diff options
Diffstat (limited to 'erts')
-rw-r--r-- | erts/doc/src/notes.xml | 43 | ||||
-rw-r--r-- | erts/emulator/beam/erl_process.c | 284 | ||||
-rw-r--r-- | erts/emulator/drivers/common/inet_drv.c | 9 | ||||
-rw-r--r-- | erts/emulator/sys/common/erl_osenv.c | 10 | ||||
-rw-r--r-- | erts/emulator/test/bif_SUITE.erl | 16 | ||||
-rw-r--r-- | erts/emulator/test/process_SUITE.erl | 54 | ||||
-rw-r--r-- | erts/vsn.mk | 2 |
7 files changed, 259 insertions, 159 deletions
diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml index ed0946d6ba..856020dfc9 100644 --- a/erts/doc/src/notes.xml +++ b/erts/doc/src/notes.xml @@ -31,6 +31,49 @@ </header> <p>This document describes the changes made to the ERTS application.</p> +<section><title>Erts 10.0.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a rare bug that could cause processes to be + scheduled after they had been freed.</p> + <p> + Own Id: OTP-15067 Aux Id: ERL-573 </p> + </item> + </list> + </section> + + + <section><title>Known Bugs and Problems</title> + <list> + <item> + <p>Fixed a race condition in the inet driver that could + cause receive to hang when the emulator was compiled with + gcc 8.</p> + <p> + Own Id: OTP-15158 Aux Id: ERL-654 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The keys used in <c>os:getenv</c> and <c>os:putenv</c> + are case-insensitive again on Windows.</p> + <p> + Own Id: OTP-15147 Aux Id: ERL-644 </p> + </item> + </list> + </section> + +</section> + <section><title>Erts 10.0</title> <section><title>Fixed Bugs and Malfunctions</title> diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c index 8253ec4f40..11b52526d5 100644 --- a/erts/emulator/beam/erl_process.c +++ b/erts/emulator/beam/erl_process.c @@ -3761,6 +3761,8 @@ dequeue_process(ErtsRunQueue *runq, int prio_q, erts_aint32_t *statep) ERTS_THR_DATA_DEPENDENCY_READ_MEMORY_BARRIER; state = erts_atomic32_read_nob(&p->state); + ASSERT(state & ERTS_PSFLG_IN_RUNQ); + if (statep) *statep = state; @@ -3768,8 +3770,7 @@ dequeue_process(ErtsRunQueue *runq, int prio_q, erts_aint32_t *statep) rqi = &runq->procs.prio_info[prio]; - if (p) - unqueue_process(runq, rpq, rqi, prio, NULL, p); + unqueue_process(runq, rpq, rqi, prio, NULL, p); return p; } @@ -4088,7 +4089,7 @@ evacuate_run_queue(ErtsRunQueue *rq, erts_runq_unlock(to_rq); smp_notify_inc_runq(to_rq); - erts_runq_lock(to_rq); + erts_runq_lock(rq); } if (rq->ports.start) { @@ -4157,22 +4158,17 @@ evacuate_run_queue(ErtsRunQueue *rq, free_proxy_proc(proc); else { erts_aint32_t clr_bits; -#ifdef DEBUG - erts_aint32_t old; -#endif clr_bits = ERTS_PSFLG_IN_RUNQ; clr_bits |= qbit << ERTS_PSFLGS_IN_PRQ_MASK_OFFSET; -#ifdef DEBUG - old = -#else - (void) -#endif - erts_atomic32_read_band_mb(&proc->state, - ~clr_bits); - ASSERT((old & clr_bits) == clr_bits); + state = erts_atomic32_read_band_mb(&proc->state, ~clr_bits); + ASSERT((state & clr_bits) == clr_bits); + if (state & ERTS_PSFLG_FREE) { + /* free and not queued by proxy */ + erts_proc_dec_refc(proc); + } } goto handle_next_proc; @@ -6208,13 +6204,14 @@ fin_dirty_enq_s_change(Process *p, /* Already enqueue by someone else... */ if (pstruct_reserved) { /* We reserved process struct for enqueue; clear it... */ -#ifdef DEBUG - erts_aint32_t old = -#else - (void) -#endif - erts_atomic32_read_band_nob(&p->state, ~ERTS_PSFLG_IN_RUNQ); - ASSERT(old & ERTS_PSFLG_IN_RUNQ); + erts_aint32_t state; + + state = erts_atomic32_read_band_nob(&p->state, ~ERTS_PSFLG_IN_RUNQ); + ASSERT(state & ERTS_PSFLG_IN_RUNQ); + + if (state & ERTS_PSFLG_FREE) { + erts_proc_dec_refc(p); + } } return 0; } @@ -6407,8 +6404,9 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p, == ERTS_PSFLG_ACTIVE)); n &= ~running_flgs; - if ((a & (ERTS_PSFLG_ACTIVE_SYS|ERTS_PSFLG_DIRTY_ACTIVE_SYS)) - || (a & (ERTS_PSFLG_ACTIVE|ERTS_PSFLG_SUSPENDED)) == ERTS_PSFLG_ACTIVE) { + if ((!!(a & (ERTS_PSFLG_ACTIVE_SYS|ERTS_PSFLG_DIRTY_ACTIVE_SYS)) + | ((a & (ERTS_PSFLG_ACTIVE|ERTS_PSFLG_SUSPENDED)) == ERTS_PSFLG_ACTIVE)) + & !(a & ERTS_PSFLG_FREE)) { enqueue = check_enqueue_in_prio_queue(p, &enq_prio, &n, a); } a = erts_atomic32_cmpxchg_mb(&p->state, n, e); @@ -6655,62 +6653,72 @@ erts_schedule_process(Process *p, erts_aint32_t state, ErtsProcLocks locks) schedule_process(p, state, locks); } +/* Enqueues the given sys task on the process and schedules it. The task may be + * NULL if only scheduling is desired. */ static ERTS_INLINE erts_aint32_t -active_sys_enqueue(Process *p, erts_aint32_t state, - erts_aint32_t enable_flags, int status_locked) -{ - /* - * This function may or may not be called with status locke held. - * It always returns without the status lock held! - */ - unsigned int prof_runnable_procs = erts_system_profile_flags.runnable_procs; - erts_aint32_t n, a = state, enq_prio = -1; - int slocked = status_locked; +active_sys_enqueue(Process *p, ErtsProcSysTask *sys_task, + erts_aint32_t task_prio, erts_aint32_t enable_flags, + erts_aint32_t state, erts_aint32_t *fail_state_p) +{ + int runnable_procs = erts_system_profile_flags.runnable_procs; + erts_aint32_t n, a, enq_prio, fail_state; + int already_scheduled; + int status_locked; int enqueue; /* < 0 -> use proxy */ - /* Status lock prevents out of order "runnable proc" trace msgs */ - ERTS_LC_ASSERT(slocked || !(ERTS_PROC_LOCK_STATUS & erts_proc_lc_my_proc_locks(p))); - ERTS_LC_ASSERT(!slocked || (ERTS_PROC_LOCK_STATUS & erts_proc_lc_my_proc_locks(p))); - - if (!prof_runnable_procs) { - if (slocked) { - erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS); - slocked = 0; - } - } - else { - if (!slocked) { - erts_proc_lock(p, ERTS_PROC_LOCK_STATUS); - slocked = !0; - } - } + enable_flags |= ERTS_PSFLG_ACTIVE_SYS; + fail_state = *fail_state_p; + already_scheduled = 0; + status_locked = 0; + enq_prio = -1; + a = state; + ERTS_LC_ASSERT(!(ERTS_PROC_LOCK_STATUS & erts_proc_lc_my_proc_locks(p))); + ASSERT(fail_state & (ERTS_PSFLG_EXITING | ERTS_PSFLG_FREE)); + ASSERT(!(fail_state & enable_flags)); ASSERT(!(state & ERTS_PSFLG_PROXY)); + /* When runnable_procs is enabled, we need to take the status lock to + * prevent trace messages from being sent in the wrong order. The lock must + * be held over the call to add2runq. + * + * Otherwise, we only need to take it when we're enqueuing a task and can + * safely release it before add2runq. */ + if (sys_task || runnable_procs) { + erts_proc_lock(p, ERTS_PROC_LOCK_STATUS); + status_locked = 1; + } + while (1) { erts_aint32_t e; n = e = a; - if (a & ERTS_PSFLG_FREE) - goto cleanup; /* We don't want to schedule free processes... */ + if (a & fail_state) { + *fail_state_p = a & fail_state; + goto cleanup; + } enqueue = ERTS_ENQUEUE_NOT; - n |= enable_flags; - n |= ERTS_PSFLG_ACTIVE_SYS; + n |= enable_flags; + if (!(a & (ERTS_PSFLG_RUNNING | ERTS_PSFLG_RUNNING_SYS | ERTS_PSFLG_DIRTY_RUNNING - | ERTS_PSFLG_DIRTY_RUNNING_SYS))) + | ERTS_PSFLG_DIRTY_RUNNING_SYS))) { enqueue = check_enqueue_in_prio_queue(p, &enq_prio, &n, a); + } + a = erts_atomic32_cmpxchg_mb(&p->state, n, e); - if (a == e) + if (a == e) { break; - if (a == n && enqueue == ERTS_ENQUEUE_NOT) - goto cleanup; + } + else if (a == n && enqueue == ERTS_ENQUEUE_NOT) { + already_scheduled = 1; + break; + } } - if (prof_runnable_procs) { - + if (!already_scheduled && runnable_procs) { if (!(a & (ERTS_PSFLG_ACTIVE_SYS | ERTS_PSFLG_RUNNING | ERTS_PSFLG_RUNNING_SYS @@ -6720,19 +6728,56 @@ active_sys_enqueue(Process *p, erts_aint32_t state, /* We activated a prevously inactive process */ profile_runnable_proc(p, am_active); } - - erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS); - slocked = 0; } - add2runq(enqueue, enq_prio, p, n, NULL); + if (sys_task) { + ErtsProcSysTaskQs *stqs = p->sys_task_qs; -cleanup: + if (!stqs) { + sys_task->next = sys_task->prev = sys_task; - if (slocked) - erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS); + stqs = proc_sys_task_queues_alloc(); - ERTS_LC_ASSERT(!(ERTS_PROC_LOCK_STATUS & erts_proc_lc_my_proc_locks(p))); + stqs->qmask = 1 << task_prio; + stqs->ncount = 0; + stqs->q[PRIORITY_MAX] = NULL; + stqs->q[PRIORITY_HIGH] = NULL; + stqs->q[PRIORITY_NORMAL] = NULL; + stqs->q[PRIORITY_LOW] = NULL; + stqs->q[task_prio] = sys_task; + + p->sys_task_qs = stqs; + } + else { + if (!stqs->q[task_prio]) { + sys_task->next = sys_task->prev = sys_task; + + stqs->q[task_prio] = sys_task; + stqs->qmask |= 1 << task_prio; + } + else { + sys_task->next = stqs->q[task_prio]; + sys_task->prev = stqs->q[task_prio]->prev; + sys_task->next->prev = sys_task; + sys_task->prev->next = sys_task; + ASSERT(stqs->qmask & (1 << task_prio)); + } + } + } + + if (status_locked && !runnable_procs) { + erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS); + status_locked = 0; + } + + if (!already_scheduled) { + add2runq(enqueue, enq_prio, p, n, NULL); + } + +cleanup: + if (status_locked) { + erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS); + } return n; } @@ -6740,103 +6785,41 @@ cleanup: erts_aint32_t erts_proc_sys_schedule(Process *p, erts_aint32_t state, erts_aint32_t enable_flag) { - /* We are not allowed to call this function with status lock held... */ - return active_sys_enqueue(p, state, enable_flag, 0); + erts_aint32_t fail_state = ERTS_PSFLG_FREE; + + return active_sys_enqueue(p, NULL, 0, enable_flag, state, &fail_state); } static int schedule_process_sys_task(Process *p, erts_aint32_t prio, ErtsProcSysTask *st, erts_aint32_t *fail_state_p) { - int res; - int locked; - ErtsProcSysTaskQs *stqs, *free_stqs; erts_aint32_t fail_state, state; - fail_state = *fail_state_p; - - res = 1; /* prepare for success */ - st->next = st->prev = st; /* Prep for empty prio queue */ + /* Elevate priority if needed. */ state = erts_atomic32_read_nob(&p->state); - locked = 0; - free_stqs = NULL; - if (state & ERTS_PSFLG_SYS_TASKS) - stqs = NULL; - else { - alloc_qs: - stqs = proc_sys_task_queues_alloc(); - stqs->qmask = 1 << prio; - stqs->ncount = 0; - stqs->q[PRIORITY_MAX] = NULL; - stqs->q[PRIORITY_HIGH] = NULL; - stqs->q[PRIORITY_NORMAL] = NULL; - stqs->q[PRIORITY_LOW] = NULL; - stqs->q[prio] = st; - } - - if (!locked) { - locked = 1; - erts_proc_lock(p, ERTS_PROC_LOCK_STATUS); - - state = erts_atomic32_read_nob(&p->state); - if (state & fail_state) { - erts_proc_unlock(p, ERTS_PROC_LOCK_STATUS); - *fail_state_p = (state & fail_state); - free_stqs = stqs; - res = 0; - goto cleanup; - } - } - - if (!p->sys_task_qs) { - if (stqs) - p->sys_task_qs = stqs; - else - goto alloc_qs; - } - else { - free_stqs = stqs; - stqs = p->sys_task_qs; - if (!stqs->q[prio]) { - stqs->q[prio] = st; - stqs->qmask |= 1 << prio; - } - else { - st->next = stqs->q[prio]; - st->prev = stqs->q[prio]->prev; - st->next->prev = st; - st->prev->next = st; - ASSERT(stqs->qmask & (1 << prio)); - } - } - if (ERTS_PSFLGS_GET_ACT_PRIO(state) > prio) { - erts_aint32_t n, a, e; - /* Need to elevate actual prio */ + erts_aint32_t n, a, e; - a = state; - do { - if (ERTS_PSFLGS_GET_ACT_PRIO(a) <= prio) { - n = a; - break; - } - n = e = a; - n &= ~ERTS_PSFLGS_ACT_PRIO_MASK; - n |= (prio << ERTS_PSFLGS_ACT_PRIO_OFFSET); - a = erts_atomic32_cmpxchg_nob(&p->state, n, e); - } while (a != e); - state = n; - } - - /* active_sys_enqueue() always return with status lock unlocked */ - (void) active_sys_enqueue(p, state, ERTS_PSFLG_SYS_TASKS, locked); + a = state; + do { + if (ERTS_PSFLGS_GET_ACT_PRIO(a) <= prio) { + n = a; + break; + } + n = e = a; + n &= ~ERTS_PSFLGS_ACT_PRIO_MASK; + n |= (prio << ERTS_PSFLGS_ACT_PRIO_OFFSET); + a = erts_atomic32_cmpxchg_nob(&p->state, n, e); + } while (a != e); -cleanup: + state = n; + } - if (free_stqs) - proc_sys_task_queues_free(free_stqs); + fail_state = *fail_state_p; - return res; + return !(active_sys_enqueue(p, st, prio, ERTS_PSFLG_SYS_TASKS, + state, fail_state_p) & fail_state); } static ERTS_INLINE int @@ -9563,6 +9546,7 @@ Process *erts_schedule(ErtsSchedulerData *esdp, Process *p, int calls) } else if (state & ERTS_PSFLG_FREE) { /* free and not queued by proxy */ + ASSERT(state & ERTS_PSFLG_IN_RUNQ); erts_proc_dec_refc(p); } if (!is_normal_sched) diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c index 6fd3bb9fbf..5e9afdc5ca 100644 --- a/erts/emulator/drivers/common/inet_drv.c +++ b/erts/emulator/drivers/common/inet_drv.c @@ -1034,6 +1034,7 @@ typedef struct { inet_async_op* oph; /* queue head or NULL */ inet_async_op* opt; /* queue tail or NULL */ inet_async_op op_queue[INET_MAX_ASYNC]; /* call queue */ + int op_ref; /* queue reference generator */ int active; /* 0 = passive, 1 = active, 2 = active once */ Sint16 active_count; /* counter for {active,N} */ @@ -1299,8 +1300,7 @@ static int packet_inet_input(udp_descriptor* udesc, HANDLE event); /* convert descriptor pointer to inet_descriptor pointer */ #define INETP(d) (&(d)->inet) -static int async_ref = 0; /* async reference id generator */ -#define NEW_ASYNC_ID() ((async_ref++) & 0xffff) +#define NEW_ASYNC_ID(desc) ((desc)->op_ref++ & 0xffff) /* check for transition from active to passive */ #define INET_CHECK_ACTIVE_TO_PASSIVE(inet) \ @@ -1955,7 +1955,7 @@ static void enq_multi_op(tcp_descriptor *desc, char *buf, int req, ErlDrvTermData caller, MultiTimerData *timeout, ErlDrvMonitor *monitorp) { - int id = NEW_ASYNC_ID(); + int id = NEW_ASYNC_ID(INETP(desc)); enq_old_multi_op(desc,id,req,caller,timeout,monitorp); if (buf != NULL) put_int16(id, buf); @@ -2024,7 +2024,7 @@ static int remove_multi_op(tcp_descriptor *desc, int *id_p, int *req_p, static int enq_async_w_tmo(inet_descriptor* desc, char* buf, int req, unsigned timeout, ErlDrvMonitor *monitorp) { - int id = NEW_ASYNC_ID(); + int id = NEW_ASYNC_ID(desc); inet_async_op* opp; if ((opp = desc->oph) == NULL) /* queue empty */ @@ -8461,6 +8461,7 @@ static ErlDrvData inet_start(ErlDrvPort port, int size, int protocol) desc->delimiter = '\n'; /* line delimiting char */ desc->oph = NULL; desc->opt = NULL; + desc->op_ref = 0; desc->peer_ptr = NULL; desc->name_ptr = NULL; diff --git a/erts/emulator/sys/common/erl_osenv.c b/erts/emulator/sys/common/erl_osenv.c index 9f54d1dff0..487ff87116 100644 --- a/erts/emulator/sys/common/erl_osenv.c +++ b/erts/emulator/sys/common/erl_osenv.c @@ -75,7 +75,15 @@ static int compare_env_keys(const erts_osenv_data_t a, const erts_osenv_data_t b #include "erl_rbtree.h" static int compare_env_keys(const erts_osenv_data_t a, const erts_osenv_data_t b) { - int relation = sys_memcmp(a.data, b.data, MIN(a.length, b.length)); + int relation; + +#ifdef __WIN32__ + /* Environment variables are case-insensitive on Windows. */ + relation = _wcsnicmp((const WCHAR*)a.data, (const WCHAR*)b.data, + MIN(a.length, b.length) / sizeof(WCHAR)); +#else + relation = sys_memcmp(a.data, b.data, MIN(a.length, b.length)); +#endif if(relation != 0) { return relation; diff --git a/erts/emulator/test/bif_SUITE.erl b/erts/emulator/test/bif_SUITE.erl index 32bfcd5520..9e7bcd5255 100644 --- a/erts/emulator/test/bif_SUITE.erl +++ b/erts/emulator/test/bif_SUITE.erl @@ -36,7 +36,8 @@ error_stacktrace_during_call_trace/1, group_leader_prio/1, group_leader_prio_dirty/1, is_process_alive/1, - process_info_blast/1]). + process_info_blast/1, + os_env_case_sensitivity/1]). suite() -> [{ct_hooks,[ts_install_cth]}, @@ -51,7 +52,7 @@ all() -> erl_crash_dump_bytes, min_max, erlang_halt, is_builtin, error_stacktrace, error_stacktrace_during_call_trace, group_leader_prio, group_leader_prio_dirty, - is_process_alive, process_info_blast]. + is_process_alive, process_info_blast, os_env_case_sensitivity]. %% Uses erlang:display to test that erts_printf does not do deep recursion display(Config) when is_list(Config) -> @@ -443,6 +444,17 @@ os_env_long(Min, Max, Value) -> true = os:unsetenv(EnvVar), os_env_long(Min+1, Max, Value). +os_env_case_sensitivity(Config) when is_list(Config) -> + %% The keys in os:getenv/putenv must be case-insensitive on Windows, and + %% case-sensitive elsewhere. + true = os:putenv("os_env_gurka", "gaffel"), + Expected = case os:type() of + {win32, _} -> "gaffel"; + _ -> false + end, + Expected = os:getenv("OS_ENV_GURKA"), + ok. + %% Test that string:to_integer does not Halloc in wrong order. otp_7526(Config) when is_list(Config) -> ok = test_7526(256). diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl index 585c5a1871..57eb082d64 100644 --- a/erts/emulator/test/process_SUITE.erl +++ b/erts/emulator/test/process_SUITE.erl @@ -59,6 +59,7 @@ no_priority_inversion2/1, system_task_blast/1, system_task_on_suspended/1, + system_task_failed_enqueue/1, gc_request_when_gc_disabled/1, gc_request_blast_when_gc_disabled/1]). -export([prio_server/2, prio_client/2, init/1, handle_event/2]). @@ -106,7 +107,7 @@ groups() -> otp_7738_resume]}, {system_task, [], [no_priority_inversion, no_priority_inversion2, - system_task_blast, system_task_on_suspended, + system_task_blast, system_task_on_suspended, system_task_failed_enqueue, gc_request_when_gc_disabled, gc_request_blast_when_gc_disabled]}]. init_per_suite(Config) -> @@ -2625,6 +2626,57 @@ system_task_on_suspended(Config) when is_list(Config) -> ok end. +%% When a system task couldn't be enqueued due to the process being in an +%% incompatible state, it would linger in the system task list and get executed +%% anyway the next time the process was scheduled. This would result in a +%% double-free at best. +%% +%% This test continuously purges modules while other processes run dirty code, +%% which will provoke this error as ERTS_PSTT_CPC can't be enqueued while a +%% process is running dirty code. +system_task_failed_enqueue(Config) when is_list(Config) -> + case erlang:system_info(dirty_cpu_schedulers) of + N when N > 0 -> + system_task_failed_enqueue_1(Config); + _ -> + {skipped, "No dirty scheduler support"} + end. + +system_task_failed_enqueue_1(Config) -> + Priv = proplists:get_value(priv_dir, Config), + + Purgers = [spawn_link(fun() -> purge_loop(Priv, Id) end) + || Id <- lists:seq(1, erlang:system_info(schedulers))], + Hogs = [spawn_link(fun() -> dirty_loop() end) + || _ <- lists:seq(1, erlang:system_info(dirty_cpu_schedulers))], + + ct:sleep(5000), + + [begin + unlink(Pid), + exit(Pid, kill) + end || Pid <- (Purgers ++ Hogs)], + + ok. + +purge_loop(PrivDir, Id) -> + Mod = "failed_enq_" ++ integer_to_list(Id), + Path = PrivDir ++ "/" ++ Mod, + file:write_file(Path ++ ".erl", + "-module('" ++ Mod ++ "').\n" ++ + "-export([t/0]).\n" ++ + "t() -> ok."), + purge_loop_1(Path). +purge_loop_1(Path) -> + {ok, Mod} = compile:file(Path, []), + erlang:delete_module(Mod), + erts_code_purger:purge(Mod), + purge_loop_1(Path). + +dirty_loop() -> + ok = erts_debug:dirty_cpu(reschedule, 10000), + dirty_loop(). + gc_request_when_gc_disabled(Config) when is_list(Config) -> AIS = erts_debug:set_internal_state(available_internal_state, true), gc_request_when_gc_disabled_do(ref), diff --git a/erts/vsn.mk b/erts/vsn.mk index 519556119d..1df1b9142b 100644 --- a/erts/vsn.mk +++ b/erts/vsn.mk @@ -18,7 +18,7 @@ # %CopyrightEnd% # -VSN = 10.0 +VSN = 10.0.2 # Port number 4365 in 4.2 # Port number 4366 in 4.3 |