From f39f667a69cf5c4bc0dd4555537615022767f0f9 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Wed, 14 May 2014 13:50:48 +0200 Subject: score: Simplify _Thread_Change_priority() The function to change a thread priority was too complex. Simplify it with a new scheduler operation. This increases the average case performance due to the simplified logic. The interrupt disabled critical section is a bit prolonged since now the extract, update and enqueue steps are executed atomically. This should however not impact the worst-case interrupt latency since at least for the Deterministic Priority Scheduler this sequence can be carried out with a wee bit of instructions and no loops. Add _Scheduler_Change_priority() to replace the sequence of - _Thread_Set_transient(), - _Scheduler_Extract(), - _Scheduler_Enqueue(), and - _Scheduler_Enqueue_first(). Delete STATES_TRANSIENT, _States_Is_transient() and _Thread_Set_transient() since this state is now superfluous. With this change it is possible to get rid of the SCHEDULER_SMP_NODE_IN_THE_AIR state. This considerably simplifies the implementation of the new SMP locking protocols. --- cpukit/score/Makefile.am | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) (limited to 'cpukit/score/Makefile.am') diff --git a/cpukit/score/Makefile.am b/cpukit/score/Makefile.am index 8fb11d7bdf..ed68ee0072 100644 --- a/cpukit/score/Makefile.am +++ b/cpukit/score/Makefile.am @@ -208,9 +208,7 @@ libscore_a_SOURCES += src/schedulerdefaultupdate.c ## SCHEDULERPRIORITY_C_FILES libscore_a_SOURCES += src/schedulerpriority.c \ src/schedulerpriorityblock.c \ - src/schedulerpriorityenqueue.c \ - src/schedulerpriorityenqueuefirst.c \ - src/schedulerpriorityextract.c \ + src/schedulerprioritychangepriority.c \ src/schedulerpriorityprioritycompare.c \ src/schedulerpriorityschedule.c \ src/schedulerpriorityunblock.c \ @@ -220,11 +218,7 @@ libscore_a_SOURCES += src/schedulerpriority.c \ ## SCHEDULERSIMPLE_C_FILES libscore_a_SOURCES += src/schedulersimple.c \ src/schedulersimpleblock.c \ - src/schedulersimpleenqueue.c \ - src/schedulersimpleenqueuefirst.c \ - src/schedulersimpleextract.c \ - src/schedulersimplereadyqueueenqueue.c \ - src/schedulersimplereadyqueueenqueuefirst.c \ + src/schedulersimplechangepriority.c \ src/schedulersimpleschedule.c \ src/schedulersimpleunblock.c \ src/schedulersimpleyield.c @@ -233,9 +227,7 @@ libscore_a_SOURCES += src/schedulersimple.c \ libscore_a_SOURCES += src/scheduleredf.c \ src/scheduleredfallocate.c \ src/scheduleredfblock.c \ - src/scheduleredfenqueue.c \ - src/scheduleredfenqueuefirst.c \ - src/scheduleredfextract.c \ + src/scheduleredfchangepriority.c \ src/scheduleredfprioritycompare.c \ src/scheduleredfreleasejob.c \ src/scheduleredfschedule.c \ @@ -282,7 +274,7 @@ libscore_a_SOURCES += src/thread.c src/threadchangepriority.c \ src/threadget.c src/threadhandler.c src/threadinitialize.c \ src/threadloadenv.c src/threadready.c \ src/threadrestart.c src/threadsetpriority.c \ - src/threadsetstate.c src/threadsettransient.c \ + src/threadsetstate.c \ src/threadstackallocate.c src/threadstackfree.c src/threadstart.c \ src/threadstartmultitasking.c src/iterateoverthreads.c \ src/threadblockingoperationcancel.c -- cgit v1.2.3