AP_HAL: implement AP_HAL::MemberProc via FastDelegate.h

this provides a more portable way to encapsulate member functions in
variables

libraries/AP_HAL/AP_HAL_Namespace.h

@@ -2,6 +2,9 @@
 #ifndef __AP_HAL_NAMESPACE_H__
 #define __AP_HAL_NAMESPACE_H__
 
+#include "string.h"
+#include "utility/FastDelegate.h"
+
 namespace AP_HAL {
 
     /* Toplevel pure virtual class Hal.*/
@@ -32,9 +35,13 @@ namespace AP_HAL {
     class Stream;
     class BetterStream;
 
-    /* Typdefs for function pointers (Procedure, Timed Procedure) */
+    /* Typdefs for function pointers (Procedure, Member Procedure) 
+
+       For member functions we use the FastDelegate delegates class
+       which allows us to encapculate a member function as a type
+     */
     typedef void(*Proc)(void);
-    typedef void(*TimedProc)(void *);
+    typedef fastdelegate::FastDelegate0<> MemberProc;
 
     /**
      * Global names for all of the existing SPI devices on all platforms.
@@ -51,5 +58,7 @@ namespace AP_HAL {
 
 }
 
+// macro to hide the details of AP_HAL::MemberProc
+#define AP_HAL_MEMBERPROC(func) fastdelegate::MakeDelegate(this, func)
 
 #endif // __AP_HAL_NAMESPACE_H__

libraries/AP_HAL/Scheduler.h

@@ -19,10 +19,10 @@ public:
                                              uint16_t min_time_ms) = 0;
 
     // register a high priority timer task
-    virtual void     register_timer_process(AP_HAL::TimedProc, void *) = 0;
+    virtual void     register_timer_process(AP_HAL::MemberProc) = 0;
 
     // register a low priority IO task
-    virtual void     register_io_process(AP_HAL::TimedProc, void *) = 0;
+    virtual void     register_io_process(AP_HAL::MemberProc) = 0;
 
     // suspend and resume both timer and IO processes
     virtual void     suspend_timer_procs() = 0;
@@ -30,7 +30,7 @@ public:
 
     virtual bool     in_timerprocess() = 0;
     
-    virtual void     register_timer_failsafe(AP_HAL::TimedProc,
+    virtual void     register_timer_failsafe(AP_HAL::Proc,
                                              uint32_t period_us) = 0;
 
     virtual bool     system_initializing() = 0;