From c42be504c92d76d2e06d0fc8ebd05fc913376d2d Mon Sep 17 00:00:00 2001
From: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date: Wed, 16 Nov 2016 14:50:09 +0100
Subject: 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.
---
 cpukit/posix/include/rtems/posix/spinlockimpl.h | 81 ++++++++++++-------------
 1 file changed, 38 insertions(+), 43 deletions(-)

(limited to 'cpukit/posix/include/rtems/posix/spinlockimpl.h')

diff --git a/cpukit/posix/include/rtems/posix/spinlockimpl.h b/cpukit/posix/include/rtems/posix/spinlockimpl.h
index f1b5639bd1..36ef6677a0 100644
--- a/cpukit/posix/include/rtems/posix/spinlockimpl.h
+++ b/cpukit/posix/include/rtems/posix/spinlockimpl.h
@@ -11,6 +11,8 @@
  *  COPYRIGHT (c) 1989-2011.
  *  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.
@@ -19,62 +21,55 @@
 #ifndef _RTEMS_POSIX_SPINLOCKIMPL_H
 #define _RTEMS_POSIX_SPINLOCKIMPL_H
 
-#include <rtems/posix/spinlock.h>
-#include <rtems/score/corespinlockimpl.h>
-#include <rtems/score/objectimpl.h>
-
 #include <pthread.h>
 
+#include <rtems/score/isrlevel.h>
+
+#if defined(RTEMS_SMP)
+#include <rtems/score/percpu.h>
+#include <rtems/score/smplockticket.h>
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/**
- * The following defines the information control block used to manage
- * this class of objects.
- */
+#if SIZEOF_PTHREAD_SPINLOCK_T > 4
+#define POSIX_SPINLOCKS_ARE_SELF_CONTAINED
+#endif
 
-extern Objects_Information _POSIX_Spinlock_Information;
+typedef struct {
+#if defined(RTEMS_SMP)
+  SMP_ticket_lock_Control Lock;
+#else
+  unsigned int reserved[ 2 ];
+#endif
+  ISR_Level interrupt_state;
+} POSIX_Spinlock_Control;
 
-/**
- * @brief Allocate a spinlock control block.
- *
- * This function allocates a spinlock control block from
- * the inactive chain of free spinlock control blocks.
- */
-RTEMS_INLINE_ROUTINE POSIX_Spinlock_Control *_POSIX_Spinlock_Allocate( void )
-{
-  return (POSIX_Spinlock_Control *) 
-    _Objects_Allocate( &_POSIX_Spinlock_Information );
-}
+#if !defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+#if defined(RTEMS_SMP)
+extern POSIX_Spinlock_Control _POSIX_Spinlock_Global;
 
-/**
- * @brief Free a spinlock control block.
- *
- * This routine frees a spinlock control block to the
- * inactive chain of free spinlock control blocks.
- */
-RTEMS_INLINE_ROUTINE void _POSIX_Spinlock_Free (
-  POSIX_Spinlock_Control *the_spinlock
-)
-{
-  _Objects_Free( &_POSIX_Spinlock_Information, &the_spinlock->Object );
-}
+extern uint32_t _POSIX_Spinlock_Owner;
+#endif
+
+extern int _POSIX_Spinlock_Nest_level;
+#endif
 
 RTEMS_INLINE_ROUTINE POSIX_Spinlock_Control *_POSIX_Spinlock_Get(
-  pthread_spinlock_t *spinlock,
-  ISR_lock_Context   *lock_context
+  pthread_spinlock_t *lock
 )
 {
-  if ( spinlock == NULL ) {
-    return NULL;
-  }
-
-  return (POSIX_Spinlock_Control *) _Objects_Get(
-    *spinlock,
-    lock_context,
-    &_POSIX_Spinlock_Information
-  );
+#if defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+  return (POSIX_Spinlock_Control *) lock;
+#elif defined(RTEMS_SMP)
+  (void) lock;
+  return &_POSIX_Spinlock_Global;
+#else
+  (void) lock;
+  return NULL;
+#endif
 }
 
 #ifdef __cplusplus
-- 
cgit v1.2.3