pthread_create(3T)                                       pthread_create(3T)
                               Pthread Library

 NAME
      pthread_create() - create a new thread of execution.

 SYNOPSIS
      #include <pthread.h>

      int pthread_create(
         pthread_t *thread,
         const pthread_attr_t *attr,
         void *(*start_routine)(void *),
         void *arg
      );

 PARAMETERS
           thread    Pointer to the location where the created thread's ID
                     is to be returned.

           attr      Pointer to the thread attributes object describing the
                     characteristics of the created thread. If the value is
                     NULL, default attributes will be used.

           start_routine
                     Function to be executed by the newly created thread.

           arg       Parameter to be passed to the created thread's
                     start_routine.

 DESCRIPTION
      The pthread_create() function is used to create a new independent
      thread within the calling process.  The thread will be created
      according to the attributes specified by attr.  If attr is NULL, the
      default attributes will be used.  The values of the attributes in attr
      describe the characteristics of the to-be-created thread in detail.
      Refer to the function pthread_attr_init() for a list of the default
      attribute values.  A single attributes object can be used in multiple
      calls to the function pthread_create().

      When a thread is created with an attributes object, the attributes
      are, in effect, copied into the created thread.  Consequently, any
      change to the attributes object will not affect any previously created
      threads.  Once all threads needing a specific attributes object have
      been created, the attributes object is no longer needed and may be
      destroyed.

      When the new thread is created, it will execute start_routine(), which
      has only one parameter, arg.  If start_routine() returns, an implicit
      call to pthread_exit() is made.  The return value of start_routine()
      is used as the thread's exit status.

      The created thread's scheduling policy and priority, contention scope,
      detach state, stack size, and stack address are initialized according


 pthread_create(3T)                                       pthread_create(3T)
                               Pthread Library

      to their respective attributes in attr.  The thread's signal mask is
      inherited from the creating thread.  The thread's set of pending
      signals is cleared.

      Refer to pthread_exit(3T), pthread_detach(3T), and pthread_join(3T)
      for more information on thread termination and synchronizing with
      terminated threads.

      On success, the ID of the created thread is returned in thread.  If
      pthread_create() fails, a thread is not created and the contents of
      thread are undefined.

      Thread IDs are guaranteed to be unique only within a process.

      NOTE: If the main thread returns from main(), an implicit call to
      exit() is made.  The return value of main() is used as the process'
      exit status.  The main thread can terminate without causing the
      process to terminate by calling pthread_exit().

 RETURN VALUE
      Upon successful completion, pthread_create() returns zero. Otherwise,
      an error number is returned to indicate the error (the errno variable
      is not set).

 ERRORS
      If any of the following occur, the pthread_create() function returns
      the corresponding error number:

           [EINVAL]       attr in an invalid thread attributes object.

           [EINVAL]       The value specified by thread is invalid.

           [EAGAIN]       The necessary resources to create another thread
                          are not available, or the number of threads in the
                          calling process already equals
                          PTHREAD_THREADS_MAX.

           [EINVAL]       The scheduling policy or scheduling attributes
                          specified in attr are invalid.

           [EPERM]        The caller does not have the appropriate
                          privileges to create a thread with the scheduling
                          policy and parameters specified in attr.

 NOTES
      It is unspecified whether joinable threads that have exited but
      haven't been joined count against the PTHREAD_THREADS_MAX limit.

 AUTHOR
      pthread_create() was derived from the IEEE POSIX P1003.1c standard.


 pthread_create(3T)                                       pthread_create(3T)
                               Pthread Library

 SEE ALSO
      pthread_exit(3T), pthread_join(3T), fork(2).

 STANDARDS CONFORMANCE
      pthread_create(): POSIX 1003.1c.