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.

6 files changed, 122 insertions, 185 deletions

diff --git a/cpukit/posix/src/pspin.c b/cpukit/posix/src/pspin.c
deleted file mode 100644
index 6c466bcab5..0000000000
--- a/cpukit/posix/src/pspin.c
+++ /dev/null
@@ -1,51 +0,0 @@
-/**
- *  @file
- *
- *  This file contains the initialization of the POSIX Spinlock Manager.
- */
-
-/*
- *  COPYRIGHT (c) 1989-2013.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  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.
- */
-
-#if HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include <limits.h>
-
-#include <rtems/system.h>
-#include <rtems/config.h>
-#include <rtems/sysinit.h>
-#include <rtems/posix/spinlockimpl.h>
-
-Objects_Information _POSIX_Spinlock_Information;
-
-/**
- *  @brief _POSIX_Spinlock_Manager_initialization
- */
-static void _POSIX_Spinlock_Manager_initialization(void)
-{
-  _Objects_Initialize_information(
-    &_POSIX_Spinlock_Information,    /* object information table */
-    OBJECTS_POSIX_API,               /* object API */
-    OBJECTS_POSIX_SPINLOCKS,         /* object class */
-    Configuration_POSIX_API.maximum_spinlocks,
-                                     /* maximum objects of this class */
-    sizeof( POSIX_Spinlock_Control ),/* size of this object's control block */
-    true,                            /* true if the name is a string */
-    _POSIX_PATH_MAX,                 /* maximum length of each object's name */
-    NULL                             /* Proxy extraction support callout */
-  );
-}
-
-RTEMS_SYSINIT_ITEM(
-  _POSIX_Spinlock_Manager_initialization,
-  RTEMS_SYSINIT_POSIX_SPINLOCK,
-  RTEMS_SYSINIT_ORDER_MIDDLE
-);
diff --git a/cpukit/posix/src/pspindestroy.c b/cpukit/posix/src/pspindestroy.c
index 42a6e76806..f5de88f04b 100644
--- a/cpukit/posix/src/pspindestroy.c
+++ b/cpukit/posix/src/pspindestroy.c
@@ -9,6 +9,8 @@
  *  COPYRIGHT (c) 1989-2007.
  *  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.
@@ -20,33 +22,13 @@
 
 #include <rtems/posix/spinlockimpl.h>
 
-#include <errno.h>
-
 int pthread_spin_destroy( pthread_spinlock_t *spinlock )
 {
+#if defined(RTEMS_SMP) && defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
   POSIX_Spinlock_Control *the_spinlock;
-  ISR_lock_Context        lock_context;
-
-  _Objects_Allocator_lock();
-
-  the_spinlock = _POSIX_Spinlock_Get( spinlock, &lock_context );
-  if ( the_spinlock == NULL ) {
-    _Objects_Allocator_unlock();
-    return EINVAL;
-  }
 
-  _CORE_spinlock_Acquire_critical( &the_spinlock->Spinlock, &lock_context );
-
-  if ( _CORE_spinlock_Is_busy( &the_spinlock->Spinlock ) ) {
-    _CORE_spinlock_Release( &the_spinlock->Spinlock, &lock_context );
-    _Objects_Allocator_unlock();
-    return EBUSY;
-  }
-
-  _CORE_spinlock_Release( &the_spinlock->Spinlock, &lock_context );
-
-  _Objects_Close( &_POSIX_Spinlock_Information, &the_spinlock->Object );
-  _POSIX_Spinlock_Free( the_spinlock );
-  _Objects_Allocator_unlock();
+  the_spinlock = _POSIX_Spinlock_Get( spinlock );
+  _SMP_ticket_lock_Destroy( &the_spinlock->Lock );
+#endif
   return 0;
 }
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;
 }
diff --git a/cpukit/posix/src/pspinlock.c b/cpukit/posix/src/pspinlock.c
index a2db911698..a9b04d8392 100644
--- a/cpukit/posix/src/pspinlock.c
+++ b/cpukit/posix/src/pspinlock.c
@@ -9,6 +9,8 @@
  *  COPYRIGHT (c) 1989-2007.
  *  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.
@@ -19,24 +21,92 @@
 #endif
 
 #include <rtems/posix/spinlockimpl.h>
-#include <rtems/posix/posixapi.h>
+
+#if defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+RTEMS_STATIC_ASSERT(
+#if defined(RTEMS_SMP)
+  offsetof( POSIX_Spinlock_Control, Lock.next_ticket )
+#else
+  offsetof( POSIX_Spinlock_Control, reserved[ 0 ] )
+#endif
+    == offsetof( pthread_spinlock_t, _Lock._next_ticket ),
+  POSIX_SPINLOCK_T_LOCK_NEXT_TICKET
+);
+
+RTEMS_STATIC_ASSERT(
+#if defined(RTEMS_SMP)
+  offsetof( POSIX_Spinlock_Control, Lock.now_serving )
+#else
+  offsetof( POSIX_Spinlock_Control, reserved[ 1 ] )
+#endif
+    == offsetof( pthread_spinlock_t, _Lock._now_serving ),
+  POSIX_SPINLOCK_T_LOCK_NOW_SERVING
+);
+
+RTEMS_STATIC_ASSERT(
+  offsetof( POSIX_Spinlock_Control, interrupt_state )
+    == offsetof( pthread_spinlock_t, _interrupt_state ),
+  POSIX_SPINLOCK_T_INTERRUPT_STATE
+);
+
+RTEMS_STATIC_ASSERT(
+  sizeof( POSIX_Spinlock_Control ) == sizeof( pthread_spinlock_t ),
+  POSIX_SPINLOCK_T_SIZE
+);
+#else
+#if defined(RTEMS_SMP)
+POSIX_Spinlock_Control _POSIX_Spinlock_Global;
+
+uint32_t _POSIX_Spinlock_Owner = 0xffffffff;
+#endif
+
+int _POSIX_Spinlock_Nest_level;
+#endif
 
 int pthread_spin_lock( pthread_spinlock_t *spinlock )
 {
   POSIX_Spinlock_Control *the_spinlock;
-  ISR_lock_Context        lock_context;
-  Status_Control          status;
+  ISR_Level               level;
+#if defined(RTEMS_SMP) && defined(RTEMS_PROFILING)
+  Per_CPU_Control        *cpu_self;
+#endif
 
-  the_spinlock = _POSIX_Spinlock_Get( spinlock, &lock_context );
-  if ( the_spinlock == NULL ) {
-    return EINVAL;
+  the_spinlock = _POSIX_Spinlock_Get( spinlock );
+  _ISR_Local_disable( level );
+#if defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+#if defined(RTEMS_SMP)
+#if defined(RTEMS_PROFILING)
+  /* The lock statistics are incorrect in case of nested pthread spinlocks */
+  cpu_self = _Per_CPU_Get();
+#endif
+  _SMP_ticket_lock_Acquire(
+    &the_spinlock->Lock,
+    &cpu_self->Lock_stats,
+    &cpu_self->Lock_stats_context
+  );
+#endif
+  the_spinlock->interrupt_state = level;
+#else
+#if defined(RTEMS_SMP)
+  if ( _POSIX_Spinlock_Owner != _SMP_Get_current_processor() ) {
+#if defined(RTEMS_PROFILING)
+    cpu_self = _Per_CPU_Get();
+#endif
+    _SMP_ticket_lock_Acquire(
+      &the_spinlock->Lock,
+      &cpu_self->Lock_stats,
+      &cpu_self->Lock_stats_context
+    );
+    _POSIX_Spinlock_Owner = _SMP_Get_current_processor();
+#endif
   }
 
-  status = _CORE_spinlock_Seize(
-    &the_spinlock->Spinlock,
-    true,
-    0,
-    &lock_context
-  );
-  return _POSIX_Get_error( status );
+  if ( ++_POSIX_Spinlock_Nest_level == 1) {
+    the_spinlock->interrupt_state = level;
+  }
+#endif
+  return 0;
 }
+
+int pthread_spin_trylock( pthread_spinlock_t *spinlock )
+  RTEMS_ALIAS( pthread_spin_lock );
diff --git a/cpukit/posix/src/pspintrylock.c b/cpukit/posix/src/pspintrylock.c
deleted file mode 100644
index a8264aba97..0000000000
--- a/cpukit/posix/src/pspintrylock.c
+++ /dev/null
@@ -1,42 +0,0 @@
-/**
- * @file
- *
- * @brief Wait at a Spinlock
- * @ingroup POSIXAPI
- */
-
-/*
- *  COPYRIGHT (c) 1989-2007.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  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.
- */
-
-#if HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include <rtems/posix/spinlockimpl.h>
-#include <rtems/posix/posixapi.h>
-
-int pthread_spin_trylock( pthread_spinlock_t *spinlock )
-{
-  POSIX_Spinlock_Control *the_spinlock;
-  ISR_lock_Context        lock_context;
-  Status_Control          status;
-
-  the_spinlock = _POSIX_Spinlock_Get( spinlock, &lock_context );
-  if ( the_spinlock == NULL ) {
-    return EINVAL;
-  }
-
-  status = _CORE_spinlock_Seize(
-    &the_spinlock->Spinlock,
-    false,
-    0,
-    &lock_context
-  );
-  return _POSIX_Get_error( status );
-}
diff --git a/cpukit/posix/src/pspinunlock.c b/cpukit/posix/src/pspinunlock.c
index b92473d7c1..b508df7384 100644
--- a/cpukit/posix/src/pspinunlock.c
+++ b/cpukit/posix/src/pspinunlock.c
@@ -11,6 +11,8 @@
  *  COPYRIGHT (c) 1989-2007.
  *  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.
@@ -21,19 +23,33 @@
 #endif
 
 #include <rtems/posix/spinlockimpl.h>
-#include <rtems/posix/posixapi.h>
 
-int pthread_spin_unlock( pthread_spinlock_t *spinlock )
+int pthread_spin_unlock( pthread_spinlock_t *lock )
 {
   POSIX_Spinlock_Control *the_spinlock;
-  ISR_lock_Context        lock_context;
-  Status_Control          status;
+  ISR_Level               level;
 
-  the_spinlock = _POSIX_Spinlock_Get( spinlock, &lock_context );
-  if ( the_spinlock == NULL ) {
-    return EINVAL;
+  the_spinlock = _POSIX_Spinlock_Get( lock );
+  level = the_spinlock->interrupt_state;
+#if defined(POSIX_SPINLOCKS_ARE_SELF_CONTAINED)
+#if defined(RTEMS_SMP)
+  _SMP_ticket_lock_Release(
+    &the_spinlock->Lock,
+    &_Per_CPU_Get()->Lock_stats_context
+  );
+#endif
+  _ISR_Local_enable( level );
+#else
+  if ( --_POSIX_Spinlock_Nest_level == 0 ) {
+#if defined(RTEMS_SMP)
+    _POSIX_Spinlock_Owner = 0xffffffff;
+    _SMP_ticket_lock_Release(
+      &the_spinlock->Lock,
+      &_Per_CPU_Get()->Lock_stats_context
+    );
+#endif
+    _ISR_Local_enable( level );
   }
-
-  status = _CORE_spinlock_Surrender( &the_spinlock->Spinlock, &lock_context );
-  return _POSIX_Get_error( status );
+#endif
+  return 0;
 }