[PATCH 18/19] manual: Add pthread_attr_setsigmask_np, pthread_attr_getsigmask_np

[Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>]

And the PTHREAD_ATTR_NO_SIGMASK_NP constant.
---
 manual/threads.texi | 47 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/manual/threads.texi b/manual/threads.texi
index a425635179..28d7cf2abd 100644
--- a/manual/threads.texi
+++ b/manual/threads.texi
@@ -625,6 +625,7 @@ the standard.
 @menu
 * Default Thread Attributes::             Setting default attributes for
 					  threads in a process.
+* Initial Thread Signal Mask::            Setting the initial mask of threads.
 * Waiting with Explicit Clocks::          Functions for waiting with an
                                           explicit clock specification.
 @end menu
@@ -671,6 +672,52 @@ The system does not have sufficient memory.
 @end table
 @end deftypefun
 
+@node Initial Thread Signal Mask
+@subsubsection Controlling the Initial Signal Mask of a New Thread
+
+@Theglibc{} provides a way to specify the initial signal mask of a
+thread created using @code{pthread_create}, passing a thread attribute
+object configured for this purpose.
+
+These functions achieve the same effect as blocking all signals using
+@code{pthread_sigmask} before creating the thread, and setting the
+desired signal mask from the new thread, but in a more explicit
+fashion.
+
+@deftypefun int pthread_attr_setsigmask_np (pthread_attr_t *@var{attr}, const sigset_t *@var{sigmask})
+@standards{GNU, pthread.h}
+@safety{@prelim{}@mtsafe{}@asunsafe{@ascuheap{}}@acunsafe{@acsmem{}}}
+Change the initial signal mask specified by @var{attr}.  If
+@var{sigmask} is not @code{NULL}, the initial signal mask for new
+threads created with @var{attr} is set to @code{*@var{sigmask}}.  If
+@var{sigmask} is @code{NULL}, @var{attr} will no longer specify an
+explicit signal mask, so that the initial signal mask of the new
+thread is inherited from the parent thread creating the new thread.
+
+This function returns zero on success, and @code{ENOMEM} on memory
+allocation failure.
+@end deftypefun
+
+@deftypefun int pthread_attr_getsigmask_np (const pthread_attr_t *@var{attr}, sigset_t *@var{sigmask})
+@standards{GNU, pthread.h}
+@safety{@prelim{}@mtsafe{}@asunsafe{@ascuheap{}}@acunsafe{@acsmem{}}}
+Retrieve the initial signal mask stored in @var{attr} and write it ot
+@code{*@var{sigmask}}.  If the signal mask has not been set, return
+the special constant @code{PTHREAD_ATTR_NO_SIGMASK_NP}, otherwise
+return zero.
+
+Obtaining the signal mask only works if it has been previously stored
+by @code{pthread_attr_setsigmask_np}.  For example, the
+@code{pthread_getattr_np} function does not obtain the current signal
+mask of the specified thread, and @code{pthread_attr_setsigmask_np}
+will subsequently report the signal mask as unset.
+@end deftypefun
+
+@deftypevr Macro int PTHREAD_ATTR_NO_SIGMASK_NP
+The special value returned by @code{pthread_attr_setsigmask_np} to
+indicate that no signal mask has been set for the attribute.
+@end deftypevr
+
 @node Waiting with Explicit Clocks
 @subsubsection Functions for Waiting According to a Specific Clock
 
-- 
2.25.4