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| .TH PTHREAD_ATTR_SETSIGMASK_NP 3 2021-03-22 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| pthread_attr_setsigmask_np, pthread_attr_getsigmask_np \- set/get |
| signal mask attribute in thread attributes object |
| .SH SYNOPSIS |
| .nf |
| .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" |
| .B #include <pthread.h> |
| .PP |
| .BI "int pthread_attr_setsigmask_np(pthread_attr_t *" attr , |
| .BI " const sigset_t *" sigmask ); |
| .BI "int pthread_attr_getsigmask_np(const pthread_attr_t *" attr , |
| .BI " sigset_t *" sigmask ); |
| .PP |
| Compile and link with \fI\-pthread\fP. |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR pthread_attr_setsigmask_np () |
| function sets the signal mask attribute of the |
| thread attributes object referred to by |
| .I attr |
| to the value specified in |
| .IR *sigmask . |
| If |
| .I sigmask |
| is specified as NULL, then any existing signal mask attribute in |
| .I attr |
| is unset. |
| .PP |
| The |
| .BR pthread_attr_getsigmask_np () |
| function returns the signal mask attribute of the thread attributes object |
| referred to by |
| .IR attr |
| in the buffer pointed to by |
| .IR sigmask . |
| If the signal mask attribute is currently unset, |
| then this function returns the special value |
| .B PTHREAD_ATTR_NO_SIGMASK_NP |
| as its result. |
| .SH RETURN VALUE |
| The |
| .BR pthread_attr_setsigmask_np () |
| function returns 0 on success, or a nonzero error number on failure. |
| .PP |
| the |
| .BR pthread_attr_getsigmask_np () |
| function returns either 0 or |
| .BR PTHREAD_ATTR_NO_SIGMASK_NP . |
| When 0 is returned, the signal mask attribute is returned via |
| .IR sigmask . |
| A return value of |
| .B PTHREAD_ATTR_NO_SIGMASK_NP |
| indicates that the signal mask attribute is not set in |
| .IR attr . |
| .PP |
| On error, these functions return a positive error number. |
| .SH ERRORS |
| .TP |
| .B ENOMEM |
| .RB ( pthread_attr_setsigmask_np ()) |
| Could not allocate memory. |
| .SH VERSIONS |
| These functions are provided by glibc since version 2.32. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .ad l |
| .nh |
| .TS |
| allbox; |
| lbx lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR pthread_attr_setsigmask_np (), |
| .BR pthread_attr_getsigmask_np () |
| T} Thread safety MT-Safe |
| .TE |
| .hy |
| .ad |
| .sp 1 |
| .SH CONFORMING TO |
| These functions are nonstandard GNU extensions; |
| hence the suffix "_np" (nonportable) in the names. |
| .SH NOTES |
| The signal mask attribute determines the signal mask that will be assigned to |
| a thread created using the thread attributes object |
| .IR attr . |
| If this attribute is not set, then a thread created using |
| .I attr |
| will inherit a copy of the creating thread's signal mask. |
| .PP |
| For more details on signal masks, see |
| .BR sigprocmask (2). |
| For a description of a set of macros |
| that can be used to manipulate and inspect signal sets, see |
| .BR sigsetops (3). |
| .PP |
| In the absence of |
| .BR pthread_attr_setsigmask_np () |
| it is possible to create a thread with a desired signal mask as follows: |
| .IP \(bu 2 |
| The creating thread uses |
| .BR pthread_sigmask (3) |
| to save its current signal mask and set its mask to block all signals. |
| .IP \(bu |
| The new thread is then created using |
| .BR pthread_create (); |
| the new thread will inherit the creating thread's signal mask. |
| .IP \(bu |
| The new thread sets its signal mask to the desired value using |
| .BR pthread_sigmask (3). |
| .IP \(bu |
| The creating thread restores its signal mask to the original value. |
| .PP |
| 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. |
| .SH SEE ALSO |
| .BR sigprocmask (2), |
| .BR pthread_attr_init (3), |
| .BR pthread_sigmask (3), |
| .BR pthreads (7), |
| .BR signal (7) |