X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fthread.c;h=3092fc078e80919e0c00d98ce86c41b86e7c6ae3;hb=b85552a9ed94019afd70b11b069f3c9b0afdaaa8;hp=ffd14db15b551e3ecd9c82a9ea9ef393357e6fd8;hpb=6b7b0266343826426a3efffa3b8b8d4d552f8f97;p=sbcl.git diff --git a/src/runtime/thread.c b/src/runtime/thread.c index ffd14db..3092fc0 100644 --- a/src/runtime/thread.c +++ b/src/runtime/thread.c @@ -3,6 +3,7 @@ #include #include #include +#include #ifndef CLONE_PARENT /* lameass glibc 2.2 doesn't define this */ #define CLONE_PARENT 0x00008000 /* even though the manpage documents it */ #endif @@ -14,16 +15,14 @@ #include "target-arch-os.h" #include "os.h" #include "globals.h" -#ifdef LISP_FEATURE_GENCGC -#include "gencgc.h" -#endif #include "dynbind.h" #include "genesis/cons.h" #define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */ int dynamic_values_bytes=4096*sizeof(lispobj); /* same for all threads */ struct thread *all_threads; -lispobj all_threads_lock; +volatile lispobj all_threads_lock; +volatile int countdown_to_gc; extern struct interrupt_data * global_interrupt_data; void get_spinlock(lispobj *word,int value); @@ -137,6 +136,7 @@ pid_t create_thread(lispobj initial_function) { th->binding_stack_pointer=th->binding_stack_start; th->this=th; th->pid=0; + th->state=STATE_RUNNING; #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD th->alien_stack_pointer=((void *)th->alien_stack_start + ALIEN_STACK_SIZE-4); /* naked 4. FIXME */ @@ -211,7 +211,7 @@ pid_t create_thread(lispobj initial_function) { * to ensure that we don't have >1 thread with pid=0 on the list at once */ protect_control_stack_guard_page(th->pid,1); - all_threads_lock=0; + release_spinlock(&all_threads_lock); th->pid=kid_pid; /* child will not start until this is set */ #ifndef LISP_FEATURE_SB_THREAD new_thread_trampoline(all_threads); /* call_into_lisp */ @@ -235,6 +235,8 @@ void destroy_thread (struct thread *th) gc_alloc_update_page_tables(0, &th->alloc_region); #endif get_spinlock(&all_threads_lock,th->pid); + if(countdown_to_gc>0) countdown_to_gc--; + th->state=STATE_STOPPED; if(th==all_threads) all_threads=th->next; else { @@ -242,7 +244,7 @@ void destroy_thread (struct thread *th) while(th1->next!=th) th1=th1->next; th1->next=th->next; /* unlink */ } - all_threads_lock=0; + 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)) @@ -260,6 +262,10 @@ struct thread *find_thread_by_pid(pid_t pid) return 0; } +/* 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. */ +#if defined LISP_FEATURE_SB_THREAD void block_sigcont(void) { /* don't allow ourselves to receive SIGCONT while we're in the @@ -267,20 +273,19 @@ void block_sigcont(void) */ sigset_t newset; sigemptyset(&newset); - sigaddset(&newset,SIGCONT); + sigaddset(&newset,SIG_DEQUEUE); sigprocmask(SIG_BLOCK, &newset, 0); } -/* This is 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. */ -#if defined LISP_FEATURE_SB_THREAD void unblock_sigcont_and_sleep(void) { sigset_t set; sigemptyset(&set); - sigaddset(&set,SIGCONT); - sigwaitinfo(&set,0); + sigaddset(&set,SIG_DEQUEUE); + do { + errno=0; + sigwaitinfo(&set,0); + }while(errno==EINTR); sigprocmask(SIG_UNBLOCK,&set,0); } @@ -289,6 +294,66 @@ int interrupt_thread(pid_t pid, lispobj function) union sigval sigval; sigval.sival_int=function; - sigqueue(pid, SIG_INTERRUPT_THREAD, sigval); + return sigqueue(pid, SIG_INTERRUPT_THREAD, sigval); +} + +/* 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 thread 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. + * At any given time, countdown_to_gc should reflect the number of threads + * signalled but which haven't yet come to rest + */ + +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(); + struct thread *tail=0; + int finished=0; + do { + get_spinlock(&all_threads_lock,th->pid); + if(tail!=all_threads) { + /* new threads always get consed onto the front of all_threads, + * and may be created by any thread that we haven't signalled + * yet or hasn't received our signal and stopped yet. So, check + * for them on each time around */ + for(p=all_threads;p!=tail;p=p->next) { + if(p==th) continue; + /* if the head of all_threads is removed during + * gc_stop_the_world, we may take a second trip through the + * list and end up counting twice as many threads to wait for + * as actually exist */ + if(p->state!=STATE_RUNNING) continue; + countdown_to_gc++; + p->state=STATE_STOPPING; + /* Note no return value check from kill(). If the + * thread had been reaped already, we kill it and + * increment countdown_to_gc anyway. This is to avoid + * complicating the logic in destroy_thread, which would + * otherwise have to know whether the thread died before or + * after it was killed + */ + kill(p->pid,SIG_STOP_FOR_GC); + } + tail=all_threads; + } else { + finished=(countdown_to_gc==0); + } + release_spinlock(&all_threads_lock); + sched_yield(); + } while(!finished); +} + +void gc_start_the_world() +{ + struct thread *p,*th=arch_os_get_current_thread(); + get_spinlock(&all_threads_lock,th->pid); + for(p=all_threads;p;p=p->next) { + if(p==th) continue; + p->state=STATE_RUNNING; + kill(p->pid,SIGCONT); + } + release_spinlock(&all_threads_lock); } #endif