pthread_attr_setsigmask_np - Man Page

set/get signal mask attribute in thread attributes object


POSIX threads library (libpthread, -lpthread)


#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);


The pthread_attr_setsigmask_np() function sets the signal mask attribute of the thread attributes object referred to by attr to the value specified in *sigmask. If sigmask is specified as NULL, then any existing signal mask attribute in attr is unset.

The pthread_attr_getsigmask_np() function returns the signal mask attribute of the thread attributes object referred to by attr in the buffer 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 attribute is returned via sigmask. A return value of PTHREAD_ATTR_NO_SIGMASK_NP indicates that the signal mask attribute is not set in attr.

On error, these functions return a positive error number.



(pthread_attr_setsigmask_np()) Could not allocate memory.


For an explanation of the terms used in this section, see attributes(7).

pthread_attr_setsigmask_np(), pthread_attr_getsigmask_np()Thread safetyMT-Safe


GNU; hence the suffix "_np" (nonportable) in the names.


glibc 2.32.


The signal mask attribute determines the signal mask that will be assigned to a thread created using the thread attributes object attr. If this attribute is not set, then a thread created using attr will inherit a copy of the creating thread's signal mask.

For more details on signal masks, see sigprocmask(2). For a description of a set of macros that can be used to manipulate and inspect signal 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:

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 desired value.

See Also

sigprocmask(2), pthread_attr_init(3), pthread_sigmask(3), pthreads(7), signal(7)

Referenced By

pthread_attr_init(3), pthread_sigmask(3).

The man page pthread_attr_getsigmask_np(3) is an alias of pthread_attr_setsigmask_np(3).

2023-10-31 Linux man-pages 6.06