/* * %CopyrightBegin% * * Copyright Ericsson AB 1996-2022. 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% */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include /* offsetof() */ #include "sys.h" #include "erl_vm.h" #include "global.h" #include "erl_process.h" #include "erl_map.h" #include "bif.h" #include "erl_proc_sig_queue.h" #include "erl_nfunc_sched.h" #include "dist.h" #include "beam_catches.h" #include "beam_common.h" #include "erl_global_literals.h" #ifdef USE_VM_PROBES #include "dtrace-wrapper.h" #endif static Eterm *get_freason_ptr_from_exc(Eterm exc); static ErtsCodePtr next_catch(Process* c_p, Eterm *reg); static void terminate_proc(Process* c_p, Eterm Value); static void save_stacktrace(Process* c_p, ErtsCodePtr pc, Eterm* reg, const ErtsCodeMFA *bif_mfa, Eterm args); static Eterm make_arglist(Process* c_p, Eterm* reg, int a); /* * erts_dirty_process_main() is what dirty schedulers execute. Since they handle * only NIF calls they do not need to be able to execute all BEAM * instructions. */ void erts_dirty_process_main(ErtsSchedulerData *esdp) { Process* c_p = NULL; ErtsMonotonicTime start_time; #ifdef DEBUG ERTS_DECLARE_DUMMY(Eterm pid); #endif /* Pointer to X registers: x(1)..x(N); reg[0] is used when doing GC, * in all other cases x0 is used. */ Eterm* reg = (esdp->registers)->x_reg_array.d; /* * Top of heap (next free location); grows upwards. */ Eterm* HTOP = NULL; /* Stack pointer. Grows downwards; points * to last item pushed (normally a saved * continuation pointer). */ Eterm* E = NULL; /* * Pointer to next threaded instruction. */ const BeamInstr *I = NULL; ERTS_MSACC_DECLARE_CACHE_X() /* a cached value of the tsd pointer for msacc */ /* * start_time always positive for dirty CPU schedulers, * and negative for dirty I/O schedulers. */ if (ERTS_SCHEDULER_IS_DIRTY_CPU(esdp)) { start_time = erts_get_monotonic_time(NULL); ASSERT(start_time >= 0); } else { start_time = ERTS_SINT64_MIN; ASSERT(start_time < 0); } goto do_dirty_schedule; context_switch: c_p->current = erts_code_to_codemfa(I); /* Pointer to Mod, Func, Arity */ c_p->arity = c_p->current->arity; { int reds_used; Eterm* argp; int i; /* * Make sure that there is enough room for the argument registers to be saved. */ if (c_p->arity > c_p->max_arg_reg) { /* * Yes, this is an expensive operation, but you only pay it the first * time you call a function with more than 6 arguments which is * scheduled out. This is better than paying for 26 words of wasted * space for most processes which never call functions with more than * 6 arguments. */ Uint size = c_p->arity * sizeof(c_p->arg_reg[0]); if (c_p->arg_reg != c_p->def_arg_reg) { c_p->arg_reg = (Eterm *) erts_realloc(ERTS_ALC_T_ARG_REG, (void *) c_p->arg_reg, size); } else { c_p->arg_reg = (Eterm *) erts_alloc(ERTS_ALC_T_ARG_REG, size); } c_p->max_arg_reg = c_p->arity; } /* * Save the argument registers and everything else. */ argp = c_p->arg_reg; for (i = c_p->arity - 1; i >= 0; i--) { argp[i] = reg[i]; } SWAPOUT; c_p->i = I; do_dirty_schedule: if (start_time < 0) { /* * Dirty I/O scheduler: * One reduction consumed regardless of * time spent in the dirty NIF. */ reds_used = esdp->virtual_reds + 1; } else { /* * Dirty CPU scheduler: * Reductions based on time consumed by * the dirty NIF. */ Sint64 treds; treds = erts_time2reds(start_time, erts_get_monotonic_time(esdp)); treds += esdp->virtual_reds; reds_used = treds > INT_MAX ? INT_MAX : (int) treds; } if (c_p && ERTS_PROC_GET_PENDING_SUSPEND(c_p)) erts_proc_sig_handle_pending_suspend(c_p); PROCESS_MAIN_CHK_LOCKS(c_p); ERTS_UNREQ_PROC_MAIN_LOCK(c_p); ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p); c_p = erts_schedule(esdp, c_p, reds_used); if (start_time >= 0) { start_time = erts_get_monotonic_time(esdp); ASSERT(start_time >= 0); } } ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p); #ifdef DEBUG pid = c_p->common.id; /* Save for debugging purposes */ #endif ERTS_REQ_PROC_MAIN_LOCK(c_p); PROCESS_MAIN_CHK_LOCKS(c_p); ERTS_MSACC_UPDATE_CACHE_X(); /* Set fcalls even though we ignore it, so we don't * confuse code accessing it... */ c_p->fcalls = CONTEXT_REDS; #ifndef BEAMASM if (ERTS_PROC_GET_SAVED_CALLS_BUF(c_p)) { c_p->fcalls = 0; } #endif if (erts_atomic32_read_nob(&c_p->state) & ERTS_PSFLG_DIRTY_RUNNING_SYS) { erts_execute_dirty_system_task(c_p); goto do_dirty_schedule; } else { const ErtsCodeMFA *codemfa; Eterm* argp; int i, exiting; reg = esdp->registers->x_reg_array.d; argp = c_p->arg_reg; for (i = c_p->arity - 1; i >= 0; i--) { reg[i] = argp[i]; CHECK_TERM(reg[i]); } /* * We put the original reduction count in the process structure, to reduce * the code size (referencing a field in a struct through a pointer stored * in a register gives smaller code than referencing a global variable). */ I = (const BeamInstr*)c_p->i; SWAPIN; #ifdef USE_VM_PROBES if (DTRACE_ENABLED(process_scheduled)) { DTRACE_CHARBUF(process_buf, DTRACE_TERM_BUF_SIZE); DTRACE_CHARBUF(fun_buf, DTRACE_TERM_BUF_SIZE); dtrace_proc_str(c_p, process_buf); if (ERTS_PROC_IS_EXITING(c_p)) { sys_strcpy(fun_buf, ""); } else { const ErtsCodeMFA *cmfa = erts_find_function_from_pc(c_p->i); if (cmfa) { dtrace_fun_decode(c_p, cmfa, NULL, fun_buf); } else { erts_snprintf(fun_buf, sizeof(DTRACE_CHARBUF_NAME(fun_buf)), "", *I); } } DTRACE2(process_scheduled, process_buf, fun_buf); } #endif /* * call_nif is always first instruction in function: * * I[-3]: Module * I[-2]: Function * I[-1]: Arity * I[0]: &&call_nif * I[1]: Function pointer to NIF function * I[2]: Pointer to erl_module_nif * I[3]: Function pointer to dirty NIF * * This layout is determined by the ErtsNativeFunc struct */ ERTS_MSACC_SET_STATE_CACHED_X(ERTS_MSACC_STATE_NIF); codemfa = erts_code_to_codemfa(I); DTRACE_NIF_ENTRY(c_p, codemfa); c_p->current = codemfa; SWAPOUT; PROCESS_MAIN_CHK_LOCKS(c_p); ERTS_UNREQ_PROC_MAIN_LOCK(c_p); ASSERT(!ERTS_PROC_IS_EXITING(c_p)); if (BeamIsOpCode(I[0], op_call_bif_W)) { exiting = erts_call_dirty_bif(esdp, c_p, I, reg); } else { ASSERT(BeamIsOpCode(I[0], op_call_nif_WWW)); exiting = erts_call_dirty_nif(esdp, c_p, I, reg); } ASSERT(!(c_p->flags & F_HIBERNATE_SCHED)); PROCESS_MAIN_CHK_LOCKS(c_p); ERTS_REQ_PROC_MAIN_LOCK(c_p); ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p); ERTS_MSACC_SET_STATE_CACHED_X(ERTS_MSACC_STATE_EMULATOR); if (exiting) goto do_dirty_schedule; ASSERT(!ERTS_PROC_IS_EXITING(c_p)); DTRACE_NIF_RETURN(c_p, codemfa); ERTS_HOLE_CHECK(c_p); SWAPIN; I = c_p->i; goto context_switch; } } void copy_out_registers(Process *c_p, Eterm *reg) { /* * Make sure that there is enough room for the argument registers to be saved. */ if (c_p->arity > c_p->max_arg_reg) { /* * Yes, this is an expensive operation, but you only pay it the first * time you call a function with more than 6 arguments which is * scheduled out. This is better than paying for 26 words of wasted * space for most processes which never call functions with more than * 6 arguments. */ Uint size = c_p->arity * sizeof(c_p->arg_reg[0]); if (c_p->arg_reg != c_p->def_arg_reg) { c_p->arg_reg = (Eterm *) erts_realloc(ERTS_ALC_T_ARG_REG, (void *) c_p->arg_reg, size); } else { c_p->arg_reg = (Eterm *) erts_alloc(ERTS_ALC_T_ARG_REG, size); } c_p->max_arg_reg = c_p->arity; } /* * Save the argument registers and everything else. */ sys_memcpy(c_p->arg_reg,reg,c_p->arity * sizeof(Eterm)); } void copy_in_registers(Process *c_p, Eterm *reg) { #ifdef DEBUG int i; for (i = 0; i < c_p->arity; i++) { CHECK_TERM(c_p->arg_reg[i]); } #endif sys_memcpy(reg, c_p->arg_reg, c_p->arity * sizeof(Eterm)); } void check_monitor_long_schedule(Process *c_p, Uint64 start_time, ErtsCodePtr start_time_i) { Sint64 diff = erts_timestamp_millis() - start_time; if (diff > 0 && (Uint) diff > erts_system_monitor_long_schedule) { const ErtsCodeMFA *inptr = erts_find_function_from_pc(start_time_i); const ErtsCodeMFA *outptr = erts_find_function_from_pc(c_p->i); monitor_long_schedule_proc(c_p,inptr,outptr,(Uint) diff); } } ErtsCodeMFA * ubif2mfa(void* uf) { int i; for (i = 0; erts_u_bifs[i].bif; i++) { if (erts_u_bifs[i].bif == uf) return &BIF_TRAP_EXPORT(erts_u_bifs[i].exp_ix)->info.mfa; } erts_exit(ERTS_ERROR_EXIT, "bad u bif: %p\n", uf); return NULL; } /* * Mapping from the error code 'class tag' to atoms. */ Eterm exception_tag[NUMBER_EXC_TAGS] = { am_error, /* 0 */ am_exit, /* 1 */ am_throw, /* 2 */ }; /* * Mapping from error code 'index' to atoms. */ Eterm error_atom[NUMBER_EXIT_CODES] = { am_internal_error, /* 0 */ am_normal, /* 1 */ am_internal_error, /* 2 */ am_badarg, /* 3 */ am_badarith, /* 4 */ am_badmatch, /* 5 */ am_function_clause, /* 6 */ am_case_clause, /* 7 */ am_if_clause, /* 8 */ am_undef, /* 9 */ am_badfun, /* 10 */ am_badarity, /* 11 */ am_timeout_value, /* 12 */ am_noproc, /* 13 */ am_notalive, /* 14 */ am_system_limit, /* 15 */ am_try_clause, /* 16 */ am_notsup, /* 17 */ am_badmap, /* 18 */ am_badkey, /* 19 */ am_badrecord, /* 20 */ }; /* Returns the return address at E[0] in printable form, skipping tracing in * the same manner as gather_stacktrace. * * This is needed to generate correct stacktraces when throwing errors from * instructions that return like an ordinary function, such as call_nif. */ ErtsCodePtr erts_printable_return_address(Process* p, Eterm *E) { Eterm *stack_bottom = STACK_START(p); Eterm *scanner = E; ASSERT(is_CP(scanner[0])); while (scanner < stack_bottom) { ErtsCodePtr return_address; erts_inspect_frame(scanner, &return_address); if (BeamIsReturnTrace(return_address)) { scanner += CP_SIZE + 2; } else if (BeamIsReturnTimeTrace(return_address)) { scanner += CP_SIZE + 1; } else if (BeamIsReturnToTrace(return_address)) { scanner += CP_SIZE; } else { return return_address; } } ERTS_ASSERT(!"No continuation pointer on stack"); return NULL; } /* * When a new exception is raised, the current stack trace information * is quick-saved in a small structure allocated on the heap. Depending * on how the exception is eventually caught (perhaps by causing the * current process to terminate), the saved information may be used to * create a symbolic (human-readable) representation of the stack trace * at the point of the original exception. */ ErtsCodePtr handle_error(Process* c_p, ErtsCodePtr pc, Eterm* reg, const ErtsCodeMFA *bif_mfa) { Eterm* hp; Eterm Value = c_p->fvalue; Eterm Args = am_true; ASSERT(c_p->freason != TRAP); /* Should have been handled earlier. */ if (c_p->freason & EXF_RESTORE_NFUNC) erts_nfunc_restore_error(c_p, &pc, reg, &bif_mfa); #ifdef DEBUG if (bif_mfa) { /* Verify that bif_mfa does not point into our native function wrapper */ ErtsNativeFunc *nep = ERTS_PROC_GET_NFUNC_TRAP_WRAPPER(c_p); ASSERT(!nep || !ErtsInArea(bif_mfa, (char *)nep, sizeof(ErtsNativeFunc))); } #endif c_p->i = pc; /* In case we call erts_exit(). */ /* * Check if we have an arglist and possibly an `error_info` term * for the top level call. If so, this is encoded in Value, so we * have to dig out the real Value as well as the Arglist and the * `error_info` term. */ if (c_p->freason & EXF_ARGLIST) { Eterm* tp; tp = tuple_val(Value); Value = tp[1]; Args = tp[2]; switch (arityval(tp[0])) { case 2: break; case 3: /* Dig out the `error_info` term passed to error/3. */ ASSERT(c_p->freason & EXF_HAS_EXT_INFO); c_p->fvalue = tp[3]; break; default: ASSERT(0); break; } } /* * Save the stack trace info if the EXF_SAVETRACE flag is set. The * main reason for doing this separately is to allow throws to later * become promoted to errors without losing the original stack * trace, even if they have passed through one or more catch and * rethrow. It also makes the creation of symbolic stack traces much * more modular. */ if (c_p->freason & EXF_SAVETRACE) { save_stacktrace(c_p, pc, reg, bif_mfa, Args); } /* * Throws that are not caught are turned into 'nocatch' errors */ if ((c_p->freason & EXF_THROWN) && (c_p->catches <= 0) ) { hp = HAlloc(c_p, 3); Value = TUPLE2(hp, am_nocatch, Value); c_p->freason = EXC_ERROR; } /* Get the fully expanded error term */ Value = expand_error_value(c_p, c_p->freason, Value); /* Stabilize the exception flags so no further expansion is done. */ c_p->freason = PRIMARY_EXCEPTION(c_p->freason); /* Clear out error term from process structure to avoid keeping garbage. */ c_p->fvalue = NIL; /* Find a handler or die */ if ((c_p->catches > 0 || IS_TRACED_FL(c_p, F_EXCEPTION_TRACE)) && !(c_p->freason & EXF_PANIC)) { ErtsCodePtr new_pc; /* The Beam handler code (catch_end or try_end) checks reg[0] * for THE_NON_VALUE to see if the previous code finished * abnormally. If so, reg[1], reg[2] and reg[3] should hold * the term, trace, and exception class, respectively. Note * that the handler code will only need to move the class * to reg[0] to have all registers correctly set up for the * code that follows. */ reg[0] = THE_NON_VALUE; reg[1] = Value; reg[2] = c_p->ftrace; reg[3] = exception_tag[GET_EXC_CLASS(c_p->freason)]; if ((new_pc = next_catch(c_p, reg))) { #if defined(BEAMASM) && (defined(NATIVE_ERLANG_STACK) || defined(__aarch64__)) /* In order to make use of native call and return * instructions, when beamasm uses the native stack it * doesn't include the CP in the current stack frame, * relying on the call and return instructions to do that * for us. * * Therefore, we need to bump the stack pointer as if this were an * ordinary return. */ if (erts_frame_layout == ERTS_FRAME_LAYOUT_FP_RA) { FRAME_POINTER(c_p) = (Eterm*)cp_val(c_p->stop[0]); } c_p->stop += CP_SIZE; #else /* To avoid keeping stale references. */ c_p->stop[0] = NIL; #endif #ifdef ERTS_SUPPORT_OLD_RECV_MARK_INSTRS /* No longer safe to use this position */ erts_msgq_recv_marker_clear(c_p, erts_old_recv_marker_id); #endif c_p->ftrace = NIL; return new_pc; } if (c_p->catches > 0) erts_exit(ERTS_ERROR_EXIT, "Catch not found"); } ERTS_UNREQ_PROC_MAIN_LOCK(c_p); terminate_proc(c_p, Value); ERTS_REQ_PROC_MAIN_LOCK(c_p); return NULL; } /* * Find the nearest catch handler */ static ErtsCodePtr next_catch(Process* c_p, Eterm *reg) { int active_catches = c_p->catches > 0; ErtsCodePtr return_to_trace_address = NULL; int have_return_to_trace = 0; Eterm *ptr, *prev; ErtsCodePtr handler; ptr = prev = c_p->stop; ASSERT(ptr <= STACK_START(c_p)); /* This function is only called if we have active catch tags or have * previously called a function that was exception-traced. As the exception * trace flag isn't cleared after the traced function returns (and the * catch tag inserted by it is gone), it's possible to land here with an * empty stack, and the process should simply die when that happens. */ if (ptr == STACK_START(c_p)) { ASSERT(!active_catches && IS_TRACED_FL(c_p, F_EXCEPTION_TRACE)); return NULL; } while (ptr < STACK_START(c_p)) { Eterm val = ptr[0]; if (is_catch(val)) { if (active_catches) { goto found_catch; } ptr++; } else if (is_CP(val)) { ErtsCodePtr return_address; const Eterm *frame; prev = ptr; frame = erts_inspect_frame(ptr, &return_address); if (BeamIsReturnTrace(return_address)) { if (return_address == beam_exception_trace) { ErtsTracer *tracer; ErtsCodeMFA *mfa; mfa = (ErtsCodeMFA*)cp_val(frame[0]); tracer = ERTS_TRACER_FROM_ETERM(&frame[1]); ASSERT_MFA(mfa); erts_trace_exception(c_p, mfa, reg[3], reg[1], tracer); } ptr += CP_SIZE + 2; } else if (BeamIsReturnTimeTrace(return_address)) { ptr += CP_SIZE + 1; } else if (BeamIsReturnToTrace(return_address)) { have_return_to_trace = 1; /* Record next cp */ return_to_trace_address = NULL; ptr += CP_SIZE; } else { /* This is an ordinary call frame: if the previous frame was a * return_to trace we should record this CP as a return_to * candidate. */ if (have_return_to_trace) { return_to_trace_address = return_address; have_return_to_trace = 0; } else { return_to_trace_address = NULL; } ptr += CP_SIZE; } } else { ptr++; } } return NULL; found_catch: ASSERT(ptr < STACK_START(c_p)); c_p->stop = prev; if (IS_TRACED_FL(c_p, F_TRACE_RETURN_TO) && return_to_trace_address) { /* The stackframe closest to the catch contained an * return_to_trace entry, so since the execution now * continues after the catch, a return_to trace message * would be appropriate. */ erts_trace_return_to(c_p, return_to_trace_address); } /* Clear the try_tag or catch_tag in the stack frame so that we * don't have to do it in the JITted code for the try_case * instruction. (Unfortunately, a catch_end will still need to * clear the catch_tag because it is executed even when no * exception has occurred.) */ handler = catch_pc(*ptr); *ptr = NIL; return handler; } /* * Terminating the process when an exception is not caught */ static void terminate_proc(Process* c_p, Eterm Value) { Eterm *hp; Eterm Args = NIL; /* Add a stacktrace if this is an error. */ if (GET_EXC_CLASS(c_p->freason) == EXTAG_ERROR) { Value = add_stacktrace(c_p, Value, c_p->ftrace); } c_p->ftrace = NIL; /* EXF_LOG is a primary exception flag */ if (c_p->freason & EXF_LOG) { int alive = erts_is_alive; erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf(); /* Build the format message */ erts_dsprintf(dsbufp, "Error in process ~p "); if (alive) erts_dsprintf(dsbufp, "on node ~p "); erts_dsprintf(dsbufp, "with exit value:~n~p~n"); /* Build the args in reverse order */ hp = HAlloc(c_p, 2); Args = CONS(hp, Value, Args); if (alive) { hp = HAlloc(c_p, 2); Args = CONS(hp, erts_this_node->sysname, Args); } hp = HAlloc(c_p, 2); Args = CONS(hp, c_p->common.id, Args); erts_send_error_term_to_logger(c_p->group_leader, dsbufp, Args); } /* * If we use a shared heap, the process will be garbage-collected. * Must zero c_p->arity to indicate that there are no live registers. */ c_p->arity = 0; erts_do_exit_process(c_p, Value); } /* * Build and add a symbolic stack trace to the error value. */ Eterm add_stacktrace(Process* c_p, Eterm Value, Eterm exc) { Eterm Where = build_stacktrace(c_p, exc); Eterm* hp = HAlloc(c_p, 3); return TUPLE2(hp, Value, Where); } /* * Forming the correct error value from the internal error code. * This does not update c_p->fvalue or c_p->freason. */ Eterm expand_error_value(Process* c_p, Uint freason, Eterm Value) { Eterm* hp; Uint r; r = GET_EXC_INDEX(freason); ASSERT(r < NUMBER_EXIT_CODES); /* range check */ ASSERT(is_value(Value)); switch (r) { case (GET_EXC_INDEX(EXC_PRIMARY)): /* Primary exceptions use fvalue as it is */ break; case (GET_EXC_INDEX(EXC_BADMATCH)): case (GET_EXC_INDEX(EXC_CASE_CLAUSE)): case (GET_EXC_INDEX(EXC_TRY_CLAUSE)): case (GET_EXC_INDEX(EXC_BADFUN)): case (GET_EXC_INDEX(EXC_BADARITY)): case (GET_EXC_INDEX(EXC_BADMAP)): case (GET_EXC_INDEX(EXC_BADKEY)): case (GET_EXC_INDEX(EXC_BADRECORD)): /* Some common exceptions: value -> {atom, value} */ ASSERT(is_value(Value)); hp = HAlloc(c_p, 3); Value = TUPLE2(hp, error_atom[r], Value); break; default: /* Other exceptions just use an atom as descriptor */ Value = error_atom[r]; break; } #ifdef DEBUG ASSERT(Value != am_internal_error); #endif return Value; } static void gather_stacktrace(Process* p, struct StackTrace* s, int depth) { ErtsCodePtr prev; Eterm *ptr; if (depth == 0) { return; } prev = s->depth ? s->trace[s->depth - 1] : s->pc; ptr = p->stop; /* * Traverse the stack backwards and add all unique continuation * pointers to the buffer, up to the maximum stack trace size. * * Skip trace stack frames. */ ASSERT(ptr >= STACK_TOP(p) && ptr <= STACK_START(p)); while (ptr < STACK_START(p) && depth > 0) { if (is_CP(*ptr)) { ErtsCodePtr return_address; erts_inspect_frame(ptr, &return_address); if (BeamIsReturnTrace(return_address)) { ptr += CP_SIZE + 2; } else if (BeamIsReturnTimeTrace(return_address)) { ptr += CP_SIZE + 1; } else if (BeamIsReturnToTrace(return_address)) { ptr += CP_SIZE; } else { if (return_address != prev) { ErtsCodePtr adjusted_address; /* Record non-duplicates only */ prev = return_address; #ifdef BEAMASM /* Some instructions (e.g. call) are shorter than one word, * so we will need to subtract one byte from the pointer * to avoid ending up before the start of the * instruction. */ adjusted_address = ((char*)return_address) - 1; #else /* Subtract one word from the pointer. */ adjusted_address = ((char*)return_address) - sizeof(UWord); #endif s->trace[s->depth++] = adjusted_address; depth--; } ptr += CP_SIZE; } } else { ptr++; } } } /* * Quick-saving the stack trace in an internal form on the heap. Note * that c_p->ftrace will point to a cons cell which holds the given args * and the saved data (encoded as a bignum). * * There is an issue with line number information. Line number * information is associated with the address *before* an operation * that may fail or be stored on the stack. But continuation * pointers point after its call instruction, not before. To avoid * finding the wrong line number, we'll need to adjust them so that * they point at the beginning of the call instruction or inside the * call instruction. Since its impractical to point at the beginning, * we'll do the simplest thing and decrement the continuation pointers * by one word in threaded interpreter and by one byte in BEAMASM. * * Here is an example of what can go wrong. Without the adjustment * of continuation pointers, the call at line 42 below would seem to * be at line 43: * * line 42 * call ... * line 43 * gc_bif ... * * (It would be much better to put the arglist - when it exists - in the * error value instead of in the actual trace; e.g. '{badarg, Args}' * instead of using 'badarg' with Args in the trace. The arglist may * contain very large values, and right now they will be kept alive as * long as the stack trace is live. Preferably, the stack trace should * always be small, so that it does not matter if it is long-lived. * However, it is probably not possible to ever change the format of * error terms.) */ static void save_stacktrace(Process* c_p, ErtsCodePtr pc, Eterm* reg, const ErtsCodeMFA *bif_mfa, Eterm args) { struct StackTrace* s; int sz; int depth = erts_backtrace_depth; /* max depth (never negative) */ Eterm error_info = THE_NON_VALUE; if (depth > 0) { /* There will always be a current function */ depth --; } /* Create a container for the exception data */ sz = (offsetof(struct StackTrace, trace) + sizeof(ErtsCodePtr) * depth + sizeof(Eterm) - 1) / sizeof(Eterm); s = (struct StackTrace *) HAlloc(c_p, 1 + sz); /* The following fields are inside the bignum */ s->header = make_pos_bignum_header(sz); s->freason = c_p->freason; s->depth = 0; /* * If the failure was in a BIF other than 'error/1', 'error/2', * 'error/3', 'exit/1', or 'throw/1', save BIF MFA and save the * argument registers by consing up an arglist. */ if (bif_mfa) { Eterm *hp; Eterm format_module = THE_NON_VALUE; if (bif_mfa->module == am_erlang) { switch (bif_mfa->function) { case am_error: if (bif_mfa->arity == 1 || bif_mfa->arity == 2 || bif_mfa->arity == 3) goto non_bif_stacktrace; break; case am_exit: if (bif_mfa->arity == 1) goto non_bif_stacktrace; break; case am_throw: if (bif_mfa->arity == 1) goto non_bif_stacktrace; break; default: break; } } s->current = bif_mfa; /* Save first stack entry */ ASSERT(pc); if (depth > 0) { s->trace[s->depth++] = pc; depth--; } s->pc = NULL; /* * All format_error/2 functions for BIFs must be in separate modules, * to allow them to be removed from application systems with tight * storage constraints. */ switch (bif_mfa->module) { /* Erts */ case am_atomics: format_module = am_erl_erts_errors; break; case am_counters: format_module = am_erl_erts_errors; break; case am_erlang: format_module = am_erl_erts_errors; break; case am_erts_internal: format_module = am_erl_erts_errors; break; case am_persistent_term: format_module = am_erl_erts_errors; break; /* Kernel */ case am_os: format_module = am_erl_kernel_errors; break; /* STDLIB */ case am_binary: format_module = am_erl_stdlib_errors; break; case am_ets: format_module = am_erl_stdlib_errors; break; case am_lists: format_module = am_erl_stdlib_errors; break; case am_maps: format_module = am_erl_stdlib_errors; break; case am_math: format_module = am_erl_stdlib_errors; break; case am_re: format_module = am_erl_stdlib_errors; break; case am_unicode: format_module = am_erl_stdlib_errors; break; default: ASSERT((c_p->freason & EXF_HAS_EXT_INFO) == 0); break; } if (is_value(format_module)) { if (c_p->freason & EXF_HAS_EXT_INFO) { hp = HAlloc(c_p, MAP2_SZ); error_info = MAP2(hp, am_cause, c_p->fvalue, am_module, format_module); } else { hp = HAlloc(c_p, MAP1_SZ); error_info = MAP1(hp, am_module, format_module); } } args = make_arglist(c_p, reg, bif_mfa->arity); } else { if (c_p->freason & EXF_HAS_EXT_INFO && is_map(c_p->fvalue)) { error_info = c_p->fvalue; } non_bif_stacktrace: s->current = c_p->current; /* * For a function_clause error, the arguments are in the beam * registers and c_p->current is set. */ if ( (GET_EXC_INDEX(s->freason)) == (GET_EXC_INDEX(EXC_FUNCTION_CLAUSE)) ) { int a; ASSERT(s->current); a = s->current->arity; args = make_arglist(c_p, reg, a); s->pc = NULL; /* Ignore pc */ } else { s->pc = pc; } } if (c_p->freason == EXC_ERROR_3) { error_info = c_p->fvalue; } /* Package args and stack trace */ { Eterm *hp; Uint sz = 4; if (is_value(error_info)) { sz += 3 + 2; } hp = HAlloc(c_p, sz); if (is_non_value(error_info)) { error_info = NIL; } else { error_info = TUPLE2(hp, am_error_info, error_info); hp += 3; error_info = CONS(hp, error_info, NIL); hp += 2; } c_p->ftrace = TUPLE3(hp, make_big((Eterm *) s), args, error_info); } /* Save the actual stack trace */ gather_stacktrace(c_p, s, depth); } void erts_save_stacktrace(Process* p, struct StackTrace* s, int depth) { gather_stacktrace(p, s, depth); } /* * Getting the relevant fields from the term pointed to by ftrace */ static struct StackTrace *get_trace_from_exc(Eterm exc) { if (exc == NIL) { return NULL; } else { Eterm* tuple_ptr = tuple_val(exc); ASSERT(tuple_ptr[0] == make_arityval(3)); return (struct StackTrace *) big_val(tuple_ptr[1]); } } void erts_sanitize_freason(Process* c_p, Eterm exc) { struct StackTrace *s = get_trace_from_exc(exc); if (s == NULL) { c_p->freason = EXC_ERROR; } else { c_p->freason = PRIMARY_EXCEPTION(s->freason); } } static Eterm get_args_from_exc(Eterm exc) { if (exc == NIL) { return NIL; } else { Eterm* tuple_ptr = tuple_val(exc); ASSERT(tuple_ptr[0] == make_arityval(3)); return tuple_ptr[2]; } } static Eterm get_error_info_from_exc(Eterm exc) { if (exc == NIL) { return NIL; } else { Eterm* tuple_ptr = tuple_val(exc); ASSERT(tuple_ptr[0] == make_arityval(3)); return tuple_ptr[3]; } } static int is_raised_exc(Eterm exc) { if (exc == NIL) { return 0; } else { Eterm* tuple_ptr = tuple_val(exc); return bignum_header_is_neg(*big_val(tuple_ptr[1])); } } static Eterm *get_freason_ptr_from_exc(Eterm exc) { static Eterm dummy_freason; struct StackTrace* s; if (exc == NIL) { /* * It is not exactly clear when exc can be NIL. Probably only * when the exception has been generated from native code. * Return a pointer to an Eterm that can be safely written and * ignored. */ return &dummy_freason; } else { Eterm* tuple_ptr = tuple_val(exc); ASSERT(tuple_ptr[0] == make_arityval(3)); s = (struct StackTrace *) big_val(tuple_ptr[1]); return &s->freason; } } int raw_raise(Eterm stacktrace, Eterm exc_class, Eterm value, Process *c_p) { Eterm* freason_ptr; /* * Note that the i_raise instruction will override c_p->freason * with the freason field stored inside the StackTrace struct in * ftrace. Therefore, we must take care to store the class both * inside the StackTrace struct and in c_p->freason (important if * the class is different from the class of the original * exception). */ freason_ptr = get_freason_ptr_from_exc(stacktrace); if (exc_class == am_error) { *freason_ptr = c_p->freason = EXC_ERROR & ~EXF_SAVETRACE; c_p->fvalue = value; c_p->ftrace = stacktrace; return 0; } else if (exc_class == am_exit) { *freason_ptr = c_p->freason = EXC_EXIT & ~EXF_SAVETRACE; c_p->fvalue = value; c_p->ftrace = stacktrace; return 0; } else if (exc_class == am_throw) { *freason_ptr = c_p->freason = EXC_THROWN & ~EXF_SAVETRACE; c_p->fvalue = value; c_p->ftrace = stacktrace; return 0; } else { return 1; } } /* * Creating a list with the argument registers */ static Eterm make_arglist(Process* c_p, Eterm* reg, int a) { Eterm args = NIL; Eterm* hp = HAlloc(c_p, 2*a); while (a > 0) { args = CONS(hp, reg[a-1], args); hp += 2; a--; } return args; } /* * Building a symbolic representation of a saved stack trace. Note that * the exception object 'exc', unless NIL, points to a cons cell which * holds the given args and the quick-saved data (encoded as a bignum). * * If the bignum is negative, the given args is a complete stacktrace. */ Eterm build_stacktrace(Process* c_p, Eterm exc) { struct StackTrace* s; Eterm args; int depth; FunctionInfo fi; FunctionInfo* stk; FunctionInfo* stkp; Eterm res = NIL; Uint heap_size; Eterm* hp; Eterm mfa; Eterm error_info; int i; if (! (s = get_trace_from_exc(exc))) { return NIL; } else if (is_raised_exc(exc)) { return get_args_from_exc(exc); } /* * Find the current function. If the saved s->pc is null, then the * saved s->current should already contain the proper value. */ if (s->pc != NULL) { erts_lookup_function_info(&fi, s->pc, 1); } else if (GET_EXC_INDEX(s->freason) == GET_EXC_INDEX(EXC_FUNCTION_CLAUSE)) { erts_lookup_function_info(&fi, erts_codemfa_to_code(s->current), 1); } else { erts_set_current_function(&fi, s->current); } depth = s->depth; /* * If fi.current is still NULL, and we have no * stack at all, default to the initial function * (e.g. spawn_link(erlang, abs, [1])). */ if (fi.mfa == NULL) { if (depth <= 0) erts_set_current_function(&fi, &c_p->u.initial); args = am_true; /* Just in case */ } else { args = get_args_from_exc(exc); } error_info = get_error_info_from_exc(exc); /* * Initialize needed heap. */ heap_size = fi.mfa ? fi.needed + 2 : 0; /* * Look up all saved continuation pointers and calculate * needed heap space. */ stk = stkp = (FunctionInfo *) erts_alloc(ERTS_ALC_T_TMP, depth*sizeof(FunctionInfo)); for (i = 0; i < depth; i++) { erts_lookup_function_info(stkp, s->trace[i], 1); if (stkp->mfa) { heap_size += stkp->needed + 2; stkp++; } } /* * Allocate heap space and build the stacktrace. */ hp = HAlloc(c_p, heap_size); while (stkp > stk) { stkp--; hp = erts_build_mfa_item(stkp, hp, am_true, &mfa, NIL); res = CONS(hp, mfa, res); hp += 2; } if (fi.mfa) { hp = erts_build_mfa_item(&fi, hp, args, &mfa, error_info); res = CONS(hp, mfa, res); hp += 2; } erts_free(ERTS_ALC_T_TMP, (void *) stk); return res; } Export* call_error_handler(Process* p, const ErtsCodeMFA *mfa, Eterm* reg, Eterm func) { Eterm* hp; Export* ep; int arity; Eterm args; Uint sz; int i; DBG_TRACE_MFA_P(mfa, "call_error_handler"); /* * Search for the error_handler module. */ ep = erts_find_function(erts_proc_get_error_handler(p), func, 3, erts_active_code_ix()); if (ep == NULL) { /* No error handler */ p->current = mfa; p->freason = EXC_UNDEF; return 0; } /* * Create a list with all arguments in the x registers. */ arity = mfa->arity; sz = 2 * arity; if (HeapWordsLeft(p) < sz) { erts_garbage_collect(p, sz, reg, arity); } hp = HEAP_TOP(p); HEAP_TOP(p) += sz; args = NIL; for (i = arity-1; i >= 0; i--) { args = CONS(hp, reg[i], args); hp += 2; } /* * Set up registers for call to error_handler:/3. */ reg[0] = mfa->module; reg[1] = mfa->function; reg[2] = args; return ep; } static Export* apply_setup_error_handler(Process* p, Eterm module, Eterm function, Uint arity, Eterm* reg) { Export* ep; /* * Find the export table index for the error handler. Return NULL if * there is no error handler module. */ if ((ep = erts_active_export_entry(erts_proc_get_error_handler(p), am_undefined_function, 3)) == NULL) { return NULL; } else { int i; Uint sz = 2*arity; Eterm* hp; Eterm args = NIL; /* * Always copy args from registers to a new list; this ensures * that we have the same behaviour whether or not this was * called from apply or fixed_apply (any additional last * THIS-argument will be included, assuming that arity has been * properly adjusted). */ hp = HAlloc(p, sz); for (i = arity-1; i >= 0; i--) { args = CONS(hp, reg[i], args); hp += 2; } reg[0] = module; reg[1] = function; reg[2] = args; } return ep; } static ERTS_INLINE void apply_bif_error_adjustment(Process *p, Export *ep, Eterm *reg, Uint arity, ErtsCodePtr I, Uint stack_offset) { int apply_only; Uint need; need = stack_offset /* bytes */ / sizeof(Eterm); apply_only = stack_offset == 0; /* * I is only set when the apply is a tail call, i.e., * from the instructions i_apply_only, i_apply_last_P, * and apply_last_IP. */ if (!(I && (ep->bif_number == BIF_error_1 || ep->bif_number == BIF_error_2 || ep->bif_number == BIF_error_3 || ep->bif_number == BIF_exit_1 || ep->bif_number == BIF_throw_1))) { return; } /* * We are about to tail apply one of the BIFs erlang:error/1, * erlang:error/2, erlang:error/3, erlang:exit/1, or * erlang:throw/1. Error handling of these BIFs is special! * * We need the topmost continuation pointer to point into the calling * function when handling the error after the BIF has been applied. This in * order to get the topmost stackframe correct. * * Note that these BIFs will unconditionally cause an exception to be * raised. That is, our modifications of the stack will be corrected by the * error handling code. */ if (need == 0) { need = CP_SIZE; /* i_apply_only */ } if (HeapWordsLeft(p) < need) { erts_garbage_collect(p, (int) need, reg, arity+1); } if (apply_only) { /* * Called from the i_apply_only instruction. * * Push the continuation pointer for the current function to the stack. */ p->stop -= need; switch (erts_frame_layout) { case ERTS_FRAME_LAYOUT_RA: p->stop[0] = make_cp(I); break; case ERTS_FRAME_LAYOUT_FP_RA: p->stop[0] = make_cp(FRAME_POINTER(p)); p->stop[1] = make_cp(I); FRAME_POINTER(p) = &p->stop[0]; break; } } else { /* * Called from an i_apply_last_* instruction. * * The calling instruction will deallocate a stack frame of size * 'stack_offset'. * * Push the continuation pointer for the current function to the stack, * and then add a dummy stackframe for the i_apply_last* instruction * to discard. */ switch (erts_frame_layout) { case ERTS_FRAME_LAYOUT_RA: p->stop[0] = make_cp(I); break; case ERTS_FRAME_LAYOUT_FP_RA: p->stop[0] = make_cp(FRAME_POINTER(p)); p->stop[1] = make_cp(I); FRAME_POINTER(p) = &p->stop[0]; break; } p->stop -= need; } } Export* apply(Process* p, Eterm* reg, ErtsCodePtr I, Uint stack_offset) { int arity; Export* ep; Eterm tmp; Eterm module = reg[0]; Eterm function = reg[1]; Eterm args = reg[2]; /* * Check the arguments which should be of the form apply(Module, * Function, Arguments) where Function is an atom and * Arguments is an arity long list of terms. */ if (is_not_atom(function)) { /* * No need to test args here -- done below. */ error: p->freason = BADARG; error2: reg[0] = module; reg[1] = function; reg[2] = args; return NULL; } while (1) { Eterm m, f, a; if (is_not_atom(module)) goto error; if (module != am_erlang || function != am_apply) break; /* Adjust for multiple apply of apply/3... */ a = args; if (is_list(a)) { Eterm *consp = list_val(a); m = CAR(consp); a = CDR(consp); if (is_list(a)) { consp = list_val(a); f = CAR(consp); a = CDR(consp); if (is_list(a)) { consp = list_val(a); a = CAR(consp); if (is_nil(CDR(consp))) { /* erlang:apply/3 */ module = m; function = f; args = a; if (is_not_atom(f)) goto error; continue; } } } } break; /* != erlang:apply/3 */ } /* * Walk down the 3rd parameter of apply (the argument list) and copy * the parameters to the x registers (reg[]). */ tmp = args; arity = 0; while (is_list(tmp)) { if (arity < (MAX_REG - 1)) { reg[arity++] = CAR(list_val(tmp)); tmp = CDR(list_val(tmp)); } else { p->freason = SYSTEM_LIMIT; goto error2; } } if (is_not_nil(tmp)) { /* Must be well-formed list */ goto error; } /* * Get the index into the export table, or failing that the export * entry for the error handler. * * Note: All BIFs have export entries; thus, no special case is needed. */ if ((ep = erts_active_export_entry(module, function, arity)) == NULL) { if ((ep = apply_setup_error_handler(p, module, function, arity, reg)) == NULL) goto error; } apply_bif_error_adjustment(p, ep, reg, arity, I, stack_offset); DTRACE_GLOBAL_CALL_FROM_EXPORT(p, ep); return ep; } Export* fixed_apply(Process* p, Eterm* reg, Uint arity, ErtsCodePtr I, Uint stack_offset) { Export* ep; Eterm module; Eterm function; module = reg[arity]; /* The THIS pointer already in place */ function = reg[arity+1]; if (is_not_atom(function)) { Eterm bad_args; error: bad_args = make_arglist(p, reg, arity); p->freason = BADARG; reg[0] = module; reg[1] = function; reg[2] = bad_args; return NULL; } if (is_not_atom(module)) goto error; /* Handle apply of apply/3... */ if (module == am_erlang && function == am_apply && arity == 3) { return apply(p, reg, I, stack_offset); } /* * Get the index into the export table, or failing that the export * entry for the error handler module. * * Note: All BIFs have export entries; thus, no special case is needed. */ if ((ep = erts_active_export_entry(module, function, arity)) == NULL) { if ((ep = apply_setup_error_handler(p, module, function, arity, reg)) == NULL) goto error; } apply_bif_error_adjustment(p, ep, reg, arity, I, stack_offset); DTRACE_GLOBAL_CALL_FROM_EXPORT(p, ep); return ep; } int erts_hibernate(Process* c_p, Eterm* reg) { int arity; Eterm tmp; Eterm module = reg[0]; Eterm function = reg[1]; Eterm args = reg[2]; if (is_not_atom(module) || is_not_atom(function)) { /* * No need to test args here -- done below. */ error: c_p->freason = BADARG; error2: reg[0] = module; reg[1] = function; reg[2] = args; return 0; } arity = 0; tmp = args; while (is_list(tmp)) { if (arity < MAX_REG) { tmp = CDR(list_val(tmp)); arity++; } else { c_p->freason = SYSTEM_LIMIT; goto error2; } } if (is_not_nil(tmp)) { /* Must be well-formed list */ goto error; } /* * At this point, arguments are known to be good. */ if (c_p->arg_reg != c_p->def_arg_reg) { /* Save some memory */ erts_free(ERTS_ALC_T_ARG_REG, c_p->arg_reg); c_p->arg_reg = c_p->def_arg_reg; c_p->max_arg_reg = sizeof(c_p->def_arg_reg)/sizeof(c_p->def_arg_reg[0]); } #ifdef USE_VM_PROBES if (DTRACE_ENABLED(process_hibernate)) { ErtsCodeMFA cmfa = { module, function, arity}; DTRACE_CHARBUF(process_name, DTRACE_TERM_BUF_SIZE); DTRACE_CHARBUF(mfa_buf, DTRACE_TERM_BUF_SIZE); dtrace_fun_decode(c_p, &cmfa, process_name, mfa_buf); DTRACE2(process_hibernate, process_name, mfa_buf); } #endif /* * Arrange for the process to be resumed at the given MFA with * the stack cleared. */ c_p->arity = 3; c_p->arg_reg[0] = module; c_p->arg_reg[1] = function; c_p->arg_reg[2] = args; c_p->stop = c_p->hend - CP_SIZE; /* Keep first continuation pointer */ switch(erts_frame_layout) { case ERTS_FRAME_LAYOUT_RA: ASSERT(c_p->stop[0] == make_cp(beam_normal_exit)); break; case ERTS_FRAME_LAYOUT_FP_RA: FRAME_POINTER(c_p) = &c_p->stop[0]; ASSERT(c_p->stop[0] == make_cp(NULL)); ASSERT(c_p->stop[1] == make_cp(beam_normal_exit)); break; } c_p->catches = 0; c_p->i = beam_run_process; /* * If there are no waiting messages, garbage collect and * shrink the heap. */ erts_proc_lock(c_p, ERTS_PROC_LOCK_MSGQ|ERTS_PROC_LOCK_STATUS); if (!erts_proc_sig_fetch(c_p)) { erts_proc_unlock(c_p, ERTS_PROC_LOCK_MSGQ|ERTS_PROC_LOCK_STATUS); c_p->fvalue = NIL; PROCESS_MAIN_CHK_LOCKS(c_p); erts_garbage_collect_hibernate(c_p); ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p); PROCESS_MAIN_CHK_LOCKS(c_p); erts_proc_lock(c_p, ERTS_PROC_LOCK_MSGQ|ERTS_PROC_LOCK_STATUS); if (!erts_proc_sig_fetch(c_p)) erts_atomic32_read_band_relb(&c_p->state, ~ERTS_PSFLG_ACTIVE); ASSERT(!ERTS_PROC_IS_EXITING(c_p)); } erts_proc_unlock(c_p, ERTS_PROC_LOCK_MSGQ|ERTS_PROC_LOCK_STATUS); c_p->current = &BIF_TRAP_EXPORT(BIF_hibernate_3)->info.mfa; c_p->flags |= F_HIBERNATE_SCHED; /* Needed also when woken! */ return 1; } ErtsCodePtr call_fun(Process* p, /* Current process. */ int arity, /* Number of arguments for Fun. */ Eterm* reg, /* Contents of registers. */ Eterm args) /* THE_NON_VALUE or pre-built list of arguments. */ { ErtsCodeIndex code_ix; ErtsCodePtr code_ptr; ErlFunThing *funp; Eterm fun; fun = reg[arity]; if (is_not_any_fun(fun)) { p->current = NULL; p->freason = EXC_BADFUN; p->fvalue = fun; return NULL; } funp = (ErlFunThing*)fun_val(fun); code_ix = erts_active_code_ix(); code_ptr = (funp->entry.disp)->addresses[code_ix]; if (ERTS_LIKELY(code_ptr != beam_unloaded_fun && funp->arity == arity)) { for (int i = 0, num_free = funp->num_free; i < num_free; i++) { reg[i + arity] = funp->env[i]; } #ifdef USE_VM_CALL_PROBES if (is_local_fun(funp)) { DTRACE_LOCAL_CALL(p, erts_code_to_codemfa(code_ptr)); } else { Export *ep = funp->entry.exp; ASSERT(is_external_fun(funp) && funp->next == NULL); DTRACE_GLOBAL_CALL(p, &ep->info.mfa); } #endif return code_ptr; } else { /* Something wrong here. First build a list of the arguments. */ if (is_non_value(args)) { Uint sz = 2 * arity; Eterm *hp; args = NIL; if (HeapWordsLeft(p) < sz) { erts_garbage_collect(p, sz, reg, arity+1); fun = reg[arity]; funp = (ErlFunThing*)fun_val(fun); } hp = HEAP_TOP(p); HEAP_TOP(p) += sz; for (int i = arity - 1; i >= 0; i--) { args = CONS(hp, reg[i], args); hp += 2; } } if (funp->arity != arity) { /* There is a fun defined, but the call has the wrong arity. */ Eterm *hp = HAlloc(p, 3); p->freason = EXC_BADARITY; p->fvalue = TUPLE2(hp, fun, args); return NULL; } else { ErlFunEntry *fe; Eterm module; Module *modp; Export *ep; /* There is no module loaded that defines the fun, either because * the fun is newly created from the external representation (the * module has never been loaded), or the module defining the fun * has been unloaded. */ ASSERT(is_local_fun(funp) && code_ptr == beam_unloaded_fun); fe = funp->entry.fun; module = fe->module; ERTS_THR_READ_MEMORY_BARRIER; if (fe->pend_purge_address) { /* 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). */ ep = erts_suspend_process_on_pending_purge_lambda(p, fe); } 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). */ p->current = NULL; p->freason = EXC_BADFUN; p->fvalue = fun; return NULL; } /* 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; } } ASSERT(ep); reg[0] = module; reg[1] = fun; reg[2] = args; reg[3] = NIL; return ep->dispatch.addresses[code_ix]; } } } ErtsCodePtr apply_fun(Process* p, Eterm fun, Eterm args, Eterm* reg) { int arity; Eterm tmp; /* * Walk down the 3rd parameter of apply (the argument list) and copy * the parameters to the x registers (reg[]). */ tmp = args; arity = 0; while (is_list(tmp)) { if (arity < MAX_REG-1) { reg[arity++] = CAR(list_val(tmp)); tmp = CDR(list_val(tmp)); } else { p->freason = SYSTEM_LIMIT; return NULL; } } if (is_not_nil(tmp)) { /* Must be well-formed list */ p->freason = EXC_BADARG; return NULL; } reg[arity] = fun; return call_fun(p, arity, reg, args); } int is_function2(Eterm Term, Uint arity) { if (is_any_fun(Term)) { ErlFunThing *funp = (ErlFunThing*)fun_val(Term); return funp->arity == arity; } return 0; } Eterm get_map_element(Eterm map, Eterm key) { Uint32 hx; const Eterm *vs; if (is_flatmap(map)) { flatmap_t *mp; Eterm *ks; Uint i; Uint n; mp = (flatmap_t *)flatmap_val(map); ks = flatmap_get_keys(mp); vs = flatmap_get_values(mp); n = flatmap_get_size(mp); if (is_immed(key)) { for (i = 0; i < n; i++) { if (ks[i] == key) { return vs[i]; } } } else { for (i = 0; i < n; i++) { if (EQ(ks[i], key)) { return vs[i]; } } } return THE_NON_VALUE; } ASSERT(is_hashmap(map)); hx = hashmap_make_hash(key); vs = erts_hashmap_get(hx,key,map); return vs ? *vs : THE_NON_VALUE; } Eterm get_map_element_hash(Eterm map, Eterm key, Uint32 hx) { const Eterm *vs; if (is_flatmap(map)) { flatmap_t *mp; Eterm *ks; Uint i; Uint n; mp = (flatmap_t *)flatmap_val(map); ks = flatmap_get_keys(mp); vs = flatmap_get_values(mp); n = flatmap_get_size(mp); if (is_immed(key)) { for (i = 0; i < n; i++) { if (ks[i] == key) { return vs[i]; } } } else { for (i = 0; i < n; i++) { if (EQ(ks[i], key)) { return vs[i]; } } } return THE_NON_VALUE; } ASSERT(is_hashmap(map)); ASSERT(hx == hashmap_make_hash(key)); vs = erts_hashmap_get(hx, key, map); return vs ? *vs : THE_NON_VALUE; } #define GET_TERM(term, dest) \ do { \ Eterm src = (Eterm)(term); \ switch (loader_tag(src)) { \ case LOADER_X_REG: \ dest = x(loader_x_reg_index(src)); \ break; \ case LOADER_Y_REG: \ dest = y(loader_y_reg_index(src)); \ break; \ default: \ dest = src; \ break; \ } \ } while(0) Eterm erts_gc_new_map(Process* p, Eterm* reg, Uint live, Uint n, const Eterm* ptr) { Uint i; Uint need = n + 1 /* hdr */ + 1 /*size*/ + 1 /* ptr */ + 1 /* arity */; Eterm keys; Eterm *mhp,*thp; Eterm *E; flatmap_t *mp; ErtsHeapFactory factory; if (n > 2*MAP_SMALL_MAP_LIMIT) { Eterm res; if (HeapWordsLeft(p) < n) { erts_garbage_collect(p, n, reg, live); } mhp = p->htop; thp = p->htop; E = p->stop; for (i = 0; i < n/2; i++) { GET_TERM(*ptr++, *mhp++); GET_TERM(*ptr++, *mhp++); } p->htop = mhp; erts_factory_proc_init(&factory, p); res = erts_hashmap_from_array(&factory, thp, n/2, 0); erts_factory_close(&factory); return res; } if (HeapWordsLeft(p) < need) { erts_garbage_collect(p, need, reg, live); } thp = p->htop; mhp = thp + (n == 0 ? 0 : 1) + n/2; E = p->stop; if (n == 0) { keys = ERTS_GLOBAL_LIT_EMPTY_TUPLE; } else { keys = make_tuple(thp); *thp++ = make_arityval(n/2); } mp = (flatmap_t *)mhp; mhp += MAP_HEADER_FLATMAP_SZ; mp->thing_word = MAP_HEADER_FLATMAP; mp->size = n/2; mp->keys = keys; for (i = 0; i < n/2; i++) { GET_TERM(*ptr++, *thp++); GET_TERM(*ptr++, *mhp++); } p->htop = mhp; return make_flatmap(mp); } Eterm erts_gc_new_small_map_lit(Process* p, Eterm* reg, Eterm keys_literal, Uint live, const Eterm* ptr) { Eterm* keys = tuple_val(keys_literal); Uint n = arityval(*keys); Uint need = n + 1 /* hdr */ + 1 /*size*/ + 1 /* ptr */ + 1 /* arity */; Uint i; flatmap_t *mp; Eterm *mhp; Eterm *E; ASSERT(n <= MAP_SMALL_MAP_LIMIT); if (HeapWordsLeft(p) < need) { erts_garbage_collect(p, need, reg, live); } mhp = p->htop; E = p->stop; mp = (flatmap_t *)mhp; mhp += MAP_HEADER_FLATMAP_SZ; mp->thing_word = MAP_HEADER_FLATMAP; mp->size = n; mp->keys = keys_literal; for (i = 0; i < n; i++) { GET_TERM(*ptr++, *mhp++); } p->htop = mhp; return make_flatmap(mp); } Eterm erts_gc_update_map_assoc(Process* p, Eterm* reg, Uint live, Uint n, const Eterm* new_p) { Uint num_old; Uint num_updates; Uint need; flatmap_t *old_mp, *mp; Eterm res; Eterm* hp; Eterm* E; Eterm* old_keys; Eterm* old_vals; Eterm new_key; Eterm* kp; Eterm map; num_updates = n / 2; map = reg[live]; if (is_not_flatmap(map)) { Uint32 hx; Eterm val; ASSERT(is_hashmap(map)); res = map; E = p->stop; while(num_updates--) { /* assoc can't fail */ GET_TERM(new_p[0], new_key); GET_TERM(new_p[1], val); hx = hashmap_make_hash(new_key); res = erts_hashmap_insert(p, hx, new_key, val, res, 0); new_p += 2; } return res; } old_mp = (flatmap_t *) flatmap_val(map); num_old = flatmap_get_size(old_mp); /* * If the old map is empty, create a new map. */ if (num_old == 0) { return erts_gc_new_map(p, reg, live, n, new_p); } /* * Allocate heap space for the worst case (i.e. all keys in the * update list are new). */ need = 2*(num_old+num_updates) + 1 + MAP_HEADER_FLATMAP_SZ; if (HeapWordsLeft(p) < need) { erts_garbage_collect(p, need, reg, live+1); map = reg[live]; old_mp = (flatmap_t *)flatmap_val(map); } /* * Build the skeleton for the map, ready to be filled in. * * +-----------------------------------+ * | (Space for aritvyal for keys) | <-----------+ * +-----------------------------------+ | * | (Space for key 1) | | <-- kp * +-----------------------------------+ | * . | * . | * . | * +-----------------------------------+ | * | (Space for last key) | | * +-----------------------------------+ | * | MAP_HEADER | | * +-----------------------------------+ | * | (Space for number of keys/values) | | * +-----------------------------------+ | * | Boxed tuple pointer >----------------+ * +-----------------------------------+ * | (Space for value 1) | <-- hp * +-----------------------------------+ */ E = p->stop; kp = p->htop + 1; /* Point to first key */ hp = kp + num_old + num_updates; res = make_flatmap(hp); mp = (flatmap_t *)hp; hp += MAP_HEADER_FLATMAP_SZ; mp->thing_word = MAP_HEADER_FLATMAP; mp->keys = make_tuple(kp-1); old_vals = flatmap_get_values(old_mp); old_keys = flatmap_get_keys(old_mp); GET_TERM(*new_p, new_key); n = num_updates; /* * Fill in keys and values, until we run out of either updates * or old values and keys. */ for (;;) { Eterm key; Sint c; ASSERT(kp < (Eterm *)mp); key = *old_keys; if ((c = CMP_TERM(key, new_key)) < 0) { /* Copy old key and value */ *kp++ = key; *hp++ = *old_vals; old_keys++, old_vals++, num_old--; } else { /* Replace or insert new */ GET_TERM(new_p[1], *hp++); if (c > 0) { /* If new key */ *kp++ = new_key; } else { /* If replacement */ *kp++ = key; old_keys++, old_vals++, num_old--; } n--; if (n == 0) { break; } else { new_p += 2; GET_TERM(*new_p, new_key); } } if (num_old == 0) { break; } } /* * At this point, we have run out of either old keys and values, * or the update list. In other words, at least of one n and * num_old must be zero. */ if (n > 0) { /* * All old keys and values have been copied, but there * are still new keys and values in the update list that * must be copied. */ ASSERT(num_old == 0); while (n-- > 0) { GET_TERM(new_p[0], *kp++); GET_TERM(new_p[1], *hp++); new_p += 2; } } else { /* * All updates are now done. We may still have old * keys and values that we must copy. */ ASSERT(n == 0); while (num_old-- > 0) { ASSERT(kp < (Eterm *)mp); *kp++ = *old_keys++; *hp++ = *old_vals++; } } /* * Calculate how many values that are unused at the end of the * key tuple and fill it out with a bignum header. */ if ((n = (Eterm *)mp - kp) > 0) { *kp = make_pos_bignum_header(n-1); } /* * Fill in the size of the map in both the key tuple and in the map. */ n = kp - p->htop - 1; /* Actual number of keys/values */ *p->htop = make_arityval(n); p->htop = hp; mp->size = n; /* The expensive case, need to build a hashmap */ if (n > MAP_SMALL_MAP_LIMIT) { ErtsHeapFactory factory; erts_factory_proc_init(&factory, p); res = erts_hashmap_from_ks_and_vs(&factory,flatmap_get_keys(mp), flatmap_get_values(mp),n); erts_factory_close(&factory); } return res; } /* * Update values for keys that already exist in the map. */ Eterm erts_gc_update_map_exact(Process* p, Eterm* reg, Uint live, Uint n, const Eterm* new_p) { Uint i; Uint num_old; Uint need; flatmap_t *old_mp, *mp; Eterm res; Eterm* old_hp; Eterm* hp; Eterm* E; Eterm* old_keys; Eterm* old_vals; Eterm new_key; Eterm map; int changed = 0; n /= 2; /* Number of values to be updated */ ASSERT(n > 0); map = reg[live]; if (is_not_flatmap(map)) { Uint32 hx; Eterm val; /* apparently the compiler does not emit is_map instructions, * bad compiler */ if (is_not_hashmap(map)) { p->freason = BADMAP; p->fvalue = map; return THE_NON_VALUE; } res = map; E = p->stop; while(n--) { GET_TERM(new_p[0], new_key); GET_TERM(new_p[1], val); hx = hashmap_make_hash(new_key); res = erts_hashmap_insert(p, hx, new_key, val, res, 1); if (is_non_value(res)) { p->fvalue = new_key; p->freason = BADKEY; return res; } new_p += 2; } return res; } old_mp = (flatmap_t *) flatmap_val(map); num_old = flatmap_get_size(old_mp); /* * If the old map is empty, fail. */ if (num_old == 0) { E = p->stop; p->freason = BADKEY; GET_TERM(new_p[0], p->fvalue); return THE_NON_VALUE; } /* * Allocate the exact heap space needed. */ need = num_old + MAP_HEADER_FLATMAP_SZ; if (HeapWordsLeft(p) < need) { erts_garbage_collect(p, need, reg, live+1); map = reg[live]; old_mp = (flatmap_t *)flatmap_val(map); } /* * Update map, keeping the old key tuple. */ old_hp = p->htop; hp = p->htop; E = p->stop; old_vals = flatmap_get_values(old_mp); old_keys = flatmap_get_keys(old_mp); res = make_flatmap(hp); mp = (flatmap_t *)hp; hp += MAP_HEADER_FLATMAP_SZ; mp->thing_word = MAP_HEADER_FLATMAP; mp->size = num_old; mp->keys = old_mp->keys; /* Get array of key/value pairs to be updated */ GET_TERM(*new_p, new_key); /* Update all values */ for (i = 0; i < num_old; i++) { if (!EQ(*old_keys, new_key)) { /* Not same keys */ *hp++ = *old_vals; } else { GET_TERM(new_p[1], *hp); if(*hp != *old_vals) changed = 1; hp++; n--; if (n == 0) { /* * All updates done. Copy remaining values * if any changed or return the original one. */ if(changed) { for (i++, old_vals++; i < num_old; i++) { *hp++ = *old_vals++; } ASSERT(hp == p->htop + need); p->htop = hp; return res; } else { p->htop = old_hp; return map; } } else { new_p += 2; GET_TERM(*new_p, new_key); } } old_vals++, old_keys++; } /* * Updates left. That means that at least one the keys in the * update list did not previously exist. */ ASSERT(hp == p->htop + need); p->freason = BADKEY; p->fvalue = new_key; return THE_NON_VALUE; } #undef GET_TERM int catchlevel(Process *p) { return p->catches; } /* * Check if the given function is built-in (i.e. a BIF implemented in C). * * Returns 0 if not built-in, and a non-zero value if built-in. */ int erts_is_builtin(Eterm Mod, Eterm Name, int arity) { Export e; Export* ep; if (Mod == am_erlang) { /* * Special case for built-in functions that are implemented * as instructions as opposed to SNIFs. */ if (Name == am_apply && (arity == 2 || arity == 3)) { return 1; } else if (Name == am_yield && arity == 0) { return 1; } } e.info.mfa.module = Mod; e.info.mfa.function = Name; e.info.mfa.arity = arity; if ((ep = export_get(&e)) == NULL) { return 0; } return ep->bif_number != -1; } /* * Return the current number of reductions consumed by the given process. * To get the total number of reductions, p->reds must be added. */ Uint erts_current_reductions(Process *c_p, Process *p) { Sint reds_left; if (c_p != p || !(erts_atomic32_read_nob(&c_p->state) & ERTS_PSFLG_RUNNING)) { return 0; #ifndef BEAMASM /* BEAMASM doesn't use negative reductions for save_calls. */ } else if (c_p->fcalls < 0 && ERTS_PROC_GET_SAVED_CALLS_BUF(c_p)) { reds_left = c_p->fcalls + CONTEXT_REDS; #endif } else { reds_left = c_p->fcalls; } return REDS_IN(c_p) - reds_left - erts_proc_sched_data(p)->virtual_reds; }