From 454f2ef1c95a9d543fc5a66eca4f286a3144b7ce Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= Date: Mon, 20 Dec 2010 11:56:50 +0100 Subject: Remove timer-thread implementation --- erts/emulator/beam/erl_time_sup.c | 13 -- erts/emulator/beam/sys.h | 11 -- erts/emulator/beam/time.c | 147 +--------------------- erts/emulator/beam/utils.c | 7 -- erts/emulator/sys/unix/erl_unix_sys.h | 7 -- erts/emulator/sys/unix/sys.c | 223 ---------------------------------- 6 files changed, 5 insertions(+), 403 deletions(-) (limited to 'erts/emulator') diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c index 932bf678cd..ca4b54188e 100644 --- a/erts/emulator/beam/erl_time_sup.c +++ b/erts/emulator/beam/erl_time_sup.c @@ -358,10 +358,6 @@ static int clock_resolution; ** instead of something like select. */ -#if defined(ERTS_TIMER_THREAD) -static ERTS_INLINE void init_erts_deliver_time(const SysTimeval *inittv) { } -static ERTS_INLINE void do_erts_deliver_time(const SysTimeval *current) { } -#else static SysTimeval last_delivered; static void init_erts_deliver_time(const SysTimeval *inittv) @@ -393,7 +389,6 @@ static void do_erts_deliver_time(const SysTimeval *current) last_delivered = cur_time; } } -#endif int erts_init_time_sup(void) @@ -786,7 +781,6 @@ get_sys_now(Uint* megasec, Uint* sec, Uint* microsec) to a struct timeval representing current time (to save a gettimeofday() where possible) or NULL */ -#if !defined(ERTS_TIMER_THREAD) void erts_deliver_time(void) { SysTimeval now; @@ -797,7 +791,6 @@ void erts_deliver_time(void) { erts_smp_mtx_unlock(&erts_timeofday_mtx); } -#endif /* get *real* time (not ticks) remaining until next timeout - if there isn't one, give a "long" time, that is guaranteed @@ -806,9 +799,7 @@ void erts_deliver_time(void) { void erts_time_remaining(SysTimeval *rem_time) { int ticks; -#if !defined(ERTS_TIMER_THREAD) SysTimeval cur_time; -#endif long elapsed; /* erts_next_time() returns no of ticks to next timeout or -1 if none */ @@ -822,9 +813,6 @@ void erts_time_remaining(SysTimeval *rem_time) /* next timeout after ticks ticks */ ticks *= CLOCK_RESOLUTION; -#if defined(ERTS_TIMER_THREAD) - elapsed = 0; -#else erts_smp_mtx_lock(&erts_timeofday_mtx); get_tolerant_timeofday(&cur_time); @@ -839,7 +827,6 @@ void erts_time_remaining(SysTimeval *rem_time) rem_time->tv_sec = rem_time->tv_usec = 0; return; } -#endif rem_time->tv_sec = (ticks - elapsed) / 1000; rem_time->tv_usec = 1000 * ((ticks - elapsed) % 1000); } diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h index 5a4dad0a28..dff2dc37a2 100644 --- a/erts/emulator/beam/sys.h +++ b/erts/emulator/beam/sys.h @@ -39,13 +39,6 @@ #define ENABLE_CHILD_WAITER_THREAD 1 #endif -/* The ERTS_TIMER_TREAD #define must be visible to the - erl_${OS}_sys.h #include files: it controls whether - certain optional facilities should be defined or not. */ -#if defined(ERTS_SMP) && 0 -#define ERTS_TIMER_THREAD -#endif - #if defined (__WIN32__) # include "erl_win_sys.h" #elif defined (VXWORKS) @@ -562,11 +555,7 @@ extern char *erts_default_arg0; extern char os_type[]; extern int sys_init_time(void); -#if defined(ERTS_TIMER_THREAD) -#define erts_deliver_time() -#else extern void erts_deliver_time(void); -#endif extern void erts_time_remaining(SysTimeval *); extern int erts_init_time_sup(void); extern void erts_sys_init_float(void); diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c index 20522f6f19..4f491aa66f 100644 --- a/erts/emulator/beam/time.c +++ b/erts/emulator/beam/time.c @@ -107,70 +107,10 @@ static ErlTimer *tiw_min_ptr; /* Actual interval time chosen by sys_init_time() */ static int itime; /* Constant after init */ -#if defined(ERTS_TIMER_THREAD) -static SysTimeval time_start; /* start of current time interval */ -static erts_aint_t ticks_end; /* time_start+ticks_end == time_wakeup */ -static erts_aint_t ticks_latest; /* delta from time_start at latest time update*/ - -static ERTS_INLINE erts_aint_t time_gettimeofday(SysTimeval *now) -{ - erts_aint_t elapsed; - - erts_get_timeval(now); - now->tv_usec = 1000 * (now->tv_usec / 1000); /* ms resolution */ - elapsed = (1000 * (now->tv_sec - time_start.tv_sec) + - (now->tv_usec - time_start.tv_usec) / 1000); - // elapsed /= CLOCK_RESOLUTION; - return elapsed; -} - -static erts_aint_t do_time_update(void) -{ - SysTimeval now; - erts_aint_t elapsed; - - elapsed = time_gettimeofday(&now); - ticks_latest = elapsed; - return elapsed; -} - -static ERTS_INLINE erts_aint_t do_time_read(void) -{ - return ticks_latest; -} - -static erts_aint_t do_time_reset(void) -{ - SysTimeval now; - erts_aint_t elapsed; - - elapsed = time_gettimeofday(&now); - time_start = now; - ticks_end = LONG_MAX; - ticks_latest = 0; - return elapsed; -} - -static ERTS_INLINE void do_time_init(void) -{ - (void)do_time_reset(); -} - -#else erts_smp_atomic_t do_time; /* set at clock interrupt */ -static ERTS_INLINE erts_aint_t do_time_read(void) -{ - return erts_smp_atomic_read(&do_time); -} -static ERTS_INLINE erts_aint_t do_time_update(void) -{ - return do_time_read(); -} -static ERTS_INLINE void do_time_init(void) -{ - erts_smp_atomic_init(&do_time, (erts_aint_t) 0); -} -#endif +static ERTS_INLINE erts_aint_t do_time_read(void) { return erts_smp_atomic_read(&do_time); } +static ERTS_INLINE erts_aint_t do_time_update(void) { return do_time_read(); } +static ERTS_INLINE void do_time_init(void) { erts_smp_atomic_init(&do_time, 0L); } /* get the time (in units of itime) to the next timeout, or -1 if there are no timeouts */ @@ -225,7 +165,6 @@ static erts_aint_t next_time_internal(void) /* PRE: tiw_lock taken by caller */ return ((min >= dt) ? (min - dt) : 0); } -#if !defined(ERTS_TIMER_THREAD) /* Private export to erl_time_sup.c */ erts_aint_t erts_next_time(void) { @@ -237,7 +176,6 @@ erts_aint_t erts_next_time(void) erts_smp_mtx_unlock(&tiw_lock); return ret; } -#endif static ERTS_INLINE void bump_timer_internal(erts_aint_t dt) /* PRE: tiw_lock is write-locked */ { @@ -265,6 +203,7 @@ static ERTS_INLINE void bump_timer_internal(erts_aint_t dt) /* PRE: tiw_lock is if (tiw_pos == keep_pos) count--; prev = &tiw[tiw_pos]; while ((p = *prev) != NULL) { + ASSERT( p != p->next); if (p->count < count) { /* we have a timeout */ /* remove min time */ if (tiw_min_ptr == p) { @@ -322,78 +261,6 @@ erts_timer_wheel_memory_size(void) return (Uint) TIW_SIZE * sizeof(ErlTimer*); } -#if defined(ERTS_TIMER_THREAD) -static struct erts_iwait *timer_thread_iwait; - -static int timer_thread_setup_delay(SysTimeval *rem_time) -{ - erts_aint_t elapsed; - erts_aint_t ticks; - - erts_smp_mtx_lock(&tiw_lock); - elapsed = do_time_update(); - ticks = next_time_internal(); - if (ticks == -1) /* timer queue empty */ - ticks = 100*1000*1000; - if (elapsed > ticks) - elapsed = ticks; - ticks -= elapsed; - //ticks *= CLOCK_RESOLUTION; - rem_time->tv_sec = ticks / 1000; - rem_time->tv_usec = 1000 * (ticks % 1000); - ticks_end = ticks; - erts_smp_mtx_unlock(&tiw_lock); - return ticks; -} - -static void *timer_thread_start(void *ignore) -{ - SysTimeval delay; - -#ifdef ERTS_ENABLE_LOCK_CHECK - erts_lc_set_thread_name("timer"); -#endif - erts_register_blockable_thread(); - - for(;;) { - if (timer_thread_setup_delay(&delay)) { - erts_smp_activity_begin(ERTS_ACTIVITY_WAIT, NULL, NULL, NULL); - ASSERT_NO_LOCKED_LOCKS; - erts_iwait_wait(timer_thread_iwait, &delay); - ASSERT_NO_LOCKED_LOCKS; - erts_smp_activity_end(ERTS_ACTIVITY_WAIT, NULL, NULL, NULL); - } - else - erts_smp_chk_system_block(NULL, NULL, NULL); - timer_thread_bump_timer(); - ASSERT_NO_LOCKED_LOCKS; - } - /*NOTREACHED*/ - return NULL; -} - -static ERTS_INLINE void timer_thread_post_insert(Uint ticks) -{ - if ((Sint)ticks < ticks_end) - erts_iwait_interrupt(timer_thread_iwait); -} - -static void timer_thread_init(void) -{ - erts_thr_opts_t opts = ERTS_THR_OPTS_DEFAULT_INITER; - erts_tid_t tid; - - opts->detached = 1; - - timer_thread_iwait = erts_iwait_init(); - erts_thr_create(&tid, timer_thread_start, NULL, &opts); -} - -#else -static ERTS_INLINE void timer_thread_post_insert(Uint ticks) { } -static ERTS_INLINE void timer_thread_init(void) { } -#endif - /* this routine links the time cells into a free list at the start and sets the time queue as empty */ void @@ -415,8 +282,6 @@ erts_init_time(void) tiw_pos = tiw_nto = 0; tiw_min_ptr = NULL; tiw_min = 0; - - timer_thread_init(); } /* @@ -462,8 +327,6 @@ insert_timer(ErlTimer* p, Uint t) } tiw_nto++; - - timer_thread_post_insert(ticks); } void @@ -483,7 +346,7 @@ erts_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel, p->active = 1; insert_timer(p, t); erts_smp_mtx_unlock(&tiw_lock); -#if defined(ERTS_SMP) && !defined(ERTS_TIMER_THREAD) +#if defined(ERTS_SMP) if (t <= (Uint) LONG_MAX) erts_sys_schedule_interrupt_timed(1, (long) t); #endif diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c index ab37ed1d81..1d60b54d21 100644 --- a/erts/emulator/beam/utils.c +++ b/erts/emulator/beam/utils.c @@ -59,13 +59,6 @@ /* profile_scheduler mini message queue */ -#ifdef ERTS_TIMER_THREAD -/* A timer thread is not welcomed with this lock violation work around. - * - Björn-Egil - */ -#error Timer thread may not be enabled due to lock violation. -#endif - typedef struct { Uint scheduler_id; Uint no_schedulers; diff --git a/erts/emulator/sys/unix/erl_unix_sys.h b/erts/emulator/sys/unix/erl_unix_sys.h index 2d5ef882f6..824678a0bb 100644 --- a/erts/emulator/sys/unix/erl_unix_sys.h +++ b/erts/emulator/sys/unix/erl_unix_sys.h @@ -329,11 +329,4 @@ extern int exit_async(void); #define ERTS_EXIT_AFTER_DUMP _exit -#ifdef ERTS_TIMER_THREAD -struct erts_iwait; /* opaque for clients */ -extern struct erts_iwait *erts_iwait_init(void); -extern void erts_iwait_wait(struct erts_iwait *iwait, struct timeval *delay); -extern void erts_iwait_interrupt(struct erts_iwait *iwait); -#endif /* ERTS_TIMER_THREAD */ - #endif /* #ifndef _ERL_UNIX_SYS_H */ diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c index d021baa6bf..bfc04faa45 100644 --- a/erts/emulator/sys/unix/sys.c +++ b/erts/emulator/sys/unix/sys.c @@ -3109,226 +3109,3 @@ erl_sys_args(int* argc, char** argv) } *argc = j; } - -#ifdef ERTS_TIMER_THREAD - -/* - * Interruptible-wait facility: low-level synchronisation state - * and methods that are implementation dependent. - * - * Constraint: Every implementation must define 'struct erts_iwait' - * with a field 'erts_smp_atomic_t state;'. - */ - -/* values for struct erts_iwait's state field */ -#define IWAIT_WAITING 0 -#define IWAIT_AWAKE 1 -#define IWAIT_INTERRUPT 2 - -#if 0 /* XXX: needs feature test in erts/configure.in */ - -/* - * This is an implementation of the interruptible wait facility on - * top of Linux-specific futexes. - */ -#include -#define FUTEX_WAIT 0 -#define FUTEX_WAKE 1 -static int sys_futex(void *futex, int op, int val, const struct timespec *timeout) -{ - return syscall(__NR_futex, futex, op, val, timeout); -} - -struct erts_iwait { - erts_smp_atomic_t state; /* &state.counter is our futex */ -}; - -static void iwait_lowlevel_init(struct erts_iwait *iwait) { /* empty */ } - -static void iwait_lowlevel_wait(struct erts_iwait *iwait, struct timeval *delay) -{ - struct timespec timeout; - int res; - - timeout.tv_sec = delay->tv_sec; - timeout.tv_nsec = delay->tv_usec * 1000; - res = sys_futex((void*)&iwait->state.counter, FUTEX_WAIT, IWAIT_WAITING, &timeout); - if (res < 0 && errno != ETIMEDOUT && errno != EWOULDBLOCK && errno != EINTR) - perror("FUTEX_WAIT"); -} - -static void iwait_lowlevel_interrupt(struct erts_iwait *iwait) -{ - int res = sys_futex((void*)&iwait->state.counter, FUTEX_WAKE, 1, NULL); - if (res < 0) - perror("FUTEX_WAKE"); -} - -#else /* using poll() or select() */ - -/* - * This is an implementation of the interruptible wait facility on - * top of pipe(), poll() or select(), read(), and write(). - */ -struct erts_iwait { - erts_smp_atomic_t state; - int read_fd; /* wait polls and reads this fd */ - int write_fd; /* interrupt writes this fd */ -}; - -static void iwait_lowlevel_init(struct erts_iwait *iwait) -{ - int fds[2]; - - if (pipe(fds) < 0) { - perror("pipe()"); - exit(1); - } - iwait->read_fd = fds[0]; - iwait->write_fd = fds[1]; -} - -#if defined(ERTS_USE_POLL) - -#include -#define PERROR_POLL "poll()" - -static int iwait_lowlevel_poll(int read_fd, struct timeval *delay) -{ - struct pollfd pollfd; - int timeout; - - pollfd.fd = read_fd; - pollfd.events = POLLIN; - pollfd.revents = 0; - timeout = delay->tv_sec * 1000 + delay->tv_usec / 1000; - return poll(&pollfd, 1, timeout); -} - -#else /* !ERTS_USE_POLL */ - -#include -#define PERROR_POLL "select()" - -static int iwait_lowlevel_poll(int read_fd, struct timeval *delay) -{ - fd_set readfds; - - FD_ZERO(&readfds); - FD_SET(read_fd, &readfds); - return select(read_fd + 1, &readfds, NULL, NULL, delay); -} - -#endif /* !ERTS_USE_POLL */ - -static void iwait_lowlevel_wait(struct erts_iwait *iwait, struct timeval *delay) -{ - int res; - char buf[64]; - - res = iwait_lowlevel_poll(iwait->read_fd, delay); - if (res > 0) - (void)read(iwait->read_fd, buf, sizeof buf); - else if (res < 0 && errno != EINTR) - perror(PERROR_POLL); -} - -static void iwait_lowlevel_interrupt(struct erts_iwait *iwait) -{ - int res = write(iwait->write_fd, "!", 1); - if (res < 0) - perror("write()"); -} - -#endif /* using poll() or select() */ - -#if 0 /* not using poll() or select() */ -/* - * This is an implementation of the interruptible wait facility on - * top of pthread_cond_timedwait(). This has two problems: - * 1. pthread_cond_timedwait() requires an absolute time point, - * so the relative delay must be converted to absolute time. - * Worse, this breaks if the machine's time is adjusted while - * we're preparing to wait. - * 2. Each cond operation requires additional mutex lock/unlock operations. - * - * Problem 2 is probably not too bad on Linux (they'll just become - * relatively cheap futex operations), but problem 1 is the real killer. - * Only use this implementation if no better alternatives are available! - */ -struct erts_iwait { - erts_smp_atomic_t state; - pthread_cond_t cond; - pthread_mutex_t mutex; -}; - -static void iwait_lowlevel_init(struct erts_iwait *iwait) -{ - iwait->cond = (pthread_cond_t) PTHREAD_COND_INITIALIZER; - iwait->mutex = (pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER; -} - -static void iwait_lowlevel_wait(struct erts_iwait *iwait, struct timeval *delay) -{ - struct timeval tmp; - struct timespec timeout; - - /* Due to pthread_cond_timedwait()'s use of absolute - time, this must be the real gettimeofday(), _not_ - the "smoothed" one beam/erl_time_sup.c implements. */ - gettimeofday(&tmp, NULL); - - tmp.tv_sec += delay->tv_sec; - tmp.tv_usec += delay->tv_usec; - if (tmp.tv_usec >= 1000*1000) { - tmp.tv_usec -= 1000*1000; - tmp.tv_sec += 1; - } - timeout.tv_sec = tmp.tv_sec; - timeout.tv_nsec = tmp.tv_usec * 1000; - pthread_mutex_lock(&iwait->mutex); - pthread_cond_timedwait(&iwait->cond, &iwait->mutex, &timeout); - pthread_mutex_unlock(&iwait->mutex); -} - -static void iwait_lowlevel_interrupt(struct erts_iwait *iwait) -{ - pthread_mutex_lock(&iwait->mutex); - pthread_cond_signal(&iwait->cond); - pthread_mutex_unlock(&iwait->mutex); -} - -#endif /* not using POLL */ - -/* - * Interruptible-wait facility. This is just a wrapper around the - * low-level synchronisation code, where we maintain our logical - * state in order to suppress some state transitions. - */ - -struct erts_iwait *erts_iwait_init(void) -{ - struct erts_iwait *iwait = malloc(sizeof *iwait); - if (!iwait) { - perror("malloc"); - exit(1); - } - iwait_lowlevel_init(iwait); - erts_smp_atomic_init(&iwait->state, IWAIT_AWAKE); - return iwait; -} - -void erts_iwait_wait(struct erts_iwait *iwait, struct timeval *delay) -{ - if (erts_smp_atomic_xchg(&iwait->state, IWAIT_WAITING) != IWAIT_INTERRUPT) - iwait_lowlevel_wait(iwait, delay); - erts_smp_atomic_set(&iwait->state, IWAIT_AWAKE); -} - -void erts_iwait_interrupt(struct erts_iwait *iwait) -{ - if (erts_smp_atomic_xchg(&iwait->state, IWAIT_INTERRUPT) == IWAIT_WAITING) - iwait_lowlevel_interrupt(iwait); -} - -#endif /* ERTS_TIMER_THREAD */ -- cgit v1.2.3