* errno.c: Return pointer to variable actually in use.  This might
	not be the one in the thread structure.
	* internals.h (struct _pthread_descr_struct): Add new fields p_errnop
	and p_h_errnop.
	* manager.c (__pthread_manager): Set p_errnop and p_h_errnop member
	of manager thread structure.
	(pthread_handle_create): Set p_errnop and p_h_errnop members for new
	thread.
	* pthread.c: Adapt initializer for thread structures.
	(__pthread_initial_thread): Set p_errnop and p_h_errnop member.
	(__pthread_reset_main_thread): Reset p_errnop and p_h_errnop of
	current thread to global variables.
1998-01-31 17:27  Ulrich Drepper  <drepper@cygnus.com>
	* rwlock.c: New file.
	* Makefile (libpthread-routines): Add rwlock.
	* sysdeps/pthread/pthread.h: Define data structures and declare
	functions.
	* libpthread.map: Add new functions.
1997-12-18 13:50  Philip Blundell  <pb@nexus.co.uk>
	* sysdeps/arm/pt-machine.h: New file; add ARM support.
	* sysdeps/arm/Implies: likewise.
	* README: Document it.
1997-12-13  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* signals.c: Remove unneeded initializer for sigwaited, saving a
1997-04-11 01:18  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
	* semaphore.c (sem_init): Set sem_spinlock only if available.
1997-12-04 01:48  Ulrich Drepper  <drepper@cygnus.com>
	* mutex.c: Implement PTHREAD_MUTEX_CHECKERROR.
	* sysdeps/pthread/pthread.h: Define PTHREAD_MUTEX_CHECKERROR.
	* Makefile: Update from LinuxThreads 0.7.
	* internals.h. Likewise.
	* manager.c: Likewise.
	* mutex.c: Likewise.
	* pthread.c: Likewise.
	* signals.c: Likewise.
	* specific.c: Likewise.
	* Examples/ex3.c: Likewise.
1997-11-20 18:13  Ulrich Drepper  <drepper@cygnus.com>
	* pthread.c (__pthread_reset_main_thread): Close pipe only if still
	open.
1997-10-29 05:38  Ulrich Drepper  <drepper@cygnus.com>

	* wrapsyscall.c: Add socket functions which are also cancelation
	points.

1997-10-19 21:40  Wolfram Gloger  <wg@wolfram.dent.med.uni-muenchen.de>

	* specific.c (__libc_internal_tsd_set, __libc_internal_tsd_get):
	New functions for fast thread specific data within libc.

	* internals.h: Add new array p_libc_specific to struct
	_pthread_descr_struct.

	* sysdeps/pthread/bits/libc-lock.h: Declare new functions.

1997-10-13 05:39  Ulrich Drepper  <drepper@cygnus.com>

	* semaphore.h: Add __BEGIN_DECLS/__END_DECLS.
	Reported by Ralf Corsepius <corsepiu@faw.uni-ulm.de>.

1997-08-29 03:05  Ulrich Drepper  <drepper@cygnus.com>

	* internals.h (struct _pthread_descr_struct): Add definitions for
	two-level specific key handling.
	* manager.c (pthread_handle_create): Initialize specific memory array.
	* specific.c: Implement two-level key handling.
	* weaks.c: Don't provide dummy key handling.
	* sysdeps/pthread/bits/libc-lock.h: Typedef __libc_lock_t (no #define).
	Add definition of __libc_key_t.
	* sysdeps/unix/sysv/linux/bits/local_lim.h: Define PTHREAD_KEYS_MAX
	as 1024.
	Add definition of _POSIX_THREAD_DESTRUCTOR_ITERATIONS and
	PTHREAD_DESTRUCTOR_ITERATIONS.

	* manager.c (pthread_handle_create): Compare mmap result with
	MAP_FAILED.

	* ptfork.c: Rename to __pthread_atfork and make old name a weak alias.
	* sysdeps/pthread/bits/pthread.h: Add prototype for __pthread_atfork.

1997-08-22 19:04  Richard Henderson  <rth@cygnus.com>

	sysdeps/sparc -> sysdeps/sparc/sparc32
	sysdeps/sparc64 -> sysdeps/sparc/sparc64

	* internals.h: Change definition of THREAD_SELF to be an expression,
	not a statement that did a return.
	* sysdeps/alpha/pt-machine.h (THREAD_SELF): Update accordingly.
	* sysdeps/sparc/sparc32/pt-machine.h (THREAD_SELF, INIT_THREAD_SELF):
	Follow Solaris and use a "system reserved" register (%g6) to hold
	the thread descriptor.
	* sysdeps/sparc/sparc64/pt-machine.h: Likewise.

1997-08-03 00:09  Ulrich Drepper  <drepper@cygnus.com>

	* mutex.c: Correct pthread_once.  Patch by Xavier Leroy.
	* sysdeps/pthread/pthread.h: Add prototype for __pthread_once.
	* sysdeps/pthread/bits/pthread.h: Add macros for __libc_once.

	* semaphore.c: Include spinlock.h only when needed.

	* specific.c (__pthread_setsepcific, __pthread_getspecific): Reject
	keys for entries not in use.

	* weaks.c: Implement key handling functions for real.

1997-06-29  01:04  Richard Henderson  <richard@gnu.ai.mit.edu>

	Initial sparc64-linux support:
	* linuxthreads/sysdeps/sparc64/Implies: New file.
	* linuxthreads/sysdeps/sparc64/pt-machine.h: Likewise.

1997-06-29 00:48  Ulrich Drepper  <drepper@cygnus.com>

	* semaphore.c: Include spinlock.h at correct place.
	Patch by HJ Lu.

1997-06-13 10:06  Richard Henderson  <rth@tamu.edu>

	The Great Bit File Move:
	* sysdeps/alpha/semaphorebits.h: -> .../bits/semaphore.h.
	* sysdeps/powerpc/semaphorebits.h: Likewise.
	* sysdeps/pthread/cmpxchg/semaphorebits.h: Likewise.
	* sysdeps/pthread/no-cmpxchg/semaphorebits.h: Likewise.
	* sysdeps/pthread/libc-lock.h: -> bits/
	* sysdeps/pthread/stdio-lock.h: Likewise.
	* sysdeps/unix/sysv/linux/local_lim.h: Likewise.
	* sysdeps/unix/sysv/linux/posix_opt.h: Likewise.
	* semaphore.h: Likewise.
	* sysdeps/pthread/pthread.h: Likewise.

	* lockfile.c: <foo.h> -> <bits/foo.h>.
	* semaphore.h: Likewise.

	* Makefile: (headers): foo.h -> bits/foo.h.
	* sysdeps/pthread/Makefile: Likewise.

1997-04-11 01:18  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* semaphore.c (sem_init): Set sem_spinlock only if available.

	* sysdeps/m68k/pt-machine.h (testandset, __compare_and_swap): Fix
	asm constraints.

1997-04-09 03:00  Ulrich Drepper  <drepper@cygnus.com>

	Update from LinuxThreads 0.6.

	* attr.c (pthread_attr_getdetachstate): Use __sched_get_priority_max
	and __sched_get_priority_min instead of names without `__'.

	* manager.c: Rewrite large parts to implement opaque pthread_t.

	* cancel.c: Adapt for opaque pthread_t type.
	* condvar.c: Likewise.
	* errno.c: Likewise.
	* join.c: Likewise.
	* mutex.c: Likewise.
	* pthread.c: Likewise.
	* signals.c: Likewise.
	* specific.c: Likewise.
	* restart.h: Likewise.
	* queue.h: Likewise.
	* Examples/ex3.c: Likewise.
	* Examples/ex4.c: Likewise.
	* sysdeps/pthread/pthread.h: Likewise.

	* pthread.c: Accumulate time for all threads in thread manager.

	* semaphore.c: Implement fallback implementation for architectures
	sometimes missing compare-exchange operations.

	* cancel.c (pthread_cancel): Validate handle argument.
	* join.c (pthread_join): Likewise.
	(pthread_detach): Likewise.
	* signals.c (pthread_kill): Likewise.

	* spinlock.h (acquire): Use __sched_yield not sched_yield.

	* queue.h (enqueue): Enqueue thread according to priority.

	* internals.c (struct pthread_start_args): New struct for passing
	args to cloning function.
	(struct _pthread): Rename to _pthread_descr_struct and adapt for
	opaque pthread_t.

	* Examples/Makefile (clean): Pass -f option to rm.

	* sysdeps/i386/pt-machine.h: Add check for compare-exchange instruction
	and define TEST_FOR_COMPARE_AND_SWAP.
	* sysdeps/i386/i486/pt-machine.h: Removed.

	* sysdeps/unix/sysv/linux/local_lim.h (PTHREAD_THREADS_MAX): Increase
	to 1024.

1997-04-04 16:38  Ulrich Drepper  <drepper@cygnus.com>

	* restart.h (suspend): Clear p_signal before suspending.
	(suspend_with_cancellation): Likewise.
	Patch by Xavier Leroy <Xavier.Leroy@inria.fr>.

	* weaks.c: Make __pthread_key_create return 1.
	* sysdeps/pthread/libc-lock.h: Define __libc_key_create,
	__libc_getspecific, __libc_setspecific, and __libc_key_t.
	* sysdeps/pthread/stdio-lock.h: Don't care for implementation not
	using libio.

1997-03-19 15:13  Miguel de Icaza  <miguel@nuclecu.unam.mx>

	* sysdeps/sparc/pt-machine (RELEASE): Fix.

1997-03-01 07:55  Geoff Keating  <geoffk@ozemail.com.au>

	* sysdeps/powerpc/Implies: Added.
	* sysdeps/powerpc/pt-machine.h: Added.
	* sysdeps/powerpc/semaphorebits.h: Added.

1997-01-22 01:22  Ulrich Drepper  <drepper@cygnus.com>

	* linuxtheads/pthread.c (__pthread_initial_thread): Correct
	initializer.
	(__pthread_manager_thread): Likewise.
	Reported by Andreas Jaeger.

1997-01-18 22:15  Richard Henderson  <rth@tamu.edu>

	Since sigset_t no longer fits in a register, we can't pass in the
	thread's initial mask so easily.  Take this opportunity to simplify
	the clone implementation by only accepting a single void* argument.

	* linuxthreads/manager.c (__pthread_manager): Put thread vitals
	in the thread struct instead of as arguments through clone.
	(pthread_start_thread): Look for them there.
	* linuxthreads/internals.h (struct _pthread): Add p_initial_fn,
	p_initial_fn_arg, p_initial_mask.  Fix __pthread_manager proto.
	* linuxthreads/pthread.c (pthread_initialize_manager): Revise
	clone invocation.
1998-03-11 12:42:25 +00:00

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Groff

.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).