| /* |
| * 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); |
| } |