score: New thread queue implementation

Use thread wait flags for synchronization.  The enqueue operation is now
part of the initial critical section.  This is the key change and
enables fine grained locking on SMP for objects using a thread queue
like semaphores and message queues.

Update #2273.

1 files changed, 0 insertions, 80 deletions

diff --git a/cpukit/score/src/threadqprocesstimeout.c b/cpukit/score/src/threadqprocesstimeout.c
deleted file mode 100644
index dbb8f5ce45..0000000000
--- a/cpukit/score/src/threadqprocesstimeout.c
+++ /dev/null
@@ -1,80 +0,0 @@
-/**
- * @file
- * 
- * @brief Thread Queue Handler Process Timeout Handler
- * @ingroup ScoreThreadQ
- */
-
-/*
- *  COPYRIGHT (c) 1989-2008.
- *  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/score/threadqimpl.h>
-#include <rtems/score/threadimpl.h>
-
-void _Thread_queue_Process_timeout(
-  Thread_Control *the_thread
-)
-{
-  Thread_queue_Control *the_thread_queue;
-  ISR_Level             level;
-
-  /*
-   *  If the_thread_queue is not synchronized, then it is either
-   *  "nothing happened", "timeout", or "satisfied".   If the_thread
-   *  is the executing thread, then it is in the process of blocking
-   *  and it is the thread which is responsible for the synchronization
-   *  process.
-   *
-   *  If it is not satisfied, then it is "nothing happened" and
-   *  this is the "timeout" transition.  After a request is satisfied,
-   *  a timeout is not allowed to occur.
-   */
-
-  _ISR_Disable( level );
-  the_thread_queue = the_thread->Wait.queue;
-  if ( the_thread_queue != NULL ) {
-    if ( the_thread_queue->sync_state != THREAD_BLOCKING_OPERATION_SYNCHRONIZED &&
-         _Thread_Is_executing( the_thread ) ) {
-      if ( the_thread_queue->sync_state != THREAD_BLOCKING_OPERATION_SATISFIED ) {
-        the_thread->Wait.return_code = the_thread_queue->timeout_status;
-        the_thread_queue->sync_state = THREAD_BLOCKING_OPERATION_TIMEOUT;
-      }
-      _ISR_Enable( level );
-    } else {
-      _ISR_Enable( level );
-
-      /*
-       * 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.
-       */
-      _Thread_queue_Extract_with_return_code(
-        the_thread,
-        the_thread_queue->timeout_status
-      );
-    }
-  } else {
-    _ISR_Enable( level );
-  }
-}
-