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* Drop the per-task timing stats, give a summary only (#5897)Simon Marlow2012-03-021-55/+45
| | | | | | | | | | | | | | | | | | | | | | We were keeping around the Task struct (216 bytes) for every worker we ever created, even though we only keep a maximum of 6 workers per Capability. These Task structs accumulate and cause a space leak in programs that do lots of safe FFI calls; this patch frees the Task struct as soon as a worker exits. One reason we were keeping the Task structs around is because we print out per-Task timing stats in +RTS -s, but that isn't terribly useful. What is sometimes useful is knowing how *many* Tasks there were. So now I'm printing a single-line summary, this is for the program in TASKS: 2001 (1 bound, 31 peak workers (2000 total), using -N1) So although we created 2k tasks overall, there were only 31 workers active at any one time (which is exactly what we expect: the program makes 30 safe FFI calls concurrently). This also gives an indication of how many capabilities were being used, which is handy if you use +RTS -N without an explicit number.
* Allow the number of capabilities to be increased at runtime (#3729)Simon Marlow2011-12-061-0/+28
| | | | | At present the number of capabilities can only be *increased*, not decreased. The latter presents a few more challenges!
* Time handling overhaulSimon Marlow2011-11-251-3/+3
| | | | | | | | | | | | | | | | | | | | | Terminology cleanup: the type "Ticks" has been renamed "Time", which is an StgWord64 in units of TIME_RESOLUTION (currently nanoseconds). The terminology "tick" is now used consistently to mean the interval between timer signals. The ticker now always ticks in realtime (actually CLOCK_MONOTONIC if we have it). Before it used CPU time in the non-threaded RTS and realtime in the threaded RTS, but I've discovered that the CPU timer has terrible resolution (at least on Linux) and isn't much use for profiling. So now we always use realtime. This should also fix The default tick interval is now 10ms, except when profiling where we drop it to 1ms. This gives more accurate profiles without affecting runtime too much (<1%). Lots of cleanups - the resolution of Time is now in one place only (Rts.h) rather than having calculations that depend on the resolution scattered all over the RTS. I hope I found them all.
* Enable pthread_getspecific() tls for LLVM compilerDavid M Peixotto2011-10-071-1/+12
| | | | | | | | | | | | | LLVM does not support the __thread attribute for thread local storage and may generate incorrect code for global register variables. We want to allow building the runtime with LLVM-based compilers such as llvm-gcc and clang, particularly for MacOS. This patch changes the gct variable used by the garbage collector to use pthread_getspecific() for thread local storage when an llvm based compiler is used to build the runtime.
* Fix gcc 4.6 warnings; fixes #5176Ian Lynagh2011-06-251-2/+2
| | | | | | | | | | | Based on a patch from David Terei. Some parts are a little ugly (e.g. defining things that only ASSERTs use only when DEBUG is defined), so we might want to tweak things a little. I've also turned off -Werror for didn't-inline warnings, as we now get a few such warnings.
* Refactoring and tidy upSimon Marlow2011-04-111-7/+12
| | | | | | | | | | | | This is a port of some of the changes from my private local-GC branch (which is still in darcs, I haven't converted it to git yet). There are a couple of small functional differences in the GC stats: first, per-thread GC timings should now be more accurate, and secondly we now report average and maximum pause times. e.g. from minimax +RTS -N8 -s: Tot time (elapsed) Avg pause Max pause Gen 0 2755 colls, 2754 par 13.16s 0.93s 0.0003s 0.0150s Gen 1 769 colls, 769 par 3.71s 0.26s 0.0003s 0.0059s
* boundTaskExiting: don't set task->stopped unless this is the last call (#4850)Simon Marlow2010-12-211-2/+8
| | | | | | | | | | | | | | | | | The bug in this case was that we had a worker thread making a foreign call which invoked a callback (in this case it was performGC, I think). When the callback ended, boundTaskExiting() was setting task->stopped, but the Task is now per-OS-thread, so it is shared by the worker that made the original foreign call. When the foreign call returned, because task->stopped was set, the worker was not placed on the queue of spare workers. Somehow the worker woke up again, and found the spare_workers queue empty, which lead to a crash. Two bugs here: task->stopped should not have been set by boundTaskExiting (this broke when I split the Task and InCall structs, in 6.12.2), and releaseCapabilityAndQueueWorker() should not be testing task->stopped anyway, because it should only ever be called when task->stopped is false (this is now an assertion).
* Fix up the ifdefs in Task.cIan Lynagh2010-11-131-0/+4
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* Use standard task ID print style (hexadecimal).Edward Z. Yang2010-11-111-12/+12
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* Interruptible FFI calls with pthread_kill and CancelSynchronousIO. v4Edward Z. Yang2010-09-191-0/+9
| | | | | | | | | | | | | | | | | | | | | | | This is patch that adds support for interruptible FFI calls in the form of a new foreign import keyword 'interruptible', which can be used instead of 'safe' or 'unsafe'. Interruptible FFI calls act like safe FFI calls, except that the worker thread they run on may be interrupted. Internally, it replaces BlockedOnCCall_NoUnblockEx with BlockedOnCCall_Interruptible, and changes the behavior of the RTS to not modify the TSO_ flags on the event of an FFI call from a thread that was interruptible. It also modifies the bytecode format for foreign call, adding an extra Word16 to indicate interruptibility. The semantics of interruption vary from platform to platform, but the intent is that any blocking system calls are aborted with an error code. This is most useful for making function calls to system library functions that support interrupting. There is no support for pre-Vista Windows. There is a partner testsuite patch which adds several tests for this functionality.
* Windows: use a thread-local variable for myTask()Simon Marlow2010-09-151-1/+3
| | | | Which entailed fixing an incorrect #ifdef in Task.c
* Use a separate mutex to protect all_tasks, avoiding a lock-order-reversalSimon Marlow2010-07-161-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | In GHC 6.12.x I found a rare deadlock caused by this lock-order-reversal: AQ cap->lock startWorkerTask newTask AQ sched_mutex scheduleCheckBlackHoles AQ sched_mutex unblockOne_ wakeupThreadOnCapabilty AQ cap->lock so sched_mutex and cap->lock are taken in a different order in two places. This doesn't happen in the HEAD because we don't have scheduleCheckBlackHoles, but I thought it would be prudent to make this less likely to happen in the future by using a different mutex in newTask. We can clearly see that the all_tasks mutex cannot be involved in a deadlock, becasue we never call anything else while holding it.
* Fix crash in nested callbacks (#4038)Simon Marlow2010-05-071-2/+2
| | | | | Broken by "Split part of the Task struct into a separate struct InCall".
* Make the running_finalizers flag task-localSimon Marlow2010-05-051-0/+1
| | | | | Fixes a bug reported by Lennart Augustsson, whereby we could get an incorrect error from the RTS about re-entry from a finalizer,
* tidy up the end of the all_tasks list after forkingSimon Marlow2010-03-291-0/+1
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* fix bug in discardTasksExcept() that broke forkProcessSimon Marlow2010-03-111-2/+3
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* Split part of the Task struct into a separate struct InCallSimon Marlow2010-03-091-92/+163
| | | | | | | | | | | | | | | The idea is that this leaves Tasks and OSThread in one-to-one correspondence. The part of a Task that represents a call into Haskell from C is split into a separate struct InCall, pointed to by the Task and the TSO bound to it. A given OSThread/Task thus always uses the same mutex and condition variable, rather than getting a new one for each callback. Conceptually it is simpler, although there are more types and indirections in a few places now. This improves callback performance by removing some of the locks that we had to take when making in-calls. Now we also keep the current Task in a thread-local variable if supported by the OS and gcc (currently only Linux).
* RTS tidyup sweep, first phaseSimon Marlow2009-08-021-11/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The first phase of this tidyup is focussed on the header files, and in particular making sure we are exposinng publicly exactly what we need to, and no more. - Rts.h now includes everything that the RTS exposes publicly, rather than a random subset of it. - Most of the public header files have moved into subdirectories, and many of them have been renamed. But clients should not need to include any of the other headers directly, just #include the main public headers: Rts.h, HsFFI.h, RtsAPI.h. - All the headers needed for via-C compilation have moved into the stg subdirectory, which is self-contained. Most of the headers for the rest of the RTS APIs have moved into the rts subdirectory. - I left MachDeps.h where it is, because it is so widely used in Haskell code. - I left a deprecated stub for RtsFlags.h in place. The flag structures are now exposed by Rts.h. - Various internal APIs are no longer exposed by public header files. - Various bits of dead code and declarations have been removed - More gcc warnings are turned on, and the RTS code is more warning-clean. - More source files #include "PosixSource.h", and hence only use standard POSIX (1003.1c-1995) interfaces. There is a lot more tidying up still to do, this is just the first pass. I also intend to standardise the names for external RTS APIs (e.g use the rts_ prefix consistently), and declare the internal APIs as hidden for shared libraries.
* Fix #3236: emit a helpful error message when the RTS has not been initialisedSimon Marlow2009-05-181-5/+18
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* Fix some more shutdown racesSimon Marlow2008-11-191-17/+14
| | | | | | | There were races between workerTaskStop() and freeTaskManager(): we need to be sure that all Tasks have exited properly before we start tearing things down. This isn't completely straighforward, see comments for details.
* Pad Capabilities and Tasks to 64 bytesSimon Marlow2008-10-231-1/+2
| | | | | This is just good practice to avoid placing two structures heavily accessed by different CPUs on the same cache line
* workerTaskStop(): set task->cap = NULLSimon Marlow2007-03-061-0/+1
| | | | avoids an assertion failure in newBoundTask()
* Free thread local storage on shutdownIan Lynagh2007-02-221-0/+3
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* freeTaskManager: don't free Tasks that are still in useSimon Marlow2007-02-201-4/+10
| | | | See conc059.
* Free all tasks on exit, not just those on the task_free_listIan Lynagh2006-12-151-2/+3
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* Put the task on the free list in workerTaskStopIan Lynagh2006-12-151-0/+5
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* Don't free sched_mutex until freeTaskManager has finished with itSimon Marlow2006-12-121-11/+5
| | | | Also move closeMutex() etc. into freeTaskManager, this is a free-ish thing
* Add freeScheduler/freeTaskManager and call it later than exitSchedulerIan Lynagh2006-12-111-3/+17
| | | | | | | | | We were freeing the tasks in exitScheduler (stopTaskManager) before exitStorage (stat_exit), but the latter needs to walk down the list printing stats. Resulted in segfaults with commands like ghc -v0 -e main q.hs -H32m -H32m +RTS -Sstderr (where q.hs is trivial), but very sensitive to exact commandline and libc version or something.
* Split GC.c, and move storage manager into sm/ directorySimon Marlow2006-10-241-0/+1
| | | | | | | | | | | | | | | | | In preparation for parallel GC, split up the monolithic GC.c file into smaller parts. Also in this patch (and difficult to separate, unfortunatley): - Don't include Stable.h in Rts.h, instead just include it where necessary. - consistently use STATIC_INLINE in source files, and INLINE_HEADER in header files. STATIC_INLINE is now turned off when DEBUG is on, to make debugging easier. - The GC no longer takes the get_roots function as an argument. We weren't making use of this generalisation.
* free the task *after* calling closeCond and closeMutexSimon Marlow2006-08-311-1/+1
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* add sysErrorBelch() for reporting system call errorsSimon Marlow2006-08-301-1/+2
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* Add closeMutex and use it on clean upEsa Ilari Vuokko2006-08-231-0/+4
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* Match format strings and arguments for printf-like functionssven.panne@aedion.de2006-08-101-2/+2
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* fix bug in task freeingSimon Marlow2006-08-091-1/+1
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* Remove the artifical cap on the number of workersSimon Marlow2006-08-091-10/+0
| | | | | | | | | | | | See #805. This was here to catch bugs that resulted in an infinite number of worker threads being created. However, we can't put a reasonable bound on the number of worker threads, because legitimate programs may need to create large numbers of (probably blocked) worker threads. Furthermore, the OS probably has a bound on the number of threads that a process can create in any case.
* Remember to free() memory on exitSimon Marlow2006-08-081-0/+10
| | | | | Patch mostly from Lennart Augustsson in #803, with additions to Task.c by me.
* make compilation a little less noisySimon Marlow2006-06-161-2/+2
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* allow the max number of workers to scale with +RTS -NSimon Marlow2006-06-161-0/+4
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* New tracing interfaceSimon Marlow2006-06-081-5/+8
| | | | | | | | A simple interface for generating trace messages with timestamps and thread IDs attached to them. Most debugging output goes through this interface now, so it is straightforward to get timestamped debugging traces with +RTS -vt. Also, we plan to use this to generate parallelism profiles from the trace output.
* Gather timing stats for a Task when it completes.Simon Marlow2006-06-071-12/+19
| | | | | Previously we did this just for workers, now we do it for the main thread and for forkOS threads too.
* Reorganisation of the source treeSimon Marlow2006-04-071-0/+315
Most of the other users of the fptools build system have migrated to Cabal, and with the move to darcs we can now flatten the source tree without losing history, so here goes. The main change is that the ghc/ subdir is gone, and most of what it contained is now at the top level. The build system now makes no pretense at being multi-project, it is just the GHC build system. No doubt this will break many things, and there will be a period of instability while we fix the dependencies. A straightforward build should work, but I haven't yet fixed binary/source distributions. Changes to the Building Guide will follow, too.
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