Remove timer-thread implementation

6 files changed, 5 insertions, 403 deletions

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.
- * - Bj�rn-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 <asm/unistd.h>
-#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 <sys/poll.h>
-#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 <sys/select.h>
-#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 */