From a416ab17ecf9f2cb0f1e3f7bd645a8d1ce690ca2 Mon Sep 17 00:00:00 2001
From: rpj <rpj>
Date: Mon, 18 Feb 2002 03:16:52 +0000
Subject: Major reorganisation of source code; new routine and tests added.

---
 pthread_cancel.c | 180 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 180 insertions(+)
 create mode 100644 pthread_cancel.c

(limited to 'pthread_cancel.c')

diff --git a/pthread_cancel.c b/pthread_cancel.c
new file mode 100644
index 0000000..7a94d8d
--- /dev/null
+++ b/pthread_cancel.c
@@ -0,0 +1,180 @@
+/*
+ * 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) 1999,2002 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);
+}
+
-- 
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