Rtos API example

Revision:
0:9fca2b23d0ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/drivers/InterruptManager.cpp	Sat Feb 23 12:13:36 2019 +0000
@@ -0,0 +1,143 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * 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 "cmsis.h"
+#if defined(NVIC_NUM_VECTORS)
+
+// Suppress deprecation warnings since this whole
+// class is deprecated already
+#include "mbed_toolchain.h"
+#undef MBED_DEPRECATED_SINCE
+#define MBED_DEPRECATED_SINCE(...)
+
+#include "drivers/InterruptManager.h"
+#include "platform/mbed_critical.h"
+#include <string.h>
+
+#define CHAIN_INITIAL_SIZE    4
+
+namespace mbed {
+
+typedef void (*pvoidf)(void);
+
+InterruptManager* InterruptManager::_instance = (InterruptManager*)NULL;
+
+InterruptManager* InterruptManager::get() {
+
+    if (NULL == _instance) {
+        InterruptManager* temp = new InterruptManager();
+
+        // Atomically set _instance
+        core_util_critical_section_enter();
+        if (NULL == _instance) {
+            _instance = temp;
+        }
+        core_util_critical_section_exit();
+
+        // Another thread got there first so delete ours
+        if (temp != _instance) {
+            delete temp;
+        }
+
+    }
+    return _instance;
+}
+
+InterruptManager::InterruptManager() {
+    // No mutex needed in constructor
+    memset(_chains, 0, NVIC_NUM_VECTORS * sizeof(CallChain*));
+}
+
+void InterruptManager::destroy() {
+    // Not a good idea to call this unless NO interrupt at all
+    // is under the control of the handler; otherwise, a system crash
+    // is very likely to occur
+    if (NULL != _instance) {
+        delete _instance;
+        _instance = (InterruptManager*)NULL;
+    }
+}
+
+InterruptManager::~InterruptManager() {
+    for(int i = 0; i < NVIC_NUM_VECTORS; i++)
+        if (NULL != _chains[i])
+            delete _chains[i];
+}
+
+bool InterruptManager::must_replace_vector(IRQn_Type irq) {
+    lock();
+
+    int ret = false;
+    int irq_pos = get_irq_index(irq);
+    if (NULL == _chains[irq_pos]) {
+        _chains[irq_pos] = new CallChain(CHAIN_INITIAL_SIZE);
+        _chains[irq_pos]->add((pvoidf)NVIC_GetVector(irq));
+        ret = true;
+    }
+    unlock();
+    return ret;
+}
+
+pFunctionPointer_t InterruptManager::add_common(void (*function)(void), IRQn_Type irq, bool front) {
+    lock();
+    int irq_pos = get_irq_index(irq);
+    bool change = must_replace_vector(irq);
+
+    pFunctionPointer_t pf = front ? _chains[irq_pos]->add_front(function) : _chains[irq_pos]->add(function);
+    if (change)
+        NVIC_SetVector(irq, (uint32_t)&InterruptManager::static_irq_helper);
+    unlock();
+    return pf;
+}
+
+bool InterruptManager::remove_handler(pFunctionPointer_t handler, IRQn_Type irq) {
+    int irq_pos = get_irq_index(irq);
+    bool ret = false;
+
+    lock();
+    if (_chains[irq_pos] != NULL) {
+        if (_chains[irq_pos]->remove(handler)) {
+            ret = true;
+        }
+    }
+    unlock();
+
+    return ret;
+}
+
+void InterruptManager::irq_helper() {
+    _chains[__get_IPSR()]->call();
+}
+
+int InterruptManager::get_irq_index(IRQn_Type irq) {
+    // Pure function - no lock needed
+    return (int)irq + NVIC_USER_IRQ_OFFSET;
+}
+
+void InterruptManager::static_irq_helper() {
+    InterruptManager::get()->irq_helper();
+}
+
+void InterruptManager::lock() {
+    _mutex.lock();
+}
+
+void InterruptManager::unlock() {
+    _mutex.unlock();
+}
+
+} // namespace mbed
+
+#endif