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1: coobjc.h 內(nèi)聯(lián)函數(shù) 啟動協(xié)程

co_launch(^{

});

2.將block轉(zhuǎn)換成OC協(xié)程對象 COCoroutine.m 并且創(chuàng)建c的協(xié)程對象coroutine_t

        COCoroutine *co = [COCoroutine coroutineWithBlock:block onQueue:nil];

        coroutine_t  *co = coroutine_create((void (*)(void *))co_exec);
        if (stackSize > 0 && stackSize < 1024*1024) {   // Max 1M
            co->stack_size = (uint32_t)((stackSize % 16384 > 0) ? ((stackSize/16384 + 1) * 16384) : stackSize);        // Align with 16kb
        }
        //設(shè)置  coroutine_t 為當(dāng)前COCoroutine屬性 _co
        //c協(xié)程對象 coroutine_t 和 當(dāng)前 OC對象 COCoroutine 雙向引用
        _co = co;
        coroutine_setuserdata(co, (__bridge_retained void *)self, co_obj_dispose);
        //將OC綁定到couserdata
        co->userdata = userdata;
        //設(shè)置釋放回調(diào)指針
        co->userdata_dispose = ud_dispose;

3. 執(zhí)行協(xié)程 coobjc.h COCoroutine.m

return [co resume]; 

//將當(dāng)前任務(wù)放入CODispatch 隊(duì)列
3.1 self.dispatch dispatch_async_block:^{
        //將協(xié)程添加到調(diào)度程序 進(jìn)入真正的協(xié)程處理方法
        //跳轉(zhuǎn)到 coroutine_resume_im.m
        coroutine_resume(self.co);
    }];
3.1 //獲取當(dāng)前運(yùn)行的協(xié)程
    coroutine_t *coroutine_self() 
3.2 //獲取當(dāng)前運(yùn)行的協(xié)程調(diào)度器雪位。調(diào)度器跟協(xié)程關(guān)系超歌？
    // 調(diào)度器由一個(gè)主協(xié)程箩张，co->is_scheduler = true;
    // 調(diào)度器結(jié)構(gòu)
        struct coroutine_scheduler {
            coroutine_t         *main_coroutine; //跟隨調(diào)度器同時(shí)生成的主協(xié)程
            coroutine_t         *running_coroutine; //當(dāng)前正在運(yùn)行的協(xié)程
            coroutine_list_t     coroutine_queue; //等待執(zhí)行的協(xié)程
        };
    //調(diào)度結(jié)構(gòu)體肆良，全局唯一 pthread_getspecific阿逃，pthread_setspecific實(shí)現(xiàn)
    coroutine_scheduler_t 
    //里面有一個(gè)主協(xié)程
    coroutine_scheduler_t *coroutine_scheduler_self(void)

4. coroutine_resume

    4.1 //將當(dāng)前協(xié)程加入隊(duì)列
        scheduler_queue_push(scheduler, co);
    4.2 //如果當(dāng)前有正在運(yùn)行
        if (scheduler->running_coroutine) {
            //如果當(dāng)前有正在執(zhí)行的協(xié)程，插入到隊(duì)尾
            scheduler_queue_push(scheduler, scheduler->running_coroutine);
            //恢復(fù)當(dāng)前協(xié)程繼續(xù)執(zhí)行
            coroutine_yield(scheduler->running_coroutine);
        } else {
            // 當(dāng)前調(diào)度沒有協(xié)程執(zhí)行时肿，恢復(fù)調(diào)度協(xié)程
            // 調(diào)度主協(xié)程
            coroutine_resume_im(co->scheduler->main_coroutine);

            //主協(xié)程入口方法
            // 從coroutine_queue pop一個(gè)協(xié)程出來執(zhí)行
            coroutine_scheduler_main
        }

5. //執(zhí)行協(xié)程

//由主協(xié)程的入口函數(shù)調(diào)度 協(xié)程
// COROUTINE_SUSPEND

void coroutine_resume_im(coroutine_t *co)
    //創(chuàng)建pre_context
    co->pre_context = malloc(sizeof(coroutine_ucontext_t));
    //保存現(xiàn)場
    //將當(dāng)前寄存器的值寫入co->pre_context
    coroutine_getcontext(co->pre_context);

    //創(chuàng)建co->context
    co->context = calloc(1, sizeof(coroutine_ucontext_t));

    //設(shè)置入口函數(shù)為pc
    //設(shè)置sp,fp
    coroutine_makecontext(co->context, (IMP)coroutine_main, co, (void *)co->stack_top);    

//設(shè)置參數(shù)
void coroutine_makecontext (coroutine_ucontext_t *ctx, IMP func, void *arg, void *stackTop)
{
    struct coroutine_ucontext_re *uctx = (struct coroutine_ucontext_re *)ctx;
    uintptr_t stackBegin = (uintptr_t)stackTop - sizeof(uintptr_t);
    uctx->GR.__fp = stackBegin;
    uctx->GR.__sp = stackBegin;
    uctx->GR.__x[0] = (uintptr_t)arg;
    uctx->GR.__pc = (uintptr_t)func;
}
//調(diào)用匯編 執(zhí)行指令
coroutine_begin(co->context);

6. coroutine_yield

void coroutine_yield(coroutine_t *co){
    //保存現(xiàn)場庇茫，將寄存器的值寫入oc->pre_context
    //并且設(shè)置狀態(tài)，下次可以恢復(fù)調(diào)度
    co->status = COROUTINE_SUSPEND;
}

相關(guān)關(guān)鍵結(jié)構(gòu)體

typedef struct coroutine_ucontext {
    uint64_t data[100];
} coroutine_ucontext_t;

struct coroutine_ucontext_re {
    struct GPRs {
        uint64_t __x[29]; // x0-x28
        uint64_t __fp;    // Frame pointer x29
        uint64_t __lr;    // Link register x30
        uint64_t __sp;    // Stack pointer x31
        uint64_t __pc;    // Program counter
        uint64_t padding; // 16-byte align, for cpsr
    } GR;
    double  VR[32];
};

//協(xié)程先保存當(dāng)前寄存器的值到pre_context
//將寄存器的值寫入pre_context coroutine_ucontext_t
extern int coroutine_getcontext (coroutine_ucontext_t *__ucp);

//恢復(fù)現(xiàn)場螃成，將context的值讀入寄存器旦签，執(zhí)行入口函數(shù)
//由coroutine_scheduler_main 喚醒協(xié)程執(zhí)行
extern int coroutine_setcontext (coroutine_ucontext_t *__ucp);

//恢復(fù)現(xiàn)場，執(zhí)行入口函數(shù)
extern int coroutine_begin (coroutine_ucontext_t *__ucp);
//匯編指令找到pc
ldr x9, [x0, #0x100] // restore pc into lr
//跳轉(zhuǎn)到入口函數(shù)
ret x9