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Diffstat (limited to 'pthreads/create.c')
-rw-r--r-- | pthreads/create.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/pthreads/create.c b/pthreads/create.c new file mode 100644 index 000000000..9e9388b20 --- /dev/null +++ b/pthreads/create.c @@ -0,0 +1,305 @@ +/* + * create.c + * + * Description: + * This translation unit implements routines associated with spawning a new + * thread. + * + * -------------------------------------------------------------------------- + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2005 Pthreads-win32 contributors + * + * Contact Email: rpj@callisto.canberra.edu.au + * + * 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: + * http://sources.redhat.com/pthreads-win32/contributors.html + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library in the file COPYING.LIB; + * if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include "pthread.h" +#include "implement.h" +#ifndef _UWIN +#include <process.h> +#endif + +int +pthread_create (pthread_t * tid, + const pthread_attr_t * attr, + void *(*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; + register pthread_attr_t a; + HANDLE threadH = 0; + int result = EAGAIN; + int run = PTW32_TRUE; + ThreadParms *parms = NULL; + long stackSize; + int priority; + pthread_t self; + + /* + * 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 (attr != NULL) + { + a = *attr; + } + else + { + a = NULL; + } + + if ((thread = ptw32_new ()).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; + +#if defined(HAVE_SIGSET_T) + + /* + * Threads inherit their initial sigmask from their creator thread. + */ + self = pthread_self(); + tp->sigmask = ((ptw32_thread_t *)self.p)->sigmask; + +#endif /* HAVE_SIGSET_T */ + + + if (a != NULL) + { + stackSize = a->stacksize; + tp->detachState = a->detachstate; + priority = a->param.sched_priority; + +#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. + */ +#if ! defined(HAVE_SIGSET_T) + self = pthread_self (); +#endif + priority = ((ptw32_thread_t *) self.p)->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 */ + (unsigned) 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 (run) + { + ResumeThread (threadH); + } + } + +#else /* __MINGW32__ && ! __MSVCRT__ */ + + /* + * This lock will force pthread_threadStart() to wait until we have + * the thread handle and have set the priority. + */ + (void) pthread_mutex_lock (&tp->cancelLock); + + tp->threadH = + threadH = + (HANDLE) _beginthread (ptw32_threadStart, (unsigned) 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); + } + } + + (void) pthread_mutex_unlock (&tp->cancelLock); + +#endif /* __MINGW32__ && ! __MSVCRT__ */ + + 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; + } + +#ifdef _UWIN + if (result == 0) + pthread_count++; +#endif + return (result); + +} /* pthread_create */ |