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Diffstat (limited to 'pthreads/src/pthread_cancel.c')
| -rw-r--r-- | pthreads/src/pthread_cancel.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/pthreads/src/pthread_cancel.c b/pthreads/src/pthread_cancel.c new file mode 100644 index 0000000..ae60b72 --- /dev/null +++ b/pthreads/src/pthread_cancel.c @@ -0,0 +1,189 @@ +/* + * pthread_cancel.c + * + * Description: + * POSIX thread functions related to thread cancellation. + * + * -------------------------------------------------------------------------- + * + * 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" +#include "context.h" + +static void +ptw32_cancel_self (void) +{ + ptw32_throw (PTW32_EPS_CANCEL); + + /* Never reached */ +} + +static void CALLBACK +ptw32_cancel_callback (ULONG_PTR unused) +{ + ptw32_throw (PTW32_EPS_CANCEL); + + /* Never reached */ +} + +/* + * ptw32_RegisterCancelation() - + * Must have args of same type as QueueUserAPCEx because this function + * is a substitute for QueueUserAPCEx if it's not available. + */ +DWORD +ptw32_RegisterCancelation (PAPCFUNC unused1, HANDLE threadH, DWORD unused2) +{ + CONTEXT context; + + context.ContextFlags = CONTEXT_CONTROL; + GetThreadContext (threadH, &context); + PTW32_PROGCTR (context) = (DWORD_PTR) ptw32_cancel_self; + SetThreadContext (threadH, &context); + return 0; +} + +int +pthread_cancel (pthread_t thread) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function requests cancellation of 'thread'. + * + * PARAMETERS + * thread + * reference to an instance of pthread_t + * + * + * DESCRIPTION + * This function requests cancellation of 'thread'. + * NOTE: cancellation is asynchronous; use pthread_join to + * wait for termination of 'thread' if necessary. + * + * RESULTS + * 0 successfully requested cancellation, + * ESRCH no thread found corresponding to 'thread', + * ENOMEM implicit self thread create failed. + * ------------------------------------------------------ + */ +{ + int result; + int cancel_self; + pthread_t self; + ptw32_thread_t * tp; + ptw32_mcs_local_node_t stateLock; + + result = pthread_kill (thread, 0); + + if (0 != result) + { + return result; + } + + if ((self = pthread_self ()).p == NULL) + { + return ENOMEM; + }; + + /* + * For self cancellation we need to ensure that a thread can't + * deadlock itself trying to cancel itself asynchronously + * (pthread_cancel is required to be an async-cancel + * safe function). + */ + cancel_self = pthread_equal (thread, self); + + tp = (ptw32_thread_t *) thread.p; + + /* + * Lock for async-cancel safety. + */ + ptw32_mcs_lock_acquire (&tp->stateLock, &stateLock); + + if (tp->cancelType == PTHREAD_CANCEL_ASYNCHRONOUS + && tp->cancelState == PTHREAD_CANCEL_ENABLE + && tp->state < PThreadStateCanceling) + { + if (cancel_self) + { + tp->state = PThreadStateCanceling; + tp->cancelState = PTHREAD_CANCEL_DISABLE; + + ptw32_mcs_lock_release (&stateLock); + ptw32_throw (PTW32_EPS_CANCEL); + + /* Never reached */ + } + else + { + HANDLE threadH = tp->threadH; + + SuspendThread (threadH); + + if (WaitForSingleObject (threadH, 0) == WAIT_TIMEOUT) + { + tp->state = PThreadStateCanceling; + tp->cancelState = PTHREAD_CANCEL_DISABLE; + /* + * If alertdrv and QueueUserAPCEx is available then the following + * will result in a call to QueueUserAPCEx with the args given, otherwise + * this will result in a call to ptw32_RegisterCancelation and only + * the threadH arg will be used. + */ + ptw32_register_cancelation ((PAPCFUNC)ptw32_cancel_callback, threadH, 0); + ptw32_mcs_lock_release (&stateLock); + ResumeThread (threadH); + } + } + } + else + { + /* + * Set for deferred cancellation. + */ + if (tp->state < PThreadStateCancelPending) + { + tp->state = PThreadStateCancelPending; + if (!SetEvent (tp->cancelEvent)) + { + result = ESRCH; + } + } + else if (tp->state >= PThreadStateCanceling) + { + result = ESRCH; + } + + ptw32_mcs_lock_release (&stateLock); + } + + return (result); +} |