Copyright (c) 2003, 2010 The NetBSD Foundation, Inc.
All rights reserved.
This code is derived from software contributed to The NetBSD Foundation
by Christos Zoulas.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
.Dd July 9, 2010 .Dt PTHREAD_SUSPEND_NP 3 .Os .Sh NAME .Nm pthread_suspend_np , .Nm pthread_resume_np .Nd suspend/resume the given thread .Sh LIBRARY .Lb libpthread .Sh SYNOPSIS n pthread.h .Ft int .Fn pthread_suspend_np "pthread_t thread" .Ft int .Fn pthread_resume_np "pthread_t thread" .Sh DESCRIPTION The .Fn pthread_suspend_np function suspends the .Fa thread given as argument. If .Fa thread is the currently running thread as returned by .Xr pthread_self 3 , the function fails and returns .Er EDEADLK . Otherwise, it removes the named thread from the running queue, and adds it to the suspended queue. The .Fa thread will remain blocked until .Fn pthread_resume_np is called on it. In other words, .Fn pthread_resume_np resumes the .Fa thread given as argument, if it was suspended. .Sh RETURN VALUES Both functions return 0 on success and an error number indicating the reason for the failure. .Sh COMPATIBILITY These functions are non-standard extensions. .Sh ERRORS The .Fn pthread_suspend_np function may fail if: l -tag -width Er t Bq Er EDEADLK The thread requested to suspend was the currently running thread. t Bq Er ESRCH The supplied .Fa thread was invalid. .El
p The .Fn pthread_resume_np function may fail if: l -tag -width Er t Bq Er ESRCH The supplied .Fa thread was invalid. .El .Sh NOTES Some .Fn pthread_suspend_np implementations may allow suspending the current thread. This is dangerous, because the semantics of the function would then require the scheduler to schedule another thread, causing a thread context switch. Since that context switch can happen in a signal handler by someone calling .Fn pthread_suspend_np in a signal handler, this is currently not allowed.
p In .Fn pthread_resume_np the .Nx implementation does not check if the .Fa thread argument is not already suspended. Some implementations might return an error condition if .Fn pthread_resume_np is called on a non-suspended thread. .Sh SEE ALSO .Xr pthread_attr_setcreatesuspend_np 3 , .Xr pthread_self 3
Indexes created Sun Sep 21 18:09:52 GMT 2025