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* score: Add assert to _Thread_Dispatch()Sebastian Huber2017-07-041-0/+1
| | | | Update #3060.
* score: Remove rtems_ada_selfSebastian Huber2017-06-141-8/+0
| | | | | | This task variable is superfluous since we use thread-local storage now. Update #2289.
* score: Move _Thread_Scheduler_ask_for_help()Sebastian Huber2017-02-031-1/+34
| | | | | Move _Thread_Scheduler_ask_for_help(), rename it to _Thread_Ask_for_help() and make it static.
* score: Introduce _Internal_error()Sebastian Huber2016-12-121-8/+2
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* score: Remove fatal is internal indicatorSebastian Huber2016-12-091-2/+0
| | | | | | | | | The fatal is internal indicator is redundant since the fatal source and error code uniquely identify a fatal error. Keep the fatal user extension is internal parameter for backward compatibility and set it to false always. Update #2825.
* score: Robust thread dispatchSebastian Huber2016-11-231-0/+15
| | | | | | | | | | | | On SMP configurations, it is a fatal error to call blocking operating system with interrupts disabled, since this prevents delivery of inter-processor interrupts. This could lead to executing threads which are not allowed to execute resulting in undefined behaviour. The ARM Cortex-M port has a similar problem, since the interrupt state is not a part of the thread context. Update #2811.
* score: Allow interrupts during thread dispatchSebastian Huber2016-11-181-16/+1
| | | | | | | | | Use a processor-specific interrupt frame during context switches in case the executing thread is longer executes on the processor and the heir thread is about to start execution. During this period we must not use a thread stack for interrupt processing. Update #2809.
* score: Add and use _Thread_Dispatch_direct()Sebastian Huber2016-11-181-0/+16
| | | | | | | | | | This function is useful for operations which synchronously block, e.g. self restart, self deletion, yield, sleep. It helps to detect if these operations are called in the wrong context. Since the thread dispatch necessary indicator is not used, this is more robust in some SMP situations. Update #2751.
* score: Add new SMP scheduler helping protocolSebastian Huber2016-11-021-1/+77
| | | | Update #2556.
* score: Remove superfluous SMP debug supportSebastian Huber2016-09-071-2/+0
| | | | This information turned out to be useless in the last couple of months.
* score: Rename _ISR_Disable() and _ISR_Enable()Sebastian Huber2016-05-201-2/+2
| | | | | | | | | Rename _ISR_Disable() into _ISR_Local_disable(). Rename _ISR_Enable() into _ISR_Local_enable(). Remove _Debug_Is_owner_of_giant(). This is a preparation to remove the Giant lock. Update #2555.
* score: Rename _ISR_Disable_without_giant()Sebastian Huber2016-05-201-3/+3
| | | | | | | | | Rename _ISR_Disable_without_giant() into _ISR_Local_disable(). Rename _ISR_Enable_without_giant() into _ISR_Local_enable(). This is a preparation to remove the Giant lock. Update #2555.
* score: Introduce thread state lockSebastian Huber2016-05-121-8/+7
| | | | Update #2556.
* score: Fix CPU time used by executing threadsSebastian Huber2016-03-171-5/+0
| | | | | | | | | | | | | | The CPU time used of a thread was previously maintained per-processor mostly during _Thread_Dispatch(). However, on SMP configurations the actual processor of a thread is difficult to figure out since thread dispatching is a highly asynchronous process (e.g. via inter-processor interrupts). Only the intended processor of a thread is known to the scheduler easily. Do the CPU usage accounting during thread heir updates in the context of the scheduler operations. Provide the function _Thread_Get_CPU_time_used() to get the CPU usage of a thread using proper locks to get a consistent value. Close #2627.
* score: Avoid SCORE_EXTERNSebastian Huber2016-02-171-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | Delete SCORE_INIT. This finally removes the some.h: #ifndef SOME_XYZ_EXTERN #define SOME_XYZ_EXTERN extern #endif SOME_XYZ_EXTERN type xyz; some_xyz.c: #define SOME_XYZ_EXTERN #include <some.h> pattern in favour of some.h: extern type xyz; some_xyz.c #include <some.h> type xyz; Update #2559.
* Delete unused API extensionsSebastian Huber2016-02-031-1/+0
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* Optional Initial Extensions initializationSebastian Huber2016-02-031-0/+2
| | | | Update #2408.
* Require __getreent()Sebastian Huber2015-11-251-10/+0
| | | | | This function is used by Newlib since 2013-07-09 (Git commit 9b51cd8c6b9cdd067d9648a7ab952884019c56a5).
* Remove use ticks for statistics configure option.Joel Sherrill2015-06-151-11/+4
| | | | | | | | | | This was obsolete and broken based upon recent time keeping changes. Thie build option was previously enabled by adding USE_TICKS_FOR_STATISTICS=1 to the configure command line. This propagated into the code as preprocessor conditionals using the __RTEMS_USE_TICKS_FOR_STATISTICS__ conditional.
* score: Add and use _Thread_Do_dispatch()Sebastian Huber2015-03-051-30/+34
| | | | | | | | | | | | The _Thread_Dispatch() function is quite complex and the time to set up and tear down the stack frame is significant. Split this function into two parts. The complex part is now in _Thread_Do_dispatch(). Call _Thread_Do_dispatch() in _Thread_Enable_dispatch() only if necessary. This increases the average case performance. Simplify _Thread_Handler() for SMP configurations. Update #2273.
* score: Fix FP context restore via _Thread_HandlerSebastian Huber2015-02-171-36/+2
| | | | | | | | | | After a context switch we end up in the second part of _Thread_Dispatch() or in _Thread_Handler() in case of new threads. Use the same function _Thread_Restore_fp() to restore the floating-point context. It makes no sense to do this in _Thread_Start_multitasking(). This fixes also a race condition in SMP configurations. Update #2268.
* score: Implement forced thread migrationSebastian Huber2014-05-071-32/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation of task migration in RTEMS has some implications with respect to the interrupt latency. It is crucial to preserve the system invariant that a task can execute on at most one processor in the system at a time. This is accomplished with a boolean indicator in the task context. The processor architecture specific low-level task context switch code will mark that a task context is no longer executing and waits that the heir context stopped execution before it restores the heir context and resumes execution of the heir task. So there is one point in time in which a processor is without a task. This is essential to avoid cyclic dependencies in case multiple tasks migrate at once. Otherwise some supervising entity is necessary to prevent life-locks. Such a global supervisor would lead to scalability problems so this approach is not used. Currently the thread dispatch is performed with interrupts disabled. So in case the heir task is currently executing on another processor then this prolongs the time of disabled interrupts since one processor has to wait for another processor to make progress. It is difficult to avoid this issue with the interrupt latency since interrupts normally store the context of the interrupted task on its stack. In case a task is marked as not executing we must not use its task stack to store such an interrupt context. We cannot use the heir stack before it stopped execution on another processor. So if we enable interrupts during this transition we have to provide an alternative task independent stack for this time frame. This issue needs further investigation.
* score: Use common names for per-CPU variablesSebastian Huber2014-04-221-24/+24
| | | | | | | | | | | | | | | | Use "cpu" for an arbitrary Per_CPU_Control variable. Use "cpu_self" for the Per_CPU_Control of the current processor. Use "cpu_index" for an arbitrary processor index. Use "cpu_index_self" for the processor index of the current processor. Use "cpu_count" for the processor count obtained via _SMP_Get_processor_count(). Use "cpu_max" for the processor maximum obtained by rtems_configuration_get_maximum_processors().
* score: Critical fix for SMPSebastian Huber2014-04-161-1/+12
| | | | | | The _Scheduler_SMP_Allocate_processor() and _Thread_Dispatch() exchange information without locks. Make sure we use the right load/store ordering.
* score: Delete _Thread_Ticks_per_timesliceSebastian Huber2014-04-071-1/+2
| | | | Use the Configuration instead.
* score: Delete post-switch API extensionsSebastian Huber2014-03-311-1/+0
| | | | Use thread post-switch actions instead.
* score: Add thread actionsSebastian Huber2014-03-311-0/+33
| | | | | | | | | | Thread actions are the building block for efficient implementation of - Classic signals delivery, - POSIX signals delivery, - thread restart notification, - thread delete notification, - forced thread migration on SMP configurations, and - the Multiprocessor Resource Sharing Protocol (MrsP).
* Change all references of rtems.com to rtems.org.Chris Johns2014-03-211-1/+1
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* score: Add per-CPU profilingSebastian Huber2014-03-141-0/+2
| | | | | | | Add per-CPU profiling stats API. Implement the thread dispatch disable level profiling. The interrupt profiling must be implemented in CPU port specific parts (mostly assembler code). Add a support function _Profiling_Outer_most_interrupt_entry_and_exit() for this purpose.
* score: Minor _Thread_Dispatch() optimizationSebastian Huber2013-12-021-2/+1
| | | | | It is not necessary to load the executing thread control again after the context switch since it is an invariant of the executing thread.
* smp: Add and use _Assert_Owner_of_giant()Sebastian Huber2013-08-301-2/+2
| | | | | | | | | | | | | | Add and use _ISR_Disable_without_giant() and _ISR_Enable_without_giant() if RTEMS_SMP is defined. On single processor systems the ISR disable/enable was the big hammer which ensured system-wide mutual exclusion. On SMP configurations this no longer works since other processors do not care about disabled interrupts on this processor and continue to execute freely. On SMP in addition to ISR disable/enable an SMP lock must be used. Currently we have only the Giant lock so we can check easily that ISR disable/enable is used only in the right context.
* score: Per-CPU thread dispatch disable levelSebastian Huber2013-08-091-57/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a per-CPU thread dispatch disable level. So instead of one global thread dispatch disable level we have now one instance per processor. This is a major performance improvement for SMP. On non-SMP configurations this may simplifiy the interrupt entry/exit code. The giant lock is still present, but it is now decoupled from the thread dispatching in _Thread_Dispatch(), _Thread_Handler(), _Thread_Restart_self() and the interrupt entry/exit. Access to the giant lock is now available via _Giant_Acquire() and _Giant_Release(). The giant lock is still implicitly acquired via _Thread_Dispatch_decrement_disable_level(). The giant lock is only acquired for high-level operations in interrupt handlers (e.g. release of a semaphore, sending of an event). As a side-effect this change fixes the lost thread dispatch necessary indication bug in _Thread_Dispatch(). A per-CPU thread dispatch disable level greatly simplifies the SMP support for the interrupt entry/exit code since no spin locks have to be acquired in this area. It is only necessary to get the current processor index and use this to calculate the address of the own per-CPU control. This reduces the interrupt latency considerably. All elements for the interrupt entry/exit code are now part of the Per_CPU_Control structure: thread dispatch disable level, ISR nest level and thread dispatch necessary. Nothing else is required (except CPU port specific stuff like on SPARC).
* score: Rename tod.h to todimpl.hSebastian Huber2013-08-011-1/+1
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* score: Add and use _Thread_Update_cpu_time_used()Sebastian Huber2013-08-011-11/+4
| | | | Fix _times().
* smp: Delete _SMP_Request_other_cores_to_dispatch()Sebastian Huber2013-07-301-5/+0
| | | | | Use an event triggered unicast to inform remote processors about a necessary thread dispatch instead.
* score: Critical section change in _Thread_DispatchSebastian Huber2013-07-301-2/+2
| | | | | | | | | | | | | | | | If we enter _Thread_Dispatch() then _Thread_Dispatch_disable_level must be zero. Single processor RTEMS assumes that stores of non-zero values to _Thread_Dispatch_disable_level are observed by interrupts as non-zero values. Move the _Thread_Dispatch_set_disable_level( 1 ) out of the first ISR disabled critical section. In case interrupts happen between the _Thread_Dispatch_set_disable_level( 1 ) and _ISR_Disable( level ) then the interrupt will observe a non-zero _Thread_Dispatch_disable_level and will not issue a _Thread_Dispatch() and we can enter the ISR disabled section directly after interrupt processing. This change leads to symmetry between the single processor and SMP configuration.
* score: Create thread implementation headerSebastian Huber2013-07-261-17/+3
| | | | | | | | Move implementation specific parts of thread.h and thread.inl into new header file threadimpl.h. The thread.h contains now only the application visible API. Remove superfluous header file includes from various files.
* score: Merge sysstate API into one fileSebastian Huber2013-07-241-1/+0
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* score: Changes due to Newlib __DYNAMIC_REENT__Sebastian Huber2013-07-171-0/+2
| | | | | | | | | | | | | Delete _Thread_libc_reent and add __getreent() instead according to __DYNAMIC_REENT__ define. For SMP configurations __DYNAMIC_REENT__ must be defined. A Newlib including the following patch is required: 2013-07-09 Sebastian Huber <sebastian.huber@embedded-brains.de> * libc/include/sys/config.h (__DYNAMIC_REENT__): Define for RTEMS.
* scheduler: New simple SMP scheduler implementationSebastian Huber2013-06-141-1/+4
| | | | | | | | | | | | | | | | | The new Simple SMP Scheduler allocates a processor for the processor count highest priority ready threads. The thread priority and position in the ready chain are the only information to determine the scheduling decision. Threads with an allocated processor are in the scheduled chain. After initialization the scheduled chain has exactly processor count nodes. Each processor has exactly one allocated thread after initialization. All enqueue and extract operations may exchange threads with the scheduled chain. One thread will be added and another will be removed. The scheduled and ready chain is ordered according to the thread priority order. The chain insert operations are O(count of ready threads), thus this scheduler is unsuitable for most real-time applications. The thread preempt mode will be ignored.
* score: Move thread dispatch content to new fileSebastian Huber2013-06-071-0/+1
| | | | | | | Move thread dispatch declarations and inline functions to new header <rtems/score/threaddispatch.h> to make it independent of the Thread_Control structure. This avoids a cyclic dependency in case thread dispatch functions are used for the object implementation.
* score: Add API extensions post switch listSebastian Huber2012-12-051-2/+2
| | | | | | | | Move post switch hook from API_extensions_Control to new API_extensions_Post_switch_control. Rename _API_extensions_Run_postswitch() in _API_extensions_Run_post_switch(). Add _API_extensions_Post_switch_list and _API_extensions_Add_post_switch().
* Score misc: Clean up Doxygen #4 (GCI 2012)Alexandre Devienne2012-11-281-16/+7
| | | | | | | This patch is a task from GCI 2012 which improves the Doxygen comments in the RTEMS source. http://www.google-melange.com/gci/task/view/google/gci2012/7985215
* score: Inline _API_extensions_Run_postswitch()Sebastian Huber2012-11-221-1/+1
| | | | | The _API_extensions_Run_postswitch() function is only used in _Thread_Dispatch(). Avoid superfluous load of _Thread_Executing.
* score: Add and use <rtems/score/userextimpl.h>Sebastian Huber2012-11-221-1/+1
| | | | | This file contains the parts of <rtems/score/userext.h> that are only necessary for the RTEMS implementation.
* score: Critical fix for thread dispatchingSebastian Huber2012-10-071-4/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The changes in _Thread_Dispatch() of commits dad36c52b8be5d7b46bc7af85655055db7208652 and d4dc7c8196355f08044e67a3f5c1e19485f17ff1 introduced a severe bug which destroys the real-time properties of RTEMS completely. Consider the following scenario. We have three tasks L (lowest priority), M (middle priority), and H (highest priority). Now let a thread dispatch from M to L happen. An interrupt occurs in _Thread_Dispatch() here: void _Thread_Dispatch( void ) { [...] post_switch: _ISR_Enable( level ); <-- INTERRUPT <-- AFTER INTERRUPT _Thread_Unnest_dispatch(); _API_extensions_Run_postswitch(); } The interrupt event makes task H ready. The interrupt code will see _Thread_Dispatch_disable_level > 0 and thus doesn't perform a _Thread_Dispatch(). Now we return to position "AFTER INTERRUPT". This means task L executes now although task H is ready! Task H will execute once someone calls _Thread_Dispatch().
* threaddispatch.c: Fix typoJoel Sherrill2012-10-021-1/+1
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* Remove All CVS Id Strings Possible Using a ScriptJoel Sherrill2012-05-111-2/+0
| | | | | | | | | | | | Script does what is expected and tries to do it as smartly as possible. + remove occurrences of two blank comment lines next to each other after Id string line removed. + remove entire comment blocks which only exited to contain CVS Ids + If the processing left a blank line at the top of a file, it was removed.
* 2011-08-22 Jennifer Averett <Jennifer.Averett@OARcorp.com>Jennifer Averett2011-08-221-1/+2
| | | | | | | | PR 1876 * score/Makefile.am, score/include/rtems/score/isr.h, score/src/isr.c, score/src/smp.c, score/src/smplock.c, score/src/threaddispatch.c, score/src/threaddispatchdisablelevel.c: Add smp isr support. * score/src/isrsmp.c: New file.
* 2011-05-26 Jennifer Averett <Jennifer.Averett@OARcorp.com>Jennifer Averett2011-05-261-3/+20
| | | | | | | | PR 1796/cpukit * sapi/src/exshutdown.c, score/include/rtems/score/percpu.h, score/include/rtems/score/smp.h, score/src/smp.c, score/src/threaddispatch.c, score/src/threadhandler.c: Added SMP interprocess communications.
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