Diff: simple-mbed-cloud-client/mbed-cloud-client/sal-stack-nanostack-eventloop/source/system_timer.c

Revision:

0:8f0bb79ddd48

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/simple-mbed-cloud-client/mbed-cloud-client/sal-stack-nanostack-eventloop/source/system_timer.c	Tue May 04 08:55:12 2021 +0000
@@ -0,0 +1,373 @@
+/*
+ * Copyright (c) 2014-2015 ARM Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "ns_types.h"
+#include "ns_list.h"
+#include "timer_sys.h"
+#include "platform/arm_hal_interrupt.h"
+#include "platform/arm_hal_timer.h"
+#include "nsdynmemLIB.h"
+#include "eventOS_event.h"
+#include "eventOS_event_timer.h"
+#include "event.h"
+#include "eventOS_callback_timer.h"
+
+#include "ns_timer.h"
+
+#ifndef ST_MAX
+#define ST_MAX 6
+#endif
+
+static sys_timer_struct_s startup_sys_timer_pool[ST_MAX];
+
+#define TIMER_SLOTS_PER_MS          20
+NS_STATIC_ASSERT(1000 % EVENTOS_EVENT_TIMER_HZ == 0, "Need whole number of ms per tick")
+#define TIMER_SYS_TICK_PERIOD       (1000 / EVENTOS_EVENT_TIMER_HZ) // milliseconds
+
+// timer_sys_ticks must be read in critical section to guarantee
+// atomicity on 16-bit platforms
+static volatile uint32_t timer_sys_ticks;
+
+static NS_LIST_DEFINE(system_timer_free, sys_timer_struct_s, event.link);
+static NS_LIST_DEFINE(system_timer_list, sys_timer_struct_s, event.link);
+
+
+static sys_timer_struct_s *sys_timer_dynamically_allocate(void);
+static void timer_sys_interrupt(void);
+static void timer_sys_add(sys_timer_struct_s *timer);
+
+#ifndef NS_EVENTLOOP_USE_TICK_TIMER
+static int8_t platform_tick_timer_start(uint32_t period_ms);
+/* Implement platform tick timer using eventOS timer */
+// platform tick timer callback function
+static void (*tick_timer_callback)(void);
+static int8_t tick_timer_id = -1;	// eventOS timer id for tick timer
+
+// EventOS timer callback function
+static void tick_timer_eventOS_callback(int8_t timer_id, uint16_t slots)
+{
+    // Not interested in timer id or slots
+    (void)slots;
+    // Call the tick timer callback
+    if (tick_timer_callback != NULL && timer_id == tick_timer_id) {
+        platform_tick_timer_start(TIMER_SYS_TICK_PERIOD);
+        tick_timer_callback();
+    }
+}
+
+static int8_t platform_tick_timer_register(void (*tick_timer_cb)(void))
+{
+    tick_timer_callback = tick_timer_cb;
+    tick_timer_id = eventOS_callback_timer_register(tick_timer_eventOS_callback);
+    return tick_timer_id;
+}
+
+static int8_t platform_tick_timer_start(uint32_t period_ms)
+{
+    return eventOS_callback_timer_start(tick_timer_id, TIMER_SLOTS_PER_MS * period_ms);
+}
+
+static int8_t platform_tick_timer_stop(void)
+{
+    return eventOS_callback_timer_stop(tick_timer_id);
+}
+#endif // !NS_EVENTLOOP_USE_TICK_TIMER
+
+/*
+ * Initializes timers and starts system timer
+ */
+void timer_sys_init(void)
+{
+    for (uint8_t i = 0; i < ST_MAX; i++) {
+        ns_list_add_to_start(&system_timer_free, &startup_sys_timer_pool[i]);
+    }
+
+    platform_tick_timer_register(timer_sys_interrupt);
+    platform_tick_timer_start(TIMER_SYS_TICK_PERIOD);
+}
+
+
+
+/*-------------------SYSTEM TIMER FUNCTIONS--------------------------*/
+void timer_sys_disable(void)
+{
+    platform_tick_timer_stop();
+}
+
+/*
+ * Starts ticking system timer interrupts every 10ms
+ */
+int8_t timer_sys_wakeup(void)
+{
+    return platform_tick_timer_start(TIMER_SYS_TICK_PERIOD);
+}
+
+
+static void timer_sys_interrupt(void)
+{
+    system_timer_tick_update(1);
+}
+
+
+
+/* * * * * * * * * */
+
+static sys_timer_struct_s *sys_timer_dynamically_allocate(void)
+{
+    return ns_dyn_mem_alloc(sizeof(sys_timer_struct_s));
+}
+
+static sys_timer_struct_s *timer_struct_get(void)
+{
+    sys_timer_struct_s *timer;
+    platform_enter_critical();
+    timer = ns_list_get_first(&system_timer_free);
+    if (timer) {
+        ns_list_remove(&system_timer_free, timer);
+    } else {
+        timer = sys_timer_dynamically_allocate();
+    }
+    platform_exit_critical();
+    return timer;
+}
+
+void timer_sys_event_free(arm_event_storage_t *event)
+{
+    platform_enter_critical();
+    sys_timer_struct_s *timer = NS_CONTAINER_OF(event, sys_timer_struct_s, event);
+    if (timer->period == 0) {
+        // Non-periodic - return to free list
+        ns_list_add_to_start(&system_timer_free, timer);
+    } else {
+        // Periodic - check due time of next launch
+        timer->launch_time += timer->period;
+        if (TICKS_BEFORE_OR_AT(timer->launch_time, timer_sys_ticks)) {
+            // next event is overdue - queue event now
+            eventOS_event_send_timer_allocated(&timer->event);
+        } else {
+            // add back to timer queue for the future
+            timer_sys_add(timer);
+        }
+    }
+    platform_exit_critical();
+}
+
+void timer_sys_event_cancel_critical(struct arm_event_storage *event)
+{
+    sys_timer_struct_s *timer = NS_CONTAINER_OF(event, sys_timer_struct_s, event);
+    timer->period = 0;
+    // If its unqueued it is on my timer list, otherwise it is in event-loop.
+    if (event->state == ARM_LIB_EVENT_UNQUEUED) {
+        ns_list_remove(&system_timer_list, timer);
+    }
+}
+
+uint32_t eventOS_event_timer_ticks(void)
+{
+    uint32_t ret_val;
+    // Enter/exit critical is a bit clunky, but necessary on 16-bit platforms,
+    // which won't be able to do an atomic 32-bit read.
+    platform_enter_critical();
+    ret_val = timer_sys_ticks;
+    platform_exit_critical();
+    return ret_val;
+}
+
+/* Called internally with lock held */
+static void timer_sys_add(sys_timer_struct_s *timer)
+{
+    uint32_t at = timer->launch_time;
+
+    // Find first timer scheduled to run after us, and insert before it.
+    // (This means timers scheduled for same time run in order of request)
+    ns_list_foreach(sys_timer_struct_s, t, &system_timer_list) {
+        if (TICKS_BEFORE(at, t->launch_time)) {
+            ns_list_add_before(&system_timer_list, t, timer);
+            return;
+        }
+    }
+
+    // Didn't insert before another timer, so must be last.
+    ns_list_add_to_end(&system_timer_list, timer);
+}
+
+/* Called internally with lock held */
+static arm_event_storage_t *eventOS_event_timer_request_at_(const arm_event_t *event, uint32_t at, uint32_t period)
+{
+    // Because we use user-allocated events, they must get delivered to avoid
+    // a leak. Previously this call queued timers for invalid tasks, then they
+    // would go undelivered. Now it returns an error.
+    if (!event_tasklet_handler_id_valid(event->receiver)) {
+        return NULL;
+    }
+
+    sys_timer_struct_s *timer = timer_struct_get();
+    if (!timer) {
+        return NULL;
+    }
+
+    timer->event.data = *event;
+    timer->event.allocator = ARM_LIB_EVENT_TIMER;
+    timer->event.state = ARM_LIB_EVENT_UNQUEUED;
+    timer->launch_time = at;
+    timer->period = period;
+
+    if (TICKS_BEFORE_OR_AT(at, timer_sys_ticks)) {
+        eventOS_event_send_timer_allocated(&timer->event);
+    } else {
+        timer_sys_add(timer);
+    }
+
+    return &timer->event;
+}
+
+arm_event_storage_t *eventOS_event_timer_request_at(const arm_event_t *event, uint32_t at)
+{
+    platform_enter_critical();
+
+    arm_event_storage_t *ret = eventOS_event_timer_request_at_(event, at, 0);
+
+    platform_exit_critical();
+
+    return ret;
+}
+
+arm_event_storage_t *eventOS_event_timer_request_in(const arm_event_t *event, int32_t in)
+{
+    platform_enter_critical();
+
+    arm_event_storage_t *ret = eventOS_event_timer_request_at_(event, timer_sys_ticks + in, 0);
+
+    platform_exit_critical();
+
+    return ret;
+
+}
+
+arm_event_storage_t *eventOS_event_timer_request_every(const arm_event_t *event, int32_t period)
+{
+    if (period <= 0) {
+        return NULL;
+    }
+
+    platform_enter_critical();
+
+    arm_event_storage_t *ret = eventOS_event_timer_request_at_(event, timer_sys_ticks + period, period);
+
+    platform_exit_critical();
+
+    return ret;
+
+}
+
+int8_t eventOS_event_timer_request(uint8_t event_id, uint8_t event_type, int8_t tasklet_id, uint32_t time)
+{
+    const arm_event_t event = {
+        .event_id = event_id,
+        .event_type = event_type,
+        .receiver = tasklet_id,
+        .sender = 0,
+        .data_ptr = NULL,
+        .event_data = 0,
+        .priority = ARM_LIB_MED_PRIORITY_EVENT,
+    };
+
+    // Legacy time behaviour preserved
+
+    // Note that someone wanting 20ms gets 2 ticks, thanks to this test. 30ms would be 4 ticks.
+    // And why shouldn't they be able to get a 1-tick callback?
+    if (time > 2 * TIMER_SYS_TICK_PERIOD) {
+        time /= TIMER_SYS_TICK_PERIOD;
+        // XXX Why this? Someone wanting 50ms shouldn't get 6 ticks. Round to nearest, maybe?
+        time++;
+    } else {
+        time = 2;
+    }
+
+    platform_enter_critical();
+    arm_event_storage_t *ret = eventOS_event_timer_request_at_(&event, timer_sys_ticks + time, 0);
+    platform_exit_critical();
+    return ret?0:-1;
+}
+
+int8_t eventOS_event_timer_cancel(uint8_t event_id, int8_t tasklet_id)
+{
+    platform_enter_critical();
+
+    /* First check pending timers */
+    ns_list_foreach(sys_timer_struct_s, cur, &system_timer_list) {
+        if (cur->event.data.receiver == tasklet_id && cur->event.data.event_id == event_id) {
+            eventOS_cancel(&cur->event);
+            goto done;
+        }
+    }
+
+    /* No pending timer, so check for already-pending event */
+    arm_event_storage_t *event = eventOS_event_find_by_id_critical(tasklet_id, event_id);
+    if (event && event->allocator == ARM_LIB_EVENT_TIMER) {
+        eventOS_cancel(event);
+        goto done;
+    }
+
+    /* No match found */
+    platform_exit_critical();
+    return -1;
+
+done:
+    platform_exit_critical();
+    return 0;
+}
+
+uint32_t eventOS_event_timer_shortest_active_timer(void)
+{
+    uint32_t ret_val = 0;
+
+    platform_enter_critical();
+    sys_timer_struct_s *first = ns_list_get_first(&system_timer_list);
+    if (first == NULL) {
+        // Weird API has 0 for "no events"
+        ret_val = 0;
+    } else if (TICKS_BEFORE_OR_AT(first->launch_time, timer_sys_ticks)) {
+        // Which means an immediate/overdue event has to be 1
+        ret_val = 1;
+    } else {
+        ret_val = first->launch_time - timer_sys_ticks;
+    }
+
+    platform_exit_critical();
+    return eventOS_event_timer_ticks_to_ms(ret_val);
+}
+
+void system_timer_tick_update(uint32_t ticks)
+{
+    platform_enter_critical();
+    //Keep runtime time
+    timer_sys_ticks += ticks;
+    ns_list_foreach_safe(sys_timer_struct_s, cur, &system_timer_list) {
+        if (TICKS_BEFORE_OR_AT(cur->launch_time, timer_sys_ticks)) {
+            // Unthread from our list
+            ns_list_remove(&system_timer_list, cur);
+            // Make it an event (can't fail - no allocation)
+            // event system will call our timer_sys_event_free on event delivery.
+            eventOS_event_send_timer_allocated(&cur->event);
+        } else {
+            // List is ordered, so as soon as we see a later event, we're done.
+            break;
+        }
+    }
+
+    platform_exit_critical();
+}
+