Diff: common/InterruptManager.cpp

Revision:

144:ef7eb2e8f9f7

Parent:

0:9b334a45a8ff

diff -r 423e1876dc07 -r ef7eb2e8f9f7 common/InterruptManager.cpp
--- a/common/InterruptManager.cpp	Tue Aug 02 14:07:36 2016 +0000
+++ b/common/InterruptManager.cpp	Fri Sep 02 15:07:44 2016 +0100
@@ -1,93 +1,122 @@
-#include "cmsis.h"
-#if defined(NVIC_NUM_VECTORS)
-
-#include "InterruptManager.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)
-        _instance = new InterruptManager();
-    return _instance;
-}
-
-InterruptManager::InterruptManager() {
-    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) {
-    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));
-        return true;
-    }
-    return false;
-}
-
-pFunctionPointer_t InterruptManager::add_common(void (*function)(void), IRQn_Type irq, bool front) {
-    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);
-    return pf;
-}
-
-bool InterruptManager::remove_handler(pFunctionPointer_t handler, IRQn_Type irq) {
-    int irq_pos = get_irq_index(irq);
-
-    if (NULL == _chains[irq_pos])
-        return false;
-    if (!_chains[irq_pos]->remove(handler))
-        return false;
-    // If there's a single function left in the chain, swith the interrupt vector
-    // to call that function directly. This way we save both time and space.
-    if (_chains[irq_pos]->size() == 1 && NULL != _chains[irq_pos]->get(0)->get_function()) {
-        NVIC_SetVector(irq, (uint32_t)_chains[irq_pos]->get(0)->get_function());
-        delete _chains[irq_pos];
-        _chains[irq_pos] = (CallChain*) NULL;
-    }
-    return true;
-}
-
-void InterruptManager::irq_helper() {
-    _chains[__get_IPSR()]->call();
-}
-
-int InterruptManager::get_irq_index(IRQn_Type irq) {
-    return (int)irq + NVIC_USER_IRQ_OFFSET;
-}
-
-void InterruptManager::static_irq_helper() {
-    InterruptManager::get()->irq_helper();
-}
-
-} // namespace mbed
-
-#endif
+#include "cmsis.h"
+#if defined(NVIC_NUM_VECTORS)
+
+#include "InterruptManager.h"
+#include "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