/*
* create.c
*
* Description:
* This translation unit implements routines associated with spawning a new
* thread.
*
* --------------------------------------------------------------------------
*
* Pthreads4w - POSIX Threads Library for Win32
* Copyright(C) 1998 John E. Bossom
* Copyright(C) 1999-2018, Pthreads4w contributors
*
* Homepage: https://sourceforge.net/projects/pthreads4w/
*
* The current list of contributors is contained
* in the file CONTRIBUTORS included with the source
* code distribution. The list can also be seen at the
* following World Wide Web location:
* https://sourceforge.net/p/pthreads4w/wiki/Contributors/
*
* This file is part of Pthreads4w.
*
* Pthreads4w is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Pthreads4w is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Pthreads4w. If not, see <http://www.gnu.org/licenses/>. *
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "pthread.h"
#include "implement.h"
#if ! defined(_UWIN) && ! defined(WINCE)
#include <process.h>
#endif
int
pthread_create (pthread_t * tid,
const pthread_attr_t * attr,
void *(PTW32_CDECL *start) (void *), void *arg)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function creates a thread running the start function,
* passing it the parameter value, 'arg'. The 'attr'
* argument specifies optional creation attributes.
* The identity of the new thread is returned
* via 'tid', which should not be NULL.
*
* PARAMETERS
* tid
* pointer to an instance of pthread_t
*
* attr
* optional pointer to an instance of pthread_attr_t
*
* start
* pointer to the starting routine for the new thread
*
* arg
* optional parameter passed to 'start'
*
*
* DESCRIPTION
* This function creates a thread running the start function,
* passing it the parameter value, 'arg'. The 'attr'
* argument specifies optional creation attributes.
* The identity of the new thread is returned
* via 'tid', which should not be the NULL pointer.
*
* RESULTS
* 0 successfully created thread,
* EINVAL attr invalid,
* EAGAIN insufficient resources.
*
* ------------------------------------------------------
*/
{
pthread_t thread;
ptw32_thread_t * tp;
ptw32_thread_t * sp;
register pthread_attr_t a;
HANDLE threadH = 0;
int result = EAGAIN;
int run = PTW32_TRUE;
ThreadParms *parms = NULL;
unsigned int stackSize;
int priority;
/*
* Before doing anything, check that tid can be stored through
* without invoking a memory protection error (segfault).
* Make sure that the assignment below can't be optimised out by the compiler.
* This is assured by conditionally assigning *tid again at the end.
*/
tid->x = 0;
if (NULL == (sp = (ptw32_thread_t *)pthread_self().p))
{
goto FAIL0;
}
if (attr != NULL)
{
a = *attr;
}
else
{
a = NULL;
}
thread = ptw32_new();
if (thread.p == NULL)
{
goto FAIL0;
}
tp = (ptw32_thread_t *) thread.p;
priority = tp->sched_priority;
if ((parms = (ThreadParms *) malloc (sizeof (*parms))) == NULL)
{
goto FAIL0;
}
parms->tid = thread;
parms->start = start;
parms->arg = arg;
/*
* Threads inherit their initial sigmask and CPU affinity from their creator thread.
*/
#if defined(HAVE_SIGSET_T)
tp->sigmask = sp->sigmask;
#endif
#if defined(HAVE_CPU_AFFINITY)
tp->cpuset = sp->cpuset;
#endif
if (a != NULL)
{
#if defined(HAVE_CPU_AFFINITY)
cpu_set_t none;
cpu_set_t attr_cpuset;
((_sched_cpu_set_vector_*)&attr_cpuset)->_cpuset = a->cpuset;
CPU_ZERO(&none);
if (! CPU_EQUAL(&attr_cpuset, &none))
{
tp->cpuset = a->cpuset;
}
#endif
stackSize = (unsigned int)a->stacksize;
tp->detachState = a->detachstate;
priority = a->param.sched_priority;
if (a->thrname != NULL)
tp->name = _strdup(a->thrname);
#if (THREAD_PRIORITY_LOWEST > THREAD_PRIORITY_NORMAL)
/* WinCE */
#else
/* Everything else */
/*
* Thread priority must be set to a valid system level
* without altering the value set by pthread_attr_setschedparam().
*/
/*
* PTHREAD_EXPLICIT_SCHED is the default because Win32 threads
* don't inherit their creator's priority. They are started with
* THREAD_PRIORITY_NORMAL (win32 value). The result of not supplying
* an 'attr' arg to pthread_create() is equivalent to defaulting to
* PTHREAD_EXPLICIT_SCHED and priority THREAD_PRIORITY_NORMAL.
*/
if (PTHREAD_INHERIT_SCHED == a->inheritsched)
{
/*
* If the thread that called pthread_create() is a Win32 thread
* then the inherited priority could be the result of a temporary
* system adjustment. This is not the case for POSIX threads.
*/
priority = sp->sched_priority;
}
#endif
}
else
{
/*
* Default stackSize
*/
stackSize = PTHREAD_STACK_MIN;
}
tp->state = run ? PThreadStateInitial : PThreadStateSuspended;
tp->keys = NULL;
/*
* Threads must be started in suspended mode and resumed if necessary
* after _beginthreadex returns us the handle. Otherwise we set up a
* race condition between the creating and the created threads.
* Note that we also retain a local copy of the handle for use
* by us in case thread.p->threadH gets NULLed later but before we've
* finished with it here.
*/
#if ! defined (__MINGW32__) || defined (__MSVCRT__) || defined (__DMC__)
tp->threadH =
threadH =
(HANDLE) _beginthreadex ((void *) NULL, /* No security info */
stackSize, /* default stack size */
ptw32_threadStart,
parms,
(unsigned)
CREATE_SUSPENDED,
(unsigned *) &(tp->thread));
if (threadH != 0)
{
if (a != NULL)
{
(void) ptw32_setthreadpriority (thread, SCHED_OTHER, priority);
}
#if defined(HAVE_CPU_AFFINITY)
SetThreadAffinityMask(tp->threadH, tp->cpuset);
#endif
if (run)
{
ResumeThread (threadH);
}
}
#else
{
ptw32_mcs_local_node_t stateLock;
/*
* This lock will force pthread_threadStart() to wait until we have
* the thread handle and have set the priority.
*/
ptw32_mcs_lock_acquire(&tp->stateLock, &stateLock);
tp->threadH =
threadH =
(HANDLE) _beginthread (ptw32_threadStart, stackSize, /* default stack size */
parms);
/*
* Make the return code match _beginthreadex's.
*/
if (threadH == (HANDLE) - 1L)
{
tp->threadH = threadH = 0;
}
else
{
if (!run)
{
/*
* beginthread does not allow for create flags, so we do it now.
* Note that beginthread itself creates the thread in SUSPENDED
* mode, and then calls ResumeThread to start it.
*/
SuspendThread (threadH);
}
if (a != NULL)
{
(void) ptw32_setthreadpriority (thread, SCHED_OTHER, priority);
}
#if defined(HAVE_CPU_AFFINITY)
SetThreadAffinityMask(tp->threadH, tp->cpuset);
#endif
}
ptw32_mcs_lock_release (&stateLock);
}
#endif
result = (threadH != 0) ? 0 : EAGAIN;
/*
* Fall Through Intentionally
*/
/*
* ------------
* Failure Code
* ------------
*/
FAIL0:
if (result != 0)
{
ptw32_threadDestroy (thread);
tp = NULL;
if (parms != NULL)
{
free (parms);
}
}
else
{
*tid = thread;
}
#if defined(_UWIN)
if (result == 0)
pthread_count++;
#endif
return (result);
} /* pthread_create */