nptl: Move cancel type out of cancelhandling

Now that the thread cancellation type is not accessed concurrently
anymore, it is possible to move it out the cancelhandling.

By removing the cancel state out of the internal thread cancel handling
state there is no need to check if cancelled bit was set in CAS
operation.

It allows simplifing the cancellation wrappers and the
CANCEL_CANCELED_AND_ASYNCHRONOUS is removed.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.

1 files changed, 4 insertions, 40 deletions

diff --git a/nptl/libc-cleanup.c b/nptl/libc-cleanup.c
index 6286b8b525..180d15bc9e 100644
--- a/nptl/libc-cleanup.c
+++ b/nptl/libc-cleanup.c
@@ -27,27 +27,9 @@ __libc_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer)
 
   buffer->__prev = THREAD_GETMEM (self, cleanup);
 
-  int cancelhandling = THREAD_GETMEM (self, cancelhandling);
-
   /* Disable asynchronous cancellation for now.  */
-  if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
-    while (1)
-      {
-	int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
-						cancelhandling
-						& ~CANCELTYPE_BITMASK,
-						cancelhandling);
-	if (__glibc_likely (curval == cancelhandling))
-	  /* Successfully replaced the value.  */
-	  break;
-
-	/* Prepare for the next round.  */
-	cancelhandling = curval;
-      }
-
-  buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
-			  ? PTHREAD_CANCEL_ASYNCHRONOUS
-			  : PTHREAD_CANCEL_DEFERRED);
+  buffer->__canceltype = THREAD_GETMEM (self, canceltype);
+  THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_DEFERRED);
 
   THREAD_SETMEM (self, cleanup, buffer);
 }
@@ -60,26 +42,8 @@ __libc_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer)
 
   THREAD_SETMEM (self, cleanup, buffer->__prev);
 
-  int cancelhandling;
-  if (__builtin_expect (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED, 0)
-      && ((cancelhandling = THREAD_GETMEM (self, cancelhandling))
-	  & CANCELTYPE_BITMASK) == 0)
-    {
-      while (1)
-	{
-	  int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
-						  cancelhandling
-						  | CANCELTYPE_BITMASK,
-						  cancelhandling);
-	  if (__glibc_likely (curval == cancelhandling))
-	    /* Successfully replaced the value.  */
-	    break;
-
-	  /* Prepare for the next round.  */
-	  cancelhandling = curval;
-	}
-
+  THREAD_SETMEM (self, canceltype, buffer->__canceltype);
+  if (buffer->__canceltype == PTHREAD_CANCEL_ASYNCHRONOUS)
       __pthread_testcancel ();
-    }
 }
 libc_hidden_def (__libc_cleanup_pop_restore)