FIFO程序設計解析（隊列指針）

typedef struct {

QUEUE_DATA_TYPE *Out;

QUEUE_DATA_TYPE *In;

QUEUE_DATA_TYPE *End;

u16 NData;

u16 MaxData;

u8 (* ReadEmpty)();

u8 (* WriteFull)();

QUEUE_DATA_TYPE Buf[1];

} DataQueue;

u8 QueueCreate(void *Buf,

u32 SizeOfBuf,

u8 (* ReadEmpty)(),

u8 (* WriteFull)()

)

{

DataQueue *Queue;

if (Buf != NULL && SizeOfBuf >= (sizeof(DataQueue)))

{

Queue = (DataQueue *)Buf;//強制轉換成數據隊列類型

NVIC_SETPRIMASK(); //disable all system interrupts

Queue->MaxData = (SizeOfBuf - (u32)(((DataQueue *)0)->Buf)) /

sizeof(QUEUE_DATA_TYPE);

Queue->End = Queue->Buf + Queue->MaxData;

Queue->Out = Queue->Buf;

Queue->In = Queue->Buf;

Queue->NData = 0;

Queue->ReadEmpty = ReadEmpty;

Queue->WriteFull = WriteFull;

NVIC_RESETPRIMASK(); //enable all system interrupts

return QUEUE_OK;

}

else

{

return NOT_OK;

}

}

u8 QueueRead(QUEUE_DATA_TYPE *Ret, void *Buf)

{

u8 err;

DataQueue *Queue;

err = NOT_OK;

if (Buf != NULL)

{

Queue = (DataQueue *)Buf;

NVIC_SETPRIMASK(); //disable all system interrupts

if (Queue->NData > 0)

{

*Ret = Queue->Out[0];

Queue->Out++;

if (Queue->Out >= Queue->End)

{

Queue->Out = Queue->Buf;

}

Queue->NData--;

err = QUEUE_OK;

}

else

{

err = QUEUE_EMPTY;

if (Queue->ReadEmpty != NULL)

{

err = Queue->ReadEmpty(Ret, Queue);

}

}

NVIC_RESETPRIMASK(); //enable all system interrupts

}

return err;

}

#ifndef EN_QUEUE_WRITE

#define EN_QUEUE_WRITE 1

#endif

#if EN_QUEUE_WRITE > 0

u8 QueueWrite(void *Buf, QUEUE_DATA_TYPE Data)

{

u8 err;

DataQueue *Queue;

err = NOT_OK;

if (Buf != NULL)

{

Queue = (DataQueue *)Buf;

NVIC_SETPRIMASK(); //disable all system interrupts

if (Queue->NData < Queue->MaxData)

{

Queue->In[0] = Data;

Queue->In++;

if (Queue->In >= Queue->End)

{

Queue->In = Queue->Buf;

}

Queue->NData++;

err = QUEUE_OK;

}

else

{

err = QUEUE_FULL;

if (Queue->WriteFull != NULL)

{

err = Queue->WriteFull(Queue, Data, Q_WRITE_MODE);

}

}

NVIC_RESETPRIMASK(); //enable all system interrupts

}

return err;

}

#endif

#ifndef EN_QUEUE_WRITE_FRONT

#define EN_QUEUE_WRITE_FRONT 0

#endif

#if EN_QUEUE_WRITE_FRONT > 0

u8 QueueWriteFront(void *Buf, QUEUE_DATA_TYPE Data)

{

u8 err;

DataQueue *Queue;

err = NOT_OK;

if (Buf != NULL)

{

Queue = (DataQueue *)Buf;

if (Queue->NData < Queue->MaxData)

{

Queue->Out--;

if (Queue->Out < Queue->Buf)

{

Queue->Out = Queue->End - 1;

}

Queue->Out[0] = Data;

Queue->NData++;

err = QUEUE_OK;

}

else

{

err = QUEUE_FULL;

if (Queue->WriteFull != NULL)

{

err = Queue->WriteFull(Queue, Data, Q_WRITE_FRONT_MODE);

}

}

}

return err;

}

#endif

#ifndef EN_QUEUE_NDATA

#define EN_QUEUE_NDATA 1

#endif

#if EN_QUEUE_NDATA > 0

u16 QueueNData(void *Buf)

{

u16 temp;

temp = 0;

NVIC_SETPRIMASK(); //disable all system interrupts

if (Buf != NULL)

{

temp = ((DataQueue *)Buf)->NData;

}

NVIC_RESETPRIMASK(); //enable all system interrupts

return temp;

}

#endif

#ifndef EN_QUEUE_SIZE

#define EN_QUEUE_SIZE 1

#endif

#if EN_QUEUE_SIZE > 0

u16 QueueSize(void *Buf)

{

u16 temp;

temp = 0;

if (Buf != NULL)

{

temp = ((DataQueue *)Buf)->MaxData;

}

return temp;

}

#endif

#ifndef EN_QUEUE_FLUSH

#define EN_QUEUE_FLUSH 1

#endif

#if EN_QUEUE_FLUSH > 0

void QueueFlush(void *Buf)

{

DataQueue *Queue;

if (Buf != NULL)

{

Queue = (DataQueue *)Buf;

Queue->Out = Queue->Buf;

Queue->In = Queue->Buf;

Queue->NData = 0;

}

}

#endif

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