PTHREAD_SUSPEND_NP(3) BSD Library Functions Manual PTHREAD_SUSPEND_NP(3)NAME
pthread_suspend_np, pthread_resume_np — suspend/resume the given thread
LIBRARY
POSIX Threads Library (libpthread, -lpthread)
SYNOPSIS
#include <pthread.h>
int
pthread_suspend_np(pthread_t thread);
int
pthread_resume_np(pthread_t thread);
DESCRIPTION
The pthread_suspend_np() function suspends the thread given as argument.
If thread is the currently running thread as returned by pthread_self(3),
the function fails and returns EDEADLK. Otherwise, it removes the named
thread from the running queue, and adds it to the suspended queue. The
thread will remain blocked until pthread_resume_np() is called on it. In
other words, pthread_resume_np() resumes the thread given as argument, if
it was suspended.
RETURN VALUES
Both functions return 0 on success and an error number indicating the
reason for the failure.
COMPATIBILITY
These functions are non-standard extensions.
ERRORS
The pthread_suspend_np() function may fail if:
[EDEADLK] The thread requested to suspend was the currently run‐
ning thread.
[ESRCH] The supplied thread was invalid.
The pthread_resume_np() function may fail if:
[ESRCH] The supplied thread was invalid.
NOTES
Some pthread_suspend_np() implementations may allow suspending the cur‐
rent 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 pthread_suspend_np() in a signal handler, this
is currently not allowed.
In pthread_resume_np() the NetBSD implementation does not check if the
thread argument is not already suspended. Some implementations might
return an error condition if pthread_resume_np() is called on a non-sus‐
pended thread.
SEE ALSOpthread_attr_setcreatesuspend_np(3), pthread_self(3)BSD July 9, 2010 BSD
