C++ (Cpp) altqueue示例

示例#1

文件： channel.c 项目： Masterlvng/libtask

int
chanalt(Alt *a)
{
	int i, j, ncan, n, canblock;
	Channel *c;
	Task *t;

	needstack(512);
	for(i=0; a[i].op != CHANEND && a[i].op != CHANNOBLK; i++)
		;
	n = i;
	canblock = a[i].op == CHANEND;

	t = taskrunning;
    //所有alt指向正在运行的task
	for(i=0; i<n; i++){
		a[i].task = t;
		a[i].xalt = a;
	}
	ncan = 0;
	for(i=0; i<n; i++){
		if(altcanexec(&a[i])){
			ncan++;
		}
	}
	if(ncan){
		j = rand()%ncan;
		for(i=0; i<n; i++){
			if(altcanexec(&a[i])){
				if(j-- == 0){
                    altexec(&a[i]);
	                return i;
	            }
			}
		}
	}

	if(!canblock)
		return -1;

	for(i=0; i<n; i++){
		if(a[i].op != CHANNOP)
			altqueue(&a[i]);
	}

	taskswitch();

	/*
	 * the guy who ran the op took care of dequeueing us
	 * and then set a[0].alt to the one that was executed.
	 */
	return a[0].xalt - a;
}

示例#2

文件： channel.c 项目： BillWangCS/libtask

int
chanalt(Alt *a)
{
	int i, j, ncan, n, canblock;
	Channel *c;
	Task *t;

	needstack(512);
	for(i=0; a[i].op != CHANEND && a[i].op != CHANNOBLK; i++)
		;
	n = i;
	canblock = a[i].op == CHANEND;

	t = taskrunning;
	for(i=0; i<n; i++){
		a[i].task = t;
		a[i].xalt = a;
	}
if(dbgalt) print("alt ");
	ncan = 0;
	for(i=0; i<n; i++){
		c = a[i].c;
if(dbgalt) print(" %c:", "esrnb"[a[i].op]);
if(dbgalt) { if(c->name) print("%s", c->name); else print("%p", c); }
		if(altcanexec(&a[i])){
if(dbgalt) print("*");
			ncan++;
		}
	}
	if(ncan){
		j = rand()%ncan;
		for(i=0; i<n; i++){
			if(altcanexec(&a[i])){
				if(j-- == 0){
if(dbgalt){
c = a[i].c;
print(" => %c:", "esrnb"[a[i].op]);
if(c->name) print("%s", c->name); else print("%p", c);
print("\n");
}
					altexec(&a[i]);
					return i;
				}
			}
		}
	}
if(dbgalt)print("\n");

	if(!canblock)
		return -1;

	for(i=0; i<n; i++){
		if(a[i].op != CHANNOP)
			altqueue(&a[i]);
	}

	taskswitch();

	/*
	 * the guy who ran the op took care of dequeueing us
	 * and then set a[0].alt to the one that was executed.
	 */
	return a[0].xalt - a;
}