X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fthread.c;h=c6d2ad59a32b33e89ff4ea55e3240f946085c7bc;hb=c580293e8550414004697173f7e2c2b6bdf81070;hp=ab0db0886eab31ea383d5a85b60349a046e63e4d;hpb=2805aa2c24f28ea664658d274789a1644fe16f9b;p=sbcl.git diff --git a/src/runtime/thread.c b/src/runtime/thread.c index ab0db08..c6d2ad5 100644 --- a/src/runtime/thread.c +++ b/src/runtime/thread.c @@ -25,6 +25,13 @@ #define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */ +struct freeable_stack { + os_thread_t os_thread; + os_vm_address_t stack; +}; + +static struct freeable_stack * volatile freeable_stack = 0; + int dynamic_values_bytes=4096*sizeof(lispobj); /* same for all threads */ struct thread * volatile all_threads; extern struct interrupt_data * global_interrupt_data; @@ -35,7 +42,7 @@ extern int linux_no_threads_p; pthread_mutex_t all_threads_lock = PTHREAD_MUTEX_INITIALIZER; /* When trying to get all_threads_lock one should make sure that - * sig_stop_for_gc is not blocked. Else there would be a possible + * SIG_STOP_FOR_GC is not blocked. Else there would be a possible * deadlock: gc locks it, other thread blocks signals, gc sends stop * request to other thread and waits, other thread blocks on lock. */ void check_sig_stop_for_gc_can_arrive_or_lose() @@ -70,13 +77,35 @@ void check_sig_stop_for_gc_can_arrive_or_lose() pthread_mutex_unlock(&all_threads_lock); \ thread_sigmask(SIG_SETMASK,&_oldset,0); \ } -#endif - #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) extern lispobj call_into_lisp_first_time(lispobj fun, lispobj *args, int nargs); #endif +#endif + +static void +link_thread(struct thread *th) +{ + if (all_threads) all_threads->prev=th; + th->next=all_threads; + th->prev=0; + all_threads=th; +} + +#ifdef LISP_FEATURE_SB_THREAD +static void +unlink_thread(struct thread *th) +{ + if (th->prev) + th->prev->next = th->next; + else + all_threads = th->next; + if (th->next) + th->next->prev = th->prev; +} +#endif + static int initial_thread_trampoline(struct thread *th) { @@ -87,9 +116,11 @@ initial_thread_trampoline(struct thread *th) function = th->no_tls_value_marker; th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG; if(arch_os_thread_init(th)==0) return 1; + link_thread(th); + th->os_thread=thread_self(); + protect_control_stack_guard_page(1); + th->state = STATE_RUNNING; - 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); #else @@ -97,8 +128,38 @@ initial_thread_trampoline(struct thread *th) #endif } +#define THREAD_STRUCT_SIZE (THREAD_CONTROL_STACK_SIZE + BINDING_STACK_SIZE + \ + ALIEN_STACK_SIZE + dynamic_values_bytes + \ + 32 * SIGSTKSZ) + #ifdef LISP_FEATURE_SB_THREAD +static void +free_thread_stack_later(struct thread *thread_to_be_cleaned_up) +{ + struct freeable_stack *new_freeable_stack = 0; + if (thread_to_be_cleaned_up) { + new_freeable_stack = (struct freeable_stack *) + os_validate(0, sizeof(struct freeable_stack)); + new_freeable_stack->os_thread = thread_to_be_cleaned_up->os_thread; + new_freeable_stack->stack = (os_vm_address_t) + thread_to_be_cleaned_up->control_stack_start; + } + new_freeable_stack = (struct freeable_stack *) + swap_lispobjs((lispobj *)(void *)&freeable_stack, + (lispobj)new_freeable_stack); + if (new_freeable_stack) { + FSHOW((stderr,"/reaping %lu\n", new_freeable_stack->os_thread)); + /* Under NPTL pthread_join really waits until the thread + * exists and the stack can be safely freed. This is sadly not + * mandated by the pthread spec. */ + gc_assert(pthread_join(new_freeable_stack->os_thread, NULL) == 0); + os_invalidate(new_freeable_stack->stack, THREAD_STRUCT_SIZE); + os_invalidate((os_vm_address_t) new_freeable_stack, + sizeof(struct freeable_stack)); + } +} + /* 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 @@ -109,6 +170,7 @@ new_thread_trampoline(struct thread *th) { lispobj function; int result; + FSHOW((stderr,"/creating thread %lu\n", thread_self())); function = th->no_tls_value_marker; th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG; if(arch_os_thread_init(th)==0) { @@ -116,22 +178,43 @@ new_thread_trampoline(struct thread *th) lose("arch_os_thread_init failed\n"); } - /* wait here until our thread is linked into all_threads: see below */ + th->os_thread=thread_self(); + protect_control_stack_guard_page(1); + /* This thread is in STATE_STARTING so the GC is not sending it + * SIG_STOP_FOR_GC => no danger of deadlocking even with + * SIG_STOP_FOR_GC blocked. The lock is acquired in order not to + * enter running state with the gc running. */ + pthread_mutex_lock(&all_threads_lock); + th->state = STATE_RUNNING; + pthread_mutex_unlock(&all_threads_lock); + /* Now that we entered STATE_RUNNING let the gc suspend this + * thread. */ { - volatile os_thread_t *tid=&th->os_thread; - while(*tid<1) sched_yield(); + sigset_t sigset; + sigemptyset(&sigset); + sigaddset(&sigset, SIG_STOP_FOR_GC); + thread_sigmask(SIG_UNBLOCK, &sigset, 0); } - th->state=STATE_RUNNING; result = funcall0(function); th->state=STATE_DEAD; + + /* SIG_STOP_FOR_GC is blocked and GC might be waiting for this + * thread, but since we are already dead it won't wait long. */ + pthread_mutex_lock(&all_threads_lock); + unlink_thread(th); + pthread_mutex_unlock(&all_threads_lock); + + gc_alloc_update_page_tables(0, &th->alloc_region); + if(th->tls_cookie>=0) arch_os_thread_cleanup(th); + os_invalidate((os_vm_address_t)th->interrupt_data, + (sizeof (struct interrupt_data))); + free_thread_stack_later(th); + FSHOW((stderr,"/exiting thread %lu\n", thread_self())); return result; } -#endif /* LISP_FEATURE_SB_THREAD */ -#define THREAD_STRUCT_SIZE (THREAD_CONTROL_STACK_SIZE + BINDING_STACK_SIZE + \ - ALIEN_STACK_SIZE + dynamic_values_bytes + \ - 32 * SIGSTKSZ) +#endif /* LISP_FEATURE_SB_THREAD */ static void free_thread_struct(struct thread *th) @@ -209,8 +292,6 @@ create_thread_struct(lispobj initial_function) { th->binding_stack_pointer=th->binding_stack_start; th->this=th; 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 @@ -267,29 +348,10 @@ create_thread_struct(lispobj initial_function) { return th; } -static void -link_thread(struct thread *th,os_thread_t kid_tid) -{ - if (all_threads) all_threads->prev=th; - th->next=all_threads; - th->prev=0; - all_threads=th; - /* 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,1); - /* child will not start until this is set */ - th->os_thread=kid_tid; - FSHOW((stderr,"/created thread %lu\n",kid_tid)); -} - void create_initial_thread(lispobj initial_function) { struct thread *th=create_thread_struct(initial_function); - os_thread_t kid_tid=thread_self(); - if(th && kid_tid>0) { - link_thread(th,kid_tid); - initial_thread_trampoline(all_threads); /* no return */ + if(th) { + initial_thread_trampoline(th); /* no return */ } else lose("can't create initial thread"); } @@ -308,10 +370,7 @@ boolean create_os_thread(struct thread *th,os_thread_t *kid_tid) sigset_t newset,oldset; boolean r=1; sigemptyset(&newset); - /* Blocking deferrable signals is enough, since gc_stop_the_world - * waits until the child leaves STATE_STARTING. And why not let gc - * proceed as soon as possible? */ - sigaddset_deferrable(&newset); + sigaddset_blockable(&newset); thread_sigmask(SIG_BLOCK, &newset, &oldset); if((pthread_attr_init(&attr)) || @@ -324,61 +383,32 @@ boolean create_os_thread(struct thread *th,os_thread_t *kid_tid) return r; } -struct thread *create_thread(lispobj initial_function) { +os_thread_t create_thread(lispobj initial_function) { struct thread *th; - os_thread_t kid_tid=0; - boolean success; + os_thread_t kid_tid; if(linux_no_threads_p) return 0; - th=create_thread_struct(initial_function); - if(th==0) return 0; - - /* we must not be interrupted here after a successful - * create_os_thread, because the kid will be waiting for its - * thread struct to be linked */ + /* The new thread must be linked immediately onto all_threads for + * gc. */ GET_ALL_THREADS_LOCK("create_thread") - - success=create_os_thread(th,&kid_tid); - if (success) - link_thread(th,kid_tid); - else - free_thread_struct(th); - + /* If it is too slow most of the allocation/initialization can + * be done without the lock. */ + th = create_thread_struct(initial_function); + if (th) + link_thread(th); RELEASE_ALL_THREADS_LOCK("create_thread") + if(th==0) return 0; - if (success) - return th; - else + if (create_os_thread(th,&kid_tid)) { + return kid_tid; + } else { + GET_ALL_THREADS_LOCK("create_thread") + unlink_thread(th); + RELEASE_ALL_THREADS_LOCK("create_thread") + free_thread_struct(th); return 0; -} - -/* called from lisp from the thread object finalizer */ -void reap_dead_thread(struct thread *th) -{ - if(th->state!=STATE_DEAD) - lose("thread %p is not joinable, state=%d\n",th,th->state); -#ifdef LISP_FEATURE_GENCGC - { - sigset_t newset,oldset; - sigemptyset(&newset); - sigaddset_blockable(&newset); - thread_sigmask(SIG_BLOCK, &newset, &oldset); - gc_alloc_update_page_tables(0, &th->alloc_region); - thread_sigmask(SIG_SETMASK,&oldset,0); } -#endif - GET_ALL_THREADS_LOCK("reap_dead_thread") - FSHOW((stderr,"/reap_dead_thread: reaping %lu\n",th->os_thread)); - if(th->prev) - th->prev->next=th->next; - else all_threads=th->next; - if(th->next) - th->next->prev=th->prev; - RELEASE_ALL_THREADS_LOCK("reap_dead_thread") - if(th->tls_cookie>=0) arch_os_thread_cleanup(th); - gc_assert(pthread_join(th->os_thread,NULL)==0); - free_thread_struct(th); } /* Send the signo to os_thread, retry if the rt signal queue is @@ -402,56 +432,16 @@ static int kill_thread_safely(os_thread_t os_thread, int signo) return r; } -int interrupt_thread(struct thread *th, lispobj function) +int signal_interrupt_thread(os_thread_t os_thread) { - /* 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. - */ - lispobj c=alloc_cons(function,NIL); - sigset_t newset,oldset; - sigemptyset(&newset); - /* interrupt_thread_handler locks this spinlock with blockables - * blocked (it does so for the sake of - * arrange_return_to_lisp_function), so we must also block them or - * else SIG_STOP_FOR_GC and all_threads_lock will find a way to - * deadlock. */ - sigaddset_blockable(&newset); - thread_sigmask(SIG_BLOCK, &newset, &oldset); - if (th == arch_os_get_current_thread()) - lose("cannot interrupt current thread"); - get_spinlock(&th->interrupt_fun_lock, - (long)arch_os_get_current_thread()); - ((struct cons *)native_pointer(c))->cdr=th->interrupt_fun; - th->interrupt_fun=c; - release_spinlock(&th->interrupt_fun_lock); - thread_sigmask(SIG_SETMASK,&oldset,0); - /* Called from lisp with the thread object as a parameter. Thus, - * the object cannot be garbage collected and consequently reaped - * and joined. Because it's not joined, kill should work (even if - * the thread has died/exited). */ - { - int status=kill_thread_safely(th->os_thread,SIG_INTERRUPT_THREAD); - if (status==0) { - return 0; - } else if (status==ESRCH) { - /* This thread has exited. */ - th->interrupt_fun=NIL; - errno=ESRCH; - return -1; - } else { - lose("cannot send SIG_INTERRUPT_THREAD to thread=%lu: %d, %s", - th->os_thread,status,strerror(status)); - } + int status = kill_thread_safely(os_thread, SIG_INTERRUPT_THREAD); + if (status == 0) { + return 0; + } else if (status == ESRCH) { + return -1; + } else { + lose("cannot send SIG_INTERRUPT_THREAD to thread=%lu: %d, %s", + os_thread, status, strerror(status)); } } @@ -476,8 +466,7 @@ void gc_stop_the_world() th->os_thread)); /* 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->state==STATE_RUNNING)) { + if((p!=th) && ((p->state==STATE_RUNNING))) { FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending %lu\n", p->os_thread)); status=kill_thread_safely(p->os_thread,SIG_STOP_FOR_GC); @@ -493,13 +482,11 @@ void gc_stop_the_world() FSHOW_SIGNAL((stderr,"/gc_stop_the_world:signals sent\n")); /* wait for the running threads to stop or finish */ for(p=all_threads;p;) { - gc_assert(p->os_thread!=0); - gc_assert(p->state!=STATE_STARTING); - if((p==th) || (p->state==STATE_SUSPENDED) || - (p->state==STATE_DEAD)) { - p=p->next; - } else { + if((p!=th) && (p->state==STATE_RUNNING)) { + gc_assert(p->os_thread!=0); sched_yield(); + } else { + p=p->next; } } FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n")); @@ -515,8 +502,8 @@ void gc_start_the_world() * restarting */ FSHOW_SIGNAL((stderr,"/gc_start_the_world:begin\n")); for(p=all_threads;p;p=p->next) { - gc_assert(p->os_thread!=0); - if((p!=th) && (p->state!=STATE_DEAD)) { + if((p!=th) && (p->state!=STATE_STARTING) && (p->state!=STATE_DEAD)) { + gc_assert(p->os_thread!=0); if(p->state!=STATE_SUSPENDED) { lose("gc_start_the_world: wrong thread state is %d\n", fixnum_value(p->state));