Diff: mbed-cloud-client/ns-hal-pal/ns_event_loop.c

Revision:

0:276e7a263c35

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-cloud-client/ns-hal-pal/ns_event_loop.c	Mon Jul 02 06:30:39 2018 +0000
@@ -0,0 +1,155 @@
+// ----------------------------------------------------------------------------
+// Copyright 2016-2017 ARM Ltd.
+//
+// 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_event_loop.h"
+
+#include "pal.h"
+#include "ns_trace.h"
+
+#include "eventOS_scheduler.h"
+
+#include <assert.h>
+
+
+#define TRACE_GROUP "evlp"
+
+static void event_loop_thread(const void *arg);
+
+static palThreadID_t event_thread_id = 0;
+static palMutexID_t event_mutex_id = 0;
+static palSemaphoreID_t event_start_sema_id = 0;
+static palSemaphoreID_t event_signal_sema_id = 0;
+static palSemaphoreID_t event_stop_sema_id = 0;
+static volatile bool event_stop_loop;
+
+void eventOS_scheduler_mutex_wait(void)
+{
+    palStatus_t status;
+    status = pal_osMutexWait(event_mutex_id, UINT32_MAX);
+    assert(PAL_SUCCESS == status);
+}
+
+void eventOS_scheduler_mutex_release(void)
+{
+    palStatus_t status;
+    status = pal_osMutexRelease(event_mutex_id);
+    assert(PAL_SUCCESS == status);
+}
+
+void eventOS_scheduler_signal(void)
+{
+    palStatus_t status;
+    status = pal_osSemaphoreRelease(event_signal_sema_id);
+    assert(PAL_SUCCESS == status);
+}
+
+void eventOS_scheduler_idle(void)
+{
+    int32_t counters = 0;
+    palStatus_t status;
+
+    eventOS_scheduler_mutex_release();
+
+    status = pal_osSemaphoreWait(event_signal_sema_id, UINT32_MAX, &counters);
+    assert(PAL_SUCCESS == status);
+
+    eventOS_scheduler_mutex_wait();
+}
+
+static void event_loop_thread(const void *arg)
+{
+    int32_t counters = 0;
+    palStatus_t status;
+
+    tr_debug("event_loop_thread create");
+
+    event_stop_loop = false;
+
+    status = pal_osSemaphoreWait(event_start_sema_id, UINT32_MAX, &counters);
+    assert(PAL_SUCCESS == status);
+
+    // TODO: Delete start semaphore?
+    eventOS_scheduler_mutex_wait();
+    tr_debug("event_loop_thread loop start");
+
+    // A stoppable version of eventOS_scheduler_run(void)
+    while (event_stop_loop == false) {
+        if (!eventOS_scheduler_dispatch_event()) {
+            eventOS_scheduler_idle();
+        }
+    }
+    tr_debug("event_loop_thread loop end");
+
+    // cleanup the scheduler timer resources which are not needed anymore
+    eventOS_scheduler_timer_stop();
+
+    // signal the ns_event_loop_thread_stop() that it can continue 
+    status = pal_osSemaphoreRelease(event_stop_sema_id);
+    assert(PAL_SUCCESS == status);
+}
+
+void ns_event_loop_thread_create(void)
+{
+    int32_t counters = 0;
+    palStatus_t status;
+
+    status = pal_osSemaphoreCreate(1, &event_start_sema_id);
+    assert(PAL_SUCCESS == status);
+
+    status = pal_osSemaphoreWait(event_start_sema_id, UINT32_MAX, &counters);
+    assert(PAL_SUCCESS == status);
+
+    status = pal_osSemaphoreCreate(0, &event_stop_sema_id);
+    assert(PAL_SUCCESS == status);
+
+    status = pal_osSemaphoreCreate(1, &event_signal_sema_id);
+    assert(PAL_SUCCESS == status);
+
+    status = pal_osMutexCreate(&event_mutex_id);
+    assert(PAL_SUCCESS == status);
+
+    status = pal_osThreadCreateWithAlloc(event_loop_thread, NULL, PAL_osPriorityNormal, MBED_CONF_NS_HAL_PAL_EVENT_LOOP_THREAD_STACK_SIZE, NULL, &event_thread_id);
+    assert(PAL_SUCCESS == status);
+}
+
+void ns_event_loop_thread_start(void)
+{
+    palStatus_t status;
+    status = pal_osSemaphoreRelease(event_start_sema_id);
+    assert(PAL_SUCCESS == status);
+}
+
+void ns_event_loop_thread_stop(void)
+{
+    palStatus_t status;
+
+    // request loop to stop
+    event_stop_loop = true;
+
+    // Ping the even loop at least once more so it will notice the flag and
+    // hopefully end the loop soon.
+    eventOS_scheduler_signal();
+
+    // wait until the event loop has been stopped and the thread is shutting down.
+    // Note: the PAL API does not have any better means to join with a thread termination. 
+    status = pal_osSemaphoreWait(event_stop_sema_id, UINT32_MAX, NULL);
+    assert(PAL_SUCCESS == status);
+
+    pal_osSemaphoreDelete(&event_start_sema_id);
+    pal_osSemaphoreDelete(&event_stop_sema_id);
+}