在数据队列创建函数 uint8 QueueCreate(void *Buf, uint32 SizeOfBuf, uint8 (* ReadEmpty)(), uint8 (* WriteFull)() ) { DataQueue *Queue; if (Buf != NULL && SizeOfBuf >= (sizeof(DataQueue))) /* 判断参数是否有效 */ { Queue = (DataQueue *)Buf;
OS_ENTER_CRITICAL(); /* 初始化结构体数据 */ Queue->MaxData = (SizeOfBuf - (uint32)(((DataQueue *)0)->Buf)) / sizeof(QUEUE_DATA_TYPE); Queue->End = Queue->Buf + Queue->MaxData; /* 计算数据缓冲的结束地址 */ Queue->Out = Queue->Buf; Queue->In = Queue->Buf; Queue->NData = 0; Queue->ReadEmpty = ReadEmpty; Queue->WriteFull = WriteFull;
OS_EXIT_CRITICAL();
return QUEUE_OK; } else { return NOT_OK; } } 中计算最大数据数目然后给了Queue->MaxData,试问一下(uint32)(((DataQueue *)0)->Buf什么意思呢?
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