typedef struct object {
uintptr_t lock;
Class *class;
} Object

typedef struct monitor {
pthread_mutex_t lock;
Thread *owner;
Object *obj;
int count;
int in_wait;
uintptr_t entering;
int wait_count;
Thread *wait_set;
struct monitor *next;
} Monitor;
 

比如，在底層，進行獲取 lock 動作到獲得 lock 之間有一小段狀態叫做 BLOCKED:

void monitorLock(Monitor *mon, Thread *self) {
if(mon->owner == self)
mon->count++;
else {
if(pthread_mutex_trylock(&mon->lock)) {
disableSuspend(self);

self->blocked_mon = mon;
self->blocked_count++;
self->state = BLOCKED;

pthread_mutex_lock(&mon->lock);

self->state = RUNNING;
self->blocked_mon = NULL;

enableSuspend(self);
}
mon->owner = self;
}
}