X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fthread.c;h=a6b462fad6a6b61c31c978423b7441c3140b1d07;hb=69d60b456b07a0256f08df0d02484f361ce5737c;hp=2a174d69575ce2c015bbf0ff52770f1a635bec98;hpb=78fa16bf55be44cc16845be84d98023e83fb14bc;p=sbcl.git diff --git a/src/runtime/thread.c b/src/runtime/thread.c index 2a174d6..a6b462f 100644 --- a/src/runtime/thread.c +++ b/src/runtime/thread.c @@ -11,6 +11,7 @@ #include "sbcl.h" #include "runtime.h" #include "validate.h" /* for CONTROL_STACK_SIZE etc */ +#include "alloc.h" #include "thread.h" #include "arch.h" #include "target-arch-os.h" @@ -27,18 +28,23 @@ int dynamic_values_bytes=4096*sizeof(lispobj); /* same for all threads */ struct thread *all_threads; volatile lispobj all_threads_lock; +volatile lispobj thread_start_lock; extern struct interrupt_data * global_interrupt_data; +extern int linux_no_threads_p; int initial_thread_trampoline(struct thread *th) { lispobj function; +#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) lispobj *args = NULL; +#endif + function = th->unbound_marker; th->unbound_marker = UNBOUND_MARKER_WIDETAG; if(arch_os_thread_init(th)==0) return 1; - if(th->pid < 1) lose("th->pid not set up right"); + if(th->os_thread < 1) lose("th->os_thread not set up right"); th->state=STATE_RUNNING; #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) return call_into_lisp_first_time(function,args,0); @@ -47,26 +53,38 @@ initial_thread_trampoline(struct thread *th) #endif } -/* this is the first thing that clone() runs in the child (which is - * why the silly calling convention). Basically it calls the user's - * requested lisp function after doing arch_os_thread_init and - * whatever other bookkeeping needs to be done - */ - #ifdef LISP_FEATURE_SB_THREAD +void mark_thread_dead(struct thread *th) { + funcall1(SymbolFunction(HANDLE_THREAD_EXIT),alloc_number(th->os_thread)); + /* I hope it's safe for a thread to detach itself inside a + * cancellation cleanup */ + pthread_detach(th->os_thread); + th->state=STATE_DEAD; + /* FIXME: if gc hits here it will rip the stack from under us */ +} + +/* this is the first thing that runs in the child (which is why the + * silly calling convention). Basically it calls the user's requested + * lisp function after doing arch_os_thread_init and whatever other + * bookkeeping needs to be done + */ int new_thread_trampoline(struct thread *th) { - lispobj function; + lispobj function,ret; function = th->unbound_marker; th->unbound_marker = UNBOUND_MARKER_WIDETAG; + pthread_cleanup_push((void (*) (void *))mark_thread_dead,th); if(arch_os_thread_init(th)==0) return 1; /* wait here until our thread is linked into all_threads: see below */ - while(th->pid<1) sched_yield(); + while(th->os_thread<1) sched_yield(); th->state=STATE_RUNNING; - return funcall0(function); + ret = funcall0(function); + /* execute cleanup */ + pthread_cleanup_pop(1); + return ret; } #endif /* LISP_FEATURE_SB_THREAD */ @@ -88,16 +106,15 @@ struct thread * create_thread_struct(lispobj initial_function) { BINDING_STACK_SIZE+ ALIEN_STACK_SIZE+ dynamic_values_bytes+ - 32*SIGSTKSZ - ); - if(!spaces) goto cleanup; + 32*SIGSTKSZ); + if(!spaces) + return NULL; per_thread=(union per_thread_data *) (spaces+ THREAD_CONTROL_STACK_SIZE+ BINDING_STACK_SIZE+ ALIEN_STACK_SIZE); - th=&per_thread->thread; if(all_threads) { memcpy(per_thread,arch_os_get_current_thread(), dynamic_values_bytes); @@ -129,6 +146,7 @@ struct thread * create_thread_struct(lispobj initial_function) { #endif } + th=&per_thread->thread; th->control_stack_start = spaces; th->binding_stack_start= (lispobj*)((void*)th->control_stack_start+THREAD_CONTROL_STACK_SIZE); @@ -137,8 +155,10 @@ struct thread * create_thread_struct(lispobj initial_function) { (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE); th->binding_stack_pointer=th->binding_stack_start; th->this=th; - th->pid=0; - th->state=STATE_STOPPED; + th->os_thread=0; + th->interrupt_fun=NIL; + th->interrupt_fun_lock=0; + th->state=STATE_STARTING; #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD th->alien_stack_pointer=((void *)th->alien_stack_start + ALIEN_STACK_SIZE-N_WORD_BYTES); @@ -179,7 +199,8 @@ struct thread * create_thread_struct(lispobj initial_function) { bind_variable(INTERRUPT_PENDING, NIL,th); bind_variable(INTERRUPTS_ENABLED,T,th); - th->interrupt_data=os_validate(0,(sizeof (struct interrupt_data))); + th->interrupt_data = (struct interrupt_data *) + os_validate(0,(sizeof (struct interrupt_data))); if(all_threads) memcpy(th->interrupt_data, arch_os_get_current_thread()->interrupt_data, @@ -190,58 +211,86 @@ struct thread * create_thread_struct(lispobj initial_function) { th->unbound_marker=initial_function; return th; - cleanup: - /* if(th && th->tls_cookie>=0) os_free_tls_pointer(th); */ - if(spaces) os_invalidate(spaces, - THREAD_CONTROL_STACK_SIZE+BINDING_STACK_SIZE+ - ALIEN_STACK_SIZE+dynamic_values_bytes); - return 0; } -void link_thread(struct thread *th,pid_t kid_pid) +void link_thread(struct thread *th,os_thread_t kid_tid) { sigset_t newset,oldset; sigemptyset(&newset); sigaddset_blockable(&newset); - sigprocmask(SIG_BLOCK, &newset, &oldset); + thread_sigmask(SIG_BLOCK, &newset, &oldset); - get_spinlock(&all_threads_lock,kid_pid); + get_spinlock(&all_threads_lock,kid_tid); + if (all_threads) all_threads->prev=th; th->next=all_threads; + th->prev=0; all_threads=th; - /* note that th->pid is 0 at this time. We rely on all_threads_lock - * to ensure that we don't have >1 thread with pid=0 on the list at once + /* note that th->os_thread is 0 at this time. We rely on + * all_threads_lock to ensure that we don't have >1 thread with + * os_thread=0 on the list at once */ - protect_control_stack_guard_page(th->pid,1); + protect_control_stack_guard_page(th->os_thread,1); + /* child will not start until this is set */ + th->os_thread=kid_tid; release_spinlock(&all_threads_lock); - sigprocmask(SIG_SETMASK,&oldset,0); - th->pid=kid_pid; /* child will not start until this is set */ + thread_sigmask(SIG_SETMASK,&oldset,0); } void create_initial_thread(lispobj initial_function) { struct thread *th=create_thread_struct(initial_function); - pid_t kid_pid=getpid(); - if(th && kid_pid>0) { - link_thread(th,kid_pid); + os_thread_t kid_tid=thread_self(); + if(th && kid_tid>0) { + link_thread(th,kid_tid); initial_thread_trampoline(all_threads); /* no return */ } else lose("can't create initial thread"); } #ifdef LISP_FEATURE_SB_THREAD -pid_t create_thread(lispobj initial_function) { - struct thread *th=create_thread_struct(initial_function); - pid_t kid_pid=0; +os_thread_t create_thread(lispobj initial_function) { + struct thread *th; + os_thread_t kid_tid=0; + pthread_attr_t attr; + if(linux_no_threads_p) return 0; + th=create_thread_struct(initial_function); if(th==0) return 0; - kid_pid=clone(new_thread_trampoline, - (((void*)th->control_stack_start)+ - THREAD_CONTROL_STACK_SIZE-4), - CLONE_FILES|SIG_THREAD_EXIT|CLONE_VM,th); - - if(kid_pid>0) { - link_thread(th,kid_pid); - return th->pid; +#ifdef QSHOW_SIGNALS + SHOW("create_thread:waiting on lock"); +#endif + get_spinlock(&thread_start_lock,arch_os_get_current_thread()->os_thread); +#ifdef QSHOW_SIGNALS + SHOW("create_thread:got lock"); +#endif + /* The new thread inherits the restrictive signal mask set here, + * and enables signals again when it is set up properly. */ + { + sigset_t newset,oldset; + sigemptyset(&newset); + sigaddset_blockable(&newset); + thread_sigmask(SIG_BLOCK, &newset, &oldset); + if((pthread_attr_init(&attr)) || + (pthread_attr_setstack(&attr,th->control_stack_start, + THREAD_CONTROL_STACK_SIZE-16)) || + (pthread_create + (&kid_tid,&attr,(void *(*)(void *))new_thread_trampoline,th))) + kid_tid=0; + thread_sigmask(SIG_SETMASK,&oldset,0); + } + if(kid_tid>0) { + link_thread(th,kid_tid); + /* it's started and initialized, it's safe to gc */ + release_spinlock(&thread_start_lock); +#ifdef QSHOW_SIGNALS + SHOW("create_thread:released lock"); +#endif + /* by now the kid might have already exited */ + return kid_tid; } else { + release_spinlock(&thread_start_lock); +#ifdef QSHOW_SIGNALS + SHOW("create_thread:released lock(failure)"); +#endif os_invalidate((os_vm_address_t) th->control_stack_start, ((sizeof (lispobj)) * (th->control_stack_end-th->control_stack_start)) + @@ -252,37 +301,11 @@ pid_t create_thread(lispobj initial_function) { } #endif -/* unused */ -void destroy_thread (struct thread *th) -{ - /* precondition: the unix task has already been killed and exited. - * This is called by the parent or some other thread */ -#ifdef LISP_FEATURE_GENCGC - gc_alloc_update_page_tables(0, &th->alloc_region); -#endif - get_spinlock(&all_threads_lock,th->pid); - th->unbound_marker=0; /* for debugging */ - if(th==all_threads) - all_threads=th->next; - else { - struct thread *th1=all_threads; - while(th1 && th1->next!=th) th1=th1->next; - if(th1) th1->next=th->next; /* unlink */ - } - release_spinlock(&all_threads_lock); - if(th && th->tls_cookie>=0) arch_os_thread_cleanup(th); - os_invalidate((os_vm_address_t) th->control_stack_start, - ((sizeof (lispobj)) - * (th->control_stack_end-th->control_stack_start)) + - BINDING_STACK_SIZE+ALIEN_STACK_SIZE+dynamic_values_bytes+ - 32*SIGSTKSZ); -} - -struct thread *find_thread_by_pid(pid_t pid) +struct thread *find_thread_by_os_thread(os_thread_t tid) { struct thread *th; for_each_thread(th) - if(th->pid==pid) return th; + if(th->os_thread==tid) return th; return 0; } @@ -290,20 +313,6 @@ struct thread *find_thread_by_pid(pid_t pid) /* This is not needed unless #+SB-THREAD, as there's a trivial null * unithread definition. */ -void mark_dead_threads() -{ - pid_t kid; - int status; - while(1) { - kid=waitpid(-1,&status,__WALL|WNOHANG); - if(kid<=0) break; - if(WIFEXITED(status) || WIFSIGNALED(status)) { - struct thread *th=find_thread_by_pid(kid); - if(th) th->state=STATE_DEAD; - } - } -} - void reap_dead_threads() { struct thread *th,*next,*prev=0; @@ -311,11 +320,10 @@ void reap_dead_threads() while(th) { next=th->next; if(th->state==STATE_DEAD) { - funcall1(SymbolFunction(HANDLE_THREAD_EXIT),make_fixnum(th->pid)); #ifdef LISP_FEATURE_GENCGC gc_alloc_update_page_tables(0, &th->alloc_region); #endif - get_spinlock(&all_threads_lock,th->pid); + get_spinlock(&all_threads_lock,th->os_thread); if(prev) prev->next=next; else all_threads=next; release_spinlock(&all_threads_lock); @@ -331,96 +339,123 @@ void reap_dead_threads() } } -/* These are not needed unless #+SB-THREAD, and since sigwaitinfo() - * doesn't seem to be easily available everywhere (OpenBSD...) it's - * more trouble than it's worth to compile it when not needed. */ -void block_sigcont(void) -{ - /* don't allow ourselves to receive SIGCONT while we're in the - * "ambiguous" state of being on the queue but not actually stopped. - */ - sigset_t newset; - sigemptyset(&newset); - sigaddset(&newset,SIG_DEQUEUE); - sigprocmask(SIG_BLOCK, &newset, 0); -} - -void unblock_sigcont_and_sleep(void) +int interrupt_thread(os_thread_t tid, lispobj function) { - sigset_t set; - sigemptyset(&set); - sigaddset(&set,SIG_DEQUEUE); - do { - errno=0; - sigwaitinfo(&set,0); - }while(errno==EINTR); - sigprocmask(SIG_UNBLOCK,&set,0); -} - -int interrupt_thread(pid_t pid, lispobj function) -{ - union sigval sigval; struct thread *th; - sigval.sival_int=function; for_each_thread(th) - if((th->pid==pid) && (th->state != STATE_DEAD)) - return sigqueue(pid, SIG_INTERRUPT_THREAD, sigval); + if((th->os_thread==tid) && (th->state != STATE_DEAD)) { + /* In clone_threads, if A and B both interrupt C at approximately + * the same time, it does not matter: the second signal will be + * masked until the handler has returned from the first one. + * In pthreads though, we can't put the knowledge of what function + * to call into the siginfo, so we have to store it in the + * destination thread, and do it in such a way that A won't + * clobber B's interrupt. Hence this stupid linked list. + * + * This does depend on SIG_INTERRUPT_THREAD being queued + * (as POSIX RT signals are): we need to keep + * interrupt_fun data for exactly as many signals as are + * going to be received by the destination thread. + */ + struct cons *c; + int kill_status; + /* mask the signals in case this thread is being interrupted */ + sigset_t newset,oldset; + sigemptyset(&newset); + sigaddset_blockable(&newset); + thread_sigmask(SIG_BLOCK, &newset, &oldset); + + get_spinlock(&th->interrupt_fun_lock, + (int)arch_os_get_current_thread()); + kill_status=thread_kill(th->os_thread,SIG_INTERRUPT_THREAD); + if(kill_status==0) { + c=alloc_cons(function,th->interrupt_fun); + th->interrupt_fun=c; + } + release_spinlock(&th->interrupt_fun_lock); + thread_sigmask(SIG_SETMASK,&oldset,0); + return (kill_status ? -1 : 0); + } errno=EPERM; return -1; } -int signal_thread_to_dequeue (pid_t pid) -{ - return kill (pid, SIG_DEQUEUE); -} - - /* stopping the world is a two-stage process. From this thread we signal * all the others with SIG_STOP_FOR_GC. The handler for this signal does * the usual pseudo-atomic checks (we don't want to stop a thread while - * it's in the middle of allocation) then kills _itself_ with SIGSTOP. + * it's in the middle of allocation) then waits for another SIG_STOP_FOR_GC. */ void gc_stop_the_world() { - /* stop all other threads by sending them SIG_STOP_FOR_GC */ struct thread *p,*th=arch_os_get_current_thread(); - pid_t old_pid; - int finished; - do { - finished=1; - for(p=all_threads,old_pid=p->pid; p; p=p->next) { - if(p==th) continue; - if(p->state==STATE_RUNNING) { - p->state=STATE_STOPPING; - if(kill(p->pid,SIG_STOP_FOR_GC)==-1) { - /* we can't kill the process; assume because it - * died already (and its parent is dead so never - * saw the SIGCHLD) */ - p->state=STATE_DEAD; - } - } - if((p->state!=STATE_STOPPED) && - (p->state!=STATE_DEAD)) { - finished=0; - } - } - if(old_pid!=all_threads->pid) { - finished=0; - } - } while(!finished); +#ifdef QSHOW_SIGNALS + SHOW("gc_stop_the_world:begin"); +#endif + /* keep threads from starting while the world is stopped. */ + get_spinlock(&thread_start_lock,th->os_thread); +#ifdef QSHOW_SIGNALS + SHOW("gc_stop_the_world:locked"); +#endif + /* stop all other threads by sending them SIG_STOP_FOR_GC */ + for(p=all_threads; p; p=p->next) { + while(p->state==STATE_STARTING) sched_yield(); + if((p!=th) && (p->os_thread!=0) && (p->state==STATE_RUNNING)) { + p->state=STATE_STOPPING; + if(thread_kill(p->os_thread,SIG_STOP_FOR_GC)==-1) { + /* FIXME: we can't kill the thread; assume because it died + * already */ + p->state=STATE_DEAD; + } + } + } +#ifdef QSHOW_SIGNALS + SHOW("gc_stop_the_world:signals sent"); +#endif + /* wait for the running threads to stop */ + for(p=all_threads;p;) { + if((p==th) || (p->os_thread==0) || (p->state==STATE_STARTING) || + (p->state==STATE_DEAD) || (p->state==STATE_STOPPED)) { + p=p->next; + } + } +#ifdef QSHOW_SIGNALS + SHOW("gc_stop_the_world:end"); +#endif } void gc_start_the_world() { struct thread *p,*th=arch_os_get_current_thread(); /* if a resumed thread creates a new thread before we're done with - * this loop, the new thread will get consed on the front of * - * all_threads_lock, but it won't have been stopped so won't need - * restarting */ + * this loop, the new thread will get consed on the front of + * all_threads, but it won't have been stopped so won't need + * restarting; there can be threads just starting from before + * gc_stop_the_world, though */ +#ifdef QSHOW_SIGNALS + SHOW("gc_start_the_world:begin"); +#endif for(p=all_threads;p;p=p->next) { - if((p==th) || (p->state==STATE_DEAD)) continue; - p->state=STATE_RUNNING; - kill(p->pid,SIG_STOP_FOR_GC); + if((p!=th) && (p->os_thread!=0) && (p->state!=STATE_STARTING) && + (p->state!=STATE_DEAD)) { + if(p->state!=STATE_STOPPED) { + lose("gc_start_the_world: wrong thread state is %ld\n", + fixnum_value(p->state)); + } + thread_kill(p->os_thread,SIG_STOP_FOR_GC); + } + } + /* we must wait for all threads to leave stopped state else we + * risk signal accumulation and lose any meaning of + * thread->state */ + for(p=all_threads;p;) { + gc_assert(p->state!=STATE_STOPPING); + if((p==th) || (p->os_thread==0) || (p->state!=STATE_STOPPED)) { + p=p->next; + } } + release_spinlock(&thread_start_lock); +#ifdef QSHOW_SIGNALS + SHOW("gc_start_the_world:end"); +#endif } #endif