Merge John Bossom's code into the main trunk. See ChangeLog for details.snapshot-1999-01-04-1305

This will be tagged as snapshot-1999-01-04-1305

1 files changed, 202 insertions, 44 deletions

diff --git a/cancel.c b/cancel.c
index 9dd99c6..93d6e07 100644
--- a/cancel.c
+++ b/cancel.c
@@ -5,80 +5,238 @@
  * POSIX thread functions related to thread cancellation.
  */
 
-#include <errno.h>
-
 #include "pthread.h"
 #include "implement.h"
 
+/*
+ * Code contributed by John E. Bossom <JEB>.
+ */
+
 int
-pthread_setcancelstate(int state,
-		       int *oldstate)
+pthread_setcancelstate (int state, int *oldstate)
+     /*
+      * ------------------------------------------------------
+      * DOCPUBLIC
+      *      This function atomically sets the calling thread's
+      *      cancelability state to 'state' and returns the previous
+      *      cancelability state at the location referenced by
+      *      'oldstate'
+      *
+      * PARAMETERS
+      *      type,
+      *      oldtype
+      *              PTHREAD_CANCEL_ENABLE
+      *                      cancellation is enabled,
+      *
+      *              PTHREAD_CANCEL_DISABLE
+      *                      cancellation is disabled
+      *
+      *
+      * DESCRIPTION
+      *      This function atomically sets the calling thread's
+      *      cancelability state to 'state' and returns the previous
+      *      cancelability state at the location referenced by
+      *      'oldstate'
+      *
+      *      NOTES:
+      *      1)      Use to disable cancellation around 'atomic' code that
+      *              includes cancellation points
+      *
+      * RESULTS
+      *              0               successfully set cancelability type,
+      *              EINVAL          'state' is invalid
+      *
+      * ------------------------------------------------------
+      */
 {
-  pthread_t us = pthread_self();
+  pthread_t self;
+  int result;
 
-  /* Validate the new cancellation state. */
-  if (state != PTHREAD_CANCEL_ENABLE 
-      || state != PTHREAD_CANCEL_DISABLE)
+  if (((self = pthread_self ()) != NULL) &&
+      (state == PTHREAD_CANCEL_ENABLE ||
+       state == PTHREAD_CANCEL_DISABLE))
     {
-      return EINVAL;
-    }
 
-  if (oldstate != NULL)
+      *oldstate = self->cancelState;
+      self->cancelState = state;
+      result = 0;
+
+    }
+  else
     {
-      *oldstate = us->cancelstate;
+      result = EINVAL;
     }
 
-  us->cancelstate = state;
-  return 0;
-}
+  return (result);
+
+}				/* pthread_setcancelstate */
+
 
 int
-pthread_setcanceltype(int type, int *oldtype)
+pthread_setcanceltype (int type, int *oldtype)
+     /*
+      * ------------------------------------------------------
+      * DOCPUBLIC
+      *      This function atomically sets the calling thread's
+      *      cancelability type to 'type' and returns the previous
+      *      cancelability type at the location referenced by
+      *      'oldtype'
+      *
+      * PARAMETERS
+      *      type,
+      *      oldtype
+      *              PTHREAD_CANCEL_DEFERRED
+      *                      only deferred cancelation is allowed,
+      *
+      *              PTHRAD_CANCEL_ASYNCHRONOUS
+      *                      Asynchronous cancellation is allowed
+      *
+      *
+      * DESCRIPTION
+      *      This function atomically sets the calling thread's
+      *      cancelability type to 'type' and returns the previous
+      *      cancelability type at the location referenced by
+      *      'oldtype'
+      *
+      *      NOTES:
+      *      1)      Use with caution; most code is not safe for use
+      *              with asynchronous cancelability.
+      *
+      * RESULTS
+      *              0               successfully set cancelability type,
+      *              EINVAL          'type' is invalid
+      *
+      * ------------------------------------------------------
+      */
 {
-  pthread_t us = pthread_self();
+  pthread_t self;
+  int result;
 
-  /* Validate the new cancellation type. */
-  if (type == PTHREAD_CANCEL_ASYNCHRONOUS ||
-      type != PTHREAD_CANCEL_DEFERRED)
+  if (((self = pthread_self ()) != NULL) &&
+      (type == PTHREAD_CANCEL_DEFERRED ||
+       type == PTHREAD_CANCEL_ASYNCHRONOUS))
     {
-      return EINVAL;
-    }
 
-  if (oldtype != NULL)
+      *oldtype = self->cancelType;
+      self->cancelType = type;
+      result = 0;
+
+    }
+  else
     {
-      *oldtype = us->canceltype;
+      result = EINVAL;
     }
 
-  us->canceltype = type;
-  return 0;
-}
+  return (result);
 
-int
-pthread_cancel(pthread_t thread)
+}				/* pthread_setcanceltype */
+
+void
+pthread_testcancel (void)
+     /*
+      * ------------------------------------------------------
+      * DOCPUBLIC
+      *      This function creates a deferred cancellation point
+      *      in the calling thread. The call has no effect if the
+      *      current cancelability state is
+      *              PTHREAD_CANCEL_DISABLE
+      *
+      * PARAMETERS
+      *      N/A
+      *
+      *
+      * DESCRIPTION
+      *      This function creates a deferred cancellation point
+      *      in the calling thread. The call has no effect if the
+      *      current cancelability state is
+      *              PTHREAD_CANCEL_DISABLE
+      *
+      *      NOTES:
+      *      1)      Cancellation is asynchronous. Use pthread_join
+      *              to wait for termination of thread if necessary
+      *
+      * RESULTS
+      *              N/A
+      *
+      * ------------------------------------------------------
+      */
 {
-  if (_PTHREAD_VALID(thread)
-      && thread->ptstatus != _PTHREAD_REUSE)
+  pthread_t self;
+
+  if ((self = pthread_getspecific (_pthread_selfThreadKey)) != NULL)
     {
-      thread->cancel_pending = TRUE;
-      return 0;
+
+      if (self->cancelState == PTHREAD_CANCEL_ENABLE)
+	{
+
+	  if (WaitForSingleObject (self->cancelEvent, 0) ==
+	      WAIT_OBJECT_0)
+	    {
+	      /*
+	       * Canceling!
+	       */
+	      DWORD exceptionInformation[3];
+
+	      exceptionInformation[0] = (DWORD) (0);
+	      exceptionInformation[1] = (DWORD) (0);
+
+	      RaiseException (
+			       EXCEPTION_PTHREAD_SERVICES,
+			       0,
+			       3,
+			       exceptionInformation);
+	    }
+	}
     }
 
-  return ESRCH;
-}
+}				/* pthread_testcancel */
 
-void
-pthread_testcancel(void)
+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 created semaphore,
+      *              ESRCH           no thread found corresponding to 'thread',
+      *
+      * ------------------------------------------------------
+      */
 {
-  pthread_t thread = pthread_self();
+  int result;
 
-  if (thread->cancelstate == PTHREAD_CANCEL_DISABLE)
+  if (thread != NULL)
     {
-      return;
-    }
 
-  if (thread->cancel_pending == TRUE)
+      if (!SetEvent (thread->cancelEvent))
+	{
+	  result = ESRCH;
+	}
+      else
+	{
+	  result = 0;
+	}
+
+    }
+  else
     {
-      pthread_exit(PTHREAD_CANCELED);
+      result = ESRCH;
     }
-  /* Never reached. */
+
+  return (result);
 }
+
+/* </JEB> */
+