LibAAH_RTP: Refactor TXGroup code, add unicast mode.

    aah_rx_player_core.cpp \

    aah_rx_player_ring_buffer.cpp \

    aah_rx_player_substream.cpp \

    aah_tx_group.cpp \

    aah_tx_packet.cpp \

    aah_tx_player.cpp \

    aah_tx_group.cpp \

    pipe_event.cpp

LOCAL_C_INCLUDES := \

    frameworks/base/media/libstagefright

LOCAL_SHARED_LIBRARIES := \

    libcommon_time_client \

    libbinder \

    libcommon_time_client \

    libcutils \

    libmedia \

    libstagefright \

    libstagefright_foundation \

    if (res < 0) {

        uint32_t a = ntohl(bind_addr.sin_addr.s_addr);

        uint16_t p = ntohs(bind_addr.sin_port);

        LOGE("Failed to bind socket (%d) to %d.%d.%d.%d:%hd. (errno %d)",

        LOGE("Failed to bind socket (%d) to %d.%d.%d.%d:%hu. (errno %d)",

             sock_fd_,

             (a >> 24) & 0xFF,

             (a >> 16) & 0xFF,

        LOGW("Failed to increase socket buffer size to %d.  (errno %d)",

             buf_size, errno);

    } else {

        LOGI("RX socket buffer size is now %d bytes",  buf_size);

        LOGD("RX socket buffer size is now %d bytes",  buf_size);

    }

    if (listen_addr_.sin_addr.s_addr) {

#ifndef __AAH_TX_SENDER_H__

#define __AAH_TX_SENDER_H__

#include <media/stagefright/foundation/ALooper.h>

#include <media/stagefright/foundation/AHandlerReflector.h>

#include <netinet/in.h>

#include <stdint.h>

#include <media/stagefright/foundation/ABase.h>

#include <utils/RefBase.h>

#include <utils/threads.h>

#include <utils/Vector.h>

#include "aah_tx_packet.h"

#include "pipe_event.h"

#define IP_PRINTF_HELPER(a) ((a >> 24) & 0xFF), ((a >> 16) & 0xFF), \

                            ((a >>  8) & 0xFF),  (a        & 0xFF)

namespace android {

    size_t mFillCount;

};

struct RetryPacket {

    uint32_t id;

    // TODO: endpointIP and endpointPort are no longer needed now that we use a

    // dedicated send/C&C socket for each TX group.  Removing them is a protocol

    // breaking change; something which would be good to do before 1.0 ship so

    // we don't have to maintain backwards compatibility forever.

    uint32_t endpointIP;

    uint16_t endpointPort;

    uint16_t seqStart;

    uint16_t seqEnd;

} __attribute__((packed));

class AAH_TXGroup : public virtual RefBase {

  public:

    // Obtain the instance of the TXGroup whose command and control socket is

    // currently listening on the specified port.  Alternatively, if port is 0,

    // create a new TXGroup with an ephemerally bound command and control port.

    static sp<AAH_TXGroup> getGroup(uint16_t port);

    // Obtain the instance of the TXGroup whose multicast transmit target is

    // currently set to target, or NULL if no such group exists.  To create a

    // new transmit group with a new multicast target address, call getGroup(0)

    // followed by setMulticastTXTarget.

    static sp<AAH_TXGroup> getGroup(const struct sockaddr_in* target);

    // AAH_TXGroups successfully obtained using calls to getGroup will have a

    // client reference placed on them on behalf of the caller.  When the caller

    // is finished using the group, they must call dropClientReference to remove

    // this reference.  Once call client references have been released from a TX

    // Group, the group will linger in the system for a short period of time

    // before finally expiring and being cleaned up by the command and control

    // thread.

    // 

    // TODO : someday, expose the AAH_TXGroup as a top level object in the

    // android MediaAPIs so that applications may explicitly manage TX group

    // lifecycles instead of relying on this timeout/cleanup mechanism.

    void dropClientReference();

    // Fetch the UDP port on which this TXGroup is listening for command and

    // control messages.  No need to hold any locks for this, the port is

    // established as group is created and bound, and then never changed

    // afterwards.

    uint16_t getCmdAndControlPort() const { return mCmdAndControlPort; }

    // Used by players to obtain a new program ID for this retransmission group.

    uint16_t getNewProgramID();

    // Assign a TRTP sequence number to the supplied packet and send it to all

    // registered clients.  Then place the packet into the RetryBuffer to

    // service future client retry requests.

    status_t sendPacket(const sp<TRTPPacket>& packet);

    // Sets the multicast transmit target for this TX Group.  Pass NULL to clear

    // the multicast transmit target and return to pure unicast mode.

    void setMulticastTXTarget(const struct sockaddr_in* target);

  protected:

    // TXGroups are ref counted objects; make sure that only RefBase can call

    // the destructor.

    ~AAH_TXGroup();

    static sp<AAH_TXGroup> GetInstance();

  private:

    // Definition of a helper class used to track things like when we need to

    // transmit a heartbeat, or when we will need to wake up and trim the retry

    // buffers.

    class Timeout {

      public:

        Timeout() : mSystemEndTime(0) { }

        // Set a timeout which should occur msec milliseconds from now.

        // Negative values will cancel any current timeout;

        void setTimeout(int msec);

    ALooper::handler_id handlerID() { return mReflector->id(); }

        // Return the number of milliseconds until the timeout occurs, or -1 if

        // no timeout is scheduled.

        int msecTillTimeout(nsecs_t nowTime);

        int msecTillTimeout() { return msecTillTimeout(systemTime()); }

    // an IP address and port

    struct Endpoint {

        Endpoint();

        Endpoint(uint32_t a, uint16_t p);

        bool operator<(const Endpoint& other) const;

      private:

        // The systemTime() at which the timeout will be complete, or 0 if no

        // timeout is currently scheduled.

        nsecs_t mSystemEndTime;

        uint32_t addr;

        uint16_t port;

        DISALLOW_EVIL_CONSTRUCTORS(Timeout);

    };

    uint16_t registerEndpoint(const Endpoint& endpoint);

    void unregisterEndpoint(const Endpoint& endpoint);

    // Definition of the singleton command and control receiver who will handle

    // requests from RX clients.  Requests include things like unicast group

    // management as well as retransmission requests.

    class CmdAndControlRXer : public Thread {

      public:

        CmdAndControlRXer();

        void wakeupThread();

        bool init();

      protected:

        virtual ~CmdAndControlRXer();

    enum {

        kWhatSendPacket,

        kWhatTrimRetryBuffers,

        kWhatSendHeartbeats,

      private:

        virtual bool threadLoop();

        void clearWakeupEvent();

        static const int kMaxReceiverPacketLen;

        static const uint32_t kRetryRequestID;

        static const uint32_t kFastStartRequestID;

        static const uint32_t kRetryNakID;

        int mWakeupEventFD;

        // Timeout used to track when we need to trim all of the retry buffers.

        Timeout mTrimRetryTimeout;

        DISALLOW_EVIL_CONSTRUCTORS(CmdAndControlRXer);

    };

    // fields for SendPacket messages

    static const char* kSendPacketIPAddr;

    static const char* kSendPacketPort;

    static const char* kSendPacketTRTPPacket;

    // Small utility class used to keep track of our unicast clients and when

    // they are going to time out of the group if we don't keep receiving group

    // membership reports.

    class UnicastTarget : public RefBase {

      public:

        explicit UnicastTarget(const struct sockaddr_in& endpoint) {

            mGroupTimeout.setTimeout(kUnicastClientTimeoutMsec);

            mEndpoint = endpoint;

        }

  private:

    AAH_TXGroup();

        struct sockaddr_in mEndpoint;

        Timeout mGroupTimeout;

        DISALLOW_EVIL_CONSTRUCTORS(UnicastTarget);

    };

    // A circular buffer of TRTPPackets is a retry buffer for a TX Group.

    typedef CircularBuffer< sp<TRTPPacket> > RetryBuffer;

    /***************************************************************************

     *

     * Static shared state as well as static methods.

     *

     **************************************************************************/

    // Our lock for serializing access to shared state.

    static Mutex sLock;

    static wp<AAH_TXGroup> sInstance;

    // The list of currently active TX groups.

    static Vector < sp<AAH_TXGroup> > sActiveTXGroups;

    // The singleton command and control receiver thread.

    static sp<CmdAndControlRXer> mCmdAndControlRXer;

    // State used to generate unique TRTP epochs.

    static uint32_t sNextEpoch;

    static bool sNextEpochValid;

    static uint32_t getNextEpoch();

    typedef CircularBuffer<sp<TRTPPacket> > RetryBuffer;

    /***************************************************************************

     *

     * Private methods.

     *

     **************************************************************************/

    // state maintained on a per-endpoint basis

    struct EndpointState {

        EndpointState(uint32_t epoch);

        RetryBuffer retry;

        int playerRefCount;

        uint16_t trtpSeqNumber;

        uint16_t nextProgramID;

        uint32_t epoch;

    };

    // Private constructor.  Use the static getGroup to obtain an AAH_TXGroup

    // instance.

    AAH_TXGroup();

    friend class AHandlerReflector<AAH_TXGroup>;

    void onMessageReceived(const sp<AMessage>& msg);

    void onSendPacket(const sp<AMessage>& msg);

    void doSendPacket_l(const sp<TRTPPacket>& packet,

                        const Endpoint& endpoint);

    void trimRetryBuffers();

    void sendHeartbeats();

    bool shouldSendHeartbeats_l();

    // Used by the static getGroup methods when they need to create a brand new

    // TXGroup.

    bool bindSocket();

    sp<ALooper> mLooper;

    sp<AHandlerReflector<AAH_TXGroup> > mReflector;

    // Locked version of sendPacket.

    status_t sendPacket_l(const sp<TRTPPacket>& packet);

    int mSocket;

    nsecs_t mLastSentPacketTime;

    // Send a payload to a specific target address.

    status_t sendToTarget_l(const struct sockaddr_in* target,

                            const uint8_t* payload,

                            size_t length);

    DefaultKeyedVector<Endpoint, EndpointState*> mEndpointMap;

    Mutex mEndpointLock;

    // Add a client ref to this TX Group and reset its cleanup timer.

    void addClientReference();

    static const int kRetryTrimIntervalUs;

    static const int kHeartbeatIntervalUs;

    static const int kRetryBufferCapacity;

    static const nsecs_t kHeartbeatTimeout;

    // Test used by the C&C thread to see if its time to expire and cleanup a

    // client.

    bool shouldExpire();

    class RetryReceiver : public Thread {

      private:

        friend class AAH_TXGroup;

    // Trim expired packets from this instance's retry buffer.

    void trimRetryBuffer();

        RetryReceiver(AAH_TXGroup* sender);

        virtual ~RetryReceiver();

        virtual bool threadLoop();

        void handleRetryRequest();

    // Send a heartbeat to this instance's clients to let them know that we are

    // still alive if its been a while since we sent any traffic to them.

    void sendHeartbeatIfNeeded();

        static const int kMaxReceiverPacketLen;

        static const uint32_t kRetryRequestID;

        static const uint32_t kFastStartRequestID;

        static const uint32_t kRetryNakID;

    // Handle any pending command and control requests waiting in this TX

    // group's socket.

    void handleRequests();

        AAH_TXGroup* mSender;

        PipeEvent mWakeupEvent;

    };

    // Handlers for individual command and control request types.

    void handleRetryRequest(const uint8_t* req,

                            const struct sockaddr_in* src_addr,

                            bool isFastStart);

    sp<RetryReceiver> mRetryReceiver;

};

    void handleJoinGroup(const struct sockaddr_in* src_addr);

struct RetryPacket {

    uint32_t id;

    uint32_t endpointIP;

    uint16_t endpointPort;

    uint16_t seqStart;

    uint16_t seqEnd;

} __attribute__((packed));

    void handleLeaveGroup(const struct sockaddr_in* src_addr);

    /***************************************************************************

     *

     * Private member variables

     *

     **************************************************************************/

    // Lock we use to serialize access to instance variables.

    Mutex mLock;

    // The list of packets we hold for servicing retry requests.

    RetryBuffer mRetryBuffer;

    // The number of TX Player clients currently using this TX group.

    uint32_t mClientRefCount;

    // The sequence number to assign to the next transmitted TRTP packet.

    uint16_t mTRTPSeqNumber;

    // The program ID to assign to the next TXPlayer client.  Program IDs are

    // actually unsigned 16 bit ints, but android's atomic inc routine operates

    // on ints, not shorts.  Its not a problem, we just mask out the lower 16

    // bits and call it good.

    int mNextProgramID;

    // The TRTP Epoch assigned to this transmit group.

    uint32_t mEpoch;

    // The socket we use to send packet and receive command and control

    // requests.

    int mSocket;

    // The UDP port to which our socket is bound (in host order).

    uint16_t mCmdAndControlPort;

    // The multicast target to send traffic to (if valid) For sanity's sake,

    // TXGroups are not allowed to have multiple multicast targets.

    struct sockaddr_in mMulticastTarget;

    bool mMulticastTargetValid;

    // The list of unicast client targets to send traffic to.

    //

    // TODO: right now, N for this list is expected to be small (think 1-3), and

    // is capped at something reasonable (16 right now).  If we ever need to go

    // much beyond that, we should seriously consider switching this to

    // something with O(ln) lookup time indexed by client's endpoint so we can

    // efficiently handle the regular group membership reports we need to

    // process from each client.

    Vector< sp<UnicastTarget> > mUnicastTargets;

    // Timeout used to track when the next heartbeat should be sent.

    Timeout mHeartbeatTimeout;

    // Timeout used to determine when to clean up this TXGroup after it no

    // longer has any TXPlayer clients.

    Timeout mCleanupTimeout;

    /***************************************************************************

     *

     * Class wide constants.

     *

     **************************************************************************/

    static const int kRetryTrimIntervalMsec;

    static const int kHeartbeatIntervalMsec;

    static const int kTXGroupLingerTimeMsec;

    static const int kUnicastClientTimeoutMsec;

    static const size_t kRetryBufferCapacity;

    static const size_t kMaxUnicastTargets;

    static const size_t kInitialUnicastTargetCapacity;

    static const size_t kMaxAllowedTXGroups;

    static const size_t kInitialActiveTXGroupsCapacity;

    static const uint32_t kCNC_RetryRequestID;

    static const uint32_t kCNC_FastStartRequestID;

    static const uint32_t kCNC_NakRetryRequestID;

    static const uint32_t kCNC_JoinGroupID;

    static const uint32_t kCNC_LeaveGroupID;

    static const uint32_t kCNC_NakJoinGroupID;

    DISALLOW_EVIL_CONSTRUCTORS(AAH_TXGroup);

};

}  // namespace android

    nsecs_t getExpireTime() const;

    virtual bool pack() = 0;

    bool isPacked() const { return mIsPacked; }

    // mask for the number of bits in a TRTP epoch

    static const uint32_t kTRTPEpochMask = (1 << 22) - 1;