mbed_shared_queues.cpp

00001 /* events
00002  * Copyright (c) 2017 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #include "events/mbed_shared_queues.h"
00018 
00019 #ifdef MBED_CONF_RTOS_PRESENT
00020 #include "rtos/Thread.h"
00021 using rtos::Thread;
00022 #endif
00023 
00024 using namespace events;
00025 
00026 namespace mbed {
00027 
00028 #ifdef MBED_CONF_RTOS_PRESENT
00029 /* Create an event queue, and start the thread that dispatches it. Static
00030  * variables mean this happens once the first time each template instantiation
00031  * is called. This is currently instantiated no more than twice.
00032  */
00033 template
00034 <osPriority Priority, size_t QueueSize, size_t StackSize>
00035 EventQueue *do_shared_event_queue_with_thread(const char *name)
00036 {
00037     static uint64_t queue_buffer[QueueSize / sizeof(uint64_t)];
00038     static EventQueue queue(sizeof queue_buffer, (unsigned char *) queue_buffer);
00039 
00040     static uint64_t stack[StackSize / sizeof(uint64_t)];
00041     static Thread thread(Priority, StackSize, (unsigned char *) stack, name);
00042 
00043     Thread::State state = thread.get_state();
00044     if (state == Thread::Inactive || state == Thread::Deleted) {
00045         osStatus status = thread.start(callback(&queue, &EventQueue::dispatch_forever));
00046         MBED_ASSERT(status == osOK);
00047         if (status != osOK) {
00048             return NULL;
00049         }
00050     }
00051 
00052     return &queue;
00053 }
00054 #endif
00055 
00056 EventQueue *mbed_event_queue()
00057 {
00058 #if MBED_CONF_EVENTS_SHARED_DISPATCH_FROM_APPLICATION || !defined MBED_CONF_RTOS_PRESENT
00059     /* Only create the EventQueue, but no dispatching thread */
00060     static unsigned char queue_buffer[MBED_CONF_EVENTS_SHARED_EVENTSIZE];
00061     static EventQueue queue(sizeof queue_buffer, queue_buffer);
00062 
00063     return &queue;
00064 #else
00065     return do_shared_event_queue_with_thread<osPriorityNormal, MBED_CONF_EVENTS_SHARED_EVENTSIZE, MBED_CONF_EVENTS_SHARED_STACKSIZE>("shared_event_queue");
00066 #endif
00067 }
00068 
00069 #ifdef MBED_CONF_RTOS_PRESENT
00070 EventQueue *mbed_highprio_event_queue()
00071 {
00072     return do_shared_event_queue_with_thread<osPriorityHigh, MBED_CONF_EVENTS_SHARED_HIGHPRIO_EVENTSIZE, MBED_CONF_EVENTS_SHARED_HIGHPRIO_STACKSIZE>("shared_highprio_event_queue");
00073 }
00074 #endif
00075 
00076 }