IOC lifecycle callback hooks.

initHookRegister() allows external code to be called at certains points (initHookState) during IOC startup and shutdown.

The overall states (see getIocState() ) of an IOC are:

• Void
  • From process start until iocInit()
  • After iocShutdown()
• Building
  • Transiant state during iocInit()
• Built
  • Transiant state during iocInit()
• Running
  • After iocInit() or iocRun()
• Paused
  • After iocPause()

The following C++ example shows how to use this facility:

#include <initHooks.h>
#include <epicsExport.h>
static void myHookFunction(initHookState state)
{
 if(state == initHookAfterDatabaseRunning) {
 // a good point for driver worker threads to be started.
 }
}
static void myRegistrar(void) {
 initHookRegister(&myHookFunction);
}
extern "C" {
 epicsExportRegistrar(myRegistrar);
}
// in some .dbd file add "registrar(myRegistrar)".