X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FSchedule.c;h=3ef12246bfec73c99175b0522e2d9472d7990db6;hb=21443993d5b042f97927ab92b6b38a6ff365ed1e;hp=2601f7de38d8c1383118cbe424775224fdf7f8a7;hpb=30a97b4c93f639ac168b2cc30bb1f490198dc339;p=ghc-hetmet.git diff --git a/ghc/rts/Schedule.c b/ghc/rts/Schedule.c index 2601f7d..3ef1224 100644 --- a/ghc/rts/Schedule.c +++ b/ghc/rts/Schedule.c @@ -1,5 +1,5 @@ /* --------------------------------------------------------------------------- - * $Id: Schedule.c,v 1.138 2002/04/23 06:34:27 sof Exp $ + * $Id: Schedule.c,v 1.172 2003/07/12 00:09:15 sof Exp $ * * (c) The GHC Team, 1998-2000 * @@ -84,18 +84,19 @@ #include "StgRun.h" #include "StgStartup.h" #include "Hooks.h" +#define COMPILING_SCHEDULER #include "Schedule.h" #include "StgMiscClosures.h" #include "Storage.h" #include "Interpreter.h" #include "Exception.h" #include "Printer.h" -#include "Main.h" #include "Signals.h" #include "Sanity.h" #include "Stats.h" -#include "Itimer.h" +#include "Timer.h" #include "Prelude.h" +#include "ThreadLabels.h" #ifdef PROFILING #include "Proftimer.h" #include "ProfHeap.h" @@ -121,6 +122,8 @@ #include #endif +#include +#include #include //@node Variables and Data structures, Prototypes, Includes, Main scheduling code @@ -129,7 +132,16 @@ /* Main thread queue. * Locks required: sched_mutex. */ -StgMainThread *main_threads; +StgMainThread *main_threads = NULL; + +#ifdef THREADED_RTS +// Pointer to the thread that executes main +// When this thread is finished, the program terminates +// by calling shutdownHaskellAndExit. +// It would be better to add a call to shutdownHaskellAndExit +// to the Main.main wrapper and to remove this hack. +StgMainThread *main_main_thread = NULL; +#endif /* Thread queues. * Locks required: sched_mutex. @@ -156,16 +168,18 @@ StgTSO *ccalling_threadss[MAX_PROC]; #else /* !GRAN */ -StgTSO *run_queue_hd, *run_queue_tl; -StgTSO *blocked_queue_hd, *blocked_queue_tl; -StgTSO *sleeping_queue; /* perhaps replace with a hash table? */ +StgTSO *run_queue_hd = NULL; +StgTSO *run_queue_tl = NULL; +StgTSO *blocked_queue_hd = NULL; +StgTSO *blocked_queue_tl = NULL; +StgTSO *sleeping_queue = NULL; /* perhaps replace with a hash table? */ #endif /* Linked list of all threads. * Used for detecting garbage collected threads. */ -StgTSO *all_threads; +StgTSO *all_threads = NULL; /* When a thread performs a safe C call (_ccall_GC, using old * terminology), it gets put on the suspended_ccalling_threads @@ -182,17 +196,17 @@ static StgTSO *threadStackOverflow(StgTSO *tso); /* flag set by signal handler to precipitate a context switch */ //@cindex context_switch -nat context_switch; +nat context_switch = 0; /* if this flag is set as well, give up execution */ //@cindex interrupted -rtsBool interrupted; +rtsBool interrupted = rtsFalse; /* Next thread ID to allocate. - * Locks required: sched_mutex + * Locks required: thread_id_mutex */ //@cindex next_thread_id -StgThreadID next_thread_id = 1; +static StgThreadID next_thread_id = 1; /* * Pointers to the state of the current thread. @@ -203,14 +217,15 @@ StgThreadID next_thread_id = 1; /* The smallest stack size that makes any sense is: * RESERVED_STACK_WORDS (so we can get back from the stack overflow) * + sizeofW(StgStopFrame) (the stg_stop_thread_info frame) - * + 1 (the realworld token for an IO thread) * + 1 (the closure to enter) + * + 1 (stg_ap_v_ret) + * + 1 (spare slot req'd by stg_ap_v_ret) * * A thread with this stack will bomb immediately with a stack * overflow, which will increase its stack size. */ -#define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 2) +#define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 3) #if defined(GRAN) @@ -223,17 +238,19 @@ StgTSO *CurrentTSO; */ StgTSO dummy_tso; -rtsBool ready_to_gc; +static rtsBool ready_to_gc; + +/* + * Set to TRUE when entering a shutdown state (via shutdownHaskellAndExit()) -- + * in an MT setting, needed to signal that a worker thread shouldn't hang around + * in the scheduler when it is out of work. + */ +static rtsBool shutting_down_scheduler = rtsFalse; void addToBlockedQueue ( StgTSO *tso ); static void schedule ( void ); void interruptStgRts ( void ); -#if defined(GRAN) -static StgTSO * createThread_ ( nat size, rtsBool have_lock, StgInt pri ); -#else -static StgTSO * createThread_ ( nat size, rtsBool have_lock ); -#endif static void detectBlackHoles ( void ); @@ -248,6 +265,13 @@ static void sched_belch(char *s, ...); Mutex sched_mutex = INIT_MUTEX_VAR; Mutex term_mutex = INIT_MUTEX_VAR; +/* + * A heavyweight solution to the problem of protecting + * the thread_id from concurrent update. + */ +Mutex thread_id_mutex = INIT_MUTEX_VAR; + + # if defined(SMP) static Condition gc_pending_cond = INIT_COND_VAR; nat await_death; @@ -262,21 +286,13 @@ rtsBool emitSchedule = rtsTrue; #endif #if DEBUG -char *whatNext_strs[] = { - "ThreadEnterGHC", +static char *whatNext_strs[] = { "ThreadRunGHC", - "ThreadEnterInterp", + "ThreadInterpret", "ThreadKilled", + "ThreadRelocated", "ThreadComplete" }; - -char *threadReturnCode_strs[] = { - "HeapOverflow", /* might also be StackOverflow */ - "StackOverflow", - "ThreadYielding", - "ThreadBlocked", - "ThreadFinished" -}; #endif #if defined(PAR) @@ -299,8 +315,13 @@ taskStart(void) } #endif - - +#if defined(RTS_SUPPORTS_THREADS) +void +startSchedulerTask(void) +{ + startTask(taskStart); +} +#endif //@node Main scheduling loop, Suspend and Resume, Prototypes, Main scheduling code //@subsection Main scheduling loop @@ -360,11 +381,13 @@ schedule( void ) # endif #endif rtsBool was_interrupted = rtsFalse; + StgTSOWhatNext prev_what_next; ACQUIRE_LOCK(&sched_mutex); #if defined(RTS_SUPPORTS_THREADS) waitForWorkCapability(&sched_mutex, &cap, rtsFalse); + IF_DEBUG(scheduler, sched_belch("worker thread (osthread %p): entering RTS", osThreadId())); #else /* simply initialise it in the non-threaded case */ grabCapability(&cap); @@ -418,9 +441,19 @@ schedule( void ) */ if (interrupted) { IF_DEBUG(scheduler, sched_belch("interrupted")); - deleteAllThreads(); interrupted = rtsFalse; was_interrupted = rtsTrue; +#if defined(RTS_SUPPORTS_THREADS) + // In the threaded RTS, deadlock detection doesn't work, + // so just exit right away. + prog_belch("interrupted"); + releaseCapability(cap); + startTask(taskStart); // thread-safe-call to shutdownHaskellAndExit + RELEASE_LOCK(&sched_mutex); + shutdownHaskellAndExit(EXIT_SUCCESS); +#else + deleteAllThreads(); +#endif } /* Go through the list of main threads and wake up any @@ -432,18 +465,26 @@ schedule( void ) { StgMainThread *m, **prev; prev = &main_threads; - for (m = main_threads; m != NULL; m = m->link) { + for (m = main_threads; m != NULL; prev = &m->link, m = m->link) { switch (m->tso->what_next) { case ThreadComplete: if (m->ret) { - *(m->ret) = (StgClosure *)m->tso->sp[0]; + // NOTE: return val is tso->sp[1] (see StgStartup.hc) + *(m->ret) = (StgClosure *)m->tso->sp[1]; } *prev = m->link; m->stat = Success; broadcastCondition(&m->wakeup); #ifdef DEBUG - free(m->tso->label); -#endif + removeThreadLabel((StgWord)m->tso); +#endif + if(m == main_main_thread) + { + releaseCapability(cap); + startTask(taskStart); // thread-safe-call to shutdownHaskellAndExit + RELEASE_LOCK(&sched_mutex); + shutdownHaskellAndExit(EXIT_SUCCESS); + } break; case ThreadKilled: if (m->ret) *(m->ret) = NULL; @@ -455,8 +496,15 @@ schedule( void ) } broadcastCondition(&m->wakeup); #ifdef DEBUG - free(m->tso->label); -#endif + removeThreadLabel((StgWord)m->tso); +#endif + if(m == main_main_thread) + { + releaseCapability(cap); + startTask(taskStart); // thread-safe-call to shutdownHaskellAndExit + RELEASE_LOCK(&sched_mutex); + shutdownHaskellAndExit(EXIT_SUCCESS); + } break; default: break; @@ -477,14 +525,15 @@ schedule( void ) if (m->tso->what_next == ThreadComplete || m->tso->what_next == ThreadKilled) { #ifdef DEBUG - free(m->tso->label); + removeThreadLabel((StgWord)m->tso); #endif main_threads = main_threads->link; if (m->tso->what_next == ThreadComplete) { - /* we finished successfully, fill in the return value */ - if (m->ret) { *(m->ret) = (StgClosure *)m->tso->sp[0]; }; - m->stat = Success; - return; + // We finished successfully, fill in the return value + // NOTE: return val is tso->sp[1] (see StgStartup.hc) + if (m->ret) { *(m->ret) = (StgClosure *)m->tso->sp[1]; }; + m->stat = Success; + return; } else { if (m->ret) { *(m->ret) = NULL; }; if (was_interrupted) { @@ -541,7 +590,7 @@ schedule( void ) #endif // SMP /* check for signals each time around the scheduler */ -#ifndef mingw32_TARGET_OS +#if defined(RTS_USER_SIGNALS) if (signals_pending()) { RELEASE_LOCK(&sched_mutex); /* ToDo: kill */ startSignalHandlers(); @@ -552,10 +601,13 @@ schedule( void ) /* Check whether any waiting threads need to be woken up. If the * run queue is empty, and there are no other tasks running, we * can wait indefinitely for something to happen. - * ToDo: what if another client comes along & requests another - * main thread? */ - if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) ) { + if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) +#if defined(RTS_SUPPORTS_THREADS) && !defined(SMP) + || EMPTY_RUN_QUEUE() +#endif + ) + { awaitEvent( EMPTY_RUN_QUEUE() #if defined(SMP) && allFreeCapabilities() @@ -576,7 +628,7 @@ schedule( void ) * If no threads are black holed, we have a deadlock situation, so * inform all the main threads. */ -#ifndef PAR +#if !defined(PAR) && !defined(RTS_SUPPORTS_THREADS) if ( EMPTY_THREAD_QUEUES() #if defined(RTS_SUPPORTS_THREADS) && EMPTY_QUEUE(suspended_ccalling_threads) @@ -605,7 +657,7 @@ schedule( void ) if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; } -#ifndef mingw32_TARGET_OS +#if defined(RTS_USER_SIGNALS) /* If we have user-installed signal handlers, then wait * for signals to arrive rather then bombing out with a * deadlock. @@ -682,11 +734,15 @@ schedule( void ) /* ToDo: revisit conditions (and mechanism) for shutting down a multi-threaded world */ IF_DEBUG(scheduler, sched_belch("all done, i think...shutting down.")); - shutdownHaskellAndExit(0); + RELEASE_LOCK(&sched_mutex); + shutdownHaskell(); + return; #endif } not_deadlocked: +#elif defined(RTS_SUPPORTS_THREADS) + /* ToDo: add deadlock detection in threaded RTS */ #elif defined(PAR) /* ToDo: add deadlock detection in GUM (similar to SMP) -- HWL */ #endif @@ -702,6 +758,7 @@ schedule( void ) #endif #if defined(RTS_SUPPORTS_THREADS) +#if defined(SMP) /* block until we've got a thread on the run queue and a free * capability. * @@ -709,17 +766,24 @@ schedule( void ) if ( EMPTY_RUN_QUEUE() ) { /* Give up our capability */ releaseCapability(cap); + + /* If we're in the process of shutting down (& running the + * a batch of finalisers), don't wait around. + */ + if ( shutting_down_scheduler ) { + RELEASE_LOCK(&sched_mutex); + return; + } IF_DEBUG(scheduler, sched_belch("thread %d: waiting for work", osThreadId())); waitForWorkCapability(&sched_mutex, &cap, rtsTrue); IF_DEBUG(scheduler, sched_belch("thread %d: work now available", osThreadId())); -#if 0 - while ( EMPTY_RUN_QUEUE() ) { - waitForWorkCapability(&sched_mutex, &cap); - IF_DEBUG(scheduler, sched_belch("thread %d: work now available", osThreadId())); - } -#endif + } +#else + if ( EMPTY_RUN_QUEUE() ) { + continue; // nothing to do } #endif +#endif #if defined(GRAN) if (RtsFlags.GranFlags.Light) @@ -1002,18 +1066,14 @@ schedule( void ) // expensive if there is lots of thread switching going on... IF_DEBUG(sanity,checkTSO(t)); #endif - + cap->r.rCurrentTSO = t; /* context switches are now initiated by the timer signal, unless * the user specified "context switch as often as possible", with * +RTS -C0 */ - if ( -#ifdef PROFILING - RtsFlags.ProfFlags.profileInterval == 0 || -#endif - (RtsFlags.ConcFlags.ctxtSwitchTicks == 0 + if ((RtsFlags.ConcFlags.ctxtSwitchTicks == 0 && (run_queue_hd != END_TSO_QUEUE || blocked_queue_hd != END_TSO_QUEUE || sleeping_queue != END_TSO_QUEUE))) @@ -1021,10 +1081,12 @@ schedule( void ) else context_switch = 0; +run_thread: + RELEASE_LOCK(&sched_mutex); - IF_DEBUG(scheduler, sched_belch("-->> Running TSO %ld (%p) %s ...", - t->id, t, whatNext_strs[t->what_next])); + IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...", + t->id, whatNext_strs[t->what_next])); #ifdef PROFILING startHeapProfTimer(); @@ -1033,19 +1095,17 @@ schedule( void ) /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */ /* Run the current thread */ - switch (cap->r.rCurrentTSO->what_next) { + prev_what_next = t->what_next; + switch (prev_what_next) { case ThreadKilled: case ThreadComplete: /* Thread already finished, return to scheduler. */ ret = ThreadFinished; break; - case ThreadEnterGHC: - ret = StgRun((StgFunPtr) stg_enterStackTop, &cap->r); - break; case ThreadRunGHC: ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r); break; - case ThreadEnterInterp: + case ThreadInterpret: ret = interpretBCO(cap); break; default: @@ -1060,8 +1120,8 @@ schedule( void ) #endif ACQUIRE_LOCK(&sched_mutex); - -#ifdef SMP + +#ifdef RTS_SUPPORTS_THREADS IF_DEBUG(scheduler,fprintf(stderr,"scheduler (task %ld): ", osThreadId());); #elif !defined(GRAN) && !defined(PAR) IF_DEBUG(scheduler,fprintf(stderr,"scheduler: ");); @@ -1093,9 +1153,8 @@ schedule( void ) blocks = (nat)BLOCK_ROUND_UP(cap->r.rHpAlloc * sizeof(W_)) / BLOCK_SIZE; - IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped: requesting a large block (size %d)", - t->id, t, - whatNext_strs[t->what_next], blocks)); + IF_DEBUG(scheduler,belch("--<< thread %ld (%s) stopped: requesting a large block (size %d)", + t->id, whatNext_strs[t->what_next], blocks)); // don't do this if it would push us over the // alloc_blocks_lim limit; we'll GC first. @@ -1116,14 +1175,26 @@ schedule( void ) } cap->r.rCurrentNursery->u.back = bd; - // initialise it as a nursery block - bd->step = g0s0; - bd->gen_no = 0; - bd->flags = 0; - bd->free = bd->start; + // initialise it as a nursery block. We initialise the + // step, gen_no, and flags field of *every* sub-block in + // this large block, because this is easier than making + // sure that we always find the block head of a large + // block whenever we call Bdescr() (eg. evacuate() and + // isAlive() in the GC would both have to do this, at + // least). + { + bdescr *x; + for (x = bd; x < bd + blocks; x++) { + x->step = g0s0; + x->gen_no = 0; + x->flags = 0; + } + } // don't forget to update the block count in g0s0. g0s0->n_blocks += blocks; + // This assert can be a killer if the app is doing lots + // of large block allocations. ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks); // now update the nursery to point to the new block @@ -1142,8 +1213,8 @@ schedule( void ) * maybe set context_switch and wait till they all pile in, * then have them wait on a GC condition variable. */ - IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped: HeapOverflow", - t->id, t, whatNext_strs[t->what_next])); + IF_DEBUG(scheduler,belch("--<< thread %ld (%s) stopped: HeapOverflow", + t->id, whatNext_strs[t->what_next])); threadPaused(t); #if defined(GRAN) ASSERT(!is_on_queue(t,CurrentProc)); @@ -1174,8 +1245,8 @@ schedule( void ) // DumpGranEvent(GR_DESCHEDULE, t); globalParStats.tot_stackover++; #endif - IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped, StackOverflow", - t->id, t, whatNext_strs[t->what_next])); + IF_DEBUG(scheduler,belch("--<< thread %ld (%s) stopped, StackOverflow", + t->id, whatNext_strs[t->what_next])); /* just adjust the stack for this thread, then pop it back * on the run queue. */ @@ -1215,24 +1286,29 @@ schedule( void ) * GC is finished. */ IF_DEBUG(scheduler, - if (t->what_next == ThreadEnterInterp) { - /* ToDo: or maybe a timer expired when we were in Hugs? - * or maybe someone hit ctrl-C - */ - belch("--<< thread %ld (%p; %s) stopped to switch to Hugs", - t->id, t, whatNext_strs[t->what_next]); + if (t->what_next != prev_what_next) { + belch("--<< thread %ld (%s) stopped to switch evaluators", + t->id, whatNext_strs[t->what_next]); } else { - belch("--<< thread %ld (%p; %s) stopped, yielding", - t->id, t, whatNext_strs[t->what_next]); + belch("--<< thread %ld (%s) stopped, yielding", + t->id, whatNext_strs[t->what_next]); } ); - threadPaused(t); - IF_DEBUG(sanity, //belch("&& Doing sanity check on yielding TSO %ld.", t->id); checkTSO(t)); ASSERT(t->link == END_TSO_QUEUE); + + // Shortcut if we're just switching evaluators: don't bother + // doing stack squeezing (which can be expensive), just run the + // thread. + if (t->what_next != prev_what_next) { + goto run_thread; + } + + threadPaused(t); + #if defined(GRAN) ASSERT(!is_on_queue(t,CurrentProc)); @@ -1240,6 +1316,7 @@ schedule( void ) //belch("&& Doing sanity check on all ThreadQueues (and their TSOs)."); checkThreadQsSanity(rtsTrue)); #endif + #if defined(PAR) if (RtsFlags.ParFlags.doFairScheduling) { /* this does round-robin scheduling; good for concurrency */ @@ -1249,9 +1326,10 @@ schedule( void ) PUSH_ON_RUN_QUEUE(t); } #else - /* this does round-robin scheduling; good for concurrency */ + // this does round-robin scheduling; good for concurrency APPEND_TO_RUN_QUEUE(t); #endif + #if defined(GRAN) /* add a ContinueThread event to actually process the thread */ new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc], @@ -1263,7 +1341,7 @@ schedule( void ) G_CURR_THREADQ(0)); #endif /* GRAN */ break; - + case ThreadBlocked: #if defined(GRAN) IF_DEBUG(scheduler, @@ -1307,7 +1385,8 @@ schedule( void ) * case it'll be on the relevant queue already. */ IF_DEBUG(scheduler, - fprintf(stderr, "--<< thread %d (%p) stopped: ", t->id, t); + fprintf(stderr, "--<< thread %d (%s) stopped: ", + t->id, whatNext_strs[t->what_next]); printThreadBlockage(t); fprintf(stderr, "\n")); @@ -1328,7 +1407,8 @@ schedule( void ) /* We also end up here if the thread kills itself with an * uncaught exception, see Exception.hc. */ - IF_DEBUG(scheduler,belch("--++ thread %d (%p) finished", t->id, t)); + IF_DEBUG(scheduler,belch("--++ thread %d (%s) finished", + t->id, whatNext_strs[t->what_next])); #if defined(GRAN) endThread(t, CurrentProc); // clean-up the thread #elif defined(PAR) @@ -1352,7 +1432,11 @@ schedule( void ) } #ifdef PROFILING - if (RtsFlags.ProfFlags.profileInterval==0 || performHeapProfile) { + // When we have +RTS -i0 and we're heap profiling, do a census at + // every GC. This lets us get repeatable runs for debugging. + if (performHeapProfile || + (RtsFlags.ProfFlags.profileInterval==0 && + RtsFlags.ProfFlags.doHeapProfile && ready_to_gc)) { GarbageCollect(GetRoots, rtsTrue); heapCensus(); performHeapProfile = rtsFalse; @@ -1411,11 +1495,14 @@ schedule( void ) * Singleton fork(). Do not copy any running threads. * ------------------------------------------------------------------------- */ -StgInt forkProcess(StgTSO* tso) { - +StgInt +forkProcess(StgTSO* tso) +{ #ifndef mingw32_TARGET_OS pid_t pid; StgTSO* t,*next; + StgMainThread *m; + rtsBool doKill; IF_DEBUG(scheduler,sched_belch("forking!")); @@ -1426,23 +1513,53 @@ StgInt forkProcess(StgTSO* tso) { } else { /* child */ /* wipe all other threads */ - run_queue_hd = tso; + run_queue_hd = run_queue_tl = tso; tso->link = END_TSO_QUEUE; + /* When clearing out the threads, we need to ensure + that a 'main thread' is left behind; if there isn't, + the Scheduler will shutdown next time it is entered. + + ==> we don't kill a thread that's on the main_threads + list (nor the current thread.) + + [ Attempts at implementing the more ambitious scheme of + killing the main_threads also, and then adding the + current thread onto the main_threads list if it wasn't + there already, failed -- waitThread() (for one) wasn't + up to it. If it proves to be desirable to also kill + the main threads, then this scheme will have to be + revisited (and fully debugged!) + + -- sof 7/2002 + ] + */ /* DO NOT TOUCH THE QUEUES directly because most of the code around - us is picky about finding the threat still in its queue when + us is picky about finding the thread still in its queue when handling the deleteThread() */ for (t = all_threads; t != END_TSO_QUEUE; t = next) { next = t->link; - if (t->id != tso->id) { + + /* Don't kill the current thread.. */ + if (t->id == tso->id) continue; + doKill=rtsTrue; + /* ..or a main thread */ + for (m = main_threads; m != NULL; m = m->link) { + if (m->tso->id == t->id) { + doKill=rtsFalse; + break; + } + } + if (doKill) { deleteThread(t); } } } return pid; #else /* mingw32 */ - barf("forkProcess#: primop not implemented for mingw32, sorry!"); + barf("forkProcess#: primop not implemented for mingw32, sorry! (%u)\n", tso->id); + /* pointlessly printing out the TSOs 'id' to avoid CC unused warning. */ return -1; #endif /* mingw32 */ } @@ -1456,7 +1573,8 @@ StgInt forkProcess(StgTSO* tso) { * Locks: sched_mutex held. * ------------------------------------------------------------------------- */ -void deleteAllThreads ( void ) +void +deleteAllThreads ( void ) { StgTSO* t, *next; IF_DEBUG(scheduler,sched_belch("deleting all threads")); @@ -1511,12 +1629,23 @@ suspendThread( StgRegTable *reg, IF_DEBUG(scheduler, sched_belch("thread %d did a _ccall_gc (is_concurrent: %d)", cap->r.rCurrentTSO->id,concCall)); + // XXX this might not be necessary --SDM + cap->r.rCurrentTSO->what_next = ThreadRunGHC; + threadPaused(cap->r.rCurrentTSO); cap->r.rCurrentTSO->link = suspended_ccalling_threads; suspended_ccalling_threads = cap->r.rCurrentTSO; #if defined(RTS_SUPPORTS_THREADS) - cap->r.rCurrentTSO->why_blocked = BlockedOnCCall; + if(cap->r.rCurrentTSO->blocked_exceptions == NULL) + { + cap->r.rCurrentTSO->why_blocked = BlockedOnCCall; + cap->r.rCurrentTSO->blocked_exceptions = END_TSO_QUEUE; + } + else + { + cap->r.rCurrentTSO->why_blocked = BlockedOnCCall_NoUnblockExc; + } #endif /* Use the thread ID as the token; it should be unique */ @@ -1528,15 +1657,11 @@ suspendThread( StgRegTable *reg, #if defined(RTS_SUPPORTS_THREADS) /* Preparing to leave the RTS, so ensure there's a native thread/task waiting to take over. - - ToDo: optimise this and only create a new task if there's a need - for one (i.e., if there's only one Concurrent Haskell thread alive, - there's no need to create a new task). */ - IF_DEBUG(scheduler, sched_belch("worker thread (%d): leaving RTS", tok)); - if (concCall) { - startTask(taskStart); - } + IF_DEBUG(scheduler, sched_belch("worker thread (%d, osthread %p): leaving RTS", tok, osThreadId())); + //if (concCall) { // implementing "safe" as opposed to "threadsafe" is more difficult + startTask(taskStart); + //} #endif /* Other threads _might_ be available for execution; signal this */ @@ -1547,23 +1672,17 @@ suspendThread( StgRegTable *reg, StgRegTable * resumeThread( StgInt tok, - rtsBool concCall -#if !defined(RTS_SUPPORTS_THREADS) - STG_UNUSED -#endif - ) + rtsBool concCall STG_UNUSED ) { StgTSO *tso, **prev; Capability *cap; #if defined(RTS_SUPPORTS_THREADS) /* Wait for permission to re-enter the RTS with the result. */ - if ( concCall ) { - ACQUIRE_LOCK(&sched_mutex); - grabReturnCapability(&sched_mutex, &cap); - } else { - grabCapability(&cap); - } + ACQUIRE_LOCK(&sched_mutex); + grabReturnCapability(&sched_mutex, &cap); + + IF_DEBUG(scheduler, sched_belch("worker thread (%d, osthread %p): re-entering RTS", tok, osThreadId())); #else grabCapability(&cap); #endif @@ -1582,11 +1701,22 @@ resumeThread( StgInt tok, barf("resumeThread: thread not found"); } tso->link = END_TSO_QUEUE; + +#if defined(RTS_SUPPORTS_THREADS) + if(tso->why_blocked == BlockedOnCCall) + { + awakenBlockedQueueNoLock(tso->blocked_exceptions); + tso->blocked_exceptions = NULL; + } +#endif + /* Reset blocking status */ tso->why_blocked = NotBlocked; cap->r.rCurrentTSO = tso; +#if defined(RTS_SUPPORTS_THREADS) RELEASE_LOCK(&sched_mutex); +#endif return &cap->r; } @@ -1603,10 +1733,11 @@ static void unblockThread(StgTSO *tso); * instances of Eq/Ord for ThreadIds. * ------------------------------------------------------------------------ */ -int cmp_thread(const StgTSO *tso1, const StgTSO *tso2) +int +cmp_thread(StgPtr tso1, StgPtr tso2) { - StgThreadID id1 = tso1->id; - StgThreadID id2 = tso2->id; + StgThreadID id1 = ((StgTSO *)tso1)->id; + StgThreadID id2 = ((StgTSO *)tso2)->id; if (id1 < id2) return (-1); if (id1 > id2) return 1; @@ -1618,26 +1749,25 @@ int cmp_thread(const StgTSO *tso1, const StgTSO *tso2) * * This is used in the implementation of Show for ThreadIds. * ------------------------------------------------------------------------ */ -int rts_getThreadId(const StgTSO *tso) +int +rts_getThreadId(StgPtr tso) { - return tso->id; + return ((StgTSO *)tso)->id; } #ifdef DEBUG -void labelThread(StgTSO *tso, char *label) +void +labelThread(StgPtr tso, char *label) { int len; void *buf; /* Caveat: Once set, you can only set the thread name to "" */ len = strlen(label)+1; - buf = realloc(tso->label,len); - if (buf == NULL) { - fprintf(stderr,"insufficient memory for labelThread!\n"); - free(tso->label); - } else - strncpy(buf,label,len); - tso->label = buf; + buf = stgMallocBytes(len * sizeof(char), "Schedule.c:labelThread()"); + strncpy(buf,label,len); + /* Update will free the old memory for us */ + updateThreadLabel((StgWord)tso,buf); } #endif /* DEBUG */ @@ -1658,25 +1788,12 @@ void labelThread(StgTSO *tso, char *label) #if defined(GRAN) /* currently pri (priority) is only used in a GRAN setup -- HWL */ StgTSO * -createThread(nat stack_size, StgInt pri) -{ - return createThread_(stack_size, rtsFalse, pri); -} - -static StgTSO * -createThread_(nat size, rtsBool have_lock, StgInt pri) -{ +createThread(nat size, StgInt pri) #else StgTSO * -createThread(nat stack_size) -{ - return createThread_(stack_size, rtsFalse); -} - -static StgTSO * -createThread_(nat size, rtsBool have_lock) -{ +createThread(nat size) #endif +{ StgTSO *tso; nat stack_size; @@ -1713,23 +1830,17 @@ createThread_(nat size, rtsBool have_lock) #if defined(GRAN) SET_GRAN_HDR(tso, ThisPE); #endif - tso->what_next = ThreadEnterGHC; -#ifdef DEBUG - tso->label = NULL; -#endif + // Always start with the compiled code evaluator + tso->what_next = ThreadRunGHC; /* tso->id needs to be unique. For now we use a heavyweight mutex to * protect the increment operation on next_thread_id. * In future, we could use an atomic increment instead. */ -#ifdef SMP - if (!have_lock) { ACQUIRE_LOCK(&sched_mutex); } -#endif + ACQUIRE_LOCK(&thread_id_mutex); tso->id = next_thread_id++; -#ifdef SMP - if (!have_lock) { RELEASE_LOCK(&sched_mutex); } -#endif + RELEASE_LOCK(&thread_id_mutex); tso->why_blocked = NotBlocked; tso->blocked_exceptions = NULL; @@ -1746,8 +1857,6 @@ createThread_(nat size, rtsBool have_lock) /* put a stop frame on the stack */ tso->sp -= sizeofW(StgStopFrame); SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM); - tso->su = (StgUpdateFrame*)tso->sp; - // ToDo: check this #if defined(GRAN) tso->link = END_TSO_QUEUE; @@ -1866,7 +1975,7 @@ createSparkThread(rtsSpark spark) } else { threadsCreated++; - tso = createThread_(RtsFlags.GcFlags.initialStkSize, rtsTrue); + tso = createThread(RtsFlags.GcFlags.initialStkSize); if (tso==END_TSO_QUEUE) barf("createSparkThread: Cannot create TSO"); #if defined(DIST) @@ -1907,6 +2016,13 @@ activateSpark (rtsSpark spark) } #endif +static SchedulerStatus waitThread_(/*out*/StgMainThread* m +#if defined(THREADED_RTS) + , rtsBool blockWaiting +#endif + ); + + /* --------------------------------------------------------------------------- * scheduleThread() * @@ -1917,17 +2033,12 @@ activateSpark (rtsSpark spark) * on this thread's stack before the scheduler is invoked. * ------------------------------------------------------------------------ */ -static void scheduleThread_ (StgTSO* tso, rtsBool createTask); +static void scheduleThread_ (StgTSO* tso); void -scheduleThread_(StgTSO *tso - , rtsBool createTask -#if !defined(THREADED_RTS) - STG_UNUSED -#endif - ) +scheduleThread_(StgTSO *tso) { - ACQUIRE_LOCK(&sched_mutex); + // Precondition: sched_mutex must be held. /* Put the new thread on the head of the runnable queue. The caller * better push an appropriate closure on this thread's stack @@ -1935,30 +2046,53 @@ scheduleThread_(StgTSO *tso * soon as we release the scheduler lock below. */ PUSH_ON_RUN_QUEUE(tso); -#if defined(THREADED_RTS) - /* If main() is scheduling a thread, don't bother creating a - * new task. - */ - if ( createTask ) { - startTask(taskStart); - } -#endif THREAD_RUNNABLE(); #if 0 IF_DEBUG(scheduler,printTSO(tso)); #endif - RELEASE_LOCK(&sched_mutex); } void scheduleThread(StgTSO* tso) { - return scheduleThread_(tso, rtsFalse); + ACQUIRE_LOCK(&sched_mutex); + scheduleThread_(tso); + RELEASE_LOCK(&sched_mutex); } -void scheduleExtThread(StgTSO* tso) -{ - return scheduleThread_(tso, rtsTrue); +SchedulerStatus +scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret) +{ // Precondition: sched_mutex must be held + StgMainThread *m; + + m = stgMallocBytes(sizeof(StgMainThread), "waitThread"); + m->tso = tso; + m->ret = ret; + m->stat = NoStatus; +#if defined(RTS_SUPPORTS_THREADS) + initCondition(&m->wakeup); +#endif + + /* Put the thread on the main-threads list prior to scheduling the TSO. + Failure to do so introduces a race condition in the MT case (as + identified by Wolfgang Thaller), whereby the new task/OS thread + created by scheduleThread_() would complete prior to the thread + that spawned it managed to put 'itself' on the main-threads list. + The upshot of it all being that the worker thread wouldn't get to + signal the completion of the its work item for the main thread to + see (==> it got stuck waiting.) -- sof 6/02. + */ + IF_DEBUG(scheduler, sched_belch("waiting for thread (%d)\n", tso->id)); + + m->link = main_threads; + main_threads = m; + + scheduleThread_(tso); +#if defined(THREADED_RTS) + return waitThread_(m, rtsTrue); +#else + return waitThread_(m); +#endif } /* --------------------------------------------------------------------------- @@ -2020,6 +2154,7 @@ initScheduler(void) * the scheduler. */ initMutex(&sched_mutex); initMutex(&term_mutex); + initMutex(&thread_id_mutex); initCondition(&thread_ready_cond); #endif @@ -2077,6 +2212,7 @@ exitScheduler( void ) #if defined(RTS_SUPPORTS_THREADS) stopTaskManager(); #endif + shutting_down_scheduler = rtsTrue; } /* ----------------------------------------------------------------------------- @@ -2140,30 +2276,10 @@ finishAllThreads ( void ) SchedulerStatus waitThread(StgTSO *tso, /*out*/StgClosure **ret) { - IF_DEBUG(scheduler, sched_belch("== scheduler: waiting for thread (%d)\n", tso->id)); -#if defined(THREADED_RTS) - return waitThread_(tso,ret, rtsFalse); -#else - return waitThread_(tso,ret); -#endif -} - -SchedulerStatus -waitThread_(StgTSO *tso, - /*out*/StgClosure **ret -#if defined(THREADED_RTS) - , rtsBool blockWaiting -#endif - ) -{ StgMainThread *m; SchedulerStatus stat; - ACQUIRE_LOCK(&sched_mutex); - IF_DEBUG(scheduler, sched_belch("== scheduler: waiting for thread (%d)\n", tso->id)); - m = stgMallocBytes(sizeof(StgMainThread), "waitThread"); - m->tso = tso; m->ret = ret; m->stat = NoStatus; @@ -2171,9 +2287,32 @@ waitThread_(StgTSO *tso, initCondition(&m->wakeup); #endif + /* see scheduleWaitThread() comment */ + ACQUIRE_LOCK(&sched_mutex); m->link = main_threads; main_threads = m; + IF_DEBUG(scheduler, sched_belch("waiting for thread %d", tso->id)); +#if defined(THREADED_RTS) + stat = waitThread_(m, rtsFalse); +#else + stat = waitThread_(m); +#endif + RELEASE_LOCK(&sched_mutex); + return stat; +} + +static +SchedulerStatus +waitThread_(StgMainThread* m +#if defined(THREADED_RTS) + , rtsBool blockWaiting +#endif + ) +{ + SchedulerStatus stat; + + // Precondition: sched_mutex must be held. IF_DEBUG(scheduler, sched_belch("== scheduler: new main thread (%d)\n", m->tso->id)); #if defined(RTS_SUPPORTS_THREADS) @@ -2184,13 +2323,15 @@ waitThread_(StgTSO *tso, * gets to enter the RTS directly without going via another * task/thread. */ + main_main_thread = m; RELEASE_LOCK(&sched_mutex); schedule(); + ACQUIRE_LOCK(&sched_mutex); + main_main_thread = NULL; ASSERT(m->stat != NoStatus); } else # endif { - IF_DEBUG(scheduler, sched_belch("sfoo")); do { waitCondition(&m->wakeup, &sched_mutex); } while (m->stat == NoStatus); @@ -2201,6 +2342,7 @@ waitThread_(StgTSO *tso, procStatus[MainProc] = Busy; // status of main PE CurrentProc = MainProc; // PE to run it on + RELEASE_LOCK(&sched_mutex); schedule(); #else RELEASE_LOCK(&sched_mutex); @@ -2216,13 +2358,9 @@ waitThread_(StgTSO *tso, IF_DEBUG(scheduler, fprintf(stderr, "== scheduler: main thread (%d) finished\n", m->tso->id)); - free(m); - -#if defined(THREADED_RTS) - if (blockWaiting) -#endif - RELEASE_LOCK(&sched_mutex); + stgFree(m); + // Postcondition: sched_mutex still held return stat; } @@ -2394,6 +2532,30 @@ GetRoots(evac_fn evac) #if defined(PAR) || defined(GRAN) markSparkQueue(evac); #endif + +#if defined(RTS_USER_SIGNALS) + // mark the signal handlers (signals should be already blocked) + markSignalHandlers(evac); +#endif + + // main threads which have completed need to be retained until they + // are dealt with in the main scheduler loop. They won't be + // retained any other way: the GC will drop them from the + // all_threads list, so we have to be careful to treat them as roots + // here. + { + StgMainThread *m; + for (m = main_threads; m != NULL; m = m->link) { + switch (m->tso->what_next) { + case ThreadComplete: + case ThreadKilled: + evac((StgClosure **)&m->tso); + break; + default: + break; + } + } + } } /* ----------------------------------------------------------------------------- @@ -2409,7 +2571,7 @@ GetRoots(evac_fn evac) This needs to be protected by the GC condition variable above. KH. -------------------------------------------------------------------------- */ -void (*extra_roots)(evac_fn); +static void (*extra_roots)(evac_fn); void performGC(void) @@ -2456,7 +2618,7 @@ performGCWithRoots(void (*get_roots)(evac_fn)) static StgTSO * threadStackOverflow(StgTSO *tso) { - nat new_stack_size, new_tso_size, diff, stack_words; + nat new_stack_size, new_tso_size, stack_words; StgPtr new_sp; StgTSO *dest; @@ -2497,25 +2659,19 @@ threadStackOverflow(StgTSO *tso) memcpy(new_sp, tso->sp, stack_words * sizeof(W_)); /* relocate the stack pointers... */ - diff = (P_)new_sp - (P_)tso->sp; /* In *words* */ - dest->su = (StgUpdateFrame *) ((P_)dest->su + diff); - dest->sp = new_sp; + dest->sp = new_sp; dest->stack_size = new_stack_size; - /* and relocate the update frame list */ - relocate_stack(dest, diff); - /* Mark the old TSO as relocated. We have to check for relocated * TSOs in the garbage collector and any primops that deal with TSOs. * - * It's important to set the sp and su values to just beyond the end + * It's important to set the sp value to just beyond the end * of the stack, so we don't attempt to scavenge any part of the * dead TSO's stack. */ tso->what_next = ThreadRelocated; tso->link = dest; tso->sp = (P_)&(tso->stack[tso->stack_size]); - tso->su = (StgUpdateFrame *)tso->sp; tso->why_blocked = NotBlocked; dest->mut_link = NULL; @@ -2817,6 +2973,17 @@ awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node) } #else /* !GRAN && !PAR */ + +#ifdef RTS_SUPPORTS_THREADS +void +awakenBlockedQueueNoLock(StgTSO *tso) +{ + while (tso != END_TSO_QUEUE) { + tso = unblockOneLocked(tso); + } +} +#endif + void awakenBlockedQueue(StgTSO *tso) { @@ -2936,6 +3103,9 @@ unblockThread(StgTSO *tso) case BlockedOnRead: case BlockedOnWrite: +#if defined(mingw32_TARGET_OS) + case BlockedOnDoProc: +#endif { /* take TSO off blocked_queue */ StgBlockingQueueElement *prev = NULL; @@ -2974,7 +3144,7 @@ unblockThread(StgTSO *tso) goto done; } } - barf("unblockThread (I/O): TSO not found"); + barf("unblockThread (delay): TSO not found"); } default: @@ -3063,6 +3233,9 @@ unblockThread(StgTSO *tso) case BlockedOnRead: case BlockedOnWrite: +#if defined(mingw32_TARGET_OS) + case BlockedOnDoProc: +#endif { StgTSO *prev = NULL; for (t = blocked_queue_hd; t != END_TSO_QUEUE; @@ -3099,7 +3272,7 @@ unblockThread(StgTSO *tso) goto done; } } - barf("unblockThread (I/O): TSO not found"); + barf("unblockThread (delay): TSO not found"); } default: @@ -3130,12 +3303,12 @@ unblockThread(StgTSO *tso) * the top of the stack. * * How exactly do we save all the active computations? We create an - * AP_UPD for every UpdateFrame on the stack. Entering one of these - * AP_UPDs pushes everything from the corresponding update frame + * AP_STACK for every UpdateFrame on the stack. Entering one of these + * AP_STACKs pushes everything from the corresponding update frame * upwards onto the stack. (Actually, it pushes everything up to the - * next update frame plus a pointer to the next AP_UPD object. - * Entering the next AP_UPD object pushes more onto the stack until we - * reach the last AP_UPD object - at which point the stack should look + * next update frame plus a pointer to the next AP_STACK object. + * Entering the next AP_STACK object pushes more onto the stack until we + * reach the last AP_STACK object - at which point the stack should look * exactly as it did when we killed the TSO and we can continue * execution by entering the closure on top of the stack. * @@ -3167,195 +3340,169 @@ raiseAsyncWithLock(StgTSO *tso, StgClosure *exception) void raiseAsync(StgTSO *tso, StgClosure *exception) { - StgUpdateFrame* su = tso->su; - StgPtr sp = tso->sp; + StgRetInfoTable *info; + StgPtr sp; - /* Thread already dead? */ - if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) { - return; - } - - IF_DEBUG(scheduler, sched_belch("raising exception in thread %ld.", tso->id)); - - /* Remove it from any blocking queues */ - unblockThread(tso); - - IF_DEBUG(scheduler, sched_belch("raising exception in thread %ld.", tso->id)); - /* The stack freezing code assumes there's a closure pointer on - * the top of the stack. This isn't always the case with compiled - * code, so we have to push a dummy closure on the top which just - * returns to the next return address on the stack. - */ - if ( LOOKS_LIKE_GHC_INFO((void*)*sp) ) { - *(--sp) = (W_)&stg_dummy_ret_closure; - } - - while (1) { - nat words = ((P_)su - (P_)sp) - 1; - nat i; - StgAP_UPD * ap; - - /* If we find a CATCH_FRAME, and we've got an exception to raise, - * then build the THUNK raise(exception), and leave it on - * top of the CATCH_FRAME ready to enter. - */ - if (get_itbl(su)->type == CATCH_FRAME && exception != NULL) { -#ifdef PROFILING - StgCatchFrame *cf = (StgCatchFrame *)su; -#endif - StgClosure *raise; - - /* we've got an exception to raise, so let's pass it to the - * handler in this frame. - */ - raise = (StgClosure *)allocate(sizeofW(StgClosure)+1); - TICK_ALLOC_SE_THK(1,0); - SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs); - raise->payload[0] = exception; - - /* throw away the stack from Sp up to the CATCH_FRAME. - */ - sp = (P_)su - 1; - - /* Ensure that async excpetions are blocked now, so we don't get - * a surprise exception before we get around to executing the - * handler. - */ - if (tso->blocked_exceptions == NULL) { - tso->blocked_exceptions = END_TSO_QUEUE; - } - - /* Put the newly-built THUNK on top of the stack, ready to execute - * when the thread restarts. - */ - sp[0] = (W_)raise; - tso->sp = sp; - tso->su = su; - tso->what_next = ThreadEnterGHC; - IF_DEBUG(sanity, checkTSO(tso)); - return; + // Thread already dead? + if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) { + return; } - /* First build an AP_UPD consisting of the stack chunk above the - * current update frame, with the top word on the stack as the - * fun field. - */ - ap = (StgAP_UPD *)allocate(AP_sizeW(words)); + IF_DEBUG(scheduler, + sched_belch("raising exception in thread %ld.", tso->id)); - ASSERT(words >= 0); + // Remove it from any blocking queues + unblockThread(tso); + + sp = tso->sp; - ap->n_args = words; - ap->fun = (StgClosure *)sp[0]; - sp++; - for(i=0; i < (nat)words; ++i) { - ap->payload[i] = (StgClosure *)*sp++; + // The stack freezing code assumes there's a closure pointer on + // the top of the stack, so we have to arrange that this is the case... + // + if (sp[0] == (W_)&stg_enter_info) { + sp++; + } else { + sp--; + sp[0] = (W_)&stg_dummy_ret_closure; } - - switch (get_itbl(su)->type) { - - case UPDATE_FRAME: - { - SET_HDR(ap,&stg_AP_UPD_info,su->header.prof.ccs /* ToDo */); - TICK_ALLOC_UP_THK(words+1,0); - - IF_DEBUG(scheduler, - fprintf(stderr, "scheduler: Updating "); - printPtr((P_)su->updatee); - fprintf(stderr, " with "); - printObj((StgClosure *)ap); - ); - - /* Replace the updatee with an indirection - happily - * this will also wake up any threads currently - * waiting on the result. - * - * Warning: if we're in a loop, more than one update frame on - * the stack may point to the same object. Be careful not to - * overwrite an IND_OLDGEN in this case, because we'll screw - * up the mutable lists. To be on the safe side, don't - * overwrite any kind of indirection at all. See also - * threadSqueezeStack in GC.c, where we have to make a similar - * check. - */ - if (!closure_IND(su->updatee)) { - UPD_IND_NOLOCK(su->updatee,ap); /* revert the black hole */ - } - su = su->link; - sp += sizeofW(StgUpdateFrame) -1; - sp[0] = (W_)ap; /* push onto stack */ - break; - } - case CATCH_FRAME: - { - StgCatchFrame *cf = (StgCatchFrame *)su; - StgClosure* o; + while (1) { + nat i; + + // 1. Let the top of the stack be the "current closure" + // + // 2. Walk up the stack until we find either an UPDATE_FRAME or a + // CATCH_FRAME. + // + // 3. If it's an UPDATE_FRAME, then make an AP_STACK containing the + // current closure applied to the chunk of stack up to (but not + // including) the update frame. This closure becomes the "current + // closure". Go back to step 2. + // + // 4. If it's a CATCH_FRAME, then leave the exception handler on + // top of the stack applied to the exception. + // + // 5. If it's a STOP_FRAME, then kill the thread. - /* We want a PAP, not an AP_UPD. Fortunately, the - * layout's the same. - */ - SET_HDR(ap,&stg_PAP_info,su->header.prof.ccs /* ToDo */); - TICK_ALLOC_UPD_PAP(words+1,0); + StgPtr frame; - /* now build o = FUN(catch,ap,handler) */ - o = (StgClosure *)allocate(sizeofW(StgClosure)+2); - TICK_ALLOC_FUN(2,0); - SET_HDR(o,&stg_catch_info,su->header.prof.ccs /* ToDo */); - o->payload[0] = (StgClosure *)ap; - o->payload[1] = cf->handler; + frame = sp + 1; + info = get_ret_itbl((StgClosure *)frame); - IF_DEBUG(scheduler, - fprintf(stderr, "scheduler: Built "); - printObj((StgClosure *)o); - ); - - /* pop the old handler and put o on the stack */ - su = cf->link; - sp += sizeofW(StgCatchFrame) - 1; - sp[0] = (W_)o; - break; - } - - case SEQ_FRAME: - { - StgSeqFrame *sf = (StgSeqFrame *)su; - StgClosure* o; - - SET_HDR(ap,&stg_PAP_info,su->header.prof.ccs /* ToDo */); - TICK_ALLOC_UPD_PAP(words+1,0); + while (info->i.type != UPDATE_FRAME + && (info->i.type != CATCH_FRAME || exception == NULL) + && info->i.type != STOP_FRAME) { + frame += stack_frame_sizeW((StgClosure *)frame); + info = get_ret_itbl((StgClosure *)frame); + } - /* now build o = FUN(seq,ap) */ - o = (StgClosure *)allocate(sizeofW(StgClosure)+1); - TICK_ALLOC_SE_THK(1,0); - SET_HDR(o,&stg_seq_info,su->header.prof.ccs /* ToDo */); - o->payload[0] = (StgClosure *)ap; + switch (info->i.type) { + + case CATCH_FRAME: + // If we find a CATCH_FRAME, and we've got an exception to raise, + // then build the THUNK raise(exception), and leave it on + // top of the CATCH_FRAME ready to enter. + // + { +#ifdef PROFILING + StgCatchFrame *cf = (StgCatchFrame *)frame; +#endif + StgClosure *raise; + + // we've got an exception to raise, so let's pass it to the + // handler in this frame. + // + raise = (StgClosure *)allocate(sizeofW(StgClosure)+1); + TICK_ALLOC_SE_THK(1,0); + SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs); + raise->payload[0] = exception; + + // throw away the stack from Sp up to the CATCH_FRAME. + // + sp = frame - 1; + + /* Ensure that async excpetions are blocked now, so we don't get + * a surprise exception before we get around to executing the + * handler. + */ + if (tso->blocked_exceptions == NULL) { + tso->blocked_exceptions = END_TSO_QUEUE; + } + + /* Put the newly-built THUNK on top of the stack, ready to execute + * when the thread restarts. + */ + sp[0] = (W_)raise; + sp[-1] = (W_)&stg_enter_info; + tso->sp = sp-1; + tso->what_next = ThreadRunGHC; + IF_DEBUG(sanity, checkTSO(tso)); + return; + } - IF_DEBUG(scheduler, - fprintf(stderr, "scheduler: Built "); - printObj((StgClosure *)o); - ); + case UPDATE_FRAME: + { + StgAP_STACK * ap; + nat words; + + // First build an AP_STACK consisting of the stack chunk above the + // current update frame, with the top word on the stack as the + // fun field. + // + words = frame - sp - 1; + ap = (StgAP_STACK *)allocate(PAP_sizeW(words)); + + ap->size = words; + ap->fun = (StgClosure *)sp[0]; + sp++; + for(i=0; i < (nat)words; ++i) { + ap->payload[i] = (StgClosure *)*sp++; + } + + SET_HDR(ap,&stg_AP_STACK_info, + ((StgClosure *)frame)->header.prof.ccs /* ToDo */); + TICK_ALLOC_UP_THK(words+1,0); + + IF_DEBUG(scheduler, + fprintf(stderr, "scheduler: Updating "); + printPtr((P_)((StgUpdateFrame *)frame)->updatee); + fprintf(stderr, " with "); + printObj((StgClosure *)ap); + ); + + // Replace the updatee with an indirection - happily + // this will also wake up any threads currently + // waiting on the result. + // + // Warning: if we're in a loop, more than one update frame on + // the stack may point to the same object. Be careful not to + // overwrite an IND_OLDGEN in this case, because we'll screw + // up the mutable lists. To be on the safe side, don't + // overwrite any kind of indirection at all. See also + // threadSqueezeStack in GC.c, where we have to make a similar + // check. + // + if (!closure_IND(((StgUpdateFrame *)frame)->updatee)) { + // revert the black hole + UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee,ap); + } + sp += sizeofW(StgUpdateFrame) - 1; + sp[0] = (W_)ap; // push onto stack + break; + } - /* pop the old handler and put o on the stack */ - su = sf->link; - sp += sizeofW(StgSeqFrame) - 1; - sp[0] = (W_)o; - break; - } - - case STOP_FRAME: - /* We've stripped the entire stack, the thread is now dead. */ - sp += sizeofW(StgStopFrame) - 1; - sp[0] = (W_)exception; /* save the exception */ - tso->what_next = ThreadKilled; - tso->su = (StgUpdateFrame *)(sp+1); - tso->sp = sp; - return; - - default: - barf("raiseAsync"); + case STOP_FRAME: + // We've stripped the entire stack, the thread is now dead. + sp += sizeofW(StgStopFrame); + tso->what_next = ThreadKilled; + tso->sp = sp; + return; + + default: + barf("raiseAsync"); + } } - } - barf("raiseAsync"); + barf("raiseAsync"); } /* ----------------------------------------------------------------------------- @@ -3414,63 +3561,64 @@ resurrectThreads( StgTSO *threads ) static void detectBlackHoles( void ) { - StgTSO *t = all_threads; - StgUpdateFrame *frame; + StgTSO *tso = all_threads; + StgClosure *frame; StgClosure *blocked_on; + StgRetInfoTable *info; - for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) { + for (tso = all_threads; tso != END_TSO_QUEUE; tso = tso->global_link) { - while (t->what_next == ThreadRelocated) { - t = t->link; - ASSERT(get_itbl(t)->type == TSO); + while (tso->what_next == ThreadRelocated) { + tso = tso->link; + ASSERT(get_itbl(tso)->type == TSO); } - if (t->why_blocked != BlockedOnBlackHole) { + if (tso->why_blocked != BlockedOnBlackHole) { continue; } + blocked_on = tso->block_info.closure; - blocked_on = t->block_info.closure; - - for (frame = t->su; ; frame = frame->link) { - switch (get_itbl(frame)->type) { + frame = (StgClosure *)tso->sp; + while(1) { + info = get_ret_itbl(frame); + switch (info->i.type) { case UPDATE_FRAME: - if (frame->updatee == blocked_on) { + if (((StgUpdateFrame *)frame)->updatee == blocked_on) { /* We are blocking on one of our own computations, so * send this thread the NonTermination exception. */ IF_DEBUG(scheduler, - sched_belch("thread %d is blocked on itself", t->id)); - raiseAsync(t, (StgClosure *)NonTermination_closure); + sched_belch("thread %d is blocked on itself", tso->id)); + raiseAsync(tso, (StgClosure *)NonTermination_closure); goto done; } - else { - continue; - } - - case CATCH_FRAME: - case SEQ_FRAME: - continue; + frame = (StgClosure *) ((StgUpdateFrame *)frame + 1); + continue; + case STOP_FRAME: - break; - } - break; - } + goto done; - done: ; - } + // normal stack frames; do nothing except advance the pointer + default: + (StgPtr)frame += stack_frame_sizeW(frame); + } + } + done: ; + } } //@node Debugging Routines, Index, Exception Handling Routines, Main scheduling code //@subsection Debugging Routines /* ----------------------------------------------------------------------------- - Debugging: why is a thread blocked + * Debugging: why is a thread blocked + * [Also provides useful information when debugging threaded programs + * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02] -------------------------------------------------------------------------- */ -#ifdef DEBUG - +static void printThreadBlockage(StgTSO *tso) { @@ -3481,6 +3629,11 @@ printThreadBlockage(StgTSO *tso) case BlockedOnWrite: fprintf(stderr,"is blocked on write to fd %d", tso->block_info.fd); break; +#if defined(mingw32_TARGET_OS) + case BlockedOnDoProc: + fprintf(stderr,"is blocked on proc (request: %d)", tso->block_info.async_result->reqID); + break; +#endif case BlockedOnDelay: fprintf(stderr,"is blocked until %d", tso->block_info.target); break; @@ -3511,6 +3664,9 @@ printThreadBlockage(StgTSO *tso) case BlockedOnCCall: fprintf(stderr,"is blocked on an external call"); break; + case BlockedOnCCall_NoUnblockExc: + fprintf(stderr,"is blocked on an external call (exceptions were already blocked)"); + break; #endif default: barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)", @@ -3518,6 +3674,7 @@ printThreadBlockage(StgTSO *tso) } } +static void printThreadStatus(StgTSO *tso) { @@ -3537,31 +3694,35 @@ void printAllThreads(void) { StgTSO *t; + void *label; # if defined(GRAN) char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN]; ullong_format_string(TIME_ON_PROC(CurrentProc), time_string, rtsFalse/*no commas!*/); - sched_belch("all threads at [%s]:", time_string); + fprintf(stderr, "all threads at [%s]:\n", time_string); # elif defined(PAR) char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN]; ullong_format_string(CURRENT_TIME, time_string, rtsFalse/*no commas!*/); - sched_belch("all threads at [%s]:", time_string); + fprintf(stderr,"all threads at [%s]:\n", time_string); # else - sched_belch("all threads:"); + fprintf(stderr,"all threads:\n"); # endif for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) { - fprintf(stderr, "\tthread %d ", t->id); - if (t->label) fprintf(stderr,"[\"%s\"] ",t->label); + fprintf(stderr, "\tthread %d @ %p ", t->id, (void *)t); + label = lookupThreadLabel((StgWord)t); + if (label) fprintf(stderr,"[\"%s\"] ",(char *)label); printThreadStatus(t); fprintf(stderr,"\n"); } } +#ifdef DEBUG + /* Print a whole blocking queue attached to node (debugging only). */ @@ -3744,6 +3905,7 @@ sched_belch(char *s, ...) #endif vfprintf(stderr, s, ap); fprintf(stderr, "\n"); + va_end(ap); } #endif /* DEBUG */