pthread_lock_global_np(3)				     Library Functions Manual					 pthread_lock_global_np(3)

NAME

       pthread_lock_global_np - Locks the DECthreads global mutex.

LIBRARY

       DECthreads POSIX 1003.1c Library (libpthread.so)

SYNOPSIS

       #include <pthread.h>

       int   pthread_lock_global_np(void);

STANDARDS

       None

PARAMETERS

       None

DESCRIPTION

       This  routine locks the DECthreads global mutex.  If the global mutex is currently held by another thread when a thread calls this routine,
       the calling thread waits for the global mutex to become available and then locks it.

       The thread that has locked the global mutex becomes its current owner and remains the owner until the same thread has  unlocked	it.   This
       routine returns with the global mutex in the locked state and with the current thread as the global mutex's current owner.

       Use the DECthreads global mutex when calling a library package that is not designed to run in a multithreaded environment.  Unless the doc-
       umentation for a library function specifically states that it is thread safe, assume that it is not compatible; in other words,	assume	it
       is nonreentrant.

       The  global mutex is one lock.  Any code that calls any function that is not known to be reentrant should use the same lock.  This prevents
       problems resulting from dependencies among threads that call library functions and those functions' calling other functions, and so on.

       The global mutex is a recursive mutex.  A thread that has locked the global mutex can relock it without deadlocking.   The  locking  thread
       must call pthread_unlock_global_np(3) as many times as it called this routine, to allow another thread to lock the global mutex.

RETURN VALUES

       If  an  error condition occurs, this routine returns an integer value indicating the type of error.  Possible return values are as follows:
       Successful completion.

ERRORS

       None

RELATED INFORMATION

       Functions: pthread_unlock_global_np(3)

       Manuals: Guide to DECthreads and Programmer's Guide

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															 pthread_lock_global_np(3)