RacTestScheduler

用CFBinaryHeapRef存儲(chǔ)RACTestSchedulerAction

RACTestSchedulerAction是對(duì) date， block， disposable的封裝。

使用CFBinaryHeapAddValue方法把a(bǔ)ction寫(xiě)入。
使用CFBinaryHeapGetMinimumIfPresent 方法把a(bǔ)ction取出。

    CFBinaryHeapCallBacks callbacks = (CFBinaryHeapCallBacks){
        .version = 0,
        .retain = &RACRetainScheduledAction,
        .release = &RACReleaseScheduledAction,
        .copyDescription = &CFCopyDescription,
        .compare = &RACCompareScheduledActions
    };

    _scheduledActions = CFBinaryHeapCreate(NULL, 0, &callbacks, NULL);


static CFComparisonResult RACCompareScheduledActions(const void *ptr1, const void *ptr2, void *info) {
    RACTestSchedulerAction *action1 = (__bridge id)ptr1;
    RACTestSchedulerAction *action2 = (__bridge id)ptr2;
    return CFDateCompare((__bridge CFDateRef)action1.date, (__bridge CFDateRef)action2.date, NULL);
}

是按照date的順序出隊(duì)列的。

也許取出有序性，是使用該結(jié)構(gòu)的原因～～

1、問(wèn)題1
不改變對(duì)象所有權(quán)。actionPtr拿到之后，并沒(méi)有保持強(qiáng)引用，然后立即調(diào)用CFBinaryHeapRemoveMinimumValue將actionPtr從CFBinaryHeapRef中刪除，這樣后面actionPtr不就是野指針了嗎？

            const void *actionPtr = NULL;
            if (!CFBinaryHeapGetMinimumIfPresent(self.scheduledActions, &actionPtr)) break;

            //不改變對(duì)象所有權(quán)。actionPtr拿到之后，并沒(méi)有保持強(qiáng)引用，然后立即調(diào)用CFBinaryHeapRemoveMinimumValue將actionPtr從CFBinaryHeapRef中刪除，這樣后面actionPtr不就是野指針了嗎？
            RACTestSchedulerAction *action = (__bridge id)actionPtr;
            CFBinaryHeapRemoveMinimumValue(self.scheduledActions);

            if (action.disposable.disposed) continue;

2、c類(lèi)型 用assign
assign不改變對(duì)象引用計(jì)數(shù)

///assign不改變對(duì)象引用計(jì)數(shù)
@property (nonatomic, assign, readonly) CFBinaryHeapRef scheduledActions;

dealloc中需要釋放