diff options
26 files changed, 920 insertions, 410 deletions
diff --git a/HOWTO/INSTALL.md b/HOWTO/INSTALL.md index 8632f46264..551ecdd224 100644 --- a/HOWTO/INSTALL.md +++ b/HOWTO/INSTALL.md @@ -429,6 +429,10 @@ Some of the available `configure` options are: and **not supported**. This functionality **will** be subject to backward incompatible changes. Note that you should **not** enable the dirty scheduler functionality on production systems. It is only provided for testing. + This switch also imply `--enable-new-purge-strategy` (see below). +* `--enable-new-purge-strategy` - Enable the purge strategy that will be + introduced in ERTS version 9.0 (OTP 20). Note that this switch will be + removed in OTP 20. If you or your system has special requirements please read the `Makefile` for additional configuration information. diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 6289f033b2..a146d4f2b1 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -764,6 +764,29 @@ and the operation was requested by passing option <c>{allow_gc, false}</c>.</p></item> </taglist> + <note> + <p> + Up until ERTS version 8.*, the check process code operation + checks for all types of references to the old code. That is, + direct references (e.g. return addresses on the process + stack), indirect references (<c>fun</c>s in process + context), and references to literals in the code. + </p> + <p> + As of ERTS version 9.0, the check process code operation + only checks for direct references to the code. Indirect + references via <c>fun</c>s will be ignored. If such + <c>fun</c>s exist and are used after a purge of the old + code, an exception will be raised upon usage (same as + the case when the <c>fun</c> is received by the process + after the purge). Literals will be taken care of (copied) + at a later stage. This behavior can as of ERTS version + 8.1 be enabled when + <seealso marker="doc/installation_guide:INSTALL#Advanced-configuration-and-build-of-ErlangOTP_Configuring">building OTP</seealso>, + and will automatically be enabled if dirty scheduler + support is enabled. + </p> + </note> <p>See also <seealso marker="kernel:code">code(3)</seealso>.</p> <p>Failures:</p> <taglist> diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names index dd37c682b1..ace3dc5230 100644 --- a/erts/emulator/beam/atom.names +++ b/erts/emulator/beam/atom.names @@ -65,6 +65,7 @@ atom undefined_lambda atom DOWN='DOWN' atom UP='UP' atom EXIT='EXIT' +atom abort atom aborted atom abs_path atom absoluteURI @@ -165,6 +166,7 @@ atom commandv atom compact atom compat_rel atom compile +atom complete atom compressed atom config_h atom convert_time_unit @@ -236,6 +238,7 @@ atom erlang atom ERROR='ERROR' atom error_handler atom error_logger +atom erts_code_purger atom erts_internal atom ets atom ETS_TRANSFER='ETS-TRANSFER' @@ -487,6 +490,7 @@ atom pause atom pending atom pending_driver atom pending_process +atom pending_purge_lambda atom pending_reload atom permanent atom pid @@ -496,6 +500,7 @@ atom port_count atom port_limit atom port_op atom positive +atom prepare atom print atom priority atom private diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c index 484198b339..2413ccdba9 100644 --- a/erts/emulator/beam/beam_bif_load.c +++ b/erts/emulator/beam/beam_bif_load.c @@ -37,6 +37,20 @@ #include "erl_bits.h" #include "erl_thr_progress.h" +static struct { + Eterm module; + erts_smp_mtx_t mtx; + Export *pending_purge_lambda; + Eterm *sprocs; + Eterm def_sprocs[10]; + Uint sp_size; + Uint sp_ix; + ErlFunEntry **funs; + ErlFunEntry *def_funs[10]; + Uint fe_size; + Uint fe_ix; +} purge_state; + Process *erts_code_purger = NULL; ErtsLiteralArea *erts_copy_literal_area = NULL; @@ -62,6 +76,27 @@ static void delete_code(Module* modp); static int any_heap_ref_ptrs(Eterm* start, Eterm* end, char* mod_start, Uint mod_size); static int any_heap_refs(Eterm* start, Eterm* end, char* mod_start, Uint mod_size); +static void +init_purge_state(void) +{ + purge_state.module = THE_NON_VALUE; + + erts_smp_mtx_init(&purge_state.mtx, "purge_state"); + + purge_state.pending_purge_lambda = + erts_export_put(am_erts_code_purger, am_pending_purge_lambda, 3); + + purge_state.sprocs = &purge_state.def_sprocs[0]; + purge_state.sp_size = sizeof(purge_state.def_sprocs); + purge_state.sp_size /= sizeof(purge_state.def_sprocs[0]); + purge_state.sp_ix = 0; + + purge_state.funs = &purge_state.def_funs[0]; + purge_state.fe_size = sizeof(purge_state.def_funs); + purge_state.fe_size /= sizeof(purge_state.def_funs[0]); + purge_state.fe_ix = 0; +} + void erts_beam_bif_load_init(void) { @@ -70,6 +105,8 @@ erts_beam_bif_load_init(void) release_literal_areas.first = NULL; release_literal_areas.last = NULL; #endif + + init_purge_state(); } BIF_RETTYPE code_is_module_native_1(BIF_ALIST_1) @@ -776,6 +813,8 @@ set_default_trace_pattern(Eterm module) } } +#ifndef ERTS_NEW_PURGE_STRATEGY + static ERTS_INLINE int check_mod_funs(Process *p, ErlOffHeap *off_heap, char *area, size_t area_size) { @@ -790,6 +829,8 @@ check_mod_funs(Process *p, ErlOffHeap *off_heap, char *area, size_t area_size) return 0; } +#endif + static Uint hfrag_literal_size(Eterm* start, Eterm* end, char* lit_start, Uint lit_size); static void hfrag_literal_copy(Eterm **hpp, ErlOffHeap *ohp, @@ -926,7 +967,6 @@ erts_proc_copy_literal_area(Process *c_p, int *redsp, int fcalls, int gc_allowed hfrag = erts_message_to_heap_frag(msgp); for (; hfrag; hfrag = hfrag->next) { Eterm *hp, *hp_end; - ASSERT(!check_mod_funs(c_p, &hfrag->off_heap, mod_start, mod_size)); *redsp += 1; @@ -966,9 +1006,8 @@ check_process_code(Process* rp, Module* modp, Uint flags, int *redsp, int fcalls char* mod_start; Uint mod_size; Eterm* sp; - int done_gc = 0; - ErtsMessage *msgp; - ErlHeapFragment *hfrag; + + *redsp += 1; /* * Pick up limits for the module. @@ -985,6 +1024,8 @@ check_process_code(Process* rp, Module* modp, Uint flags, int *redsp, int fcalls return am_true; } + *redsp += (STACK_START(rp) - rp->stop) / 32; + /* * Check all continuation pointers stored on the stack. */ @@ -1021,82 +1062,7 @@ check_process_code(Process* rp, Module* modp, Uint flags, int *redsp, int fcalls } } - /* - * Message queue can contains funs. - */ - - erts_smp_proc_lock(rp, ERTS_PROC_LOCK_MSGQ); - ERTS_SMP_MSGQ_MV_INQ2PRIVQ(rp); - erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_MSGQ); - - for (msgp = rp->msg.first; msgp; msgp = msgp->next) { - ErlHeapFragment *hf; - if (msgp->data.attached == ERTS_MSG_COMBINED_HFRAG) - hfrag = &msgp->hfrag; - else if (is_value(ERL_MESSAGE_TERM(msgp)) && msgp->data.heap_frag) - hfrag = msgp->data.heap_frag; - else - continue; - - for (hf = hfrag; hf; hf = hf->next) { - if (check_mod_funs(rp, &hfrag->off_heap, mod_start, mod_size)) - return am_true; - } - } - - while (1) { - - /* Check heap, stack etc... */ - if (check_mod_funs(rp, &rp->off_heap, mod_start, mod_size)) - goto try_gc; - -#ifdef DEBUG - /* Check heap fragments */ - for (hfrag = rp->mbuf; hfrag; hfrag = hfrag->next) { - /* Off heap lists should already have been moved into process */ - ASSERT(!check_mod_funs(rp, &hfrag->off_heap, mod_start, mod_size)); - } - - /* - * Message buffer fragments (matched messages) - * - off heap lists should already have been moved into - * process off heap structure. - * - Check for literals - */ - for (msgp = rp->msg_frag; msgp; msgp = msgp->next) { - hfrag = erts_message_to_heap_frag(msgp); - for (; hfrag; hfrag = hfrag->next) { - Eterm *hp, *hp_end; - ASSERT(!check_mod_funs(rp, &hfrag->off_heap, mod_start, mod_size)); - } - } -#endif - - return am_false; - - try_gc: - - if (rp->flags & F_DISABLE_GC) { - /* - * Cannot proceed. Process has disabled gc in order to - * safely leave inconsistent data on the heap and/or - * off heap lists. Need to wait for gc to be enabled - * again. - */ - return THE_NON_VALUE; - } - - if (done_gc) - return am_true; - - if (!(flags & ERTS_CPC_ALLOW_GC)) - return am_aborted; - - FLAGS(rp) |= F_NEED_FULLSWEEP; - *redsp += erts_garbage_collect_nobump(rp, 0, rp->arg_reg, rp->arity, fcalls); - done_gc = 1; - } - + return am_false; } #else /* !ERTS_NEW_PURGE_STRATEGY, i.e, old style purge... */ @@ -1470,12 +1436,11 @@ hfrag_literal_copy(Eterm **hpp, ErlOffHeap *ohp, } } -#undef in_area - #ifdef ERTS_NEW_PURGE_STRATEGY ErtsThrPrgrLaterOp later_literal_area_switch; +#ifdef ERTS_SMP static void complete_literal_area_switch(void *unused) { @@ -1484,6 +1449,7 @@ complete_literal_area_switch(void *unused) erts_resume(p, ERTS_PROC_LOCK_STATUS); erts_smp_proc_unlock(p, ERTS_PROC_LOCK_STATUS); } +#endif #endif /* ERTS_NEW_PURGE_STRATEGY */ @@ -1533,216 +1499,376 @@ BIF_RETTYPE erts_internal_release_literal_area_switch_0(BIF_ALIST_0) #endif /* ERTS_NEW_PURGE_STRATEGY */ } -#ifndef ERTS_NEW_PURGE_STRATEGY +void +erts_purge_state_add_fun(ErlFunEntry *fe) +{ + ASSERT(is_value(purge_state.module)); + if (purge_state.fe_ix >= purge_state.fe_size) { + ErlFunEntry **funs; + purge_state.fe_size += 100; + funs = erts_alloc(ERTS_ALC_T_PURGE_DATA, + sizeof(ErlFunEntry *)*purge_state.fe_size); + sys_memcpy((void *) funs, + (void *) purge_state.funs, + purge_state.fe_ix*sizeof(ErlFunEntry *)); + if (purge_state.funs != &purge_state.def_funs[0]) + erts_free(ERTS_ALC_T_PURGE_DATA, purge_state.funs); + purge_state.funs = funs; + } + purge_state.funs[purge_state.fe_ix++] = fe; +} -#ifdef ERTS_SMP -static void copy_literals_commit(void*); -#endif +Export * +erts_suspend_process_on_pending_purge_lambda(Process *c_p) +{ + erts_smp_mtx_lock(&purge_state.mtx); + if (is_value(purge_state.module)) { + /* + * The process c_p is about to call a fun in the code + * that we are trying to purge. Suspend it and call + * erts_code_purger:pending_purge_lambda/3. The process + * will be resumed when the purge completes or aborts, + * and will then try to do the call again. + */ + if (purge_state.sp_ix >= purge_state.sp_size) { + Eterm *sprocs; + purge_state.sp_size += 100; + sprocs = erts_alloc(ERTS_ALC_T_PURGE_DATA, + (sizeof(ErlFunEntry *) + * purge_state.sp_size)); + sys_memcpy((void *) sprocs, + (void *) purge_state.sprocs, + purge_state.sp_ix*sizeof(ErlFunEntry *)); + if (purge_state.sprocs != &purge_state.def_sprocs[0]) + erts_free(ERTS_ALC_T_PURGE_DATA, purge_state.sprocs); + purge_state.sprocs = sprocs; + } + purge_state.sprocs[purge_state.sp_ix++] = c_p->common.id; + erts_suspend(c_p, ERTS_PROC_LOCK_MAIN, NULL); + ERTS_VBUMP_ALL_REDS(c_p); + } + erts_smp_mtx_unlock(&purge_state.mtx); + return purge_state.pending_purge_lambda; +} -/* copy literals - * - * copy_literals.ptr = LitPtr - * copy_literals.sz = LitSz - * ------ THR PROG COMMIT ----- - * - * - check process code - * - check process code - * ... - * copy_literals.ptr = NULL - * copy_literals.sz = 0 - * ------ THR PROG COMMIT ----- - * ... - */ +static void +finalize_purge_operation(Process *c_p, int succeded) +{ + Uint ix; -#endif + if (c_p) + erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN); -BIF_RETTYPE erts_internal_copy_literals_2(BIF_ALIST_2) -{ -#ifdef ERTS_NEW_PURGE_STRATEGY - BIF_ERROR(BIF_P, EXC_NOTSUP); -#else - ErtsCodeIndex code_ix; - Eterm res = am_true; + erts_smp_mtx_lock(&purge_state.mtx); - if (BIF_P != erts_code_purger) - BIF_ERROR(BIF_P, EXC_NOTSUP); + ASSERT(purge_state.module != THE_NON_VALUE); - if (is_not_atom(BIF_ARG_1) || (am_true != BIF_ARG_2 && am_false != BIF_ARG_2)) { - BIF_ERROR(BIF_P, BADARG); - } + purge_state.module = THE_NON_VALUE; - if (!erts_try_seize_code_write_permission(BIF_P)) { - ERTS_BIF_YIELD2(bif_export[BIF_erts_internal_copy_literals_2], - BIF_P, BIF_ARG_1, BIF_ARG_2); + /* + * Resume all processes that have tried to call + * funs in this code. + */ + for (ix = 0; ix < purge_state.sp_ix; ix++) { + Process *rp = erts_pid2proc(NULL, 0, + purge_state.sprocs[ix], + ERTS_PROC_LOCK_STATUS); + if (rp) { + erts_resume(rp, ERTS_PROC_LOCK_STATUS); + erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_STATUS); + } } - code_ix = erts_active_code_ix(); + erts_smp_mtx_unlock(&purge_state.mtx); - if (BIF_ARG_2 == am_true) { - Module* modp = erts_get_module(BIF_ARG_1, code_ix); - if (!modp || !modp->old.code_hdr) { - res = am_false; - goto done; - } - if (erts_copy_literal_area) { - res = am_aborted; - goto done; - } - erts_copy_literal_area = modp->old.code_hdr->literal_area; - } else if (BIF_ARG_2 == am_false) { - erts_copy_literal_area = NULL; + if (c_p) + erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN); + + if (purge_state.sprocs != &purge_state.def_sprocs[0]) { + erts_free(ERTS_ALC_T_PURGE_DATA, purge_state.sprocs); + purge_state.sprocs = &purge_state.def_sprocs[0]; + purge_state.sp_size = sizeof(purge_state.def_sprocs); + purge_state.sp_size /= sizeof(purge_state.def_sprocs[0]); } + purge_state.sp_ix = 0; -#ifdef ERTS_SMP - ASSERT(committer_state.stager == NULL); - committer_state.stager = BIF_P; - erts_schedule_thr_prgr_later_op(copy_literals_commit, NULL, &committer_state.lop); - erts_proc_inc_refc(BIF_P); - erts_suspend(BIF_P, ERTS_PROC_LOCK_MAIN, NULL); - ERTS_BIF_YIELD_RETURN(BIF_P, am_true); -#endif -done: - erts_release_code_write_permission(); - BIF_RET(res); -#endif + if (purge_state.funs != &purge_state.def_funs[0]) { + erts_free(ERTS_ALC_T_PURGE_DATA, purge_state.funs); + purge_state.funs = &purge_state.def_funs[0]; + purge_state.fe_size = sizeof(purge_state.def_funs); + purge_state.fe_size /= sizeof(purge_state.def_funs[0]); + } + purge_state.fe_ix = 0; } -#ifndef ERTS_NEW_PURGE_STRATEGY - #ifdef ERTS_SMP -static void copy_literals_commit(void* null) { - Process* p = committer_state.stager; -#ifdef DEBUG - committer_state.stager = NULL; -#endif - erts_release_code_write_permission(); + +static ErtsThrPrgrLaterOp purger_lop_data; + +static void +resume_purger(void *unused) +{ + Process *p = erts_code_purger; erts_smp_proc_lock(p, ERTS_PROC_LOCK_STATUS); - if (!ERTS_PROC_IS_EXITING(p)) { - erts_resume(p, ERTS_PROC_LOCK_STATUS); - } + erts_resume(p, ERTS_PROC_LOCK_STATUS); erts_smp_proc_unlock(p, ERTS_PROC_LOCK_STATUS); - erts_proc_dec_refc(p); } -#endif /* ERTS_SMP */ -#endif +static void +finalize_purge_abort(void *unused) +{ + erts_fun_purge_abort_finalize(purge_state.funs, purge_state.fe_ix); -/* Do the actualy module purging and return: - * true for success - * false if no such old module - * BADARG if not an atom - */ -BIF_RETTYPE erts_internal_purge_module_1(BIF_ALIST_1) + finalize_purge_operation(NULL, 0); + + resume_purger(NULL); +} + +#endif /* ERTS_SMP */ + +BIF_RETTYPE erts_internal_purge_module_2(BIF_ALIST_2) { - ErtsCodeIndex code_ix; - BeamInstr* code; - BeamInstr* end; - Module* modp; - int is_blocking = 0; - Eterm ret; - ErtsLiteralArea *literals = NULL; + if (BIF_P != erts_code_purger) + BIF_ERROR(BIF_P, EXC_NOTSUP); - if (is_not_atom(BIF_ARG_1)) { + if (is_not_atom(BIF_ARG_1)) BIF_ERROR(BIF_P, BADARG); - } - if (!erts_try_seize_code_write_permission(BIF_P)) { - ERTS_BIF_YIELD1(bif_export[BIF_erts_internal_purge_module_1], - BIF_P, BIF_ARG_1); - } + switch (BIF_ARG_2) { - code_ix = erts_active_code_ix(); + case am_prepare: { + /* + * Prepare for purge by marking all fun + * entries referring to the code to purge + * with "pending purge" markers. + */ + ErtsCodeIndex code_ix; + Module* modp; + Eterm res; - /* - * Correct module? - */ + if (is_value(purge_state.module)) + BIF_ERROR(BIF_P, BADARG); - if ((modp = erts_get_module(BIF_ARG_1, code_ix)) == NULL) { - ERTS_BIF_PREP_RET(ret, am_false); - } - else { - erts_rwlock_old_code(code_ix); + code_ix = erts_active_code_ix(); /* - * Any code to purge? + * Correct module? */ - if (!modp->old.code_hdr) { - ERTS_BIF_PREP_RET(ret, am_false); - } + modp = erts_get_module(BIF_ARG_1, code_ix); + if (!modp) + res = am_false; else { /* - * Unload any NIF library + * Any code to purge? */ - if (modp->old.nif != NULL) { - /* ToDo: Do unload nif without blocking */ - erts_rwunlock_old_code(code_ix); - erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN); - erts_smp_thr_progress_block(); - is_blocking = 1; - erts_rwlock_old_code(code_ix); - erts_unload_nif(modp->old.nif); - modp->old.nif = NULL; + erts_rlock_old_code(code_ix); + if (!modp->old.code_hdr) + res = am_false; + else { + BeamInstr* code; + BeamInstr* end; + erts_smp_mtx_lock(&purge_state.mtx); + purge_state.module = BIF_ARG_1; + erts_smp_mtx_unlock(&purge_state.mtx); + res = am_true; + code = (BeamInstr*) modp->old.code_hdr; + end = (BeamInstr *)((char *)code + modp->old.code_length); + erts_fun_purge_prepare(code, end); +#if !defined(ERTS_NEW_PURGE_STRATEGY) + ASSERT(!erts_copy_literal_area); + erts_copy_literal_area = modp->old.code_hdr->literal_area; +#endif } - + erts_runlock_old_code(code_ix); + } + +#ifndef ERTS_SMP + BIF_RET(res); +#else + if (res != am_true) + BIF_RET(res); + else { /* - * Remove the old code. + * We'll be resumed when all schedulers are guaranteed + * to see the "pending purge" markers that we've made on + * all fun entries of the code that we are about to purge. + * Processes trying to call these funs will be suspended + * before calling the funs. That is we are guaranteed not + * to get any more direct references into the code while + * checking for such references... */ - ASSERT(erts_total_code_size >= modp->old.code_length); - erts_total_code_size -= modp->old.code_length; - code = (BeamInstr*) modp->old.code_hdr; - end = (BeamInstr *)((char *)code + modp->old.code_length); - erts_cleanup_funs_on_purge(code, end); - beam_catches_delmod(modp->old.catches, code, modp->old.code_length, - code_ix); - literals = modp->old.code_hdr->literal_area; - modp->old.code_hdr->literal_area = NULL; - erts_free(ERTS_ALC_T_CODE, (void *) code); - modp->old.code_hdr = NULL; - modp->old.code_length = 0; - modp->old.catches = BEAM_CATCHES_NIL; - erts_remove_from_ranges(code); - ERTS_BIF_PREP_RET(ret, am_true); + erts_schedule_thr_prgr_later_op(resume_purger, + NULL, + &purger_lop_data); + erts_suspend(BIF_P, ERTS_PROC_LOCK_MAIN, NULL); + ERTS_BIF_YIELD_RETURN(BIF_P, am_true); } - erts_rwunlock_old_code(code_ix); +#endif } - if (is_blocking) { - erts_smp_thr_progress_unblock(); - erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN); + + case am_abort: { + /* + * Soft purge that detected direct references into the code + * we set out to purge. Abort the purge. + */ + + if (purge_state.module != BIF_ARG_1) + BIF_ERROR(BIF_P, BADARG); + + erts_fun_purge_abort_prepare(purge_state.funs, purge_state.fe_ix); + +#if !defined(ERTS_NEW_PURGE_STRATEGY) + ASSERT(erts_copy_literal_area); + erts_copy_literal_area = NULL; +#endif +#ifndef ERTS_SMP + erts_fun_purge_abort_finalize(purge_state.funs, purge_state.fe_ix); + finalize_purge_operation(BIF_P, 0); + BIF_RET(am_false); +#else + /* + * We need to restore the code addresses of the funs in + * two stages in order to ensure that we do not get any + * stale suspended processes due to the purge abort. + * Restore address pointer (erts_fun_purge_abort_prepare); + * wait for thread progress; clear pending purge address + * pointer (erts_fun_purge_abort_finalize), and then + * resume processes that got suspended + * (finalize_purge_operation). + */ + erts_schedule_thr_prgr_later_op(finalize_purge_abort, + NULL, + &purger_lop_data); + erts_suspend(BIF_P, ERTS_PROC_LOCK_MAIN, NULL); + ERTS_BIF_YIELD_RETURN(BIF_P, am_false); +#endif } - erts_release_code_write_permission(); -#ifdef ERTS_NEW_PURGE_STRATEGY + case am_complete: { + ErtsCodeIndex code_ix; + BeamInstr* code; + Module* modp; + int is_blocking = 0; + Eterm ret; + ErtsLiteralArea *literals = NULL; - if (literals) { - ErtsLiteralAreaRef *ref; - ref = erts_alloc(ERTS_ALC_T_LITERAL_REF, - sizeof(ErtsLiteralAreaRef)); - ref->literal_area = literals; - ref->next = NULL; - erts_smp_mtx_lock(&release_literal_areas.mtx); - if (release_literal_areas.last) { - release_literal_areas.last->next = ref; - release_literal_areas.last = ref; + + /* + * We have no direct references into the code. + * Complete to purge. + */ + + if (purge_state.module != BIF_ARG_1) + BIF_ERROR(BIF_P, BADARG); + + if (!erts_try_seize_code_write_permission(BIF_P)) { + ERTS_BIF_YIELD2(bif_export[BIF_erts_internal_purge_module_2], + BIF_P, BIF_ARG_1, BIF_ARG_2); + } + + code_ix = erts_active_code_ix(); + + /* + * Correct module? + */ + + if ((modp = erts_get_module(BIF_ARG_1, code_ix)) == NULL) { + ERTS_BIF_PREP_RET(ret, am_false); } else { - release_literal_areas.first = ref; - release_literal_areas.last = ref; + + erts_rwlock_old_code(code_ix); + + /* + * Any code to purge? + */ + if (!modp->old.code_hdr) { + ERTS_BIF_PREP_RET(ret, am_false); + } + else { + /* + * Unload any NIF library + */ + if (modp->old.nif != NULL) { + /* ToDo: Do unload nif without blocking */ + erts_rwunlock_old_code(code_ix); + erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN); + erts_smp_thr_progress_block(); + is_blocking = 1; + erts_rwlock_old_code(code_ix); + erts_unload_nif(modp->old.nif); + modp->old.nif = NULL; + } + + /* + * Remove the old code. + */ + ASSERT(erts_total_code_size >= modp->old.code_length); + erts_total_code_size -= modp->old.code_length; + code = (BeamInstr*) modp->old.code_hdr; + erts_fun_purge_complete(purge_state.funs, purge_state.fe_ix); + beam_catches_delmod(modp->old.catches, code, modp->old.code_length, + code_ix); + literals = modp->old.code_hdr->literal_area; + modp->old.code_hdr->literal_area = NULL; + erts_free(ERTS_ALC_T_CODE, (void *) code); + modp->old.code_hdr = NULL; + modp->old.code_length = 0; + modp->old.catches = BEAM_CATCHES_NIL; + erts_remove_from_ranges(code); + ERTS_BIF_PREP_RET(ret, am_true); + } + erts_rwunlock_old_code(code_ix); } - erts_smp_mtx_unlock(&release_literal_areas.mtx); - erts_queue_message(erts_literal_area_collector, - 0, - erts_alloc_message(0, NULL), - am_copy_literals, - BIF_P->common.id); - } + if (is_blocking) { + erts_smp_thr_progress_unblock(); + erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN); + } + + erts_release_code_write_permission(); -#else /* !ERTS_NEW_PURGE_STRATEGY */ + finalize_purge_operation(BIF_P, ret == am_true); - erts_release_literal_area(literals); +#if !defined(ERTS_NEW_PURGE_STRATEGY) -#endif + ASSERT(erts_copy_literal_area == literals); + erts_copy_literal_area = NULL; + erts_release_literal_area(literals); + +#else /* ERTS_NEW_PURGE_STRATEGY */ + + if (literals) { + ErtsLiteralAreaRef *ref; + ref = erts_alloc(ERTS_ALC_T_LITERAL_REF, + sizeof(ErtsLiteralAreaRef)); + ref->literal_area = literals; + ref->next = NULL; + erts_smp_mtx_lock(&release_literal_areas.mtx); + if (release_literal_areas.last) { + release_literal_areas.last->next = ref; + release_literal_areas.last = ref; + } + else { + release_literal_areas.first = ref; + release_literal_areas.last = ref; + } + erts_smp_mtx_unlock(&release_literal_areas.mtx); + erts_queue_message(erts_literal_area_collector, + 0, + erts_alloc_message(0, NULL), + am_copy_literals, + BIF_P->common.id); + } - return ret; +#endif /* ERTS_NEW_PURGE_STRATEGY */ + + return ret; + } + + default: + BIF_ERROR(BIF_P, BADARG); + + } } /* diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c index c6258287c4..bc7c9165fd 100644 --- a/erts/emulator/beam/beam_emu.c +++ b/erts/emulator/beam/beam_emu.c @@ -6535,34 +6535,49 @@ call_fun(Process* p, /* Current process. */ * representation (the module has never been loaded), * or the module defining the fun has been unloaded. */ + module = fe->module; - if ((modp = erts_get_module(module, code_ix)) != NULL - && modp->curr.code_hdr != NULL) { + + ERTS_SMP_READ_MEMORY_BARRIER; + if (fe->pend_purge_address) { /* - * There is a module loaded, but obviously the fun is not - * defined in it. We must not call the error_handler - * (or we will get into an infinite loop). + * The system is currently trying to purge the + * module containing this fun. Suspend the process + * and let it try again when the purge operation is + * done (may succeed or not). */ - goto badfun; + ep = erts_suspend_process_on_pending_purge_lambda(p); + ASSERT(ep); } + else { + if ((modp = erts_get_module(module, code_ix)) != NULL + && modp->curr.code_hdr != NULL) { + /* + * There is a module loaded, but obviously the fun is not + * defined in it. We must not call the error_handler + * (or we will get into an infinite loop). + */ + goto badfun; + } - /* - * No current code for this module. Call the error_handler module - * to attempt loading the module. - */ + /* + * No current code for this module. Call the error_handler module + * to attempt loading the module. + */ - ep = erts_find_function(erts_proc_get_error_handler(p), - am_undefined_lambda, 3, code_ix); - if (ep == NULL) { /* No error handler */ - p->current = NULL; - p->freason = EXC_UNDEF; - return NULL; + ep = erts_find_function(erts_proc_get_error_handler(p), + am_undefined_lambda, 3, code_ix); + if (ep == NULL) { /* No error handler */ + p->current = NULL; + p->freason = EXC_UNDEF; + return NULL; + } } reg[0] = module; reg[1] = fun; reg[2] = args; reg[3] = NIL; - return ep->addressv[erts_active_code_ix()]; + return ep->addressv[code_ix]; } } } else if (is_export_header(hdr)) { diff --git a/erts/emulator/beam/beam_load.h b/erts/emulator/beam/beam_load.h index d52f12e6d0..1200bb9c6f 100644 --- a/erts/emulator/beam/beam_load.h +++ b/erts/emulator/beam/beam_load.h @@ -121,8 +121,10 @@ typedef struct beam_code_header { void erts_release_literal_area(struct ErtsLiteralArea_* literal_area); int erts_is_module_native(BeamCodeHeader* code); - void erts_beam_bif_load_init(void); +struct erl_fun_entry; +void erts_purge_state_add_fun(struct erl_fun_entry *fe); +Export *erts_suspend_process_on_pending_purge_lambda(Process *c_p); /* * Layout of the line table. diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab index 7ffcb26567..90ac5e9ed8 100644 --- a/erts/emulator/beam/bif.tab +++ b/erts/emulator/beam/bif.tab @@ -644,8 +644,7 @@ bif erts_debug:map_info/1 # New in 19.0 # -bif erts_internal:copy_literals/2 -bif erts_internal:purge_module/1 +bif erts_internal:purge_module/2 bif binary:split/2 bif binary:split/3 bif erts_debug:size_shared/1 diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types index 0a4a34a174..1b72a0cb59 100644 --- a/erts/emulator/beam/erl_alloc.types +++ b/erts/emulator/beam/erl_alloc.types @@ -368,6 +368,7 @@ type NLINK_LH STANDARD PROCESSES nlink_lh type CODE LONG_LIVED CODE code type LITERAL LITERAL CODE literal type LITERAL_REF SHORT_LIVED CODE literal_area_ref +type PURGE_DATA SHORT_LIVED CODE purge_data type DB_HEIR_DATA STANDARD ETS db_heir_data type DB_MS_PSDO_PROC LONG_LIVED ETS db_match_pseudo_proc type SCHDLR_DATA LONG_LIVED SYSTEM scheduler_data diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c index 3fb866733c..ef3fa07664 100644 --- a/erts/emulator/beam/erl_bif_info.c +++ b/erts/emulator/beam/erl_bif_info.c @@ -2886,6 +2886,27 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1) BIF_RET(AM_tag); #endif } + else if (ERTS_IS_ATOM_STR("check_process_code",BIF_ARG_1)) { + Eterm terms[3]; + Sint length = 1; + Uint sz = 0; + Eterm *hp, res; + DECL_AM(direct_references); + + terms[0] = AM_direct_references; +#if !defined(ERTS_NEW_PURGE_STRATEGY) + { + DECL_AM(indirect_references); + terms[1] = AM_indirect_references; + terms[2] = am_copy_literals; + length = 3; + } +#endif + erts_bld_list(NULL, &sz, length, terms); + hp = HAlloc(BIF_P, sz); + res = erts_bld_list(&hp, NULL, length, terms); + BIF_RET(res); + } BIF_ERROR(BIF_P, BADARG); } diff --git a/erts/emulator/beam/erl_fun.c b/erts/emulator/beam/erl_fun.c index 6ce1376c81..c639ba623f 100644 --- a/erts/emulator/beam/erl_fun.c +++ b/erts/emulator/beam/erl_fun.c @@ -199,14 +199,13 @@ erts_erase_fun_entry(ErlFunEntry* fe) } void -erts_cleanup_funs_on_purge(BeamInstr* start, BeamInstr* end) +erts_fun_purge_prepare(BeamInstr* start, BeamInstr* end) { int limit; HashBucket** bucket; - ErlFunEntry* to_delete = NULL; int i; - erts_fun_write_lock(); + erts_fun_read_lock(); limit = erts_fun_table.size; bucket = erts_fun_table.bucket; for (i = 0; i < limit; i++) { @@ -217,22 +216,51 @@ erts_cleanup_funs_on_purge(BeamInstr* start, BeamInstr* end) BeamInstr* addr = fe->address; if (start <= addr && addr < end) { + fe->pend_purge_address = addr; + ERTS_SMP_WRITE_MEMORY_BARRIER; fe->address = unloaded_fun; - if (erts_refc_dectest(&fe->refc, 0) == 0) { - fe->address = (void *) to_delete; - to_delete = fe; - } + erts_purge_state_add_fun(fe); } b = b->next; } } + erts_fun_read_unlock(); +} + +void +erts_fun_purge_abort_prepare(ErlFunEntry **funs, Uint no) +{ + Uint ix; - while (to_delete != NULL) { - ErlFunEntry* next = (ErlFunEntry *) to_delete->address; - erts_erase_fun_entry_unlocked(to_delete); - to_delete = next; + for (ix = 0; ix < no; ix++) { + ErlFunEntry *fe = funs[ix]; + if (fe->address == unloaded_fun) + fe->address = fe->pend_purge_address; + fe->pend_purge_address = NULL; } - erts_fun_write_unlock(); +} + +void +erts_fun_purge_abort_finalize(ErlFunEntry **funs, Uint no) +{ + Uint ix; + + for (ix = 0; ix < no; ix++) + funs[ix]->pend_purge_address = NULL; +} + +void +erts_fun_purge_complete(ErlFunEntry **funs, Uint no) +{ + Uint ix; + + for (ix = 0; ix < no; ix++) { + ErlFunEntry *fe = funs[ix]; + fe->pend_purge_address = NULL; + if (erts_refc_dectest(&fe->refc, 0) == 0) + erts_erase_fun_entry(fe); + } + ERTS_SMP_WRITE_MEMORY_BARRIER; } void @@ -294,6 +322,7 @@ fun_alloc(ErlFunEntry* template) obj->module = template->module; erts_refc_init(&obj->refc, -1); obj->address = unloaded_fun; + obj->pend_purge_address = NULL; #ifdef HIPE obj->native_address = NULL; #endif diff --git a/erts/emulator/beam/erl_fun.h b/erts/emulator/beam/erl_fun.h index 8c4deea7a0..73c3e19c1c 100644 --- a/erts/emulator/beam/erl_fun.h +++ b/erts/emulator/beam/erl_fun.h @@ -44,6 +44,7 @@ typedef struct erl_fun_entry { Eterm module; /* Tagged atom for module. */ erts_refc_t refc; /* Reference count: One for code + one for each fun object in each process. */ + BeamInstr *pend_purge_address; /* address stored during a pending purge */ } ErlFunEntry; /* @@ -81,7 +82,10 @@ ErlFunEntry* erts_put_fun_entry2(Eterm mod, int old_uniq, int old_index, void erts_erase_fun_entry(ErlFunEntry* fe); void erts_cleanup_funs(ErlFunThing* funp); -void erts_cleanup_funs_on_purge(BeamInstr* start, BeamInstr* end); +void erts_fun_purge_prepare(BeamInstr* start, BeamInstr* end); +void erts_fun_purge_abort_prepare(ErlFunEntry **funs, Uint no); +void erts_fun_purge_abort_finalize(ErlFunEntry **funs, Uint no); +void erts_fun_purge_complete(ErlFunEntry **funs, Uint no); void erts_dump_fun_entries(int, void *); #endif diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c index 788dbc3328..a1b0a398da 100644 --- a/erts/emulator/beam/erl_init.c +++ b/erts/emulator/beam/erl_init.c @@ -2260,14 +2260,19 @@ erl_start(int argc, char **argv) Eterm pid; pid = erl_system_process_otp(otp_ring0_pid, "erts_code_purger"); - erts_code_purger = erts_proc_lookup(pid); - ASSERT(erts_code_purger); + erts_code_purger + = (Process *) erts_ptab_pix2intptr_ddrb(&erts_proc, + internal_pid_index(pid)); + ASSERT(erts_code_purger && erts_code_purger->common.id == pid); erts_proc_inc_refc(erts_code_purger); #ifdef ERTS_NEW_PURGE_STRATEGY pid = erl_system_process_otp(otp_ring0_pid, "erts_literal_area_collector"); - erts_literal_area_collector = erts_proc_lookup(pid); - ASSERT(erts_literal_area_collector); + erts_literal_area_collector + = (Process *) erts_ptab_pix2intptr_ddrb(&erts_proc, + internal_pid_index(pid)); + ASSERT(erts_literal_area_collector + && erts_literal_area_collector->common.id == pid); erts_proc_inc_refc(erts_literal_area_collector); #endif diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c index 4192cf389f..06266363b5 100644 --- a/erts/emulator/beam/erl_lock_check.c +++ b/erts/emulator/beam/erl_lock_check.c @@ -96,6 +96,7 @@ static erts_lc_lock_order_t erts_lock_order[] = { { "dist_entry", "address" }, { "dist_entry_links", "address" }, { "code_write_permission", NULL }, + { "purge_state", NULL }, { "proc_status", "pid" }, { "proc_trace", "pid" }, { "ports_snapshot", NULL }, diff --git a/erts/emulator/test/code_SUITE.erl b/erts/emulator/test/code_SUITE.erl index 2347a3d4ef..34515efa3d 100644 --- a/erts/emulator/test/code_SUITE.erl +++ b/erts/emulator/test/code_SUITE.erl @@ -20,7 +20,8 @@ -module(code_SUITE). -export([all/0, suite/0, init_per_suite/1, end_per_suite/1, - versions/1,new_binary_types/1, + versions/1,new_binary_types/1, call_purged_fun_code_gone/1, + call_purged_fun_code_reload/1, call_purged_fun_code_there/1, t_check_process_code/1,t_check_old_code/1, t_check_process_code_ets/1, external_fun/1,get_chunk/1,module_md5/1,make_stub/1, @@ -34,7 +35,8 @@ suite() -> [{ct_hooks,[ts_install_cth]}]. all() -> - [versions, new_binary_types, t_check_process_code, + [versions, new_binary_types, call_purged_fun_code_gone, + call_purged_fun_code_reload, call_purged_fun_code_there, t_check_process_code, t_check_process_code_ets, t_check_old_code, external_fun, get_chunk, module_md5, make_stub, make_stub_many_funs, constant_pools, constant_refc_binaries, false_dependency, @@ -127,12 +129,169 @@ new_binary_types(Config) when is_list(Config) -> bit_sized_binary(Bin))), ok. +call_purged_fun_code_gone(Config) when is_list(Config) -> + Priv = proplists:get_value(priv_dir, Config), + Data = proplists:get_value(data_dir, Config), + call_purged_fun_test(Priv, Data, code_gone), + ok. + +call_purged_fun_code_reload(Config) when is_list(Config) -> + Priv = proplists:get_value(priv_dir, Config), + Data = proplists:get_value(data_dir, Config), + Path = code:get_path(), + true = code:add_path(Priv), + try + call_purged_fun_test(Priv, Data, code_reload) + after + code:set_path(Path) + end, + ok. + +call_purged_fun_code_there(Config) when is_list(Config) -> + Priv = proplists:get_value(priv_dir, Config), + Data = proplists:get_value(data_dir, Config), + call_purged_fun_test(Priv, Data, code_there), + ok. + +call_purged_fun_test(Priv, Data, Type) -> + File = filename:join(Data, "my_code_test2"), + Code = filename:join(Priv, "my_code_test2"), + + catch erlang:purge_module(my_code_test2), + catch erlang:delete_module(my_code_test2), + catch erlang:purge_module(my_code_test2), + + {ok,my_code_test2} = c:c(File, [{outdir,Priv}]), + + T = ets:new(my_code_test2_fun_table, []), + ets:insert(T, {my_fun,my_code_test2:make_fun(4711)}), + ets:insert(T, {my_fun2,my_code_test2:make_fun2()}), + + spawn(fun () -> + [{my_fun2,F2}] = ets:lookup(T, my_fun2), + F2(fun () -> + receive after infinity -> ok end + end, + fun () -> ok end), + exit(completed) + end), + + PurgeType = case Type of + code_gone -> + ok = file:delete(Code++".beam"), + true; + code_reload -> + true; + code_there -> + false + end, + + true = erlang:delete_module(my_code_test2), + + Purge = start_purge(my_code_test2, PurgeType), + + {P0, M0} = spawn_monitor(fun () -> + [{my_fun,F}] = ets:lookup(T, my_fun), + 4712 = F(1), + exit(completed) + end), + + wait_until(fun () -> + {status, suspended} + == process_info(P0, status) + end), + + ok = continue_purge(Purge), + + {P1, M1} = spawn_monitor(fun () -> + [{my_fun,F}] = ets:lookup(T, my_fun), + 4713 = F(2), + exit(completed) + end), + {P2, M2} = spawn_monitor(fun () -> + [{my_fun,F}] = ets:lookup(T, my_fun), + 4714 = F(3), + exit(completed) + end), + + wait_until(fun () -> + {status, suspended} + == process_info(P1, status) + end), + wait_until(fun () -> + {status, suspended} + == process_info(P2, status) + end), + + {current_function, + {erts_code_purger, + pending_purge_lambda, + 3}} = process_info(P0, current_function), + {current_function, + {erts_code_purger, + pending_purge_lambda, + 3}} = process_info(P1, current_function), + {current_function, + {erts_code_purger, + pending_purge_lambda, + 3}} = process_info(P2, current_function), + + case Type of + code_there -> + false = complete_purge(Purge); + _ -> + {true, true} = complete_purge(Purge) + end, + + case Type of + code_gone -> + receive + {'DOWN', M0, process, P0, Reason0} -> + {undef, _} = Reason0 + end, + receive + {'DOWN', M1, process, P1, Reason1} -> + {undef, _} = Reason1 + end, + receive + {'DOWN', M2, process, P2, Reason2} -> + {undef, _} = Reason2 + end; + _ -> + receive + {'DOWN', M0, process, P0, Reason0} -> + completed = Reason0 + end, + receive + {'DOWN', M1, process, P1, Reason1} -> + completed = Reason1 + end, + receive + {'DOWN', M2, process, P2, Reason2} -> + completed = Reason2 + end, + catch erlang:purge_module(my_code_test2), + catch erlang:delete_module(my_code_test2), + catch erlang:purge_module(my_code_test2) + end, + ok. + t_check_process_code(Config) when is_list(Config) -> + case check_process_code_handle(indirect_references) of + false -> {skipped, "check_process_code() ignores funs"}; + true -> t_check_process_code_test(Config) + end. + +t_check_process_code_test(Config) -> Priv = proplists:get_value(priv_dir, Config), Data = proplists:get_value(data_dir, Config), File = filename:join(Data, "my_code_test"), Code = filename:join(Priv, "my_code_test"), + catch erlang:purge_module(my_code_test), + catch erlang:delete_module(my_code_test), + catch erlang:purge_module(my_code_test), + {ok,my_code_test} = c:c(File, [{outdir,Priv}]), MyFun = fun(X, Y) -> X + Y end, %Confuse things. @@ -231,11 +390,16 @@ gc1() -> ok. %% Test check_process_code/2 in combination with a fun obtained from an ets table. t_check_process_code_ets(Config) when is_list(Config) -> - case test_server:is_native(?MODULE) of - true -> - {skip,"Native code"}; - false -> - do_check_process_code_ets(Config) + case check_process_code_handle(indirect_references) of + false -> + {skipped, "check_process_code() ignores funs"}; + true -> + case test_server:is_native(?MODULE) of + true -> + {skip,"Native code"}; + false -> + do_check_process_code_ets(Config) + end end. do_check_process_code_ets(Config) -> @@ -243,8 +407,9 @@ do_check_process_code_ets(Config) -> Data = proplists:get_value(data_dir, Config), File = filename:join(Data, "my_code_test"), - erlang:purge_module(my_code_test), - erlang:delete_module(my_code_test), + catch erlang:purge_module(my_code_test), + catch erlang:delete_module(my_code_test), + catch erlang:purge_module(my_code_test), {ok,my_code_test} = c:c(File, [{outdir,Priv}]), T = ets:new(my_code_test, []), @@ -295,8 +460,8 @@ t_check_old_code(Config) when is_list(Config) -> Data = proplists:get_value(data_dir, Config), File = filename:join(Data, "my_code_test"), - erlang:purge_module(my_code_test), - erlang:delete_module(my_code_test), + catch erlang:purge_module(my_code_test), + catch erlang:delete_module(my_code_test), catch erlang:purge_module(my_code_test), false = erlang:check_old_code(my_code_test), @@ -971,3 +1136,39 @@ flush() -> receive _ -> flush() after 0 -> ok end. id(I) -> I. + +check_process_code_handle(What) -> + lists:member(What, erlang:system_info(check_process_code)). + +wait_until(Fun) -> + case Fun() of + true -> + ok; + false -> + receive after 100 -> ok end, + wait_until(Fun) + end. + +start_purge(Mod, Type) when is_atom(Mod) + andalso ((Type == true) + orelse (Type == false)) -> + Ref = make_ref(), + erts_code_purger ! {test_purge, Mod, self(), Type, Ref}, + receive + {started, Ref} -> + Ref + end. + +continue_purge(Ref) when is_reference(Ref) -> + erts_code_purger ! {continue, Ref}, + receive + {continued, Ref} -> + ok + end. + +complete_purge(Ref) when is_reference(Ref) -> + erts_code_purger ! {complete, Ref}, + receive + {test_purge, Res, Ref} -> + Res + end. diff --git a/erts/emulator/test/code_SUITE_data/my_code_test.erl b/erts/emulator/test/code_SUITE_data/my_code_test.erl index d2386157d6..9d12aa9897 100644 --- a/erts/emulator/test/code_SUITE_data/my_code_test.erl +++ b/erts/emulator/test/code_SUITE_data/my_code_test.erl @@ -24,5 +24,3 @@ make_fun(A) -> fun(X) -> A + X end. - - diff --git a/erts/emulator/test/code_SUITE_data/my_code_test2.erl b/erts/emulator/test/code_SUITE_data/my_code_test2.erl new file mode 100644 index 0000000000..57973535d4 --- /dev/null +++ b/erts/emulator/test/code_SUITE_data/my_code_test2.erl @@ -0,0 +1,32 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1999-2016. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% + +-module(my_code_test2). + +-export([make_fun/1, make_fun2/0]). + +make_fun(A) -> + fun(X) -> A + X end. + +make_fun2() -> + fun (F1,F2) -> + F1(), + F2() + end. diff --git a/erts/preloaded/ebin/erts_code_purger.beam b/erts/preloaded/ebin/erts_code_purger.beam Binary files differindex 9133fd9853..a1eb126098 100644 --- a/erts/preloaded/ebin/erts_code_purger.beam +++ b/erts/preloaded/ebin/erts_code_purger.beam diff --git a/erts/preloaded/ebin/erts_internal.beam b/erts/preloaded/ebin/erts_internal.beam Binary files differindex 3349d05385..8d4ca152de 100644 --- a/erts/preloaded/ebin/erts_internal.beam +++ b/erts/preloaded/ebin/erts_internal.beam diff --git a/erts/preloaded/ebin/init.beam b/erts/preloaded/ebin/init.beam Binary files differindex b856bff4fe..acff82fd98 100644 --- a/erts/preloaded/ebin/init.beam +++ b/erts/preloaded/ebin/init.beam diff --git a/erts/preloaded/src/erts_code_purger.erl b/erts/preloaded/src/erts_code_purger.erl index f9208624b7..ee4fcedd2d 100644 --- a/erts/preloaded/src/erts_code_purger.erl +++ b/erts/preloaded/src/erts_code_purger.erl @@ -22,42 +22,13 @@ %% Purpose : Implement system process erts_code_purger %% to handle code module purging. --export([start/0, purge/1, soft_purge/1]). +-export([start/0, purge/1, soft_purge/1, pending_purge_lambda/3]). -spec start() -> term(). start() -> register(erts_code_purger, self()), process_flag(trap_exit, true), - try - %% Pass bad arguments to copy_literals() in - %% order to determine purge strategy used - %% by the VM... - Res = erts_internal:copy_literals(4711, badarg), - exit({copy_literals_returned, Res}) - catch - error : badarg -> %% VM use old purge strategy - old_loop(); - error : notsup -> %% VM use new purge strategy - loop(); - Type : Reason -> - %% This should not be possible... - exit({"Unexpected copy_literals() behaviour", - {Type, Reason}}) - end. - -old_loop() -> - _ = receive - {purge,Mod,From,Ref} when is_atom(Mod), is_pid(From) -> - Res = do_old_purge(Mod), - From ! {reply, purge, Res, Ref}; - - {soft_purge,Mod,From,Ref} when is_atom(Mod), is_pid(From) -> - Res = do_old_soft_purge(Mod), - From ! {reply, soft_purge, Res, Ref}; - - _Other -> ignore - end, - old_loop(). + loop(). loop() -> _ = receive @@ -69,10 +40,43 @@ loop() -> Res = do_soft_purge(Mod), From ! {reply, soft_purge, Res, Ref}; + {test_purge, Mod, From, Type, Ref} when is_atom(Mod), is_pid(From) -> + do_test_purge(Mod, From, Type, Ref); + _Other -> ignore end, loop(). +%% +%% Processes that tries to call a fun that belongs to +%% a module that currently is being purged will end +%% up here (pending_purge_lambda) in a suspended state. +%% When the purge operation completes or aborts (soft +%% purge that failed) these processes will be resumed. +%% +pending_purge_lambda(_Module, Fun, Args) -> + %% + %% When the process is resumed, the following + %% scenarios exist: + %% * The code that the fun refers to is still + %% there due to a failed soft purge. The + %% call to the fun will succeed via apply/2. + %% * The code was purged, and a current version + %% of the module is loaded which does not + %% contain this fun. The call will result + %% in an exception being raised. + %% * The code was purged, and no current + %% version of the module is loaded. An attempt + %% to load the module (via the error_handler) + %% will be made. This may or may not succeed. + %% If the module is loaded, it may or may + %% not contain the fun. The call will + %% succeed if the error_handler was able + %% to load the module and loaded module + %% contains this fun; otherwise, an exception + %% will be raised. + %% + apply(Fun, Args). %% purge(Module) %% Kill all processes running code from *old* Module, and then purge the @@ -89,22 +93,15 @@ purge(Mod) when is_atom(Mod) -> Result end. - -do_old_purge(Mod) -> - case erts_internal:copy_literals(Mod, true) of - false -> - {false, false}; - true -> - DidKill = check_proc_code(erlang:processes(), Mod, true), - true = erts_internal:copy_literals(Mod, false), - WasPurged = erts_internal:purge_module(Mod), - {WasPurged, DidKill} - end. - do_purge(Mod) -> - DidKill = check_proc_code(erlang:processes(), Mod, true), - WasPurged = erts_internal:purge_module(Mod), - {WasPurged, DidKill}. + case erts_internal:purge_module(Mod, prepare) of + false -> + {false, false}; + true -> + DidKill = check_proc_code(erlang:processes(), Mod, true), + true = erts_internal:purge_module(Mod, complete), + {true, DidKill} + end. %% soft_purge(Module) %% Purge old code only if no procs remain that run old code. @@ -119,27 +116,17 @@ soft_purge(Mod) -> Result end. - -do_old_soft_purge(Mod) -> - case erts_internal:copy_literals(Mod, true) of +do_soft_purge(Mod) -> + case erts_internal:purge_module(Mod, prepare) of false -> true; true -> - DoPurge = check_proc_code(erlang:processes(), Mod, false), - true = erts_internal:copy_literals(Mod, false), - case DoPurge of - false -> - false; - true -> - erts_internal:purge_module(Mod), - true - end - end. - -do_soft_purge(Mod) -> - case check_proc_code(erlang:processes(), Mod, false) of - false -> false; - true -> erts_internal:purge_module(Mod) + Res = check_proc_code(erlang:processes(), Mod, false), + erts_internal:purge_module(Mod, + case Res of + false -> abort; + true -> complete + end) end. %% @@ -336,3 +323,72 @@ cpc_init(CpcS, [Pid|Pids], NoReqs) -> cpc_init(CpcS, Pids, NoReqs+1). % end of check_proc_code() implementation. + +%% +%% FOR TESTING ONLY +%% +%% do_test_purge() is for testing only. The purge is done +%% as usual, but the tester can control when to enter the +%% specific phases. +%% +do_test_purge(Mod, From, Type, Ref) when Type == true; Type == false -> + Mon = erlang:monitor(process, From), + Res = case Type of + true -> do_test_hard_purge(Mod, From, Ref, Mon); + false -> do_test_soft_purge(Mod, From, Ref, Mon) + end, + From ! {test_purge, Res, Ref}, + erlang:demonitor(Mon, [flush]), + ok; +do_test_purge(_, _, _, _) -> + ok. + +do_test_soft_purge(Mod, From, Ref, Mon) -> + PrepRes = erts_internal:purge_module(Mod, prepare), + TestRes = test_progress(started, From, Mon, Ref, ok), + case PrepRes of + false -> + _ = test_progress(continued, From, Mon, Ref, TestRes), + true; + true -> + Res = check_proc_code(erlang:processes(), Mod, false), + _ = test_progress(continued, From, Mon, Ref, TestRes), + erts_internal:purge_module(Mod, + case Res of + false -> abort; + true -> complete + end) + end. + +do_test_hard_purge(Mod, From, Ref, Mon) -> + PrepRes = erts_internal:purge_module(Mod, prepare), + TestRes = test_progress(started, From, Mon, Ref, ok), + case PrepRes of + false -> + _ = test_progress(continued, From, Mon, Ref, TestRes), + {false, false}; + true -> + DidKill = check_proc_code(erlang:processes(), Mod, true), + _ = test_progress(continued, From, Mon, Ref, TestRes), + true = erts_internal:purge_module(Mod, complete), + {true, DidKill} + end. + +test_progress(_State, _From, _Mon, _Ref, died) -> + %% Test process died; continue so we wont + %% leave the system in an inconsistent + %% state... + died; +test_progress(started, From, Mon, Ref, ok) -> + From ! {started, Ref}, + receive + {'DOWN', Mon, process, From, _} -> died; + {continue, Ref} -> ok + end; +test_progress(continued, From, Mon, Ref, ok) -> + From ! {continued, Ref}, + receive + {'DOWN', Mon, process, From, _} -> died; + {complete, Ref} -> ok + end. + diff --git a/erts/preloaded/src/erts_internal.erl b/erts/preloaded/src/erts_internal.erl index 2bf430d857..2a6d626279 100644 --- a/erts/preloaded/src/erts_internal.erl +++ b/erts/preloaded/src/erts_internal.erl @@ -41,9 +41,8 @@ -export([request_system_task/3]). -export([check_process_code/3]). --export([copy_literals/2]). -export([release_literal_area_switch/0]). --export([purge_module/1]). +-export([purge_module/2]). -export([flush_monitor_messages/3]). @@ -273,20 +272,15 @@ cpc_flags(OldFlags, Bit, true) -> cpc_flags(OldFlags, Bit, false) -> OldFlags band (bnot Bit). --spec copy_literals(Module,Bool) -> 'true' | 'false' | 'aborted' when - Module :: module(), - Bool :: boolean(). -copy_literals(_Mod, _Bool) -> - erlang:nif_error(undefined). - -spec release_literal_area_switch() -> 'true' | 'false'. release_literal_area_switch() -> erlang:nif_error(undefined). --spec purge_module(Module) -> boolean() when - Module :: module(). -purge_module(_Module) -> +-spec purge_module(Module, Op) -> boolean() when + Module :: module(), + Op :: 'prepare' | 'abort' | 'complete'. +purge_module(_Module, _Op) -> erlang:nif_error(undefined). -spec system_check(Type) -> 'ok' when diff --git a/erts/preloaded/src/init.erl b/erts/preloaded/src/init.erl index 45468b3b9c..c3c2f22122 100644 --- a/erts/preloaded/src/init.erl +++ b/erts/preloaded/src/init.erl @@ -670,9 +670,9 @@ unload(_) -> do_unload(sub([heart|erlang:pre_loaded()],erlang:loaded())). do_unload([M|Mods]) -> - catch erts_internal:purge_module(M), + catch erlang:purge_module(M), catch erlang:delete_module(M), - catch erts_internal:purge_module(M), + catch erlang:purge_module(M), do_unload(Mods); do_unload([]) -> purge_all_hipe_refs(), diff --git a/lib/kernel/doc/src/code.xml b/lib/kernel/doc/src/code.xml index d3611d6a03..21f8a2d54a 100644 --- a/lib/kernel/doc/src/code.xml +++ b/lib/kernel/doc/src/code.xml @@ -651,6 +651,11 @@ ok = code:finish_loading(Prepared), <p>Purges the code for <c><anno>Module</anno></c>, that is, removes code marked as old. If some processes still linger in the old code, these processes are killed before the code is removed.</p> + <note><p>As of ERTS version 9.0, a process is only considered + to be lingering in the code if it has direct references to the code. + For more information see documentation of + <seealso marker="erts:erlang#check_process_code/3"><c>erlang:check_process_code/3</c></seealso>, + which is used in order to determine this.</p></note> <p>Returns <c>true</c> if successful and any process is needed to be killed, otherwise <c>false</c>.</p> </desc> @@ -661,6 +666,11 @@ ok = code:finish_loading(Prepared), <desc> <p>Purges the code for <c><anno>Module</anno></c>, that is, removes code marked as old, but only if no processes linger in it.</p> + <note><p>As of ERTS version 9.0, a process is only considered + to be lingering in the code if it has direct references to the code. + For more information see documentation of + <seealso marker="erts:erlang#check_process_code/3"><c>erlang:check_process_code/3</c></seealso>, + which is used in order to determine this.</p></note> <p>Returns <c>false</c> if the module cannot be purged because of processes lingering in old code, otherwise <c>true</c>.</p> </desc> diff --git a/lib/tools/test/cover_SUITE.erl b/lib/tools/test/cover_SUITE.erl index b4c9264b30..90e113c178 100644 --- a/lib/tools/test/cover_SUITE.erl +++ b/lib/tools/test/cover_SUITE.erl @@ -1001,41 +1001,40 @@ otp_6115(Config) when is_list(Config) -> %% Cover compile f1, but not f2 {ok, f1} = cover:compile(f1), + %% This test used to ensure that a process containing a + %% fun refering to cover compiled code was killed. + %% check_process_code may however ignore funs as of ERTS + %% version 8.1. The test has therefore been rewritten to + %% check that a process with a direct reference (in this + %% case a return address) to the code is killed. + %% %% If f1 is cover compiled, a process P is started with a - %% reference to the fun created in start_fail/0, and cover:stop() is - %% called, then P should be killed. - %% This is because (the fun held by P) references the cover + %% direct reference to the f1, and cover:stop() is called, + %% then P should be killed. + %% This is because of the return address to the cover %% compiled code which should be *unloaded* when cover:stop() is %% called -- running cover compiled code when there is no cover %% server and thus no ets tables to bump counters in, makes no %% sense. - Pid1 = f1:start_a(), - Pid2 = f1:start_b(), + Pid = spawn(fun () -> f1:non_tail_call_f2_wait() end), %% Now stop cover cover:stop(), %% Ensure that f1 is loaded (and not cover compiled), and that - %% both Pid1 and Pid2 are dead. + %% both Pid is dead. case code:which(f1) of Beam when is_list(Beam) -> ok; Other -> ct:fail({"f1 is not reloaded", Other}) end, - case process_info(Pid1) of + case process_info(Pid) of undefined -> ok; - _PI1 -> - RefToOldP1 = erlang:check_process_code(Pid1, f1), - ct:fail({"Pid1 still alive", RefToOldP1}) - end, - case process_info(Pid2) of - undefined -> - ok; - _PI2 -> - RefToOldP2 = erlang:check_process_code(Pid1, f2), - ct:fail({"Pid2 still alive", RefToOldP2}) + _PI -> + RefToOldP = erlang:check_process_code(Pid, f1), + ct:fail({"Pid still alive", RefToOldP}) end, file:set_cwd(CWD), diff --git a/lib/tools/test/cover_SUITE_data/otp_6115/f1.erl b/lib/tools/test/cover_SUITE_data/otp_6115/f1.erl index 5399b33f19..fc4a62e70e 100644 --- a/lib/tools/test/cover_SUITE_data/otp_6115/f1.erl +++ b/lib/tools/test/cover_SUITE_data/otp_6115/f1.erl @@ -1,13 +1,6 @@ -module(f1). --export([start_a/0, start_b/0]). +-export([non_tail_call_f2_wait/0]). -start_a() -> - f2:start(fun() -> - ok - end). - -start_b() -> - f2:start(fun fun1/0). - -fun1() -> - ok. +non_tail_call_f2_wait() -> + f2:wait(), + im_back. diff --git a/lib/tools/test/cover_SUITE_data/otp_6115/f2.erl b/lib/tools/test/cover_SUITE_data/otp_6115/f2.erl index 72a6a64c4d..4bc88035c7 100644 --- a/lib/tools/test/cover_SUITE_data/otp_6115/f2.erl +++ b/lib/tools/test/cover_SUITE_data/otp_6115/f2.erl @@ -1,13 +1,5 @@ -module(f2). --export([start/1]). +-export([wait/0]). -start(Fun) -> - spawn(fun() -> - wait(Fun) - end). - -wait(Fun) -> - receive - go -> - Fun() - end. +wait() -> + receive after infinity -> ok end. |