04-03-2007
what i did was just define a number of KEYs equal to the number of semaphores i wanted and then i created 2 struct to create the functions up and down. i didn't use a void main, just main. Why would void main be bad?
you have to release the resources??? how do you do that? aren't they released as soon as the program is done?
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LEARN ABOUT PHP
pthread_exit
PTHREAD_EXIT(3) Linux Programmer's Manual PTHREAD_EXIT(3)
NAME
pthread_exit - terminate calling thread
SYNOPSIS
#include <pthread.h>
void pthread_exit(void *retval);
Compile and link with -pthread.
DESCRIPTION
The pthread_exit() function terminates the calling thread and returns a value via retval that (if the thread is joinable) is available to
another thread in the same process that calls pthread_join(3).
Any clean-up handlers established by pthread_cleanup_push(3) that have not yet been popped, are popped (in the reverse of the order in
which they were pushed) and executed. If the thread has any thread-specific data, then, after the clean-up handlers have been executed,
the corresponding destructor functions are called, in an unspecified order.
When a thread terminates, process-shared resources (e.g., mutexes, condition variables, semaphores, and file descriptors) are not released,
and functions registered using atexit(3) are not called.
After the last thread in a process terminates, the process terminates as by calling exit(3) with an exit status of zero; thus, process-
shared resources are released and functions registered using atexit(3) are called.
RETURN VALUE
This function does not return to the caller.
ERRORS
This function always succeeds.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
+---------------+---------------+---------+
|Interface | Attribute | Value |
+---------------+---------------+---------+
|pthread_exit() | Thread safety | MT-Safe |
+---------------+---------------+---------+
CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
NOTES
Performing a return from the start function of any thread other than the main thread results in an implicit call to pthread_exit(), using
the function's return value as the thread's exit status.
To allow other threads to continue execution, the main thread should terminate by calling pthread_exit() rather than exit(3).
The value pointed to by retval should not be located on the calling thread's stack, since the contents of that stack are undefined after
the thread terminates.
BUGS
Currently, there are limitations in the kernel implementation logic for wait(2)ing on a stopped thread group with a dead thread group
leader. This can manifest in problems such as a locked terminal if a stop signal is sent to a foreground process whose thread group leader
has already called pthread_exit().
SEE ALSO
pthread_create(3), pthread_join(3), pthreads(7)
COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
Linux 2017-09-15 PTHREAD_EXIT(3)