/*
* This function simulate summing up three positive numbers
* using add function.
*
* The code deals with memory failure and invalid arguments.
* The code responds to KILL signal and kill sub-FUNK accordingly.
* The code calls sub-FUNK and YIELD.
*/
Continuation * sum(Continuation * co,
int a, int b, int c, int * ret)
{
VAR_BEGIN
int sum;
Continuation* sub;
VAR_END
if (!this || a < 0 || b < 0 || c < 0)
{ *ret = -1; EXIT(); }
if (KILL_SIGNALLED()) {
KILL_FUNC(this->sub, add, 0, 0, 0);
EXIT();
}
while (CALL_FUNK(this->sub, add, a, b, &this->sum))
YIELD();
if (this->sum == -1) // mem fail
{
*ret = -1;
EXIT();
}
while (CALL_FUNK(this->sub, add, this->sum, c, ret))
YIELD();
EXIT();
}
int main(void)
{
int ret;
int counter;
Continuation* co;
setbuf(stdout, NULL);
/* case 1: call sum FUNK
* notice that you can put other jobs in while-loop
* this is important pattern for polling event
*/
ret = 0;
co = 0; // be sure to null the pointer before using it.
while (CALL_FUNK(co, sum, 1, 2, 4, &ret))
{
sleep(1);
printf("wake up\n");
}
printf("sum 1, 2, 4 is %d\n", ret);
/* case 2: call sum FUNK
* this time we cancel the job after sleep twice
* this is also EXTREMELY important when high level
* state machine transit to new state, and you need
* to destroy the current one.
*/
ret = 0;
co = 0;
while (CALL_FUNK(co, sum, 1, 2, 4, &ret))
{
sleep(1);
printf("wake up\n");
counter++;
if (counter > 1)
{
KILL_FUNC(co, sum, 0, 0, 0, 0);
printf("funk cancelled");
break;
}
}
printf("sum 1, 2, 4 is %d\n", ret);
return 0;
}
Continuation * sum(Continuation * co,
int a, int b, int c, int * ret)
{
VAR_BEGIN
int sum;
Continuation* sub;
VAR_END
if (!this) { *ret = -1; EXIT(); }
this->sub = 0;
while(CALL_FUNK(this->sub, add, a, b,
&this->sum)) YIELD();
if (this->sum == -1) { // mem fail
*ret = -1;
EXIT();
}
while(CALL_FUNK(this->sub, add,
this->sum, c, ret)) YIELD();
EXIT();
}
