server: spice_timer_queue

Each thread can create a spice_timer_queue, for managing its
own timers.

server/Makefile.am

@@ -93,6 +93,8 @@ libspice_server_la_SOURCES =			\
 	spice.h					\
 	stat.h					\
 	spicevmc.c				\
+	spice_timer_queue.c			\
+	spice_timer_queue.h			\
 	zlib_encoder.c				\
 	zlib_encoder.h				\
 	$(NULL)

server/spice_timer_queue.c

@@ -0,0 +1,268 @@
+/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+   Copyright (C) 2013 Red Hat, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+#include <pthread.h>
+#include "red_common.h"
+#include "spice_timer_queue.h"
+#include "common/ring.h"
+
+static Ring timer_queue_list;
+static int queue_count = 0;
+static pthread_mutex_t queue_list_lock = PTHREAD_MUTEX_INITIALIZER;
+
+static void spice_timer_queue_init(void)
+{
+    ring_init(&timer_queue_list);
+}
+
+struct SpiceTimer {
+    RingItem link;
+    RingItem active_link;
+
+    SpiceTimerFunc func;
+    void *opaque;
+
+    SpiceTimerQueue *queue;
+
+    int is_active;
+    uint32_t ms;
+    uint64_t expiry_time;
+};
+
+struct SpiceTimerQueue {
+    RingItem link;
+    pthread_t thread;
+    Ring timers;
+    Ring active_timers;
+};
+
+static SpiceTimerQueue *spice_timer_queue_find(void)
+{
+    pthread_t self = pthread_self();
+    RingItem *queue_item;
+
+    RING_FOREACH(queue_item, &timer_queue_list) {
+         SpiceTimerQueue *queue = SPICE_CONTAINEROF(queue_item, SpiceTimerQueue, link);
+
+         if (pthread_equal(self, queue->thread) != 0) {
+            return queue;
+         }
+    }
+
+    return NULL;
+}
+
+static SpiceTimerQueue *spice_timer_queue_find_with_lock(void)
+{
+    SpiceTimerQueue *queue;
+
+    pthread_mutex_lock(&queue_list_lock);
+    queue = spice_timer_queue_find();
+    pthread_mutex_unlock(&queue_list_lock);
+    return queue;
+}
+
+int spice_timer_queue_create(void)
+{
+    SpiceTimerQueue *queue;
+
+    pthread_mutex_lock(&queue_list_lock);
+    if (queue_count == 0) {
+        spice_timer_queue_init();
+    }
+
+    if (spice_timer_queue_find() != NULL) {
+        spice_printerr("timer queue was already created for the thread");
+        return FALSE;
+    }
+
+    queue = spice_new0(SpiceTimerQueue, 1);
+    queue->thread = pthread_self();
+    ring_init(&queue->timers);
+    ring_init(&queue->active_timers);
+
+    ring_add(&timer_queue_list, &queue->link);
+    queue_count++;
+
+    pthread_mutex_unlock(&queue_list_lock);
+
+    return TRUE;
+}
+
+void spice_timer_queue_destroy(void)
+{
+    RingItem *item;
+    SpiceTimerQueue *queue;
+
+    pthread_mutex_lock(&queue_list_lock);
+    queue = spice_timer_queue_find();
+
+    spice_assert(queue != NULL);
+
+    while ((item = ring_get_head(&queue->timers))) {
+        SpiceTimer *timer;
+
+        timer = SPICE_CONTAINEROF(item, SpiceTimer, link);
+        spice_timer_remove(timer);
+    }
+
+    ring_remove(&queue->link);
+    free(queue);
+    queue_count--;
+
+    pthread_mutex_unlock(&queue_list_lock);
+}
+
+SpiceTimer *spice_timer_queue_add(SpiceTimerFunc func, void *opaque)
+{
+    SpiceTimer *timer = spice_new0(SpiceTimer, 1);
+    SpiceTimerQueue *queue = spice_timer_queue_find_with_lock();
+
+    spice_assert(queue != NULL);
+
+    ring_item_init(&timer->link);
+    ring_item_init(&timer->active_link);
+
+    timer->opaque = opaque;
+    timer->func = func;
+    timer->queue = queue;
+
+    ring_add(&queue->timers, &timer->link);
+
+    return timer;
+}
+
+static void _spice_timer_set(SpiceTimer *timer, uint32_t ms, uint32_t now)
+{
+    RingItem *next_item;
+    SpiceTimerQueue *queue;
+
+    if (timer->is_active) {
+        spice_timer_cancel(timer);
+    }
+
+    queue = timer->queue;
+    timer->expiry_time = now + ms;
+    timer->ms = ms;
+
+    RING_FOREACH(next_item, &queue->active_timers) {
+        SpiceTimer *next_timer = SPICE_CONTAINEROF(next_item, SpiceTimer, active_link);
+
+        if (timer->expiry_time <= next_timer->expiry_time) {
+            break;
+        }
+    }
+
+    if (next_item) {
+        ring_add_before(&timer->active_link, next_item);
+    } else {
+        ring_add_before(&timer->active_link, &queue->active_timers);
+    }
+    timer->is_active = TRUE;
+}
+
+void spice_timer_set(SpiceTimer *timer, uint32_t ms)
+{
+    struct timespec now;
+
+    spice_assert(pthread_equal(timer->queue->thread, pthread_self()) != 0);
+
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    _spice_timer_set(timer, ms, now.tv_sec * 1000 + (now.tv_nsec / 1000 / 1000));
+}
+
+void spice_timer_cancel(SpiceTimer *timer)
+{
+    spice_assert(pthread_equal(timer->queue->thread, pthread_self()) != 0);
+
+    if (!ring_item_is_linked(&timer->active_link)) {
+        spice_assert(!timer->is_active);
+        return;
+    }
+
+    spice_assert(timer->is_active);
+    ring_remove(&timer->active_link);
+    timer->is_active = FALSE;
+}
+
+void spice_timer_remove(SpiceTimer *timer)
+{
+    spice_assert(timer->queue);
+    spice_assert(ring_item_is_linked(&timer->link));
+    spice_assert(pthread_equal(timer->queue->thread, pthread_self()) != 0);
+
+    if (timer->is_active) {
+        spice_assert(ring_item_is_linked(&timer->active_link));
+        ring_remove(&timer->active_link);
+    }
+    ring_remove(&timer->link);
+    free(timer);
+}
+
+unsigned int spice_timer_queue_get_timeout_ms(void)
+{
+    struct timespec now;
+    int now_ms;
+    RingItem *head;
+    SpiceTimer *head_timer;
+    SpiceTimerQueue *queue = spice_timer_queue_find_with_lock();
+
+    spice_assert(queue != NULL);
+
+    if (ring_is_empty(&queue->active_timers)) {
+        return -1;
+    }
+
+    head = ring_get_head(&queue->active_timers);
+    head_timer = SPICE_CONTAINEROF(head, SpiceTimer, active_link);
+
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    now_ms = (now.tv_sec * 1000) - (now.tv_nsec / 1000 / 1000);
+
+    return MAX(0, ((int)head_timer->expiry_time - now_ms));
+}
+
+
+void spice_timer_queue_cb(void)
+{
+    struct timespec now;
+    uint64_t now_ms;
+    RingItem *head;
+    SpiceTimerQueue *queue = spice_timer_queue_find_with_lock();
+
+    spice_assert(queue != NULL);
+
+    if (ring_is_empty(&queue->active_timers)) {
+        return;
+    }
+
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    now_ms = (now.tv_sec * 1000) + (now.tv_nsec / 1000 / 1000);
+
+    while ((head = ring_get_head(&queue->active_timers))) {
+        SpiceTimer *timer = SPICE_CONTAINEROF(head, SpiceTimer, active_link);
+
+        if (timer->expiry_time > now_ms) {
+            break;
+        } else {
+            timer->func(timer->opaque);
+            if (timer->is_active) {
+                _spice_timer_set(timer, timer->ms, now_ms);
+            }
+        }
+    }
+}

server/spice_timer_queue.h

@@ -0,0 +1,43 @@
+/*
+   Copyright (C) 2013 Red Hat, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _H_SPICE_TIMER_QUEUE
+#define _H_SPICE_TIMER_QUEUE
+
+#include  <stdint.h>
+#include "spice.h"
+
+typedef struct SpiceTimerQueue SpiceTimerQueue;
+
+/* create/destroy a timer queue for the current thread.
+ * In order to execute the timers functions, spice_timer_queue_cb should be called
+ * periodically, according to spice_timer_queue_get_timeout_ms */
+int spice_timer_queue_create(void);
+void spice_timer_queue_destroy(void);
+
+SpiceTimer *spice_timer_queue_add(SpiceTimerFunc func, void *opaque);
+void spice_timer_set(SpiceTimer *timer, uint32_t ms);
+void spice_timer_cancel(SpiceTimer *timer);
+void spice_timer_remove(SpiceTimer *timer);
+
+/* returns the time left till the earliest timer in the queue expires.
+ * returns (unsigned)-1 if there are no active timers */
+unsigned int spice_timer_queue_get_timeout_ms(void);
+/* call the timeout callbacks of all the expired timers */
+void spice_timer_queue_cb(void);
+
+#endif