Win32 port:

Separate out the interrupt handlers into separate functions so they can be installed into the array of interrupt handlers.
Reverse the priorities of the pseudo interrupt handler and tick generate threads so the extra hand shaking event can be removed.

Source/portable/MSVC-MingW/portmacro.h

@@ -111,5 +111,15 @@ void vPortExitCritical( void );
 */
 void vPortGeneratePseudoInterrupt( unsigned long ulInterruptNumber );
 
+/*
+ * Install an interrupt handler to be called by the pseudo interrupt handler 
+ * thread.  The interrupt number must be above any used by the kernel itself
+ * (at the time of writing the kernel was using interrupt numbers 0, 1, and 2
+ * as defined above).  The number must also be lower than 32. 
+ *
+ * Interrupt handler functions must return a non-zero value if executing the
+ * handler resulted in a task switch being required. 
+ */
+void vPortSetInterruptHandler( unsigned long ulInterruptNumber, unsigned long (*pvHandler)( void ) );
 
 #endif