Bitd daemon refactoring new

configure.ac

@@ -148,6 +148,9 @@ AC_CONFIG_FILES([Makefile
                 xlators/features/snapview-server/src/Makefile
                 xlators/features/snapview-client/Makefile
                 xlators/features/snapview-client/src/Makefile
+                xlators/features/bit-rot/Makefile
+                xlators/features/bit-rot/src/Makefile
+                xlators/features/bit-rot/src/stub/Makefile
                 xlators/playground/Makefile
                 xlators/playground/template/Makefile
                 xlators/playground/template/src/Makefile

contrib/timer-wheel/find_last_bit.c

@@ -0,0 +1,66 @@
+/**
+ * @find_last_bit
+ * optimized implementation of find last bit in
+ */
+
+#ifndef BITS_PER_LONG
+#define BITS_PER_LONG 64
+#endif
+
+static inline int fls(int x)
+{
+	int r = 32;
+
+	if (!x)
+		return 0;
+	if (!(x & 0xffff0000u)) {
+		x <<= 16;
+		r -= 16;
+	}
+	if (!(x & 0xff000000u)) {
+		x <<= 8;
+		r -= 8;
+	}
+	if (!(x & 0xf0000000u)) {
+		x <<= 4;
+		r -= 4;
+	}
+	if (!(x & 0xc0000000u)) {
+		x <<= 2;
+		r -= 2;
+	}
+	if (!(x & 0x80000000u)) {
+		x <<= 1;
+		r -= 1;
+	}
+	return r;
+}
+
+
+unsigned long gf_tw_find_last_bit(const unsigned long *addr, unsigned long size)
+{
+	unsigned long words;
+	unsigned long tmp;
+
+	/* Start at final word. */
+	words = size / BITS_PER_LONG;
+
+	/* Partial final word? */
+	if (size & (BITS_PER_LONG-1)) {
+		tmp = (addr[words] & (~0UL >> (BITS_PER_LONG
+					 - (size & (BITS_PER_LONG-1)))));
+		if (tmp)
+			goto found;
+	}
+
+	while (words) {
+		tmp = addr[--words];
+		if (tmp) {
+found:
+			return words * BITS_PER_LONG + fls(tmp);
+		}
+	}
+
+	/* Not found */
+	return size;
+}

contrib/timer-wheel/timer-wheel.c

@@ -0,0 +1,250 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/time.h>
+
+#include "timer-wheel.h"
+
+static inline void
+__gf_tw_add_timer (struct tvec_base *base, struct gf_tw_timer_list *timer)
+{
+        int i;
+        unsigned long idx;
+        unsigned long expires;
+        struct list_head *vec;
+
+        expires = timer->expires;
+
+        idx = expires - base->timer_sec;
+
+        if (idx < TVR_SIZE) {
+                i = expires & TVR_MASK;
+                vec = base->tv1.vec + i;
+        } else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
+                i = (expires >> TVR_BITS) & TVN_MASK;
+                vec = base->tv2.vec + i;
+        } else if (idx < 1 << (TVR_BITS + 2*TVN_BITS)) {
+                i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
+                vec = base->tv3.vec + i;
+        } else if (idx < 1 << (TVR_BITS + 3*TVN_BITS)) {
+                i = (expires >> (TVR_BITS + 2*TVN_BITS)) & TVN_MASK;
+                vec = base->tv4.vec + i;
+        } else if (idx < 0) {
+                vec = base->tv1.vec + (base->timer_sec & TVR_MASK);
+        } else {
+                i = (expires >> (TVR_BITS + 3*TVN_BITS)) & TVN_MASK;
+                vec = base->tv5.vec + i;
+        }
+
+        list_add_tail (&timer->entry, vec);
+}
+
+/* optimized find_last_bit() */
+unsigned long gf_tw_find_last_bit(const unsigned long *, unsigned long);
+
+static inline unsigned long
+apply_slack(struct tvec_base *base, struct gf_tw_timer_list *timer)
+{
+        long delta;
+        unsigned long mask, expires, expires_limit;
+
+        expires = timer->expires;
+
+        delta = expires - base->timer_sec;
+        if (delta < 256)
+                return expires;
+
+        expires_limit = expires + delta / 256;
+        mask = expires ^ expires_limit;
+        if (mask == 0)
+                return expires;
+
+        int bit = gf_tw_find_last_bit (&mask, BITS_PER_LONG);
+        mask = (1UL << bit) - 1;
+
+        expires_limit = expires_limit & ~(mask);
+        return expires_limit;
+}
+
+static inline void
+gf_tw_detach_timer (struct gf_tw_timer_list *timer)
+{
+        struct list_head *entry = &timer->entry;
+
+        list_del (entry);
+}
+
+static inline int
+cascade (struct tvec_base *base, struct tvec *tv, int index)
+{
+        struct gf_tw_timer_list *timer, *tmp;
+        struct list_head tv_list;
+
+        list_replace_init (tv->vec + index, &tv_list);
+
+        list_for_each_entry_safe (timer, tmp, &tv_list, entry) {
+                __gf_tw_add_timer (base, timer);
+        }
+
+        return index;
+}
+
+#define INDEX(N)  ((base->timer_sec >> (TVR_BITS + N * TVN_BITS)) & TVN_MASK)
+
+/**
+ * run expired timers
+ */
+static inline void
+run_timers (struct tvec_base *base)
+{
+        unsigned long index, call_time;
+        struct gf_tw_timer_list *timer;
+
+        struct list_head work_list;
+        struct list_head *head = &work_list;
+
+        pthread_spin_lock (&base->lock);
+        {
+                index  = base->timer_sec & TVR_MASK;
+
+                if (!index &&
+                    (!cascade (base, &base->tv2, INDEX(0))) &&
+                    (!cascade (base, &base->tv3, INDEX(1))) &&
+                    (!cascade (base, &base->tv4, INDEX(2))))
+                        cascade (base, &base->tv5, INDEX(3));
+
+                call_time = base->timer_sec++;
+                list_replace_init (base->tv1.vec + index, head);
+                while (!list_empty(head)) {
+                        void (*fn)(struct gf_tw_timer_list *, void *, unsigned long);
+                        void *data;
+
+                        timer = list_first_entry (head, struct gf_tw_timer_list, entry);
+                        fn = timer->function;
+                        data = timer->data;
+
+                        gf_tw_detach_timer (timer);
+                        fn (timer, data, call_time);
+                }
+        }
+        pthread_spin_unlock (&base->lock);
+
+}
+
+void *runner (void *arg)
+{
+        struct timeval tv = {0,};
+        struct tvec_base *base = arg;
+
+        while (1) {
+                run_timers (base);
+
+                tv.tv_sec  = 1;
+                tv.tv_usec = 0;
+                (void) select (0, NULL, NULL, NULL, &tv);
+        }
+
+        return NULL;
+
+}
+
+/* interface */
+
+/**
+ * Add a timer in the timer wheel
+ */
+void gf_tw_add_timer (struct tvec_base *base, struct gf_tw_timer_list *timer)
+{
+        pthread_spin_lock (&base->lock);
+        {
+                timer->expires += base->timer_sec;
+                timer->expires = apply_slack (base, timer);
+                __gf_tw_add_timer (base, timer);
+        }
+        pthread_spin_unlock (&base->lock);
+}
+
+/**
+ * Remove a timer from the timer wheel
+ */
+void gf_tw_del_timer (struct gf_tw_timer_list *timer)
+{
+        gf_tw_detach_timer (timer);
+}
+
+int gf_tw_cleanup_timers (struct tvec_base *base)
+{
+        int ret = 0;
+        void *res = NULL;
+
+        /* terminate runner */
+        ret = pthread_cancel (base->runner);
+        if (ret != 0)
+                goto error_return;
+        ret = pthread_join (base->runner, &res);
+        if (ret != 0)
+                goto error_return;
+        if (res != PTHREAD_CANCELED)
+                goto error_return;
+
+        /* destroy lock */
+        ret = pthread_spin_destroy (&base->lock);
+        if (ret != 0)
+                goto error_return;
+
+        /* deallocated timer base */
+        free (base);
+        return 0;
+
+ error_return:
+        return -1;
+}
+
+/**
+ * Initialize various timer wheel lists and spawn a thread that
+ * invokes run_timers()
+ */
+struct tvec_base *gf_tw_init_timers ()
+{
+        int               j    = 0;
+        int               ret  = 0;
+        struct timeval    tv   = {0,};
+        struct tvec_base *base = NULL;
+
+        base = malloc (sizeof (*base));
+        if (!base)
+                goto error_return;
+
+        ret = pthread_spin_init (&base->lock, 0);
+        if (ret != 0)
+                goto error_dealloc;
+
+        for (j = 0; j < TVN_SIZE; j++) {
+                INIT_LIST_HEAD (base->tv5.vec + j);
+                INIT_LIST_HEAD (base->tv4.vec + j);
+                INIT_LIST_HEAD (base->tv3.vec + j);
+                INIT_LIST_HEAD (base->tv2.vec + j);
+        }
+
+        for (j = 0; j < TVR_SIZE; j++) {
+                INIT_LIST_HEAD (base->tv1.vec + j);
+        }
+
+        ret = gettimeofday (&tv, 0);
+        if (ret < 0)
+                goto destroy_lock;
+        base->timer_sec = tv.tv_sec;
+
+        ret = pthread_create (&base->runner, NULL, runner, base);
+        if (ret != 0)
+                goto destroy_lock;
+        return base;
+
+ destroy_lock:
+        (void) pthread_spin_destroy (&base->lock);
+ error_dealloc:
+        free (base);
+ error_return:
+        return NULL;
+}
+
+

contrib/timer-wheel/timer-wheel.h

@@ -0,0 +1,55 @@
+#ifndef __TIMER_WHEEL_H
+#define __TIMER_WHEEL_H
+
+#include <pthread.h>
+
+#include "list.h"
+
+#define TVR_BITS  8
+#define TVN_BITS  6
+#define TVR_SIZE  (1 << TVR_BITS)
+#define TVN_SIZE  (1 << TVN_BITS)
+#define TVR_MASK  (TVR_SIZE - 1)
+#define TVN_MASK  (TVN_SIZE - 1)
+
+#define BITS_PER_LONG  64
+
+struct tvec {
+        struct list_head vec[TVN_SIZE];
+};
+
+struct tvec_root {
+        struct list_head vec[TVR_SIZE];
+};
+
+struct tvec_base {
+        pthread_spinlock_t lock;      /* base lock */
+
+        pthread_t runner;             /* run_timer() */
+
+        unsigned long timer_sec;      /* time counter */
+
+        struct tvec_root tv1;
+        struct tvec tv2;
+        struct tvec tv3;
+        struct tvec tv4;
+        struct tvec tv5;
+};
+
+struct gf_tw_timer_list {
+        void *data;
+        unsigned long expires;
+
+        /** callback routine */
+        void (*function)(struct gf_tw_timer_list *, void *, unsigned long);
+
+        struct list_head entry;
+};
+
+/** The API! */
+struct tvec_base *gf_tw_init_timers ();
+int gf_tw_cleanup_timers (struct tvec_base *);
+void gf_tw_add_timer (struct tvec_base *, struct gf_tw_timer_list *);
+void gf_tw_del_timer (struct gf_tw_timer_list *);
+
+#endif