waitchannel.c

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/*
 * Copyright (c) 2023 Ali Mashtizadeh
 * All rights reserved.
 */
 
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
 
#include <sys/cdefs.h>
#include <sys/kassert.h>
#include <sys/kdebug.h>
#include <sys/queue.h>
#include <sys/thread.h>
#include <sys/spinlock.h>
#include <sys/waitchannel.h>
 
Spinlock chanListLock;
LIST_HEAD(ChanListHead, WaitChannel) chanList = LIST_HEAD_INITIALIZER(chanList);
 
void
WaitChannel_EarlyInit()
{
    Spinlock_Init(&chanListLock, "WaitChannel List", SPINLOCK_TYPE_NORMAL);
}
 
void
WaitChannel_Init(WaitChannel *wchan, const char *name)
{
    TAILQ_INIT(&wchan->chanQueue);
    strncpy(&wchan->name[0], name, WAITCHANNEL_NAMELEN);
    Spinlock_Init(&wchan->lock, name, SPINLOCK_TYPE_NORMAL);
 
    Spinlock_Lock(&chanListLock);
    LIST_INSERT_HEAD(&chanList, wchan, chanList);
    Spinlock_Unlock(&chanListLock);
}
 
void
WaitChannel_Destroy(WaitChannel *wchan)
{
    ASSERT(TAILQ_EMPTY(&wchan->chanQueue));
 
    Spinlock_Lock(&chanListLock);
    LIST_REMOVE(wchan, chanList);
    Spinlock_Unlock(&chanListLock);
 
    Spinlock_Destroy(&wchan->lock);
}
 
void
WaitChannel_Lock(WaitChannel *wchan)
{
    Spinlock_Lock(&wchan->lock);
}
 
void
WaitChannel_Sleep(WaitChannel *wchan)
{
    Thread *thr = Sched_Current();
 
    Sched_SetWaiting(thr);
    TAILQ_INSERT_TAIL(&wchan->chanQueue, thr, chanQueue);
    Spinlock_Unlock(&wchan->lock);
 
    Sched_Scheduler();
}
 
void
WaitChannel_Wake(WaitChannel *wchan)
{
    Thread *thr;
 
    Spinlock_Lock(&wchan->lock);
 
    thr = TAILQ_FIRST(&wchan->chanQueue);
    if (thr != NULL) {
        TAILQ_REMOVE(&wchan->chanQueue, thr, chanQueue);
        Sched_SetRunnable(thr);
        Thread_Release(thr);
    }
 
    Spinlock_Unlock(&wchan->lock);
}
 
void
WaitChannel_WakeAll(WaitChannel *wchan)
{
    Thread *thr;
    Thread *thrTemp;
 
    Spinlock_Lock(&wchan->lock);
 
    TAILQ_FOREACH_SAFE(thr, &wchan->chanQueue, chanQueue, thrTemp) {
        TAILQ_REMOVE(&wchan->chanQueue, thr, chanQueue);
        Sched_SetRunnable(thr);
        Thread_Release(thr);
    }
 
    Spinlock_Unlock(&wchan->lock);
}