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authorrpj <rpj>2002-02-08 01:51:17 +0000
committerrpj <rpj>2002-02-08 01:51:17 +0000
commitb29903300adc22ed277bbaa356aca8ed0c245957 (patch)
tree02921a99a145dda1e78a315cc75016443839f2e0 /cancel_cancel.c
parent14118935d2d6863a4746223d8e22c2e58ffebab5 (diff)
Copyright notice updates; module splitting; POSIX version
conditional compilation; refinements; bug fixes. See the ChangeLog.
Diffstat (limited to 'cancel_cancel.c')
-rw-r--r--cancel_cancel.c180
1 files changed, 180 insertions, 0 deletions
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+/*
+ * cancel_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) 1999,2002 Pthreads-win32 contributors
+ *
+ * Contact Email: rpj@ise.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"
+
+
+#if defined(_M_IX86) || defined(_X86_)
+#define PTW32_PROGCTR(Context) ((Context).Eip)
+#endif
+
+#if defined(_MIPS_)
+#define PTW32_PROGCTR(Context) ((Context).Fir)
+#endif
+
+#if defined(_ALPHA_)
+#define PTW32_PROGCTR(Context) ((Context).Fir)
+#endif
+
+#if defined(_PPC_)
+#define PTW32_PROGCTR(Context) ((Context).Iar)
+#endif
+
+#if !defined(PTW32_PROGCTR)
+#error Module contains CPU-specific code; modify and recompile.
+#endif
+
+static INLINE void
+ptw32_cancel_self(void)
+{
+ ptw32_throw(PTW32_EPS_CANCEL);
+
+ /* Never reached */
+}
+
+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;
+
+ if (thread == NULL )
+ {
+ return ESRCH;
+ }
+
+ result = 0;
+ if ((self = pthread_self()) == NULL)
+ {
+ return ENOMEM;
+ };
+
+ /*
+ * FIXME!!
+ *
+ * Can a thread cancel itself?
+ *
+ * The standard doesn't
+ * specify an error to be returned if the target
+ * thread is itself.
+ *
+ * If it may, then we need to ensure that a thread can't
+ * deadlock itself trying to cancel itself asyncronously
+ * (pthread_cancel is required to be an async-cancel
+ * safe function).
+ */
+ cancel_self = pthread_equal(thread, self);
+
+ /*
+ * Lock for async-cancel safety.
+ */
+ (void) pthread_mutex_lock(&thread->cancelLock);
+
+ if (thread->cancelType == PTHREAD_CANCEL_ASYNCHRONOUS
+ && thread->cancelState == PTHREAD_CANCEL_ENABLE
+ && thread->state < PThreadStateCanceling )
+ {
+ if (cancel_self)
+ {
+ thread->state = PThreadStateCanceling;
+ thread->cancelState = PTHREAD_CANCEL_DISABLE;
+
+ (void) pthread_mutex_unlock(&thread->cancelLock);
+ ptw32_throw(PTW32_EPS_CANCEL);
+
+ /* Never reached */
+ }
+ else
+ {
+ HANDLE threadH = thread->threadH;
+
+ SuspendThread(threadH);
+
+ if (WaitForSingleObject(threadH, 0) == WAIT_TIMEOUT )
+ {
+ CONTEXT context;
+
+ thread->state = PThreadStateCanceling;
+ thread->cancelState = PTHREAD_CANCEL_DISABLE;
+ context.ContextFlags = CONTEXT_CONTROL;
+ GetThreadContext(threadH, &context);
+ PTW32_PROGCTR(context) = (DWORD) ptw32_cancel_self;
+ SetThreadContext(threadH, &context);
+ (void) pthread_mutex_unlock(&thread->cancelLock);
+ ResumeThread(threadH);
+ }
+ }
+ }
+ else
+ {
+ /*
+ * Set for deferred cancellation.
+ */
+ if ( thread->state >= PThreadStateCanceling
+ || !SetEvent (thread->cancelEvent))
+ {
+ result = ESRCH;
+ }
+
+ (void) pthread_mutex_unlock(&thread->cancelLock);
+ }
+
+ return (result);
+}
+