ecos: packages/kernel/current/src/sched/mlqueue.cxx comparison

comparison packages/kernel/current/src/sched/mlqueue.cxx @ 115:6ed91473a1cd ecos-sw-2000-08-21

Merge from eCos master repository on 2000-08-21-22:40:54-BST

author	jlarmour
date	Fri, 25 Aug 2000 17:32:38 +0000
parents	bf00f99aec69
children	0ec04793409a

comparison

equal deleted inserted replaced

-:5ad2b71d525e
+:6ed91473a1cd
 //####COPYRIGHTEND####
 //==========================================================================
 //#####DESCRIPTIONBEGIN####
 //
 // Author(s):    nickg
-// Contributors: nickg, jlarmour
+// Contributors: jlarmour
 // Date:         1999-02-17
 // Purpose:      Multilevel queue scheduler class implementation
 // Description:  This file contains the implementations of
 //               Cyg_Scheduler_Implementation and
 //               Cyg_SchedThread_Implementation.
 #ifdef CYGDBG_KERNEL_TRACE_TIMESLICE
 CYG_REPORT_FUNCTION();
 #endif
 CYG_ASSERT( queue_map != 0, "Run queue empty");
 CYG_ASSERT( queue_map & (1<<CYG_THREAD_MIN_PRIORITY), "Idle thread vanished!!!");
+#ifdef CYGSEM_KERNEL_SCHED_TIMESLICE_ENABLE
+if( current_thread->timeslice_enabled && --timeslice_count == 0 )
+#else
 if( --timeslice_count == 0 )
+#endif
 {
 CYG_INSTRUMENT_SCHED(TIMESLICE,0,0);
 #ifdef CYGDBG_KERNEL_TRACE_TIMESLICE
 CYG_TRACE0( true, "quantum consumed, time to reschedule" );
 #endif
 // And force the current thread to yield.
 current_thread->yield();
 }
 CYG_ASSERT( queue_map & (1<<CYG_THREAD_MIN_PRIORITY), "Idle thread vanished!!!");
 CYG_ASSERT( !run_queue[CYG_THREAD_MIN_PRIORITY].empty(), "Idle thread vanished!!!");
 #ifdef CYGDBG_KERNEL_TRACE_TIMESLICE
 CYG_REPORT_RETURN();
 #endif
 }
 #endif
 //==========================================================================
-// Cyg_Cyg_SchedThread_Implementation class members
+// Cyg_SchedThread_Implementation class members
 Cyg_SchedThread_Implementation::Cyg_SchedThread_Implementation
 (
 CYG_ADDRWORD sched_info
 )
 {
 CYG_REPORT_FUNCTION();
 CYG_REPORT_FUNCARG1("sched_info=%08x", sched_info);
-// Create all threads at maximum priority
+// Set priority to the supplied value.
 priority = (cyg_priority)sched_info;
+#ifdef CYGSEM_KERNEL_SCHED_TIMESLICE_ENABLE
+// If timeslice_enabled exists, set it true by default
+timeslice_enabled = true;
+#endif
 // point the next and prev field at this thread.
 next = prev = CYG_CLASSFROMBASE(Cyg_Thread,
 Cyg_SchedThread_Implementation,
 this);
 {
 CYG_REPORT_FUNCTION();
 CYG_REPORT_FUNCARG1("thread=%08x", thread);
 if( queue == NULL ) queue = thread;
-else queue->insert(thread);
+else {
+#ifdef CYGIMP_KERNEL_SCHED_SORTED_QUEUES
+// Insert the thread into the queue in priority order.
+if( queue == queue->next )
+{
+// There is only one other thread in the queue, join it
+// and adjust the queue pointer to point to the highest
+// priority of the two. If they are the same priority,
+// leave the pointer pointing to the oldest.
+queue->insert( thread );
+if( thread->priority < queue->priority )
+queue = thread;
+}
+else
+{
+// There is more than one thread in the queue. First check
+// whether we are of higher priority than the head and if
+// so just jump in at the front. Also check whether we are
+// lower priority than the tail and jump onto the end.
+// Otherwise we really have to search the queue to find
+// our place.
+if( thread->priority < queue->priority )
+{
+queue->insert( thread );
+queue = thread;
+}
+else if( thread->priority > queue->prev->priority )
+{
+// We are lower priority than any thread in the queue,
+// go in at the end.
+queue->prev->insert( thread );
+}
+else
+{
+// Search the queue. We do this backwards so that we
+// always add new threads after any that have the same
+// priority.
+// Because of the previous tests we know that this
+// search will terminate before we hit the head of the
+// queue, hence we do not need to check for that
+// condition.
+Cyg_Thread *qtmp = queue->prev;
+// Scan the queue until we find a higher or equal
+// priority thread.
+while( thread->priority > qtmp->priority )
+qtmp = qtmp->prev;
+// Insert ourself after the node pointed to by qtmp.
+// We do this by inserting before the next node since
+// that is the operation we have.
+qtmp->next->insert( thread );
+}
+}
+#else
+queue->prev->insert(thread);
+#endif
+}
 thread->queue = CYG_CLASSFROMBASE(Cyg_ThreadQueue,
 Cyg_ThreadQueue_Implementation,
 this);
 CYG_REPORT_RETURN();
 Cyg_ThreadQueue_Implementation::remove(Cyg_Thread *thread)
 {
 CYG_REPORT_FUNCTION();
 CYG_REPORT_FUNCARG1("thread=%08x", thread);
-// If the thread we want it the at the head
+// If the thread we want is the at the head
 // of the list, and is on its own, clear the
 // list and return. Otherwise advance to the
 // next thread and remove ours. If the thread
 // is not at the head of the list, just dequeue
 // it.
 CYG_REPORT_RETURN();
 }
 // -------------------------------------------------------------------------
+inline void
+Cyg_ThreadQueue_Implementation::set_thread_queue(Cyg_Thread *thread,
+Cyg_ThreadQueue *tq )
+{
+thread->queue = tq;
+}
+// -------------------------------------------------------------------------
+void
+Cyg_SchedulerThreadQueue_Implementation::enqueue(Cyg_Thread *thread)
+{
+CYG_REPORT_FUNCTION();
+CYG_REPORT_FUNCARG1("thread=%08x", thread);
+if( queue == NULL ) queue = thread;
+else queue->prev->insert(thread);
+set_thread_queue( thread, CYG_CLASSFROMBASE(Cyg_ThreadQueue,
+Cyg_SchedulerThreadQueue_Implementation,
+this));
+CYG_REPORT_RETURN();
+}
+// -------------------------------------------------------------------------
 #endif
 // -------------------------------------------------------------------------
 // EOF sched/mlqueue.cxx

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comparison packages/kernel/current/src/sched/mlqueue.cxx @ 115:6ed91473a1cd ecos-sw-2000-08-21