[PATCH] score: PR2172: _Thread_queue_Extract()
Sebastian Huber
sebastian.huber at embedded-brains.de
Mon Mar 31 09:42:36 UTC 2014
Add _Thread_queue_Extract_with_return_code(). On SMP this sequence in
_Thread_queue_Process_timeout() was broken:
[...]
/*
* After we enable interrupts here, a lot may happen in the
* meantime, e.g. nested interrupts may release the resource that
* times out here. So we enter _Thread_queue_Extract()
* speculatively. Inside this function we check the actual status
* under ISR disable protection. This ensures that exactly one
* executing context performs the extract operation (other parties
* may call _Thread_queue_Dequeue()). If this context won, then
* we have a timeout.
*
* We can use the_thread_queue pointer here even if
* the_thread->Wait.queue is already set to NULL since the extract
* operation will only use the thread queue discipline to select
* the right extract operation. The timeout status is set during
* thread queue initialization.
*/
we_did_it = _Thread_queue_Extract( the_thread_queue, the_thread );
if ( we_did_it ) {
the_thread->Wait.return_code = the_thread_queue->timeout_status;
}
[...]
In case _Thread_queue_Extract() successfully extracted a thread, then
this thread may start execution on a remote processor immediately and
read the the_thread->Wait.return_code before we update it here with the
timeout status. Thus it observes a successful operation even if it
timed out.
---
cpukit/score/include/rtems/score/threadqimpl.h | 23 ++++++++++++++---------
cpukit/score/src/threadqextract.c | 21 +++++++++++++++++----
cpukit/score/src/threadqextractfifo.c | 10 +++++-----
cpukit/score/src/threadqextractpriority.c | 12 +++++++-----
cpukit/score/src/threadqprocesstimeout.c | 11 +++++------
cpukit/score/src/threadqrequeue.c | 6 +++++-
testsuites/sptests/spthreadq01/init.c | 4 +---
7 files changed, 54 insertions(+), 33 deletions(-)
diff --git a/cpukit/score/include/rtems/score/threadqimpl.h b/cpukit/score/include/rtems/score/threadqimpl.h
index 040e16b..9d24812 100644
--- a/cpukit/score/include/rtems/score/threadqimpl.h
+++ b/cpukit/score/include/rtems/score/threadqimpl.h
@@ -135,15 +135,18 @@ void _Thread_queue_Requeue(
*
* @param[in] the_thread_queue is the pointer to the ThreadQ header
* @param[in] the_thread is the pointer to a thread control block that is to be removed
- *
- * @retval true The extract operation was performed by the executing context.
- * @retval false Otherwise.
*/
-bool _Thread_queue_Extract(
+void _Thread_queue_Extract(
Thread_queue_Control *the_thread_queue,
Thread_Control *the_thread
);
+void _Thread_queue_Extract_with_return_code(
+ Thread_queue_Control *the_thread_queue,
+ Thread_Control *the_thread,
+ uint32_t return_code
+);
+
/**
* @brief Extracts the_thread from the_thread_queue.
*
@@ -265,8 +268,9 @@ Thread_blocking_operation_States _Thread_queue_Enqueue_priority (
* @retval true The extract operation was performed by the executing context.
* @retval false Otherwise.
*/
-bool _Thread_queue_Extract_priority_helper(
+void _Thread_queue_Extract_priority_helper(
Thread_Control *the_thread,
+ uint32_t return_code,
bool requeuing
);
@@ -276,8 +280,8 @@ bool _Thread_queue_Extract_priority_helper(
* This macro wraps the underlying call and hides the requeuing argument.
*/
-#define _Thread_queue_Extract_priority( _the_thread ) \
- _Thread_queue_Extract_priority_helper( _the_thread, false )
+#define _Thread_queue_Extract_priority( _the_thread, _return_code ) \
+ _Thread_queue_Extract_priority_helper( _the_thread, _return_code, false )
/**
* @brief Get highest priority thread on the_thread_queue.
*
@@ -337,8 +341,9 @@ Thread_blocking_operation_States _Thread_queue_Enqueue_fifo (
* This routine removes the_thread from the_thread_queue
* and cancels any timeouts associated with this blocking.
*/
-bool _Thread_queue_Extract_fifo(
- Thread_Control *the_thread
+void _Thread_queue_Extract_fifo(
+ Thread_Control *the_thread,
+ uint32_t return_code
);
/**
diff --git a/cpukit/score/src/threadqextract.c b/cpukit/score/src/threadqextract.c
index 9563f44..0a9c9d4 100644
--- a/cpukit/score/src/threadqextract.c
+++ b/cpukit/score/src/threadqextract.c
@@ -21,9 +21,10 @@
#include <rtems/score/threadqimpl.h>
-bool _Thread_queue_Extract(
+void _Thread_queue_Extract_with_return_code(
Thread_queue_Control *the_thread_queue,
- Thread_Control *the_thread
+ Thread_Control *the_thread,
+ uint32_t return_code
)
{
/*
@@ -31,8 +32,20 @@ bool _Thread_queue_Extract(
* is a macro and the underlying methods do not have the same signature.
*/
if ( the_thread_queue->discipline == THREAD_QUEUE_DISCIPLINE_PRIORITY )
- return _Thread_queue_Extract_priority( the_thread );
+ return _Thread_queue_Extract_priority( the_thread, return_code );
else /* must be THREAD_QUEUE_DISCIPLINE_FIFO */
- return _Thread_queue_Extract_fifo( the_thread );
+ return _Thread_queue_Extract_fifo( the_thread, return_code );
+
+}
+void _Thread_queue_Extract(
+ Thread_queue_Control *the_thread_queue,
+ Thread_Control *the_thread
+)
+{
+ _Thread_queue_Extract_with_return_code(
+ the_thread_queue,
+ the_thread,
+ the_thread->Wait.return_code
+ );
}
diff --git a/cpukit/score/src/threadqextractfifo.c b/cpukit/score/src/threadqextractfifo.c
index 6ddd001..80fc7f3 100644
--- a/cpukit/score/src/threadqextractfifo.c
+++ b/cpukit/score/src/threadqextractfifo.c
@@ -25,8 +25,9 @@
#include <rtems/score/threadimpl.h>
#include <rtems/score/watchdogimpl.h>
-bool _Thread_queue_Extract_fifo(
- Thread_Control *the_thread
+void _Thread_queue_Extract_fifo(
+ Thread_Control *the_thread,
+ uint32_t return_code
)
{
ISR_Level level;
@@ -35,12 +36,13 @@ bool _Thread_queue_Extract_fifo(
if ( !_States_Is_waiting_on_thread_queue( the_thread->current_state ) ) {
_ISR_Enable( level );
- return false;
+ return;
}
_Chain_Extract_unprotected( &the_thread->Object.Node );
the_thread->Wait.queue = NULL;
+ the_thread->Wait.return_code = return_code;
if ( !_Watchdog_Is_active( &the_thread->Timer ) ) {
_ISR_Enable( level );
@@ -56,6 +58,4 @@ bool _Thread_queue_Extract_fifo(
if ( !_Objects_Is_local_id( the_thread->Object.id ) )
_Thread_MP_Free_proxy( the_thread );
#endif
-
- return true;
}
diff --git a/cpukit/score/src/threadqextractpriority.c b/cpukit/score/src/threadqextractpriority.c
index 724652a..2f2555b 100644
--- a/cpukit/score/src/threadqextractpriority.c
+++ b/cpukit/score/src/threadqextractpriority.c
@@ -24,8 +24,9 @@
#include <rtems/score/threadimpl.h>
#include <rtems/score/watchdogimpl.h>
-bool _Thread_queue_Extract_priority_helper(
+void _Thread_queue_Extract_priority_helper(
Thread_Control *the_thread,
+ uint32_t return_code,
bool requeuing
)
{
@@ -44,7 +45,7 @@ bool _Thread_queue_Extract_priority_helper(
_ISR_Disable( level );
if ( !_States_Is_waiting_on_thread_queue( the_thread->current_state ) ) {
_ISR_Enable( level );
- return false;
+ return;
}
/*
@@ -86,9 +87,12 @@ bool _Thread_queue_Extract_priority_helper(
if ( requeuing ) {
_ISR_Enable( level );
- return true;
+ return;
}
+ the_thread->Wait.queue = NULL;
+ the_thread->Wait.return_code = return_code;
+
if ( !_Watchdog_Is_active( &the_thread->Timer ) ) {
_ISR_Enable( level );
} else {
@@ -102,6 +106,4 @@ bool _Thread_queue_Extract_priority_helper(
if ( !_Objects_Is_local_id( the_thread->Object.id ) )
_Thread_MP_Free_proxy( the_thread );
#endif
-
- return true;
}
diff --git a/cpukit/score/src/threadqprocesstimeout.c b/cpukit/score/src/threadqprocesstimeout.c
index feb0921..6169019 100644
--- a/cpukit/score/src/threadqprocesstimeout.c
+++ b/cpukit/score/src/threadqprocesstimeout.c
@@ -51,8 +51,6 @@ void _Thread_queue_Process_timeout(
}
_ISR_Enable( level );
} else {
- bool we_did_it;
-
_ISR_Enable( level );
/*
@@ -70,10 +68,11 @@ void _Thread_queue_Process_timeout(
* right extract operation. The timeout status is set during thread
* queue initialization.
*/
- we_did_it = _Thread_queue_Extract( the_thread_queue, the_thread );
- if ( we_did_it ) {
- the_thread->Wait.return_code = the_thread_queue->timeout_status;
- }
+ _Thread_queue_Extract_with_return_code(
+ the_thread_queue,
+ the_thread,
+ the_thread_queue->timeout_status
+ );
}
} else {
_ISR_Enable( level );
diff --git a/cpukit/score/src/threadqrequeue.c b/cpukit/score/src/threadqrequeue.c
index 4eed7b3..ee15b3d 100644
--- a/cpukit/score/src/threadqrequeue.c
+++ b/cpukit/score/src/threadqrequeue.c
@@ -45,7 +45,11 @@ void _Thread_queue_Requeue(
_ISR_Disable( level );
if ( _States_Is_waiting_on_thread_queue( the_thread->current_state ) ) {
_Thread_queue_Enter_critical_section( tq );
- _Thread_queue_Extract_priority_helper( the_thread, true );
+ _Thread_queue_Extract_priority_helper(
+ the_thread,
+ the_thread->Wait.return_code,
+ true
+ );
(void) _Thread_queue_Enqueue_priority( tq, the_thread, &level_ignored );
}
_ISR_Enable( level );
diff --git a/testsuites/sptests/spthreadq01/init.c b/testsuites/sptests/spthreadq01/init.c
index ffaf3e9..233f3df 100644
--- a/testsuites/sptests/spthreadq01/init.c
+++ b/testsuites/sptests/spthreadq01/init.c
@@ -31,16 +31,14 @@ void threadq_first_empty(
)
{
Thread_queue_Control tq;
- bool we_did_it;
printf( "Init - initialize thread queue for %s\n", discipline_string );
_Thread_queue_Initialize( &tq, discipline, 0x01, 3 );
puts( "Init - _Thread_queue_Extract - thread not blocked on a thread queue" );
_Thread_Disable_dispatch();
- we_did_it = _Thread_queue_Extract( &tq, _Thread_Executing );
+ _Thread_queue_Extract( &tq, _Thread_Executing );
_Thread_Enable_dispatch();
- rtems_test_assert( !we_did_it );
/* is there more to check? */
}
--
1.7.7
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