X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fthread.c;h=e1586801591e56ac236de9d0f41caff73989a5e8;hb=e5d96999ae4388181ddb0c113313f26afbe997e8;hp=2a6bc40f785ebf075c853cc44f834dd1ba50c132;hpb=426bde0954ef91387b8ab0d4528fad9ec02fa24c;p=sbcl.git diff --git a/src/runtime/thread.c b/src/runtime/thread.c index 2a6bc40..e158680 100644 --- a/src/runtime/thread.c +++ b/src/runtime/thread.c @@ -1,16 +1,38 @@ +/* + * This software is part of the SBCL system. See the README file for + * more information. + * + * This software is derived from the CMU CL system, which was + * written at Carnegie Mellon University and released into the + * public domain. The software is in the public domain and is + * provided with absolutely no warranty. See the COPYING and CREDITS + * files for more information. + */ + +#include "sbcl.h" + #include #include #include +#ifndef LISP_FEATURE_WIN32 #include +#endif #include #include #include #include +#ifndef LISP_FEATURE_WIN32 #include +#endif + +#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER +#include +#include +#include +#endif -#include "sbcl.h" #include "runtime.h" -#include "validate.h" /* for CONTROL_STACK_SIZE etc */ +#include "validate.h" /* for BINDING_STACK_SIZE etc */ #include "alloc.h" #include "thread.h" #include "arch.h" @@ -23,78 +45,99 @@ #include "interr.h" /* for lose() */ #include "gc-internal.h" -#define ALIEN_STACK_SIZE (1*1024*1024) /* 1Mb size chosen at random */ +#ifdef LISP_FEATURE_WIN32 +/* + * Win32 doesn't have SIGSTKSZ, and we're not switching stacks anyway, + * so define it arbitrarily + */ +#define SIGSTKSZ 1024 +#endif + +#if defined(LISP_FEATURE_DARWIN) && defined(LISP_FEATURE_SB_THREAD) +#define DELAY_THREAD_POST_MORTEM 5 +#define LOCK_CREATE_THREAD +#endif + +#ifdef LISP_FEATURE_FREEBSD +#define CREATE_CLEANUP_THREAD +#define LOCK_CREATE_THREAD +#endif + +#ifdef LISP_FEATURE_SB_THREAD +struct thread_post_mortem { +#ifdef DELAY_THREAD_POST_MORTEM + struct thread_post_mortem *next; +#endif + os_thread_t os_thread; + pthread_attr_t *os_attr; + os_vm_address_t os_address; +}; + +#ifdef DELAY_THREAD_POST_MORTEM +static int pending_thread_post_mortem_count = 0; +pthread_mutex_t thread_post_mortem_lock = PTHREAD_MUTEX_INITIALIZER; +#endif +static struct thread_post_mortem * volatile pending_thread_post_mortem = 0; +#endif -int dynamic_values_bytes=4096*sizeof(lispobj); /* same for all threads */ +int dynamic_values_bytes=TLS_SIZE*sizeof(lispobj); /* same for all threads */ struct thread *all_threads; -volatile lispobj all_threads_lock; extern struct interrupt_data * global_interrupt_data; -extern int linux_no_threads_p; #ifdef LISP_FEATURE_SB_THREAD -/* 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 - * 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() -{ - /* Get the current sigmask, by blocking the empty set. */ - sigset_t empty,current; - sigemptyset(&empty); - thread_sigmask(SIG_BLOCK, &empty, ¤t); - if (sigismember(¤t,SIG_STOP_FOR_GC)) - lose("SIG_STOP_FOR_GC is blocked\n"); - if (SymbolValue(INTERRUPTS_ENABLED,arch_os_get_current_thread()) == NIL) - lose("interrupts disabled\n"); - if (arch_pseudo_atomic_atomic(NULL)) - lose("n pseudo atomic\n"); -} - -#ifdef QSHOW_SIGNALS -#define FSHOW_SIGNAL FSHOW -#else -#define FSHOW_SIGNAL(args) -#endif - -#define GET_ALL_THREADS_LOCK(name) \ - { \ - sigset_t _newset,_oldset; \ - sigemptyset(&_newset); \ - sigaddset_blockable(&_newset); \ - sigdelset(&_newset,SIG_STOP_FOR_GC); \ - thread_sigmask(SIG_BLOCK, &_newset, &_oldset); \ - check_sig_stop_for_gc_can_arrive_or_lose(); \ - FSHOW_SIGNAL((stderr,"/%s:waiting on lock=%ld, thread=%ld\n",name, \ - all_threads_lock,arch_os_get_current_thread()->os_thread)); \ - get_spinlock(&all_threads_lock,(long)arch_os_get_current_thread()); \ - FSHOW_SIGNAL((stderr,"/%s:got lock, thread=%ld\n", \ - name,arch_os_get_current_thread()->os_thread)); - -#define RELEASE_ALL_THREADS_LOCK(name) \ - FSHOW_SIGNAL((stderr,"/%s:released lock\n",name)); \ - release_spinlock(&all_threads_lock); \ - thread_sigmask(SIG_SETMASK,&_oldset,0); \ - } +pthread_mutex_t all_threads_lock = PTHREAD_MUTEX_INITIALIZER; +#ifdef LOCK_CREATE_THREAD +static pthread_mutex_t create_thread_lock = PTHREAD_MUTEX_INITIALIZER; +#endif +#ifdef LISP_FEATURE_GCC_TLS +__thread struct thread *current_thread; +#endif #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 -int +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) { 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; + 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(); +#ifndef LISP_FEATURE_WIN32 + protect_control_stack_guard_page(1, NULL); + protect_binding_stack_guard_page(1, NULL); + protect_alien_stack_guard_page(1, NULL); +#endif - 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 @@ -103,6 +146,105 @@ initial_thread_trampoline(struct thread *th) } #ifdef LISP_FEATURE_SB_THREAD +#define THREAD_STATE_LOCK_SIZE \ + (sizeof(pthread_mutex_t))+(sizeof(pthread_cond_t)) +#else +#define THREAD_STATE_LOCK_SIZE 0 +#endif + +#define THREAD_STRUCT_SIZE (thread_control_stack_size + BINDING_STACK_SIZE + \ + ALIEN_STACK_SIZE + \ + THREAD_STATE_LOCK_SIZE + \ + dynamic_values_bytes + \ + 32 * SIGSTKSZ + \ + THREAD_ALIGNMENT_BYTES) + +#ifdef LISP_FEATURE_SB_THREAD +/* THREAD POST MORTEM CLEANUP + * + * Memory allocated for the thread stacks cannot be reclaimed while + * the thread is still alive, so we need a mechanism for post mortem + * cleanups. FIXME: We actually have three, for historical reasons as + * the saying goes. Do we really need three? Nikodemus guesses that + * not anymore, now that we properly call pthread_attr_destroy before + * freeing the stack. */ + +static struct thread_post_mortem * +plan_thread_post_mortem(struct thread *corpse) +{ + if (corpse) { + struct thread_post_mortem *post_mortem = malloc(sizeof(struct thread_post_mortem)); + gc_assert(post_mortem); + post_mortem->os_thread = corpse->os_thread; + post_mortem->os_attr = corpse->os_attr; + post_mortem->os_address = corpse->os_address; +#ifdef DELAY_THREAD_POST_MORTEM + post_mortem->next = NULL; +#endif + return post_mortem; + } else { + /* FIXME: When does this happen? */ + return NULL; + } +} + +static void +perform_thread_post_mortem(struct thread_post_mortem *post_mortem) +{ +#ifdef CREATE_POST_MORTEM_THREAD + pthread_detach(pthread_self()); +#endif + if (post_mortem) { + gc_assert(!pthread_join(post_mortem->os_thread, NULL)); + gc_assert(!pthread_attr_destroy(post_mortem->os_attr)); + free(post_mortem->os_attr); + os_invalidate(post_mortem->os_address, THREAD_STRUCT_SIZE); + free(post_mortem); + } +} + +static void +schedule_thread_post_mortem(struct thread *corpse) +{ + struct thread_post_mortem *post_mortem = NULL; + if (corpse) { + post_mortem = plan_thread_post_mortem(corpse); + +#ifdef DELAY_THREAD_POST_MORTEM + pthread_mutex_lock(&thread_post_mortem_lock); + /* First stick the new post mortem to the end of the queue. */ + if (pending_thread_post_mortem) { + struct thread_post_mortem *next = pending_thread_post_mortem; + while (next->next) { + next = next->next; + } + next->next = post_mortem; + } else { + pending_thread_post_mortem = post_mortem; + } + /* Then, if there are enough things in the queue, clean up one + * from the head -- or increment the count, and null out the + * post_mortem we have. */ + if (pending_thread_post_mortem_count > DELAY_THREAD_POST_MORTEM) { + post_mortem = pending_thread_post_mortem; + pending_thread_post_mortem = post_mortem->next; + } else { + pending_thread_post_mortem_count++; + post_mortem = NULL; + } + pthread_mutex_unlock(&thread_post_mortem_lock); + /* Finally run, the cleanup, if any. */ + perform_thread_post_mortem(post_mortem); +#elif defined(CREATE_POST_MORTEM_THREAD) + gc_assert(!pthread_create(&thread, NULL, perform_thread_post_mortem, post_mortem)); +#else + post_mortem = (struct thread_post_mortem *) + swap_lispobjs((lispobj *)(void *)&pending_thread_post_mortem, + (lispobj)post_mortem); + perform_thread_post_mortem(post_mortem); +#endif + } +} /* this is the first thing that runs in the child (which is why the * silly calling convention). Basically it calls the user's requested @@ -113,59 +255,134 @@ int new_thread_trampoline(struct thread *th) { lispobj function; - function = th->unbound_marker; - th->unbound_marker = UNBOUND_MARKER_WIDETAG; - if(arch_os_thread_init(th)==0) return 1; + int result, lock_ret; + + FSHOW((stderr,"/creating thread %lu\n", thread_self())); + check_deferrables_blocked_or_lose(); + check_gc_signals_unblocked_or_lose(); + function = th->no_tls_value_marker; + th->no_tls_value_marker = NO_TLS_VALUE_MARKER_WIDETAG; + if(arch_os_thread_init(th)==0) { + /* FIXME: handle error */ + lose("arch_os_thread_init failed\n"); + } - /* wait here until our thread is linked into all_threads: see below */ - while(th->os_thread<1) sched_yield(); + th->os_thread=thread_self(); + protect_control_stack_guard_page(1, NULL); + protect_binding_stack_guard_page(1, NULL); + protect_alien_stack_guard_page(1, NULL); + /* Since GC can only know about this thread from the all_threads + * list and we're just adding this thread to it, there is no + * danger of deadlocking even with SIG_STOP_FOR_GC blocked (which + * it is not). */ + lock_ret = pthread_mutex_lock(&all_threads_lock); + gc_assert(lock_ret == 0); + link_thread(th); + lock_ret = pthread_mutex_unlock(&all_threads_lock); + gc_assert(lock_ret == 0); + + result = funcall0(function); + + /* Block GC */ + block_blockable_signals(); + set_thread_state(th, 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. */ + lock_ret = pthread_mutex_lock(&all_threads_lock); + gc_assert(lock_ret == 0); + + gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &th->alloc_region); + unlink_thread(th); + pthread_mutex_unlock(&all_threads_lock); + gc_assert(lock_ret == 0); - th->state=STATE_RUNNING; - return funcall0(function); + if(th->tls_cookie>=0) arch_os_thread_cleanup(th); + pthread_mutex_destroy(th->state_lock); + pthread_cond_destroy(th->state_cond); + + os_invalidate((os_vm_address_t)th->interrupt_data, + (sizeof (struct interrupt_data))); + +#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER + FSHOW((stderr, "Deallocating mach port %x\n", THREAD_STRUCT_TO_EXCEPTION_PORT(th))); + mach_port_move_member(mach_task_self(), + THREAD_STRUCT_TO_EXCEPTION_PORT(th), + MACH_PORT_NULL); + mach_port_deallocate(mach_task_self(), + THREAD_STRUCT_TO_EXCEPTION_PORT(th)); + mach_port_destroy(mach_task_self(), + THREAD_STRUCT_TO_EXCEPTION_PORT(th)); +#endif + + schedule_thread_post_mortem(th); + FSHOW((stderr,"/exiting thread %lu\n", thread_self())); + return result; } + #endif /* LISP_FEATURE_SB_THREAD */ +static void +free_thread_struct(struct thread *th) +{ + if (th->interrupt_data) + os_invalidate((os_vm_address_t) th->interrupt_data, + (sizeof (struct interrupt_data))); + os_invalidate((os_vm_address_t) th->os_address, + THREAD_STRUCT_SIZE); +} + /* this is called from any other thread to create the new one, and * initialize all parts of it that can be initialized from another * thread */ -struct thread * create_thread_struct(lispobj initial_function) { +static struct thread * +create_thread_struct(lispobj initial_function) { union per_thread_data *per_thread; struct thread *th=0; /* subdue gcc */ void *spaces=0; + void *aligned_spaces=0; +#ifdef LISP_FEATURE_SB_THREAD + unsigned int i; +#endif - /* may as well allocate all the spaces at once: it saves us from + /* May as well allocate all the spaces at once: it saves us from * having to decide what to do if only some of the allocations - * succeed */ - spaces=os_validate(0, - THREAD_CONTROL_STACK_SIZE+ - BINDING_STACK_SIZE+ - ALIEN_STACK_SIZE+ - dynamic_values_bytes+ - 32*SIGSTKSZ); + * succeed. SPACES must be appropriately aligned, since the GC + * expects the control stack to start at a page boundary -- and + * the OS may have even more rigorous requirements. We can't rely + * on the alignment passed from os_validate, since that might + * assume the current (e.g. 4k) pagesize, while we calculate with + * the biggest (e.g. 64k) pagesize allowed by the ABI. */ + spaces=os_validate(0, THREAD_STRUCT_SIZE); if(!spaces) - return NULL; + return NULL; + /* Aligning up is safe as THREAD_STRUCT_SIZE has + * THREAD_ALIGNMENT_BYTES padding. */ + aligned_spaces = (void *)((((unsigned long)(char *)spaces) + + THREAD_ALIGNMENT_BYTES-1) + &~(unsigned long)(THREAD_ALIGNMENT_BYTES-1)); per_thread=(union per_thread_data *) - (spaces+ - THREAD_CONTROL_STACK_SIZE+ + (aligned_spaces+ + thread_control_stack_size+ BINDING_STACK_SIZE+ - ALIEN_STACK_SIZE); + ALIEN_STACK_SIZE + + THREAD_STATE_LOCK_SIZE); - if(all_threads) { - memcpy(per_thread,arch_os_get_current_thread(), - dynamic_values_bytes); - } else { #ifdef LISP_FEATURE_SB_THREAD - int i; - for(i=0;i<(dynamic_values_bytes/sizeof(lispobj));i++) - per_thread->dynamic_values[i]=UNBOUND_MARKER_WIDETAG; - if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) + for(i = 0; i < (dynamic_values_bytes / sizeof(lispobj)); i++) + per_thread->dynamic_values[i] = NO_TLS_VALUE_MARKER_WIDETAG; + if (all_threads == 0) { + if(SymbolValue(FREE_TLS_INDEX,0)==UNBOUND_MARKER_WIDETAG) { SetSymbolValue (FREE_TLS_INDEX, + /* FIXME: should be MAX_INTERRUPTS -1 ? */ make_fixnum(MAX_INTERRUPTS+ sizeof(struct thread)/sizeof(lispobj)), 0); + SetSymbolValue(TLS_INDEX_LOCK,make_fixnum(0),0); + } #define STATIC_TLS_INIT(sym,field) \ ((struct symbol *)(sym-OTHER_POINTER_LOWTAG))->tls_index= \ make_fixnum(THREAD_SLOT_OFFSET_WORDS(field)) @@ -176,26 +393,33 @@ struct thread * create_thread_struct(lispobj initial_function) { STATIC_TLS_INIT(CONTROL_STACK_END,control_stack_end); STATIC_TLS_INIT(ALIEN_STACK,alien_stack_pointer); #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64) - STATIC_TLS_INIT(PSEUDO_ATOMIC_ATOMIC,pseudo_atomic_atomic); - STATIC_TLS_INIT(PSEUDO_ATOMIC_INTERRUPTED,pseudo_atomic_interrupted); + STATIC_TLS_INIT(PSEUDO_ATOMIC_BITS,pseudo_atomic_bits); #endif #undef STATIC_TLS_INIT -#endif } +#endif th=&per_thread->thread; - th->control_stack_start = spaces; + th->os_address = spaces; + th->control_stack_start = aligned_spaces; th->binding_stack_start= - (lispobj*)((void*)th->control_stack_start+THREAD_CONTROL_STACK_SIZE); + (lispobj*)((void*)th->control_stack_start+thread_control_stack_size); th->control_stack_end = th->binding_stack_start; th->alien_stack_start= (lispobj*)((void*)th->binding_stack_start+BINDING_STACK_SIZE); 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_SB_THREAD + th->os_attr=malloc(sizeof(pthread_attr_t)); + th->state_lock=(pthread_mutex_t *)((void *)th->alien_stack_start + + ALIEN_STACK_SIZE); + pthread_mutex_init(th->state_lock, NULL); + th->state_cond=(pthread_cond_t *)((void *)th->state_lock + + (sizeof(pthread_mutex_t))); + pthread_cond_init(th->state_cond, NULL); +#endif + th->state=STATE_RUNNING; #ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD th->alien_stack_pointer=((void *)th->alien_stack_start + ALIEN_STACK_SIZE-N_WORD_BYTES); @@ -203,8 +427,7 @@ struct thread * create_thread_struct(lispobj initial_function) { th->alien_stack_pointer=((void *)th->alien_stack_start); #endif #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64) - th->pseudo_atomic_interrupted=0; - th->pseudo_atomic_atomic=0; + th->pseudo_atomic_bits=0; #endif #ifdef LISP_FEATURE_GENCGC gc_set_region_empty(&th->alloc_region); @@ -223,8 +446,7 @@ struct thread * create_thread_struct(lispobj initial_function) { #if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64) SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th); SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th); - SetSymbolValue(PSEUDO_ATOMIC_ATOMIC,(lispobj)th->pseudo_atomic_atomic,th); - SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED,th->pseudo_atomic_interrupted,th); + SetSymbolValue(PSEUDO_ATOMIC_BITS,(lispobj)th->pseudo_atomic_bits,th); #else current_binding_stack_pointer=th->binding_stack_pointer; current_control_stack_pointer=th->control_stack_start; @@ -235,179 +457,112 @@ struct thread * create_thread_struct(lispobj initial_function) { bind_variable(FREE_INTERRUPT_CONTEXT_INDEX,make_fixnum(0),th); bind_variable(INTERRUPT_PENDING, NIL,th); bind_variable(INTERRUPTS_ENABLED,T,th); + bind_variable(ALLOW_WITH_INTERRUPTS,T,th); + bind_variable(GC_PENDING,NIL,th); + bind_variable(ALLOC_SIGNAL,NIL,th); +#ifdef LISP_FEATURE_SB_THREAD + bind_variable(STOP_FOR_GC_PENDING,NIL,th); +#endif 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, - sizeof (struct interrupt_data)); - else - memcpy(th->interrupt_data,global_interrupt_data, - sizeof (struct interrupt_data)); + if (!th->interrupt_data) { + free_thread_struct(th); + return 0; + } + th->interrupt_data->pending_handler = 0; + th->interrupt_data->gc_blocked_deferrables = 0; + th->no_tls_value_marker=initial_function; - th->unbound_marker=initial_function; + th->stepping = NIL; return th; } -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; -} +#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER +mach_port_t setup_mach_exception_handling_thread(); +kern_return_t mach_thread_init(mach_port_t thread_exception_port); + +#endif 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 */ - } else lose("can't create initial thread"); + if(th) { +#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER + setup_mach_exception_handling_thread(); +#endif + initial_thread_trampoline(th); /* no return */ + } else lose("can't create initial thread\n"); } #ifdef LISP_FEATURE_SB_THREAD #ifndef __USE_XOPEN2K extern int pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr, - size_t __stacksize); + size_t __stacksize); #endif boolean create_os_thread(struct thread *th,os_thread_t *kid_tid) { /* The new thread inherits the restrictive signal mask set here, * and enables signals again when it is set up properly. */ - pthread_attr_t attr; - sigset_t newset,oldset; + sigset_t oldset; boolean r=1; - 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))) - r=0; - thread_sigmask(SIG_SETMASK,&oldset,0); - return r; -} - -struct thread *create_thread(lispobj initial_function) { - struct thread *th; - os_thread_t kid_tid=0; - boolean success; + int retcode = 0, initcode; - if(linux_no_threads_p) return 0; + FSHOW_SIGNAL((stderr,"/create_os_thread: creating new thread\n")); - th=create_thread_struct(initial_function); - if(th==0) return 0; + /* Blocking deferrable signals is enough, no need to block + * SIG_STOP_FOR_GC because the child process is not linked onto + * all_threads until it's ready. */ + thread_sigmask(SIG_BLOCK, &deferrable_sigset, &oldset); - /* 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 */ - GET_ALL_THREADS_LOCK("create_thread") - - success=create_os_thread(th,&kid_tid); - if (success) - link_thread(th,kid_tid); - else - 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); - - RELEASE_ALL_THREADS_LOCK("create_thread") - - if (success) - return th; - else - return 0; -} +#ifdef LOCK_CREATE_THREAD + retcode = pthread_mutex_lock(&create_thread_lock); + gc_assert(retcode == 0); + FSHOW_SIGNAL((stderr,"/create_os_thread: got lock\n")); +#endif -/* 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); - release_spinlock(&all_threads_lock); - thread_sigmask(SIG_SETMASK,&oldset,0); + if((initcode = pthread_attr_init(th->os_attr)) || + /* call_into_lisp_first_time switches the stack for the initial thread. For the + * others, we use this. */ + (pthread_attr_setstack(th->os_attr,th->control_stack_start,thread_control_stack_size)) || + (retcode = pthread_create + (kid_tid,th->os_attr,(void *(*)(void *))new_thread_trampoline,th))) { + FSHOW_SIGNAL((stderr, "init = %d\n", initcode)); + FSHOW_SIGNAL((stderr, printf("pthread_create returned %d, errno %d\n", retcode, errno))); + if(retcode < 0) { + perror("create_os_thread"); + } + r=0; } + +#ifdef LOCK_CREATE_THREAD + retcode = pthread_mutex_unlock(&create_thread_lock); + gc_assert(retcode == 0); + FSHOW_SIGNAL((stderr,"/create_os_thread: released lock\n")); #endif - GET_ALL_THREADS_LOCK("reap_dead_thread") - FSHOW((stderr,"/reap_dead_thread: reaping %ld\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); - 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); + thread_sigmask(SIG_SETMASK,&oldset,0); + return r; } -int interrupt_thread(struct thread *th, lispobj function) -{ - /* A thread may also become dead after this test. */ - if ((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. - */ - lispobj c=alloc_cons(function,NIL); - int kill_status; - /* interrupt_thread_handler locks this spinlock with - * interrupts blocked and it does so for the sake of - * arrange_return_to_lisp_function, so we must also block - * them. */ - sigset_t newset,oldset; - sigemptyset(&newset); - sigaddset_blockable(&newset); - thread_sigmask(SIG_BLOCK, &newset, &oldset); - get_spinlock(&th->interrupt_fun_lock, - (long)arch_os_get_current_thread()); - kill_status=thread_kill(th->os_thread,SIG_INTERRUPT_THREAD); - if(kill_status==0) { - ((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); - return (kill_status ? -1 : 0); +os_thread_t create_thread(lispobj initial_function) { + struct thread *th, *thread = arch_os_get_current_thread(); + os_thread_t kid_tid = 0; + + /* Must defend against async unwinds. */ + if (SymbolValue(INTERRUPTS_ENABLED, thread) != NIL) + lose("create_thread is not safe when interrupts are enabled.\n"); + + /* Assuming that a fresh thread struct has no lisp objects in it, + * linking it to all_threads can be left to the thread itself + * without fear of gc lossage. initial_function violates this + * assumption and must stay pinned until the child starts up. */ + th = create_thread_struct(initial_function); + if (th && !create_os_thread(th,&kid_tid)) { + free_thread_struct(th); + kid_tid = 0; } - errno=EPERM; return -1; + return kid_tid; } /* stopping the world is a two-stage process. From this thread we signal @@ -422,35 +577,51 @@ int interrupt_thread(struct thread *th, lispobj function) void gc_stop_the_world() { struct thread *p,*th=arch_os_get_current_thread(); - FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock, thread=%ld\n", - th->os_thread)); + int status, lock_ret; +#ifdef LOCK_CREATE_THREAD + /* KLUDGE: Stopping the thread during pthread_create() causes deadlock + * on FreeBSD. */ + FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on create_thread_lock\n")); + lock_ret = pthread_mutex_lock(&create_thread_lock); + gc_assert(lock_ret == 0); + FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got create_thread_lock\n")); +#endif + FSHOW_SIGNAL((stderr,"/gc_stop_the_world:waiting on lock\n")); /* keep threads from starting while the world is stopped. */ - get_spinlock(&all_threads_lock,(long)th); - FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock, thread=%ld\n", - th->os_thread)); + lock_ret = pthread_mutex_lock(&all_threads_lock); \ + gc_assert(lock_ret == 0); + + FSHOW_SIGNAL((stderr,"/gc_stop_the_world:got lock\n")); /* 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)) { - FSHOW_SIGNAL((stderr,"/gc_stop_the_world:sending sig_stop to %ld\n", + gc_assert(p->os_thread != 0); + FSHOW_SIGNAL((stderr,"/gc_stop_the_world: thread=%lu, state=%x\n", + p->os_thread, thread_state(p))); + if((p!=th) && ((thread_state(p)==STATE_RUNNING))) { + FSHOW_SIGNAL((stderr,"/gc_stop_the_world: suspending thread %lu\n", p->os_thread)); - if(thread_kill(p->os_thread,SIG_STOP_FOR_GC)==-1) { - /* we can't kill the thread; assume because it died - * since we last checked */ - p->state=STATE_DEAD; - FSHOW_SIGNAL((stderr,"/gc_stop_the_world:assuming %ld dead\n", - p->os_thread)); + /* We already hold all_thread_lock, P can become DEAD but + * cannot exit, ergo it's safe to use pthread_kill. */ + status=pthread_kill(p->os_thread,SIG_STOP_FOR_GC); + if (status==ESRCH) { + /* This thread has exited. */ + gc_assert(thread_state(p)==STATE_DEAD); + } else if (status) { + lose("cannot send suspend thread=%lu: %d, %s\n", + p->os_thread,status,strerror(status)); } } } 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; + for(p=all_threads;p;p=p->next) { + if (p!=th) { + FSHOW_SIGNAL + ((stderr, + "/gc_stop_the_world: waiting for thread=%lu: state=%x\n", + p->os_thread, thread_state(p))); + wait_for_thread_state_change(p, STATE_RUNNING); + if (p->state == STATE_RUNNING) + lose("/gc_stop_the_world: unexpected state"); } } FSHOW_SIGNAL((stderr,"/gc_stop_the_world:end\n")); @@ -459,6 +630,7 @@ void gc_stop_the_world() void gc_start_the_world() { struct thread *p,*th=arch_os_get_current_thread(); + int lock_ret; /* 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, but it won't have been stopped so won't need @@ -466,23 +638,94 @@ void gc_start_the_world() 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->state!=STATE_SUSPENDED) { - lose("gc_start_the_world: wrong thread state is %ld\n", - fixnum_value(p->state)); + if (p!=th) { + lispobj state = thread_state(p); + if (state != STATE_DEAD) { + if(state != STATE_SUSPENDED) { + lose("gc_start_the_world: wrong thread state is %d\n", + fixnum_value(state)); + } + FSHOW_SIGNAL((stderr, "/gc_start_the_world: resuming %lu\n", + p->os_thread)); + set_thread_state(p, STATE_RUNNING); } - 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;) { - if((p==th) || (p->state!=STATE_SUSPENDED)) { - p=p->next; } } - release_spinlock(&all_threads_lock); + + lock_ret = pthread_mutex_unlock(&all_threads_lock); + gc_assert(lock_ret == 0); +#ifdef LOCK_CREATE_THREAD + lock_ret = pthread_mutex_unlock(&create_thread_lock); + gc_assert(lock_ret == 0); +#endif + FSHOW_SIGNAL((stderr,"/gc_start_the_world:end\n")); } #endif + +int +thread_yield() +{ +#ifdef LISP_FEATURE_SB_THREAD + return sched_yield(); +#else + return 0; +#endif +} + +/* If the thread id given does not belong to a running thread (it has + * exited or never even existed) pthread_kill _may_ fail with ESRCH, + * but it is also allowed to just segfault, see + * . + * + * Relying on thread ids can easily backfire since ids are recycled + * (NPTL recycles them extremely fast) so a signal can be sent to + * another process if the one it was sent to exited. + * + * We send signals in two places: signal_interrupt_thread sends a + * signal that's harmless if delivered to another thread, but + * SIG_STOP_FOR_GC is fatal. + * + * For these reasons, we must make sure that the thread is still alive + * when the pthread_kill is called and return if the thread is + * exiting. */ +int +kill_safely(os_thread_t os_thread, int signal) +{ + FSHOW_SIGNAL((stderr,"/kill_safely: %lu, %d\n", os_thread, signal)); + { +#ifdef LISP_FEATURE_SB_THREAD + sigset_t oldset; + struct thread *thread; + /* pthread_kill is not async signal safe and we don't want to be + * interrupted while holding the lock. */ + thread_sigmask(SIG_BLOCK, &deferrable_sigset, &oldset); + pthread_mutex_lock(&all_threads_lock); + for (thread = all_threads; thread; thread = thread->next) { + if (thread->os_thread == os_thread) { + int status = pthread_kill(os_thread, signal); + if (status) + lose("kill_safely: pthread_kill failed with %d\n", status); + break; + } + } + pthread_mutex_unlock(&all_threads_lock); + thread_sigmask(SIG_SETMASK,&oldset,0); + if (thread) + return 0; + else + return -1; +#else + int status; + if (os_thread != 0) + lose("kill_safely: who do you want to kill? %d?\n", os_thread); + status = raise(signal); + if (status == 0) { + return 0; + } else { + lose("cannot raise signal %d, %d %s\n", + signal, status, strerror(errno)); + } +#endif + } +}