void
wunlock(RWLock *l)
{
Task *t;
if(l->writer == nil){
fprint(2, "wunlock: not locked\n");
abort();
}
l->writer = nil;
if(l->readers != 0){
fprint(2, "wunlock: readers\n");
abort();
}
while((t = l->rwaiting.head) != nil){
deltask(&l->rwaiting, t);
l->readers++;
taskready(t);
}
if(l->readers == 0 && (t = l->wwaiting.head) != nil){
deltask(&l->wwaiting, t);
l->writer = t;
taskready(t);
}
}
int
taskcreate(void (*fn)(void*), void *arg, uint stack)
{
int id;
Task *t;
//fprintf(stderr,"taskcreate 1\n");
t = taskalloc(fn, arg, stack);
//fprintf(stderr,"taskcreate 2\n");
taskcount++;
id = t->id;
//fprintf(stderr,"taskcreate 3\n");
if(nalltask%64 == 0){
alltask = (Task**) realloc(alltask, (nalltask+64)*sizeof(alltask[0]));
//fprintf(stderr,"taskcreate 4\n");
if(alltask == nil){
fprint(2, "out of memory\n");
abort();
}
}
//fprintf(stderr,"taskcreate 5\n");
t->alltaskslot = nalltask;
alltask[nalltask++] = t;
//fprintf(stderr,"taskcreate 6\n");
taskready(t);
//fprintf(stderr,"taskcreate 7\n");
return id;
}
/*
a->op is Recv: 从对应得Channel的发送队列随机取出一个Alt，
并读取数据，Alt对应的Task可以进入就绪队列了
a->op is Send: 将数据拷贝到Buffer中
*/
static void
altexec(Alt *a)
{
int i;
Altarray *ar;
Alt *other;
Channel *c;
c = a->c;
ar = chanarray(c, otherop(a->op));
if(ar && ar->n){
// 这里的逻辑目前看都是a->op == RECV才跑得到
i = rand()%ar->n;
other = ar->a[i];
// a->v = other->v
altcopy(a, other);
// 将other从Channel的队列（接收队列）中删除
altalldequeue(other->xalt);
other->xalt[0].xalt = other;
// Task重新进入就绪队列
taskready(other->task);
}else {
// 将a->v的数据放到buffer里面
altcopy(a, nil);
}
}
// 使用函数 fn 创建一个新的协程, 并添加到协程队列
int
taskcreate(void (*fn)(void*), void *arg, uint stack)
{
int id;
Task *t;
// 申请协程结构的空间以及初始化
t = taskalloc(fn, arg, stack);
// 当前协程数目 +1
taskcount++;
id = t->id;
// 存储所有协程的数组是否需要扩容
// 为什么是 nalltask % 64 == 0 是扩容的条件?
// 因为每次增加64，所以每当能整除的时候说明，空间用完
if(nalltask%64 == 0){
alltask = realloc(alltask, (nalltask+64)*sizeof(alltask[0]));
if(alltask == nil){
fprint(2, "out of memory\n");
abort();
}
}
// 放到数组尾部
t->alltaskslot = nalltask;
alltask[nalltask++] = t;
// 协程状态设置为就绪, 可以进行调度
taskready(t);
return id;
}
void
fdtask(void *v)
{
int i, ms;
PollResult result;
int rc = 0;
rc = PollResult_init(POLL, &result);
check(rc == 0, "Failed to initialize the poll result.");
tasksystem();
taskname("fdtask");
for(;;){
/* let everyone else run */
while(taskyield() > 0)
;
/* we're the only one runnable - poll for i/o */
errno = 0;
taskstate("poll");
ms = next_task_sleeptime(500);
if(SIGNALED) {
for(i = 0; i < SuperPoll_active_hot(POLL); i++) {
Task *target = (Task *)SuperPoll_data(POLL, i);
if(target) taskready(target);
SuperPoll_compact_down(POLL, i);
}
} else {
rc = SuperPoll_poll(POLL, &result, ms);
check(rc != -1, "SuperPoll failure, aborting.");
for(i = 0; i < rc; i++) {
taskready(result.hits[i].data);
}
}
wake_sleepers();
}
PollResult_clean(&result);
taskexit(0);
error:
taskexitall(1);
}
void
runlock(RWLock *l)
{
Task *t;
if (--l->readers == 0 && (t = l->wwaiting.head) != nil) {
deltask(&l->wwaiting, t);
l->writer = t;
taskready(t);
}
}
int
taskyield(void)
{
int n;
n = tasknswitch;
taskready(taskrunning);
taskstate("yield");
taskswitch();
return tasknswitch - n - 1;
}
int
taskyield(void)
{
int n;
n = tasknswitch;//用来计算自愿放弃协程后，到恢复所发生的切换次数
taskready(taskrunning);//挂到taskrunqueue后面
taskstate("yield");
taskswitch();
return tasknswitch - n - 1;
}
void
qunlock(QLock *l)
{
Task *ready;
if (l->owner == 0) {
fprint(2, "qunlock: owner=0\n");
abort();
}
if ((l->owner = ready = l->waiting.head) != nil) {
deltask(&l->waiting, ready);
taskready(ready);
}
}
static inline void wake_sleepers()
{
Task *t;
uvlong now = nsec();
while((t =sleeping.head) && now >= t->alarmtime){
deltask(&sleeping, t);
if(!t->system && --sleepingcounted == 0) taskcount--;
taskready(t);
}
}
// 协程让出 cpu
int
taskyield(void)
{
int n;
n = tasknswitch;
// 添加到就绪队列的尾部, 相当于让排在它后面的协程优先调度
taskready(taskrunning);
// 状态标识为 yield
taskstate("yield");
// 切换上下文
taskswitch();
// tasknswitch表示协程调度次数，出让到再次调用，两次相减就是出让的调度次数
return tasknswitch - n - 1;
}
void fdtask(void *v)
{
int i, ms;
PollResult result;
int rc = 0;
FDTASK = taskself();
rc = PollResult_init(POLL, &result);
check(rc == 0, "Failed to initialize the poll result.");
tasksystem();
taskname("fdtask");
for(;;){
/* let everyone else run */
while(taskyield() > 0)
;
/* we're the only one runnable - poll for i/o */
errno = 0;
taskstate("poll");
ms = next_task_sleeptime(500);
if(task_was_signaled()) {
fdtask_shutdown();
task_clear_signal();
break;
} else {
rc = SuperPoll_poll(POLL, &result, ms);
check(rc != -1, "SuperPoll failure, aborting.");
for(i = 0; i < rc; i++) {
taskready(result.hits[i].data);
}
wake_sleepers();
}
}
PollResult_clean(&result);
FDTASK = NULL;
return;
error:
taskexitall(1);
}
static int
_taskwakeup(Rendez *r, int all)
{
int i;
Task *t;
for (i = 0;; ++i) {
if (i == 1 && !all) {
break;
}
if ((t = r->waiting.head) == nil) {
break;
}
deltask(&r->waiting, t);
taskready(t);
}
return i;
}
static void
altexec(Alt *a)
{
int i;
Altarray *ar;
Alt *other;
Channel *c;
c = a->c;
ar = chanarray(c, otherop(a->op));
if(ar && ar->n){
i = rand()%ar->n;
other = ar->a[i];
altcopy(a, other);
altalldequeue(other->xalt);
other->xalt[0].xalt = other;
taskready(other->task);
}else
altcopy(a, nil);
}
int
taskcreate(void (*fn)(void*), void *arg, uint stack)
{
int id;
Task *t;
t = taskalloc(fn, arg, stack);//初始化申请Task数据结构，设置堆栈内容等
taskcount++;//当前OK的协程数目，不包括系统级别的协程
id = t->id;
if(nalltask%64 == 0){//一次申请64个槽位，只能往后放
alltask = realloc(alltask, (nalltask+64)*sizeof(alltask[0]));
if(alltask == nil){
fprint(2, "out of memory\n");
abort();
}
}
t->alltaskslot = nalltask;
alltask[nalltask++] = t;
taskready(t);//加入taskrunqueue的运行队列
return id;
}
void
fdtask(void *v)
{
int i, ms;
Task *t;
uvlong now;
tasksystem();
taskname("fdtask");
for(;;){
//fprintf(stderr,"pooling0\n");
/* let everyone else run */
taskyield();
//fprintf(stderr,"\n after yield %d\n", maysamYieldRet);
//while(taskyield() > 0);
/* we're the only one runnable - poll for i/o */
errno = 0;
taskstate("poll");
//Added by Maysam Yabandeh
//taskname("fdtask(%d)",npollfd);
if((t=sleeping.head) == nil)
ms = -1;
else{
/* sleep at most 5s */
now = nsec();
if(now >= t->alarmtime)
ms = 0;
else if(now+5*1000*1000*1000LL >= t->alarmtime)
ms = (t->alarmtime - now)/1000000;
else
ms = 5000;
}
//Added by Maysam Yabandeh
//if (ms == -1 && maysamYieldRet == 0) ms = 0;
if (ms == -1) ms = 0;
//fprintf(stderr,"pooling ms is %d npollfd is %d\n", ms, npollfd);
#ifndef USE_SHM
if(poll(pollfd, npollfd, ms) < 0){
//fprintf(stderr,"pooling error\n");
if(errno == EINTR)
continue;
fprint(2, "poll: %s\n", strerror(errno));
taskexitall(0);
}
//fprintf(stderr,"pooling2\n");
/* wake up the guys who deserve it */
for(i=0; i<npollfd; i++){
while(i < npollfd && pollfd[i].revents){
//fprintf(stderr,"pooling3\n");
taskready(polltask[i]);
--npollfd;
pollfd[i] = pollfd[npollfd];
polltask[i] = polltask[npollfd];
}
}
#else
/* wake up the guys who deserve it */
//extern mpass::MessageEndPoint msg_end_point;
mpass::MessageEndPoint *end_point = &mpass::msg_end_point;
for(i=0; i<npollfd; i++){
int &fd = pollfd[i].fd;
bool read = pollfd[i].events & POLLIN;
mpass::Connection *conn = &end_point->conn_array[fd];
if ( (read && !conn->rcv_q->is_empty()) || (!read && !conn->snd_q->is_full()) )
{
taskready(polltask[i]);
--npollfd;
pollfd[i] = pollfd[npollfd];
polltask[i] = polltask[npollfd];
}
}
#endif
//fprintf(stderr,"pooling4\n");
now = nsec();
while((t=sleeping.head) && now >= t->alarmtime){
//fprintf(stderr,"pooling5\n");
deltask(&sleeping, t);
if(!t->system && --sleepingcounted == 0)
taskcount--;
taskready(t);
}
}
}
void
fdtask(void *v)
{
int i, ms;
Task *t;
uvlong now;
tasksystem();
taskname("fdtask");
struct epoll_event events[20000];
for(;;){
/* let everyone else run */
while(taskyield() > 0)
;
/* we're the only one runnable - epoll for i/o */
errno = 0;
taskstate("epoll");
if(sleeping.head == nil && blocking.head == nil)
ms = -1;
else{
/* sleep at most 100ms */
now = nsec();
if (t) {
if(now >= t->alarmtime)
ms = 0;
else if(now+500*1000*1000LL >= t->alarmtime)
ms = (t->alarmtime - now)/1000000;
else
ms = 500;
}else{
ms = 500;
}
}
int nevents;
if((nevents = epoll_wait(epfd, events, 20000, ms)) < 0){
if(errno == EINTR)
continue;
fprint(2, "epoll: %s\n", strerror(errno));
taskexitall(0);
}
/* wake up the guys who deserve it */
for(i=0; i<nevents; i++){
//deleting it from blocking queue
for (t = blocking.head; t!= nil && t!= events[i].data.ptr; t=t->next)
;
if(t==events[i].data.ptr)
deltask(&blocking,t);
taskready((Task *)events[i].data.ptr);
}
now = nsec();
while((t=sleeping.head) && now >= t->alarmtime){
deltask(&sleeping, t);
if(!t->system && --sleepingcounted == 0)
taskcount--;
taskready(t);
}
/*wake up the guys who are blocked */
while((t=blocking.head) && now >= t->alarmtime){
deltask(&blocking, t);
if(!t->system && --blockingcounted == 0)
taskcount--;
taskready(t);
}
}
}
