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-rw-r--r--sysdeps/pthread/aio_cancel.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/sysdeps/pthread/aio_cancel.c b/sysdeps/pthread/aio_cancel.c
new file mode 100644
index 0000000000..c1cfea50c8
--- /dev/null
+++ b/sysdeps/pthread/aio_cancel.c
@@ -0,0 +1,142 @@
+/* Cancel requests associated with given file descriptor.
+   Copyright (C) 1997, 1998, 2000 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+
+/* We use an UGLY hack to prevent gcc from finding us cheating.  The
+   implementation of aio_cancel and aio_cancel64 are identical and so
+   we want to avoid code duplication by using aliases.  But gcc sees
+   the different parameter lists and prints a warning.  We define here
+   a function so that aio_cancel64 has no prototype.  */
+#define aio_cancel64 XXX
+#include <aio.h>
+/* And undo the hack.  */
+#undef aio_cancel64
+
+#include <assert.h>
+#include <errno.h>
+
+#include "aio_misc.h"
+
+
+int
+aio_cancel (fildes, aiocbp)
+     int fildes;
+     struct aiocb *aiocbp;
+{
+  struct requestlist *req = NULL;
+  int result = AIO_ALLDONE;
+
+  /* Request the mutex.  */
+  pthread_mutex_lock (&__aio_requests_mutex);
+
+  /* We are asked to cancel a specific AIO request.  */
+  if (aiocbp != NULL)
+    {
+      /* If the AIO request is not for this descriptor it has no value
+	 to look for the request block.  */
+      if (aiocbp->aio_fildes == fildes)
+	{
+	  struct requestlist *last = NULL;
+
+	  req = __aio_find_req_fd (fildes);
+
+	  if (req == NULL)
+	    {
+	    not_found:
+	      pthread_mutex_unlock (&__aio_requests_mutex);
+	      __set_errno (EINVAL);
+	      return -1;
+	    }
+
+	  while (req->aiocbp != (aiocb_union *) aiocbp)
+	    {
+	      last = req;
+	      req = req->next_prio;
+	      if (req == NULL)
+		goto not_found;
+	    }
+
+	  /* Don't remove the entry if a thread is already working on it.  */
+	  if (req->running == allocated)
+	    {
+	      result = AIO_NOTCANCELED;
+	      req = NULL;
+	    }
+	  else
+	    {
+	      /* We can remove the entry.  */
+	      __aio_remove_request (last, req, 0);
+
+	      result = AIO_CANCELED;
+
+	      req->next_prio = NULL;
+	    }
+	}
+    }
+  else
+    {
+      /* Find the beginning of the list of all requests for this
+	 desriptor.  */
+      req = __aio_find_req_fd (fildes);
+
+      /* If any request is worked on by a thread it must be the first.
+	 So either we can delete all requests or all but the first.  */
+      if (req != NULL)
+	{
+	  if (req->running == allocated)
+	    {
+	      struct requestlist *old = req;
+	      req = req->next_prio;
+	      old->next_prio = NULL;
+
+	      result = AIO_NOTCANCELED;
+
+	      if (req != NULL)
+		__aio_remove_request (old, req, 1);
+	    }
+	  else
+	    {
+	      result = AIO_CANCELED;
+
+	      /* We can remove the entry.  */
+	      __aio_remove_request (NULL, req, 1);
+	    }
+	}
+    }
+
+  /* Mark requests as canceled and send signal.  */
+  while (req != NULL)
+    {
+      struct requestlist *old = req;
+      assert (req->running == yes || req->running == queued);
+      req->aiocbp->aiocb.__error_code = ECANCELED;
+      req->aiocbp->aiocb.__return_value = -1;
+      __aio_notify (req);
+      req = req->next_prio;
+      __aio_free_request (old);
+    }
+
+  /* Release the mutex.  */
+  pthread_mutex_unlock (&__aio_requests_mutex);
+
+  return result;
+}
+
+weak_alias (aio_cancel, aio_cancel64)