PTHREAD_ATTR_SETSIGMASK_NP(Linux Programmer's ManPTHREAD_ATTR_SETSIGMASK_NP(3)
NAME
pthread_attr_setsigmask_np, pthread_attr_getsigmask_np - set/get signal
mask attribute in thread attributes object
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <pthread.h>
int pthread_attr_setsigmask_np(pthread_attr_t *attr,
const sigset_t *sigmask);
int pthread_attr_getsigmask_np(const pthread_attr_t *attr,
sigset_t *sigmask);
Compile and link with -pthread.
DESCRIPTION
The pthread_attr_setsigmask_np() function sets the signal mask attri-
bute of the thread attributes object referred to by attr to the value
specified in *sigmask. If sigmask is specified as NULL, then any ex-
isting signal mask attribute in attr is unset.
The pthread_attr_getsigmask_np() function returns the signal mask at-
tribute of the thread attributes object referred to by attr in the buf-
fer pointed to by sigmask. If the signal mask attribute is currently
unset, then this function returns the special value
PTHREAD_ATTR_NO_SIGMASK_NP as its result.
RETURN VALUE
The pthread_attr_setsigmask_np() function returns 0 on success, or a
nonzero error number on failure.
the pthread_attr_getsigmask_np() function returns either 0 or
PTHREAD_ATTR_NO_SIGMASK_NP. When 0 is returned, the signal mask attri-
bute is returned via sigmask. A return value of PTHREAD_ATTR_NO_SIG-
MASK_NP indicates that the signal mask attribute is not set in attr.
On error, these functions return a positive error number.
ERRORS
ENOMEM (pthread_attr_setsigmask_np()) Could not allocate memory.
VERSIONS
These functions are provided by glibc since version 2.32.
ATTRIBUTES
For an explanation of the terms used in this section, see at-
tributes(7).
┌───────────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├───────────────────────────────┼───────────────┼─────────┤
│pthread_attr_setsigmask_np(), │ Thread safety │ MT-Safe │
│pthread_attr_getsigmask_np() │ │ │
└───────────────────────────────┴───────────────┴─────────┘
CONFORMING TO
These functions are nonstandard GNU extensions; hence the suffix "_np"
(nonportable) in the names.
NOTES
The signal mask attribute determines the signal mask that will be as-
signed to a thread created using the thread attributes object attr. If
this attribute is not set, then a thread created using attr will in-
herit a copy of the creating thread's signal mask.
For more details on signal masks, see sigprocmask(2). For a descrip-
tion of a set of macros that can be used to manipulate and inspect sig-
nals sets, see sigsetops(3).
In the absence of pthread_attr_setsigmask_np() it is possible to create
a thread with a desired signal mask as follows:
• The creating thread uses pthread_sigmask(3) to save its current sig-
nal mask and set its mask to block all signals.
• The new thread is then created using pthread_create(); the new thread
will inherit the creating thread's signal mask.
• The new thread sets its signal mask to the desired value using
pthread_sigmask(3).
• The creating thread restores its signal mask to the original value.
Following the above steps, there is no possibility for the new thread
to receive a signal before it has adjusted its signal mask to the de-
sired value.
SEE ALSO
sigprocmask(2), pthread_attr_init(3), pthread_sigmask(3), pthreads(7),
signals(7)
COLOPHON
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description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2020-11-01 PTHREAD_ATTR_SETSIGMASK_NP(3)
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