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#ifndef FIFO_H
#define FIFO_H
#include <QtDebug>
#include <QMutex>
#include <QScopedPointer>
#include <QSharedPointer>
#include "pa_ringbuffer.h"
#include "util/class.h"
#include "util/math.h"
#include "util/reference.h"
template <class DataType>
class FIFO {
public:
explicit FIFO(int size)
: m_data(NULL) {
size = roundUpToPowerOf2(size);
// If we can't represent the next higher power of 2 then bail.
if (size < 0) {
return;
}
m_data = new DataType[size];
memset(m_data, 0, sizeof(DataType) * size);
PaUtil_InitializeRingBuffer(
&m_ringBuffer, sizeof(DataType), size, m_data);
}
virtual ~FIFO() {
delete [] m_data;
}
int readAvailable() const {
return PaUtil_GetRingBufferReadAvailable(&m_ringBuffer);
}
int writeAvailable() const {
return PaUtil_GetRingBufferWriteAvailable(&m_ringBuffer);
}
int read(DataType* pData, int count) {
return PaUtil_ReadRingBuffer(&m_ringBuffer, pData, count);
}
int write(const DataType* pData, int count) {
return PaUtil_WriteRingBuffer(&m_ringBuffer, pData, count);
}
void writeBlocking(const DataType* pData, int count) {
int written = 0;
while (written != count) {
int i = write(pData, count);
pData += i;
written += i;
}
}
int aquireWriteRegions(int count,
DataType** dataPtr1, ring_buffer_size_t* sizePtr1,
DataType** dataPtr2, ring_buffer_size_t* sizePtr2) {
return PaUtil_GetRingBufferWriteRegions(&m_ringBuffer, count,
(void**)dataPtr1, sizePtr1, (void**)dataPtr2, sizePtr2);
}
int releaseWriteRegions(int count) {
return PaUtil_AdvanceRingBufferWriteIndex(&m_ringBuffer, count);
}
int aquireReadRegions(int count,
DataType** dataPtr1, ring_buffer_size_t* sizePtr1,
DataType** dataPtr2, ring_buffer_size_t* sizePtr2) {
return PaUtil_GetRingBufferReadRegions(&m_ringBuffer, count,
(void**)dataPtr1, sizePtr1, (void**)dataPtr2, sizePtr2);
}
int releaseReadRegions(int count) {
return PaUtil_AdvanceRingBufferReadIndex(&m_ringBuffer, count);
}
int flushReadData(int count) {
int flush = math_min(readAvailable(), count);
return PaUtil_AdvanceRingBufferReadIndex(&m_ringBuffer, flush);
}
private:
DataType* m_data;
PaUtilRingBuffer m_ringBuffer;
DISALLOW_COPY_AND_ASSIGN(FIFO<DataType>);
};
// MessagePipe represents one side of a TwoWayMessagePipe. The direction of the
// pipe is with respect to the owner so sender and receiver are
// perspective-dependent. If serializeWrites is true then calls to writeMessages
// will be serialized with a mutex.
template <class SenderMessageType, class ReceiverMessageType>
class MessagePipe {
public:
MessagePipe(FIFO<SenderMessageType>& receiver_messages,
FIFO<ReceiverMessageType>& sender_messages,
BaseReferenceHolder* pTwoWayMessagePipeReference,
bool serialize_writes)
: m_receiver_messages(receiver_messages),
m_sender_messages(sender_messages),
m_pTwoWayMessagePipeReference(pTwoWayMessagePipeReference),
m_bSerializeWrites(serialize_writes) {
}
// Returns the number of ReceiverMessageType messages waiting to be read by
// the receiver. Non-blocking.
inline int messageCount() const {
return m_sender_messages.readAvailable();
}
// Read a ReceiverMessageType written by the receiver addressed to the
// sender. Non-blocking.
inline int readMessages(ReceiverMessageType* messages, int count) {
return m_sender_messages.read(messages, count);
}
// Writes up to 'count' messages from the 'message' array to the receiver
// and returns the number of successfully written messages. If
// serializeWrites is active, this method is blocking.
inline int writeMessages(const SenderMessageType* messages, int count) {
if (m_bSerializeWrites) {
m_serializationMutex.lock();
}
int result = m_receiver_messages.write(messages, count);
if (m_bSerializeWrites) {
m_serializationMutex.unlock();
}
return result;
}
private:
QMutex m_serializationMutex;
FIFO<SenderMessageType>& m_receiver_messages;
FIFO<ReceiverMessageType>& m_sender_messages;
QScopedPointer<BaseReferenceHolder> m_pTwoWayMessagePipeReference;
bool m_bSerializeWrites;
#define COMMA ,
DISALLOW_COPY_AND_ASSIGN(MessagePipe<SenderMessageType COMMA ReceiverMessageType>);
#undef COMMA
};
// TwoWayMessagePipe is a bare-bones wrapper around the above FIFO class that
// facilitates non-blocking two-way communication. To keep terminology clear,
// there are two sides to the message pipe, the sender side and the receiver
// side. The non-blocking aspect of the underlying FIFO class requires that the
// sender methods and target methods each only be called from a single thread,
// or alternatively guarded with a mutex. The most common use-case of this class
// is sending and receiving messages with the callback thread without the
// callback thread blocking.
//
// This class is an implementation detail and cannot be instantiated
// directly. Use makeTwoWayMessagePipe(...) to create a two-way pipe.
template <class SenderMessageType, class ReceiverMessageType>
class TwoWayMessagePipe {
public:
// Creates a TwoWayMessagePipe with SenderMessageType and
// ReceiverMessageType as the message types. Returns a pair of MessagePipes,
// the first is the sender's pipe (sends SenderMessageType and receives
// ReceiverMessageType messages) and the second is the receiver's pipe
// (sends ReceiverMessageType and receives SenderMessageType messages).
static QPair<MessagePipe<SenderMessageType, ReceiverMessageType>*,
MessagePipe<ReceiverMessageType, SenderMessageType>*> makeTwoWayMessagePipe(
int sender_fifo_size,
int receiver_fifo_size,
bool serialize_sender_writes,
bool serialize_receiver_writes) {
QSharedPointer<TwoWayMessagePipe<SenderMessageType, ReceiverMessageType> > pipe(
new TwoWayMessagePipe<SenderMessageType, ReceiverMessageType>(
sender_fifo_size, receiver_fifo_size));
return QPair<MessagePipe<SenderMessageType, ReceiverMessageType>*,
MessagePipe<ReceiverMessageType, SenderMessageType>*>(
new MessagePipe<SenderMessageType, ReceiverMessageType>(
pipe->m_receiver_messages, pipe->m_sender_messages,
new ReferenceHolder<TwoWayMessagePipe<SenderMessageType, ReceiverMessageType> >(pipe),
serialize_sender_writes),
new MessagePipe<ReceiverMessageType, SenderMessageType>(
pipe->m_sender_messages, pipe->m_receiver_messages,
new ReferenceHolder<TwoWayMessagePipe<SenderMessageType, ReceiverMessageType> >(pipe),
serialize_receiver_writes));
}
private:
TwoWayMessagePipe(int sender_fifo_size, int receiver_fifo_size)
: m_receiver_messages(receiver_fifo_size),
m_sender_messages(sender_fifo_size) {
}
// Messages waiting to be delivered to the receiver.
FIFO<SenderMessageType> m_receiver_messages;
// Messages waiting to be delivered to the sender.
FIFO<ReceiverMessageType> m_sender_messages;
// This #define is because the macro gets confused by the template
// parameters.
#define COMMA ,
DISALLOW_COPY_AND_ASSIGN(TwoWayMessagePipe<SenderMessageType COMMA ReceiverMessageType>);
#undef COMMA
};
#endif /* FIFO_H */
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