for bug #251, merge the performance refines.

@@ -598,6 +598,12 @@ int SrsRtmpConn::do_playing(SrsSource* source, SrsQueueRecvThread* trd)
         // collect elapse for pithy print.
         pithy_print.elapse();
         
+#ifdef SRS_PERF_QUEUE_COND_WAIT
+        // wait for message to incoming.
+        // @see https://github.com/winlinvip/simple-rtmp-server/issues/251
+        consumer->wait(SRS_PERF_MW_MIN_MSGS, mw_sleep);
+#endif
+        
         // get messages from consumer.
         // each msg in msgs.msgs must be free, for the SrsMessageArray never free them.
         int count = 0;
@@ -605,12 +611,16 @@ int SrsRtmpConn::do_playing(SrsSource* source, SrsQueueRecvThread* trd)
             srs_error("get messages from consumer failed. ret=%d", ret);
             return ret;
         }
-
-        // no messages, sleep for a while.
+        
+#ifdef SRS_PERF_QUEUE_COND_WAIT
+        // we use wait to get messages, so the count must be positive.
+        srs_assert(count > 0);
+#else
         if (count <= 0) {
             st_usleep(mw_sleep * 1000);
         }
-        srs_info("got %d msgs, mw=%d", count, mw_sleep);
+#endif
+        srs_info("got %d msgs, min=%d, mw=%d", count, SRS_PERF_MW_MIN_MSGS, mw_sleep);
 
         // reportable
         if (pithy_print.can_print()) {
@@ -995,6 +1005,13 @@ void SrsRtmpConn::change_mw_sleep(int sleep_ms)
         return;
     }
     
+    // get the sock buffer size.
+    int fd = st_netfd_fileno(stfd);
+    int onb_sbuf = 0;
+    socklen_t sock_buf_size = sizeof(int);
+    getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &onb_sbuf, &sock_buf_size);
+    
+#ifdef SRS_PERF_MW_SO_SNDBUF    
     // the bytes:
     //      4KB=4096, 8KB=8192, 16KB=16384, 32KB=32768, 64KB=65536,
     //      128KB=131072, 256KB=262144, 512KB=524288
@@ -1007,11 +1024,6 @@ void SrsRtmpConn::change_mw_sleep(int sleep_ms)
     //      2000*5000/8=1250000B(about 1220KB).
     int kbps = 5000;
     int socket_buffer_size = sleep_ms * kbps / 8;
-    
-    int fd = st_netfd_fileno(stfd);
-    int onb_sbuf = 0;
-    socklen_t sock_buf_size = sizeof(int);
-    getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &onb_sbuf, &sock_buf_size);
 
     // socket send buffer, system will double it.
     int nb_sbuf = socket_buffer_size / 2;
@@ -1022,9 +1034,13 @@ void SrsRtmpConn::change_mw_sleep(int sleep_ms)
     }
     getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &nb_sbuf, &sock_buf_size);
     
-    srs_trace("mw change sleep %d=>%d, max_msgs=%d, esbuf=%d, sbuf %d=>%d", 
+    srs_trace("mw changed sleep %d=>%d, max_msgs=%d, esbuf=%d, sbuf %d=>%d", 
         mw_sleep, sleep_ms, SRS_PERF_MW_MSGS, socket_buffer_size,
         onb_sbuf, nb_sbuf);
+#else
+    srs_trace("mw changed sleep %d=>%d, max_msgs=%d, sbuf %d", 
+        mw_sleep, sleep_ms, SRS_PERF_MW_MSGS, onb_sbuf);
+#endif
         
     mw_sleep = sleep_ms;
 }

@@ -182,7 +182,7 @@ void SrsMessageQueue::set_queue_size(double queue_size)
     queue_size_ms = (int)(queue_size * 1000);
 }
 
-int SrsMessageQueue::enqueue(SrsSharedPtrMessage* msg, bool* is_overflow)
+int SrsMessageQueue::enqueue(SrsSharedPtrMessage* msg)
 {
     int ret = ERROR_SUCCESS;
     
@@ -197,11 +197,6 @@ int SrsMessageQueue::enqueue(SrsSharedPtrMessage* msg, bool* is_overflow)
     msgs.push_back(msg);
 
     while (av_end_time - av_start_time > queue_size_ms) {
-        // notice the caller queue already overflow and shrinked.
-        if (is_overflow) {
-            *is_overflow = true;
-        }
-        
         shrink();
     }
     
@@ -211,7 +206,7 @@ int SrsMessageQueue::enqueue(SrsSharedPtrMessage* msg, bool* is_overflow)
 int SrsMessageQueue::dump_packets(int max_count, SrsSharedPtrMessage** pmsgs, int& count)
 {
     int ret = ERROR_SUCCESS;
-
+    
     int nb_msgs = (int)msgs.size();
     if (nb_msgs <= 0) {
         return ret;
@@ -308,6 +303,13 @@ SrsConsumer::SrsConsumer(SrsSource* _source)
     jitter = new SrsRtmpJitter();
     queue = new SrsMessageQueue();
     should_update_source_id = false;
+    
+#ifdef SRS_PERF_QUEUE_COND_WAIT
+    mw_wait = st_cond_new();
+    mw_min_msgs = 0;
+    mw_duration = 0;
+    mw_waiting = false;
+#endif
 }
 
 SrsConsumer::~SrsConsumer()
@@ -315,6 +317,10 @@ SrsConsumer::~SrsConsumer()
     source->on_consumer_destroy(this);
     srs_freep(jitter);
     srs_freep(queue);
+    
+#ifdef SRS_PERF_QUEUE_COND_WAIT
+    st_cond_destroy(mw_wait);
+#endif
 }
 
 void SrsConsumer::set_queue_size(double queue_size)
@@ -344,11 +350,25 @@ int SrsConsumer::enqueue(SrsSharedPtrMessage* __msg, bool atc, int tba, int tbv,
             return ret;
         }
     }
-
-    if ((ret = queue->enqueue(msg, NULL)) != ERROR_SUCCESS) {
+    
+    if ((ret = queue->enqueue(msg)) != ERROR_SUCCESS) {
         return ret;
     }
     
+    #ifdef SRS_PERF_QUEUE_COND_WAIT
+    // fire the mw when msgs is enough.
+    if (mw_waiting) {
+        int duration_ms = queue->duration();
+        bool match_min_msgs = queue->size() > mw_min_msgs;
+        
+        // when duration ok, signal to flush.
+        if (match_min_msgs && duration_ms > mw_duration) {
+            st_cond_signal(mw_wait);
+            mw_waiting = false;
+        }
+    }
+    #endif
+    
     return ret;
 }
 
@@ -376,6 +396,27 @@ int SrsConsumer::dump_packets(SrsMessageArray* msgs, int& count)
     return ret;
 }
 
+#ifdef SRS_PERF_QUEUE_COND_WAIT
+void SrsConsumer::wait(int nb_msgs, int duration)
+{
+    mw_min_msgs = nb_msgs;
+    mw_duration = duration;
+    
+    int duration_ms = queue->duration();
+    bool match_min_msgs = queue->size() > mw_min_msgs;
+    
+    // when duration ok, signal to flush.
+    if (match_min_msgs && duration_ms > mw_duration) {
+        return;
+    }
+    
+    // the enqueue will notify this cond.
+    mw_waiting = true;
+    // wait for msgs to incoming.
+    st_cond_wait(mw_wait);
+}
+#endif
+
 int SrsConsumer::on_play_client_pause(bool is_pause)
 {
     int ret = ERROR_SUCCESS;

@@ -134,12 +134,11 @@ public:
     /**
     * enqueue the message, the timestamp always monotonically.
     * @param msg, the msg to enqueue, user never free it whatever the return code.
-    * @param is_overflow, whether overflow and shrinked. NULL to ignore.
     */
-    virtual int enqueue(SrsSharedPtrMessage* msg, bool* is_overflow = NULL);
+    virtual int enqueue(SrsSharedPtrMessage* msg);
     /**
     * get packets in consumer queue.
-    * @pmsgs SrsCommonMessages*[], used to store the msgs, user must alloc it.
+    * @pmsgs SrsSharedPtrMessage*[], used to store the msgs, user must alloc it.
     * @count the count in array, output param.
     * @max_count the max count to dequeue, must be positive.
     */
@@ -165,6 +164,14 @@ private:
     bool paused;
     // when source id changed, notice all consumers
     bool should_update_source_id;
+#ifdef SRS_PERF_QUEUE_COND_WAIT
+    // the cond wait for mw.
+    // @see https://github.com/winlinvip/simple-rtmp-server/issues/251
+    st_cond_t mw_wait;
+    bool mw_waiting;
+    int mw_min_msgs;
+    int mw_duration;
+#endif
 public:
     SrsConsumer(SrsSource* _source);
     virtual ~SrsConsumer();
@@ -200,6 +207,14 @@ public:
     * @max_count the max count to dequeue, must be positive.
     */
     virtual int dump_packets(SrsMessageArray* msgs, int& count);
+#ifdef SRS_PERF_QUEUE_COND_WAIT
+    /**
+    * wait for messages incomming, atleast nb_msgs and in duration.
+    * @param nb_msgs the messages count to wait.
+    * @param duration the messgae duration to wait.
+    */
+    virtual void wait(int nb_msgs, int duration);
+#endif
     /**
     * when client send the pause message.
     */

@@ -103,6 +103,22 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * @remark, recomment to 128.
 */
 #define SRS_PERF_MW_MSGS 128
+/**
+* whether set the socket send buffer size.
+* @see https://github.com/winlinvip/simple-rtmp-server/issues/251
+*/
+#undef SRS_PERF_MW_SO_SNDBUF
+/**
+* whether set the socket recv buffer size.
+* @see https://github.com/winlinvip/simple-rtmp-server/issues/251
+*/
+#undef SRS_PERF_MW_SO_RCVBUF
+/**
+* whether use cond wait to send messages.
+* @remark this improve performance for large connectios.
+* @see https://github.com/winlinvip/simple-rtmp-server/issues/251
+*/
+#undef SRS_PERF_QUEUE_COND_WAIT
 
 /**
 * how many chunk stream to cache, [0, N].

@@ -37,7 +37,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 class SrsProtocol;
 class ISrsProtocolReaderWriter;
-class ISrsCommonMessage;
 class SrsCommonMessage;
 class SrsCreateStreamPacket;
 class SrsFMLEStartPacket;

@@ -755,10 +755,17 @@ int SrsProtocol::do_send_messages(SrsSharedPtrMessage** msgs, int nb_msgs)
         
         // always write the header event payload is empty.
         while (p < pend) {
-            // header use iov[0].
-            generate_chunk_header(c0c3_cache, &msg->header, p == msg->payload, iov);
+            // always has header
+            int nbh = 0;
+            char* header = NULL;
+            generate_chunk_header(c0c3_cache, &msg->header, p == msg->payload, &nbh, &header);
+            srs_assert(nbh > 0);
             
-            // payload use iov[1].
+            // header iov
+            iov[0].iov_base = header;
+            iov[0].iov_len = nbh;
+            
+            // payload iov
             int payload_size = pend - p;
             if (payload_size > out_chunk_size) {
                 payload_size = out_chunk_size;
@@ -781,14 +788,14 @@ int SrsProtocol::do_send_messages(SrsSharedPtrMessage** msgs, int nb_msgs)
                 int realloc_size = sizeof(iovec) * nb_out_iovs;
                 out_iovs = (iovec*)realloc(out_iovs, realloc_size);
             }
-
-            // to next c0c3 header cache
-            c0c3_cache_index += iov[0].iov_len;
-            c0c3_cache = out_c0c3_caches + c0c3_cache_index;
             
             // to next pair of iovs
             iov_index += 2;
             iov = out_iovs + iov_index;
+
+            // to next c0c3 header cache
+            c0c3_cache_index += nbh;
+            c0c3_cache = out_c0c3_caches + c0c3_cache_index;
             
             // the cache header should never be realloc again,
             // for the ptr is set to iovs, so we just warn user to set larger
@@ -898,7 +905,7 @@ int SrsProtocol::do_send_and_free_packet(SrsPacket* packet, int stream_id)
     return ret;
 }
 
-void SrsProtocol::generate_chunk_header(char* cache, SrsMessageHeader* mh, bool c0, iovec* iov)
+void SrsProtocol::generate_chunk_header(char* cache, SrsMessageHeader* mh, bool c0, int* pnbh, char** ph) 
 {
     // to directly set the field.
     char* pp = NULL;
@@ -975,8 +982,8 @@ void SrsProtocol::generate_chunk_header(char* cache, SrsMessageHeader* mh, bool
     }
     
     // always has header
-    iov->iov_base = cache;
-    iov->iov_len = p - cache;
+    *pnbh = p - cache;
+    *ph = cache;
 }
 
 int SrsProtocol::do_decode_message(SrsMessageHeader& header, SrsStream* stream, SrsPacket** ppacket)

@@ -496,9 +496,11 @@ private:
     * generate the chunk header for msg.
     * @param mh, the header of msg to send.
     * @param c0, whether the first chunk, the c0 chunk.
-    * @param iov, output the header and size to iovec.
+    * @param pnbh, output the size of header.
+    * @param ph, output the header cache.
+    *       user should never free it, it's cached header.
     */
-    virtual void generate_chunk_header(char* cache, SrsMessageHeader* mh, bool c0, iovec* iov);
+    virtual void generate_chunk_header(char* cache, SrsMessageHeader* mh, bool c0, int* pnbh, char** ph);
     /**
     * imp for decode_message
     */