[PATCH 5/8] score: Add ISR lock to Objects_Control
Sebastian Huber
sebastian.huber at embedded-brains.de
Wed Mar 4 15:07:05 UTC 2015
This enables per-object SMP locks on SMP configurations and is the first
step to support fine-grained locking. On uni-processor configuration
there will be no overhead. The _Objects_Acquire() is intended to
replace _Objects_Get_isr_disable().
Update #2273.
---
cpukit/score/Makefile.am | 1 +
cpukit/score/include/rtems/score/object.h | 3 +
cpukit/score/include/rtems/score/objectimpl.h | 80 +++++++++++++++++++++++++++
cpukit/score/src/objectacquire.c | 80 +++++++++++++++++++++++++++
cpukit/score/src/objectclose.c | 2 +
5 files changed, 166 insertions(+)
create mode 100644 cpukit/score/src/objectacquire.c
diff --git a/cpukit/score/Makefile.am b/cpukit/score/Makefile.am
index a2d440b..509a243 100644
--- a/cpukit/score/Makefile.am
+++ b/cpukit/score/Makefile.am
@@ -202,6 +202,7 @@ libscore_a_SOURCES += src/objectallocate.c src/objectclose.c \
src/objectgetinfo.c src/objectgetinfoid.c src/objectapimaximumclass.c \
src/objectnamespaceremove.c \
src/objectactivecount.c
+libscore_a_SOURCES += src/objectacquire.c
## SCHEDULER_C_FILES
libscore_a_SOURCES += src/log2table.c
diff --git a/cpukit/score/include/rtems/score/object.h b/cpukit/score/include/rtems/score/object.h
index 70e5fe6..d0cb579 100644
--- a/cpukit/score/include/rtems/score/object.h
+++ b/cpukit/score/include/rtems/score/object.h
@@ -23,6 +23,7 @@
#include <rtems/score/basedefs.h>
#include <rtems/score/cpu.h>
#include <rtems/score/chain.h>
+#include <rtems/score/isrlock.h>
#ifdef __cplusplus
extern "C" {
@@ -236,6 +237,8 @@ typedef struct {
Objects_Id id;
/** This is the object's name. */
Objects_Name name;
+ /** This is the object's ISR lock. */
+ ISR_LOCK_DEFINE( Lock )
} Objects_Control;
#if defined( RTEMS_MULTIPROCESSING )
diff --git a/cpukit/score/include/rtems/score/objectimpl.h b/cpukit/score/include/rtems/score/objectimpl.h
index 2928eff..c681c9a 100644
--- a/cpukit/score/include/rtems/score/objectimpl.h
+++ b/cpukit/score/include/rtems/score/objectimpl.h
@@ -591,6 +591,83 @@ Objects_Control *_Objects_Get_no_protection(
);
/**
+ * @brief Acquires an object by its identifier.
+ *
+ * This function is similar to _Objects_Get_isr_disable(). It acquires the
+ * object specific ISR lock for local objects. Thread dispatching is not
+ * disabled for local objects. For remote objects thread dispatching is
+ * disabled.
+ *
+ * @param[in] information The object information.
+ * @param[in] id The object identifier.
+ * @param[in] location The location of the object.
+ * @param[in] lock_context The lock context for local objects.
+ *
+ * @retval object The object corresponding to the identifier.
+ * @retval NULL No object exists in this domain for this identifer.
+ *
+ * @see _Objects_Release(), _Objects_Release_and_ISR_enable(), and
+ * _Objects_Release_and_thread_dispatch_disable().
+ */
+Objects_Control *_Objects_Acquire(
+ const Objects_Information *information,
+ Objects_Id id,
+ Objects_Locations *location,
+ ISR_lock_Context *lock_context
+);
+
+/**
+ * @brief Releases a local object.
+ *
+ * @param[in] the_object The local object acquired by _Objects_Acquire().
+ * @param[in] lock_context The lock context initialized by _Objects_Acquire().
+ */
+RTEMS_INLINE_ROUTINE void _Objects_Release(
+ Objects_Control *the_object,
+ ISR_lock_Context *lock_context
+)
+{
+ _ISR_lock_Release( &the_object->Lock, lock_context );
+}
+
+/**
+ * @brief Releases a local object and restores the interrupt level.
+ *
+ * @param[in] the_object The local object acquired by _Objects_Acquire().
+ * @param[in] lock_context The lock context initialized by _Objects_Acquire().
+ */
+RTEMS_INLINE_ROUTINE void _Objects_Release_and_ISR_enable(
+ Objects_Control *the_object,
+ ISR_lock_Context *lock_context
+)
+{
+ _ISR_lock_Release_and_ISR_enable( &the_object->Lock, lock_context );
+}
+
+/**
+ * @brief Releases a local object, disables thread dispatching and restores the
+ * interrupt level.
+ *
+ * @param[in] the_object The local object acquired by _Objects_Acquire().
+ * @param[in] lock_context The lock context initialized by _Objects_Acquire().
+ *
+ * @return The current processor.
+ */
+RTEMS_INLINE_ROUTINE Per_CPU_Control *
+_Objects_Release_and_thread_dispatch_disable(
+ Objects_Control *the_object,
+ ISR_lock_Context *lock_context
+)
+{
+ Per_CPU_Control *cpu_self = _Per_CPU_Get();
+
+ _Thread_Dispatch_disable_critical( cpu_self );
+ _Objects_Release_and_ISR_enable( the_object, lock_context );
+
+ return cpu_self;
+}
+
+/**
* Like @ref _Objects_Get, but is used to find "next" open object.
*
* @param[in] information points to an object class information block.
@@ -903,6 +980,7 @@ RTEMS_INLINE_ROUTINE void _Objects_Open(
_Assert( the_object != NULL );
the_object->name = name;
+ _ISR_lock_Initialize( &the_object->Lock, "Object" );
_Objects_Set_local_object(
information,
@@ -927,6 +1005,7 @@ RTEMS_INLINE_ROUTINE void _Objects_Open_u32(
{
/* ASSERT: information->is_string == false */
the_object->name.name_u32 = name;
+ _ISR_lock_Initialize( &the_object->Lock, "Object" );
_Objects_Set_local_object(
information,
@@ -953,6 +1032,7 @@ RTEMS_INLINE_ROUTINE void _Objects_Open_string(
/* ASSERT: information->is_string */
the_object->name.name_p = name;
#endif
+ _ISR_lock_Initialize( &the_object->Lock, "Object" );
_Objects_Set_local_object(
information,
diff --git a/cpukit/score/src/objectacquire.c b/cpukit/score/src/objectacquire.c
new file mode 100644
index 0000000..57d38f4
--- /dev/null
+++ b/cpukit/score/src/objectacquire.c
@@ -0,0 +1,80 @@
+/**
+ * @file
+ *
+ * @brief Object Acquire
+ *
+ * @ingroup ScoreObject
+ */
+
+/*
+ * Copyright (c) 2015 embedded brains GmbH. All rights reserved.
+ *
+ * embedded brains GmbH
+ * Dornierstr. 4
+ * 82178 Puchheim
+ * Germany
+ * <rtems at embedded-brains.de>
+ *
+ * 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/score/objectimpl.h>
+
+Objects_Control *_Objects_Acquire(
+ const Objects_Information *information,
+ Objects_Id id,
+ Objects_Locations *location,
+ ISR_lock_Context *lock_context
+)
+{
+ Objects_Control *the_object;
+ uint32_t index;
+
+ index = id - information->minimum_id + 1;
+
+ if ( information->maximum >= index ) {
+ /*
+ * On uni-processor configurations we disable interrupts before we use the
+ * local table. This prevents use of freed memory in case the object
+ * information is extended in between. On SMP configurations bad things
+ * can happen, see https://devel.rtems.org/ticket/2280.
+ */
+#if !defined(RTEMS_SMP)
+ ISR_Level level;
+
+ _ISR_Disable( level );
+#endif
+ if ( ( the_object = information->local_table[ index ] ) != NULL ) {
+ *location = OBJECTS_LOCAL;
+#if defined(RTEMS_SMP)
+ _ISR_lock_ISR_disable_and_acquire( &the_object->Lock, lock_context );
+#else
+ lock_context->isr_level = level;
+#endif
+
+ return the_object;
+ }
+#if !defined(RTEMS_SMP)
+ _ISR_Enable( level );
+#endif
+ *location = OBJECTS_ERROR;
+
+ return NULL;
+ }
+
+ *location = OBJECTS_ERROR;
+
+#if defined(RTEMS_MULTIPROCESSING)
+ _Objects_MP_Is_remote( information, id, location, &the_object );
+
+ return the_object;
+#else
+ return NULL;
+#endif
+}
diff --git a/cpukit/score/src/objectclose.c b/cpukit/score/src/objectclose.c
index 52eb10c..25c7aa1 100644
--- a/cpukit/score/src/objectclose.c
+++ b/cpukit/score/src/objectclose.c
@@ -28,4 +28,6 @@ void _Objects_Close(
_Objects_Invalidate_Id( information, the_object );
_Objects_Namespace_remove( information, the_object );
+
+ _ISR_lock_Destroy( &the_object->Lock );
}
--
1.8.4.5
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