diff options
Diffstat (limited to 'erts/emulator/beam/erl_nif.c')
| -rw-r--r-- | erts/emulator/beam/erl_nif.c | 402 |
1 files changed, 388 insertions, 14 deletions
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c index b7425b9e45..62191c4abf 100644 --- a/erts/emulator/beam/erl_nif.c +++ b/erts/emulator/beam/erl_nif.c @@ -1913,8 +1913,6 @@ int enif_snprintf(char *buffer, size_t size, const char* format, ...) /* dummy node in circular list */ struct enif_resource_type_t resource_type_list; -#define SIZEOF_ErlNifResource(SIZE) (offsetof(ErtsResource,data) + (SIZE)) - static ErlNifResourceType* find_resource_type(Eterm module, Eterm name) { ErlNifResourceType* type; @@ -2083,6 +2081,7 @@ static void commit_opened_resource_types(struct erl_module_nif* lib) type->owner = lib; type->dtor = ort->new_callbacks.dtor; type->stop = ort->new_callbacks.stop; + type->down = ort->new_callbacks.down; if (type->dtor != NULL) { erts_refc_inc(&lib->rt_dtor_cnt, 1); @@ -2108,12 +2107,148 @@ static void rollback_opened_resource_types(void) } } +struct destroy_monitor_ctx +{ + Binary* resource_bin; + int exiting_procs; + int scheduler; +}; + +static void destroy_one_monitor(ErtsMonitor* mon, void* context) +{ + struct destroy_monitor_ctx* ctx = (struct destroy_monitor_ctx*) context; + Process* rp; + ErtsMonitor *rmon = NULL; + int is_exiting; + + ASSERT(mon->type == MON_ORIGIN); + ASSERT(is_internal_pid(mon->u.pid)); + ASSERT(is_internal_ref(mon->ref)); + + if (ctx->scheduler > 0) { /* Normal scheduler */ + rp = erts_proc_lookup(mon->u.pid); + } + else { +#ifdef ERTS_SMP + rp = erts_proc_lookup_inc_refc(mon->u.pid); +#else + ASSERT(!"nif monitor destruction in non-scheduler thread"); + rp = NULL; +#endif + } + + if (!rp) { + is_exiting = 1; + } + if (rp) { + erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK); + if (ERTS_PROC_IS_EXITING(rp)) { + is_exiting = 1; + } else { + rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), mon->ref); + ASSERT(rmon); + is_exiting = 0; + } + erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK); +#ifdef ERTS_SMP + if (ctx->scheduler <= 0) + erts_proc_dec_refc(rp); +#endif + } + if (is_exiting) { + ctx->exiting_procs++; + /* +1 for exiting process */ + erts_refc_inc(&ctx->resource_bin->refc, ctx->exiting_procs); + } + + /* ToDo: Delay destruction after monitor_locks */ + if (rmon) { + ASSERT(rmon->type == MON_NIF_TARGET); + ASSERT(&ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(rmon->u.pid)->binary == ctx->resource_bin); + erts_destroy_monitor(rmon); + } + erts_destroy_monitor(mon); +} + +static int destroy_all_monitors(ErtsMonitor* monitors, Binary* bin) +{ + struct destroy_monitor_ctx ctx; + + execution_state(NULL, NULL, &ctx.scheduler); + + ctx.resource_bin = bin; + ctx.exiting_procs = 0; + erts_sweep_monitors(monitors, &destroy_one_monitor, &ctx); + return ctx.exiting_procs == 0; +} + + +#ifdef ERTS_SMP +# define NIF_RESOURCE_DTOR &nif_resource_dtor +#else +# define NIF_RESOURCE_DTOR &nosmp_nif_resource_dtor_prologue + +/* + * NO-SMP: Always run resource destructor on scheduler thread + * as we may have to remove process monitors. + */ +static int nif_resource_dtor(Binary*); + +static void nosmp_nif_resource_dtor_scheduled(void* vbin) +{ + erts_bin_free((Binary*)vbin); +} + +static int nosmp_nif_resource_dtor_prologue(Binary* bin) +{ + if (is_scheduler()) { + return nif_resource_dtor(bin); + } + else { + erts_schedule_misc_aux_work(1, nosmp_nif_resource_dtor_scheduled, bin); + return 0; /* do not free */ + } +} + +#endif /* !ERTS_SMP */ static int nif_resource_dtor(Binary* bin) { ErtsResource* resource = (ErtsResource*) ERTS_MAGIC_BIN_UNALIGNED_DATA(bin); ErlNifResourceType* type = resource->type; - ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == &nif_resource_dtor); + ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == NIF_RESOURCE_DTOR); + + if (resource->monitors) { + ErtsResourceMonitors* rm = resource->monitors; + ErtsMonitor* root; + + ASSERT(type->down); + erts_smp_mtx_lock(&rm->lock); + ASSERT(erts_refc_read(&bin->refc, 0) == 0); + root = rm->root; + if (root) { + rm->root = NULL; + if (!destroy_all_monitors(root, bin)) { + /* + * Resource death struggle prolonged to serve exiting process(es). + * Destructor will be called again when last exiting process + * tries to fire its MON_NIF_TARGET monitor (and fails). + * + * This resource is doomed. It has no "real" references and + * should get not get called upon to do anything except the + * final destructor call. + */ + ASSERT(erts_refc_read(&bin->refc, 1)); +#ifdef DEBUG + resource->dbg_is_dying = 1; +#endif + erts_smp_mtx_unlock(&rm->lock); + return 0; + } + } + erts_smp_mtx_unlock(&rm->lock); + erts_smp_mtx_destroy(&rm->lock); + } if (type->dtor != NULL) { struct enif_msg_environment_t msg_env; @@ -2141,20 +2276,99 @@ void erts_resource_stop(ErtsResource* resource, ErlNifEvent e, post_nif_noproc(&msg_env); } -void* enif_alloc_resource(ErlNifResourceType* type, size_t size) +/* SVERK SVERK: Move to ?.h */ +void erts_ref_to_driver_monitor(Eterm ref, ErlDrvMonitor*); + +void erts_fire_nif_monitor(ErtsResource* resource, Eterm pid, Eterm ref) { - Binary* bin = erts_create_magic_binary_x(SIZEOF_ErlNifResource(size), - &nif_resource_dtor, - 1); /* unaligned */ - ErtsResource* resource = ERTS_MAGIC_BIN_UNALIGNED_DATA(bin); + ErtsMonitor* rmon; + ErtsBinary* bin = ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource); + struct enif_msg_environment_t msg_env; + ErlNifPid nif_pid; + ErlNifMonitor nif_monitor; + ErtsResourceMonitors* rmp = resource->monitors; + + ASSERT(rmp); + ASSERT(resource->type->down); + + erts_smp_mtx_lock(&rmp->lock); + rmon = erts_remove_monitor(&rmp->root, ref); + if (!rmon) { + erts_smp_mtx_unlock(&rmp->lock); + /* -1 for exiting process */ + if (erts_refc_dectest(&bin->binary.refc, 0) == 0) { + erts_bin_free(&bin->binary); + } + return; + } + ASSERT(!resource->dbg_is_dying); + if (erts_refc_inctest(&bin->binary.refc, 1) < 2) { + /* + * Racing resource destruction. + * To avoid a more complex refc-dance with destructing thread + * we avoid calling 'down' and just silently remove the monitor. + * There are no real references left to this resource and we have + * monitors_lock, so it's safe to reset refc back to zero. + * This can happen even for non smp as destructor calls may be scheduled. + */ + erts_refc_init(&bin->binary.refc, 0); + erts_smp_mtx_unlock(&rmp->lock); + } + else { + erts_smp_mtx_unlock(&rmp->lock); + + ASSERT(rmon->u.pid == pid); + erts_ref_to_driver_monitor(ref, &nif_monitor); + nif_pid.pid = pid; + pre_nif_noproc(&msg_env, resource->type->owner, NULL); + resource->type->down(&msg_env.env, resource->data, &nif_pid, &nif_monitor); + post_nif_noproc(&msg_env); + + if (erts_refc_dectest(&bin->binary.refc, 0) == 0) { + erts_bin_free(&bin->binary); + } + } + erts_destroy_monitor(rmon); +} + +void* enif_alloc_resource(ErlNifResourceType* type, size_t data_sz) +{ + size_t magic_sz = offsetof(ErtsResource,data); + Binary* bin; + ErtsResource* resource; + size_t monitors_offs; + + if (type->down) { + /* Put ErtsResourceMonitors after user data and properly aligned */ + monitors_offs = ((data_sz + ERTS_ALLOC_ALIGN_BYTES - 1) + & ~((size_t)ERTS_ALLOC_ALIGN_BYTES - 1)); + magic_sz += monitors_offs + sizeof(ErtsResourceMonitors); + } + else { + ERTS_UNDEF(monitors_offs, 0); + magic_sz += data_sz; + } + bin = erts_create_magic_binary_x(magic_sz, NIF_RESOURCE_DTOR, + 1); /* unaligned */ + resource = ERTS_MAGIC_BIN_UNALIGNED_DATA(bin); ASSERT(type->owner && type->next && type->prev); /* not allowed in load/upgrade */ resource->type = type; erts_refc_inc(&bin->refc, 1); #ifdef DEBUG erts_refc_init(&resource->nif_refc, 1); + resource->dbg_is_dying = 0; #endif erts_refc_inc(&resource->type->refc, 2); + if (type->down) { + resource->monitors = (ErtsResourceMonitors*) (resource->data + monitors_offs); + erts_smp_mtx_init(&resource->monitors->lock, "resource_monitors"); + resource->monitors->root = NULL; + resource->monitors->user_data_sz = data_sz; + } + else { + resource->monitors = NULL; + } return resource->data; } @@ -2163,7 +2377,8 @@ void enif_release_resource(void* obj) ErtsResource* resource = DATA_TO_RESOURCE(obj); ErtsBinary* bin = ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource); - ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == &nif_resource_dtor); + ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == NIF_RESOURCE_DTOR); + ASSERT(!resource->dbg_is_dying); #ifdef DEBUG erts_refc_dec(&resource->nif_refc, 0); #endif @@ -2177,18 +2392,27 @@ void enif_keep_resource(void* obj) ErtsResource* resource = DATA_TO_RESOURCE(obj); ErtsBinary* bin = ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource); - ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == &nif_resource_dtor); + ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(bin) == NIF_RESOURCE_DTOR); + ASSERT(!resource->dbg_is_dying); #ifdef DEBUG erts_refc_inc(&resource->nif_refc, 1); #endif erts_refc_inc(&bin->binary.refc, 2); } +Eterm erts_bld_resource_ref(Eterm** hpp, ErlOffHeap* oh, ErtsResource* resource) +{ + ErtsBinary* bin = ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource); + ASSERT(!resource->dbg_is_dying); + return erts_mk_magic_binary_term(hpp, oh, &bin->binary); +} + ERL_NIF_TERM enif_make_resource(ErlNifEnv* env, void* obj) { ErtsResource* resource = DATA_TO_RESOURCE(obj); ErtsBinary* bin = ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource); Eterm* hp = alloc_heap(env,PROC_BIN_SIZE); + ASSERT(!resource->dbg_is_dying); return erts_mk_magic_binary_term(&hp, &MSO(env->proc), &bin->binary); } @@ -2217,7 +2441,7 @@ int enif_get_resource(ErlNifEnv* env, ERL_NIF_TERM term, ErlNifResourceType* typ }*/ mbin = pb->val; resource = (ErtsResource*) ERTS_MAGIC_BIN_UNALIGNED_DATA(mbin); - if (ERTS_MAGIC_BIN_DESTRUCTOR(mbin) != &nif_resource_dtor + if (ERTS_MAGIC_BIN_DESTRUCTOR(mbin) != NIF_RESOURCE_DTOR || resource->type != type) { return 0; } @@ -2228,8 +2452,13 @@ int enif_get_resource(ErlNifEnv* env, ERL_NIF_TERM term, ErlNifResourceType* typ size_t enif_sizeof_resource(void* obj) { ErtsResource* resource = DATA_TO_RESOURCE(obj); - Binary* bin = &ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource)->binary; - return ERTS_MAGIC_BIN_UNALIGNED_DATA_SIZE(bin) - offsetof(ErtsResource,data); + if (resource->monitors) { + return resource->monitors->user_data_sz; + } + else { + Binary* bin = &ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(resource)->binary; + return ERTS_MAGIC_BIN_UNALIGNED_DATA_SIZE(bin) - offsetof(ErtsResource,data); + } } @@ -2830,6 +3059,150 @@ int enif_map_iterator_get_pair(ErlNifEnv *env, return 0; } +int enif_monitor_process(ErlNifEnv* env, void* obj, const ErlNifPid* target_pid, + ErlNifMonitor* monitor) +{ + int scheduler; + ErtsResource* rsrc = DATA_TO_RESOURCE(obj); + Process *rp; + Eterm tmp[REF_THING_SIZE]; + Eterm ref; + int retval; + + ASSERT(ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(rsrc)->magic_binary.destructor + == NIF_RESOURCE_DTOR); + ASSERT(!rsrc->dbg_is_dying); + ASSERT(!rsrc->monitors == !rsrc->type->down); + + + if (!rsrc->monitors) { + ASSERT(!rsrc->type->down); + return -1; + } + ASSERT(rsrc->type->down); + + execution_state(env, NULL, &scheduler); + +#ifdef ERTS_SMP + if (scheduler > 0) /* Normal scheduler */ + rp = erts_proc_lookup_raw(target_pid->pid); + else + rp = erts_proc_lookup_raw_inc_refc(target_pid->pid); +#else + if (scheduler <= 0) { + erts_exit(ERTS_ABORT_EXIT, "enif_monitor_process: called from " + "non-scheduler thread on non-SMP VM"); + } + rp = erts_proc_lookup(target_pid->pid); +#endif + + if (!rp) + return 1; + + ref = erts_make_ref_in_buffer(tmp); + + erts_smp_mtx_lock(&rsrc->monitors->lock); + erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK); + if (ERTS_PSFLG_FREE & erts_smp_atomic32_read_nob(&rp->state)) { + retval = 1; + } + else { + erts_add_monitor(&rsrc->monitors->root, MON_ORIGIN, ref, rp->common.id, NIL); + erts_add_monitor(&ERTS_P_MONITORS(rp), MON_NIF_TARGET, ref, (UWord)rsrc, NIL); + retval = 0; + } + erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK); + erts_smp_mtx_unlock(&rsrc->monitors->lock); + +#ifdef ERTS_SMP + if (scheduler <= 0) + erts_proc_dec_refc(rp); +#endif + if (monitor) + erts_ref_to_driver_monitor(ref,monitor); + + return retval; +} + +int enif_demonitor_process(ErlNifEnv* env, void* obj, const ErlNifMonitor* monitor) +{ + int scheduler; + ErtsResource* rsrc = DATA_TO_RESOURCE(obj); + ErtsBinary* bin = ERTS_MAGIC_BIN_FROM_UNALIGNED_DATA(rsrc); + Process *rp; + ErtsMonitor *mon; + ErtsMonitor *rmon = NULL; + Eterm ref_heap[REF_THING_SIZE]; + Eterm ref; + int is_exiting; + + ASSERT(bin->magic_binary.destructor == NIF_RESOURCE_DTOR); + ASSERT(!rsrc->dbg_is_dying); + + execution_state(env, NULL, &scheduler); + + memcpy(ref_heap, monitor, sizeof(Eterm)*REF_THING_SIZE); + ref = make_internal_ref(ref_heap); + erts_smp_mtx_lock(&rsrc->monitors->lock); + mon = erts_remove_monitor(&rsrc->monitors->root, ref); + + if (mon == NULL) { + erts_smp_mtx_unlock(&rsrc->monitors->lock); + return 1; + } + + ASSERT(mon->type == MON_ORIGIN); + ASSERT(is_internal_pid(mon->u.pid)); + +#ifdef ERTS_SMP + if (scheduler > 0) /* Normal scheduler */ + rp = erts_proc_lookup(mon->u.pid); + else + rp = erts_proc_lookup_inc_refc(mon->u.pid); +#else + if (scheduler <= 0) { + erts_exit(ERTS_ABORT_EXIT, "enif_demonitor_process: called from " + "non-scheduler thread on non-SMP VM"); + } + rp = erts_proc_lookup(mon->u.pid); +#endif + + if (!rp) { + is_exiting = 1; + } + else { + erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK); + if (ERTS_PROC_IS_EXITING(rp)) { + is_exiting = 1; + } else { + rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref); + ASSERT(rmon); + is_exiting = 0; + } + erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK); + +#ifdef ERTS_SMP + if (scheduler <= 0) + erts_proc_dec_refc(rp); +#endif + } + if (is_exiting) { + /* +1 for exiting process */ + erts_refc_inc(&bin->binary.refc, 2); + } + erts_smp_mtx_unlock(&rsrc->monitors->lock); + + if (rmon) { + ASSERT(rmon->type == MON_NIF_TARGET); + ASSERT(rmon->u.resource == rsrc); + erts_destroy_monitor(rmon); + } + erts_destroy_monitor(mon); + + return 0; +} + + /*************************************************************************** ** load_nif/2 ** ***************************************************************************/ @@ -3303,7 +3676,8 @@ erts_unload_nif(struct erl_module_nif* lib) void erl_nif_init() { - ERTS_CT_ASSERT((offsetof(ErtsResource,data) % 8) == ERTS_MAGIC_BIN_BYTES_TO_ALIGN); + ERTS_CT_ASSERT((offsetof(ErtsResource,data) % 8) + == ERTS_MAGIC_BIN_BYTES_TO_ALIGN); resource_type_list.next = &resource_type_list; resource_type_list.prev = &resource_type_list; |