Classic Mac System 7 and later time manager InsTime/RmvTime stress test

time_manager_stress_test.c

/** 
	A program for testing InsTime/RmvTime cycles during timer events
	
	
	Reading list:
	- Inside Macintosh: Processes, Ch. 3 Time Manager, Using the Time Manager
	
	
	To use, in THINK C 5.x
	1. Create a THINK C 5.x project called "time manager stress test"
	2. Add (Source -> Add...) this .c file
	3. Add Mactraps (from Think C::Mac Libraries)
	4. Add ANSI-small (from Think C::C Libraries)
	5. Using ResEdit, create a new resource file in the same location as the project called "time manager stress test.rsrc"
	6. Add a WIND resource with the default ID 128 and save it.
	7. In THINK C, Project -> Run or Project -> Build Application...
*/


#include <Timer.h>
#include <stdio.h>

#define malloc NewPtr
#define free DisposePtr

#define APP_NEW(obj_type) ((obj_type *)    NewPtr(sizeof(obj_type)))
#define SYS_NEW(obj_type) ((obj_type *) NewPtrSys(sizeof(obj_type)))


#define START_DELAY 1000 // ms
#define STEP_DELAY  0    // ms

long int i;

typedef void (*BetterTimerProcPtr)(TMTask * self);

struct TMTaskWithA5World {
	TMTask tmTask;
	long int a5World;
	BetterTimerProcPtr innerTimerFunc;
};


pascal struct TMTaskWithA5World * GetTMInfo()
	= {0x2E89};   // MOVE.L A1,(SP)

pascal void handleOuterTimer() {
	int oldA5World;
	struct TMTaskWithA5World * task;
	
	task = GetTMInfo();
	
	oldA5World = SetA5(task->a5World);

	task->innerTimerFunc((TMTask *) task);

	SetA5(oldA5World);
	
}


TMTask * createTMTask(BetterTimerProcPtr func) {
	struct TMTaskWithA5World * task;

	task = SYS_NEW(struct TMTaskWithA5World);
	
	if (task) {
		task->tmTask.tmAddr = &handleOuterTimer;
		task->tmTask.tmCount = 0;
		task->tmTask.tmWakeUp = 0;
		task->tmTask.tmReserved = 0;
		task->a5World = SetCurrentA5();
		task->innerTimerFunc = func;
	}
	return (TMTask *) task;
}


void handleFirstTimer(TMTask * self) {
	i++;
	
	PrimeTime(self, STEP_DELAY);
}

void handleSecondTimer(TMTask * self) {

}


int main(void) {
	TMTask *firstTask, *secondTask;
	WindowPtr theWindow;
	char buf[512];
	int prevI;
	BetterTimerProcPtr firstTimerHandler, secondTimerHandler;
	
	InitGraf(&thePort);
	InitFonts();
	InitWindows();
	
	
	firstTask = createTMTask(&handleFirstTimer);
	secondTask = createTMTask(&handleSecondTimer);
	
	theWindow = GetNewWindow(128, 0L, (WindowPtr)-1L);
	SetPort(theWindow);
	
	if (firstTask) {
		InsTime(firstTask);
	
		PrimeTime(firstTask, START_DELAY);
	}

	i = 0;
		
	prevI = -1;
	while(!Button()) {
	
		if (i != prevI) {
			prevI = i;
			
			EraseRect(&theWindow->portRect);
			
			MoveTo(30,50);
			DrawString("\p- Continuous InsTime RmvTime cycles on a task in the foreground");
			
		
			MoveTo(30,75);
			
			sprintf(buf, " - Runs of a separate task from the Time Manager (count: %ld)", i);
			buf[0] = strlen(buf) - 1;
			DrawString(buf);
			
			MoveTo(30,100);
			DrawString("\pClick to close");
		}
		if (secondTask) {
			InsTime(secondTask);
			RmvTime(secondTask);
		}
	}
	
	if (firstTask) {
		RmvTime(firstTask);
	
		free(firstTask);
	}
	
	if (secondTask)
	free(secondTask);
	
	return 0;
}

I created this to more easily reproduce a multithreading locking bug in Basilisk II / SheepShaver