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pthread_mutex_lock(3)
NAME
  pthread_mutex_lock - Locks an unlocked mutex

SYNOPSIS
  #include <pthread.h>

  int pthread_mutex_lock(
	  pthread_mutex_t *mutex );

LIBRARY
  DECthreads POSIX 1003.1c Library (libpthread.so)

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  IEEE Std 1003.1c-1995, POSIX System Application Program Interface

PARAMETERS
  mutex
      Mutex to be locked.

DESCRIPTION
  This routine locks a mutex with behavior that depends upon the type of
  mutex, as follows:

    ·  If a normal or default mutex is specified, a deadlock can result if
       the current owner of the mutex calls this routine in an attempt to
       lock the mutex a second time. (The deadlock is not detected or
       reported.)

    ·  If a recursive mutex is specified, the current owner of the mutex can
       relock the same mutex without blocking. The lock count is incremented
       for each recursive lock within the thread.

    ·  If an errorcheck mutex is specified and the current owner tries to
       lock the mutex a second time, this routine reports the [EDEADLK]
       error. If the mutex is locked by another thread, the calling thread
       waits for the mutex to become available.

  Use the pthread_mutexattr_settype(3) routine to set the type of the mutex
  to normal, default, recursive, or errorcheck. For more information about
  types of mutexes, see the description of pthread_mutexattr_settype(3).

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

  A recursive or errorcheck mutex records the identity of the thread that
  locks it, allowing debuggers to display this information. In most cases,
  normal and default mutexes do not record the owning thread's identity.

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

  0   Successful completion.

  [EDEADLK]
      A deadlock condition is detected.

  [EINVAL]
      The value specified by mutex is not a valid mutex.

ERRORS
  None

SEE ALSO
  Functions: pthread_mutexattr_settype(3), pthread_mutex_destroy(3),
  pthread_mutex_init(3), pthread_mutex_trylock(3), pthread_mutex_unlock(3)

  Manuals: Guide to DECthreads and Programmer's Guide

Index for Section 3

Alphabetical listing for P

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