posix: Add self-contained pthread spinlock

Turn pthread_spinlock_t into a self-contained object.  On uni-processor
configurations, interrupts are disabled in the lock/trylock operations
and the previous interrupt status is restored in the corresponding
unlock operations.  On SMP configurations, a ticket lock is a acquired
and released in addition.

The self-contained pthread_spinlock_t object is defined by Newlib in
<sys/_pthreadtypes.h>.

typedef struct {
  struct _Ticket_lock_Control _lock;
  __uint32_t                  _interrupt_state;
} pthread_spinlock_t;

This implementation is simple and efficient.  However, this test case of
the Linux Test Project would fail due to call of printf() and sleep()
during spin lock ownership:

https://github.com/linux-test-project/ltp/blob/master/testcases/open_posix_testsuite/conformance/interfaces/pthread_spin_lock/1-2.c

There is only limited support for profiling on SMP configurations.

Delete CORE spinlock implementation.

Update #2674.

1 files changed, 7 insertions, 45 deletions

diff --git a/cpukit/posix/src/pspininit.c b/cpukit/posix/src/pspininit.c
index bc131e2e81..313633a11e 100644
--- a/cpukit/posix/src/pspininit.c
+++ b/cpukit/posix/src/pspininit.c
@@ -11,6 +11,8 @@
  *  COPYRIGHT (c) 1989-2006.
  *  On-Line Applications Research Corporation (OAR).
  *
+ *  Copyright (c) 2016 embedded brains GmbH
+ *
  *  The license and distribution terms for this file may be
  *  found in the file LICENSE in this distribution or at
  *  http://www.rtems.org/license/LICENSE.
@@ -20,58 +22,18 @@
 #include "config.h"
 #endif
 
-#include <pthread.h>
-#include <errno.h>
-
-#include <rtems/system.h>
 #include <rtems/posix/spinlockimpl.h>
 
-/*
- *  pthread_spinlock_init
- *
- *  This directive creates a spinlock.  A spinlock id is returned.
- *
- *  Input parameters:
- *    spinlock         - pointer to spinlock id
- *    pshared          - is this spinlock shared between processes
- *
- *  Output parameters:
- *    spinlock     - spinlock id
- *    0           - if successful
- *    error code  - if unsuccessful
- */
-
 int pthread_spin_init(
   pthread_spinlock_t  *spinlock,
   int                  pshared
 )
 {
-  POSIX_Spinlock_Control   *the_spinlock;
+#if defined(RTEMS_SMP) && defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+  POSIX_Spinlock_Control *the_spinlock;
 
-  if ( !spinlock )
-    return EINVAL;
-
-  switch ( pshared ) {
-    case PTHREAD_PROCESS_PRIVATE:    /* only supported values */
-      break;
-    case PTHREAD_PROCESS_SHARED:
-    default:
-      return EINVAL;
-  }
-
-  the_spinlock = _POSIX_Spinlock_Allocate();
-
-  if ( !the_spinlock ) {
-    _Objects_Allocator_unlock();
-    return EAGAIN;
-  }
-
-  _CORE_spinlock_Initialize( &the_spinlock->Spinlock );
-
-  _Objects_Open_u32( &_POSIX_Spinlock_Information, &the_spinlock->Object, 0 );
-
-  *spinlock = the_spinlock->Object.id;
-
-  _Objects_Allocator_unlock();
+  the_spinlock = _POSIX_Spinlock_Get( spinlock );
+  _SMP_ticket_lock_Initialize( &the_spinlock->Lock );
+#endif
   return 0;
 }