Replaced callback type to Event in core classes

In the core classes, the callback event type (used for 'attach'-like
functions) was 'Callback<void()>'. This commit changes the type to
Event, which allows the callbacks to be used both like regular
callbacks, or enqueued in an event queue for deferred execution. The
commit preserves backward compatibility (the default behaviour is still
to run the callbacks immediately (like 'Callback' does), not defer
them).

Event and Callback have similar constructors and attach()
functions, so it was enough to replace one type with the other, without
other code changes. Future similar changes to the API should be able to
follow the same pattern.

Author: Bogdan Marinescu

hal/api/CAN.h

@@ -22,7 +22,7 @@
 
 #include "can_api.h"
 #include "can_helper.h"
-#include "Callback.h"
+#include "Event.h"
 #include "PlatformMutex.h"
 
 namespace mbed {
@@ -214,7 +214,7 @@ class CAN {
      *  @param func A pointer to a void function, or 0 to set as none
      *  @param event Which CAN interrupt to attach the member function to (CAN::RxIrq for message received, CAN::TxIrq for transmitted or aborted, CAN::EwIrq for error warning, CAN::DoIrq for data overrun, CAN::WuIrq for wake-up, CAN::EpIrq for error passive, CAN::AlIrq for arbitration lost, CAN::BeIrq for bus error)
      */
-    void attach(Callback<void()> func, IrqType type=RxIrq);
+    void attach(const Event& func, IrqType type=RxIrq);
 
    /** Attach a member function to call whenever a CAN frame received interrupt
     *  is generated.
@@ -248,7 +248,7 @@ class CAN {
     virtual void lock();
     virtual void unlock();
     can_t               _can;
-    Callback<void()>    _irq[IrqCnt];
+    Event               _irq[IrqCnt];
     PlatformMutex       _mutex;
 };
 

hal/api/InterruptIn.h

@@ -22,7 +22,7 @@
 
 #include "gpio_api.h"
 #include "gpio_irq_api.h"
-#include "Callback.h"
+#include "Event.h"
 #include "critical.h"
 #include "toolchain.h"
 
@@ -83,7 +83,7 @@ class InterruptIn {
      *
      *  @param func A pointer to a void function, or 0 to set as none
      */
-    void rise(Callback<void()> func);
+    void rise(const Event& func);
 
     /** Attach a member function to call when a rising edge occurs on the input
      *
@@ -107,7 +107,7 @@ class InterruptIn {
      *
      *  @param func A pointer to a void function, or 0 to set as none
      */
-    void fall(Callback<void()> func);
+    void fall(const Event& func);
 
     /** Attach a member function to call when a falling edge occurs on the input
      *
@@ -149,8 +149,8 @@ class InterruptIn {
     gpio_t gpio;
     gpio_irq_t gpio_irq;
 
-    Callback<void()> _rise;
-    Callback<void()> _fall;
+    Event _rise;
+    Event _fall;
 };
 
 } // namespace mbed

hal/api/SerialBase.h

@@ -21,7 +21,7 @@
 #if DEVICE_SERIAL
 
 #include "Stream.h"
-#include "Callback.h"
+#include "Event.h"
 #include "serial_api.h"
 #include "toolchain.h"
 
@@ -97,7 +97,7 @@ class SerialBase {
      *  @param func A pointer to a void function, or 0 to set as none
      *  @param type Which serial interrupt to attach the member function to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)
      */
-    void attach(Callback<void()> func, IrqType type=RxIrq);
+    void attach(const Event& func, IrqType type=RxIrq);
 
     /** Attach a member function to call whenever a serial interrupt is generated
      *
@@ -246,7 +246,7 @@ class SerialBase {
 #endif
 
     serial_t         _serial;
-    Callback<void()> _irq[IrqCnt];
+    Event            _irq[IrqCnt];
     int              _baud;
 
 };

hal/api/Ticker.h

@@ -17,7 +17,7 @@
 #define MBED_TICKER_H
 
 #include "TimerEvent.h"
-#include "Callback.h"
+#include "Event.h"
 #include "toolchain.h"
 
 namespace mbed {
@@ -72,7 +72,7 @@ class Ticker : public TimerEvent {
      *  @param func pointer to the function to be called
      *  @param t the time between calls in seconds
      */
-    void attach(Callback<void()> func, float t) {
+    void attach(const Event& func, float t) {
         attach_us(func, t * 1000000.0f);
     }
 
@@ -98,7 +98,7 @@ class Ticker : public TimerEvent {
      *  @param fptr pointer to the function to be called
      *  @param t the time between calls in micro-seconds
      */
-    void attach_us(Callback<void()> func, timestamp_t t) {
+    void attach_us(const Event& func, timestamp_t t) {
         _function.attach(func);
         setup(t);
     }
@@ -134,7 +134,7 @@ class Ticker : public TimerEvent {
 
 protected:
     timestamp_t         _delay;     /**< Time delay (in microseconds) for re-setting the multi-shot callback. */
-    Callback<void()>    _function;  /**< Callback. */
+    Event               _function;  /**< Callback. */
 };
 
 } // namespace mbed

hal/common/CAN.cpp

@@ -101,7 +101,7 @@ int CAN::filter(unsigned int id, unsigned int mask, CANFormat format, int handle
     return ret;
 }
 
-void CAN::attach(Callback<void()> func, IrqType type) {
+void CAN::attach(const Event& func, IrqType type) {
     lock();
     if (func) {
         _irq[(CanIrqType)type].attach(func);

hal/common/InterruptIn.cpp

@@ -50,7 +50,7 @@ void InterruptIn::mode(PinMode pull) {
     core_util_critical_section_exit();
 }
 
-void InterruptIn::rise(Callback<void()> func) {
+void InterruptIn::rise(const Event& func) {
     core_util_critical_section_enter();
     if (func) {
         _rise.attach(func);
@@ -62,7 +62,7 @@ void InterruptIn::rise(Callback<void()> func) {
     core_util_critical_section_exit();
 }
 
-void InterruptIn::fall(Callback<void()> func) {
+void InterruptIn::fall(const Event& func) {
     core_util_critical_section_enter();
     if (func) {
         _fall.attach(func);

hal/common/SerialBase.cpp

@@ -67,7 +67,7 @@ int SerialBase::writeable() {
     return ret;
 }
 
-void SerialBase::attach(Callback<void()> func, IrqType type) {
+void SerialBase::attach(const Event& func, IrqType type) {
     lock();
     // Disable interrupts when attaching interrupt handler
     core_util_critical_section_enter();