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man pages section 3: Basic Library Functions

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Updated: Wednesday, July 27, 2022



thr_exit - terminate the calling thread


#include <thread.h> 

void thr_exit(void *status);


The thr_exit() function terminates the calling thread, in a similar way that exit(3C) terminates the calling process. If the calling thread is not detached, then the thread's ID and the exit status specified by status are retained. The value status is then made available to any successful join with the terminating thread (see thr_join(3C)); otherwise, status is disregarded allowing the thread's ID to be reclaimed immediately.

Any cancellation cleanup handlers that have been pushed and not yet popped are popped in the reverse order that they were pushed and then executed. After all cancellation cleanup handlers have been executed, if the thread has any thread-specific data, appropriate destructor functions will be called in an unspecified order. Thread termination does not release any application visible process resources, including, but not limited to, mutexes and file descriptors, nor does it perform any process level cleanup actions, including, but not limited to, calling any atexit() routines that might exist.

An exiting thread runs with all signals blocked. All thread termination functions, including cancellation cleanup handlers and thread-specific data destructor functions, are called with all signals blocked.

If any thread, including the main() thread, calls thr_exit(), only that thread will exit.

If main() returns or exits (either implicitly or explicitly), or any thread explicitly calls exit(), the entire process will exit.

The behavior of thr_exit() is undefined if called from a cancellation cleanup handler or destructor function that was invoked as a result of either an implicit or explicit call to thr_exit().

After a thread has terminated, the result of access to local (auto) variables of the thread is undefined. Thus, references to local variables of the exiting thread should not be used for the thr_exit() status parameter value.

If any thread (except the main() thread) implicitly or explicitly returns, the result is the same as if the thread called thr_exit() and it will return the value of status as the exit code.

The process will terminate with an exit status of 0 after the last non-daemon thread has terminated (including the main() thread). This behavior is the same as if the application had called exit() with a 0 argument at thread termination time.

Return Values

The thr_exit() function cannot return to its caller.


No errors are defined.


See attributes(7) for descriptions of the following attributes:


See Also

exit(3C), thr_create(3C), thr_join(3C), thr_keycreate(3C), attributes(7), standards(7)


Although only POSIX implements cancellation, cancellation can be used with Solaris threads, due to their interoperability.

The status argument should not reference any variables local to the calling thread.