opengles: improve throughput of TCP socket

Disable the TCP Nagle algorithm to drastically improve the
throughput of small packets when creating the TCP socket used
to talk with the OpenGLES renderer library.

Coupled with a corresponding change in the server part of the
code, this improves performance of most applications significantly.

+ get rid of shouldSetSockOpt field, by performing the buffer
  adjustment just after the socket is created.

Change-Id: Ibacca834ff98d1e9a92fb735f450b925e373fdc0

1 files changed, 16 insertions, 16 deletions

diff --git a/android/hw-pipe-net.c b/android/hw-pipe-net.c
index dade446..b3bc6c9 100644
--- a/android/hw-pipe-net.c
+++ b/android/hw-pipe-net.c
@@ -68,7 +68,6 @@ typedef struct {
     int             wakeWanted;
     LoopIo          io[1];
     AsyncConnector  connector[1];
-    int             shouldSetSocketOpt;
 } NetPipe;
 
 static void
@@ -192,7 +191,6 @@ netPipe_initFromAddress( void* hwpipe, const SockAddress*  address, Looper* loop
 
     pipe->hwpipe = hwpipe;
     pipe->state  = STATE_INIT;
-    pipe->shouldSetSocketOpt = 0;
 
     {
         AsyncStatus  status;
@@ -246,19 +244,6 @@ netPipe_sendBuffers( void* opaque, const GoldfishPipeBuffer* buffers, int numBuf
     const GoldfishPipeBuffer* buff = buffers;
     const GoldfishPipeBuffer* buffEnd = buff + numBuffers;
 
-#ifdef _WIN32
-    if (pipe->shouldSetSocketOpt == 1) {
-        int sndbuf = 128 * 1024;
-        int len = sizeof(sndbuf);
-        if (setsockopt(pipe->io->fd, SOL_SOCKET, SO_SNDBUF,
-                       (char*)&sndbuf, len) == SOCKET_ERROR) {
-            D("Failed to set SO_SNDBUF to %d error=0x%x\n",
-               sndbuf, WSAGetLastError());
-        }
-        pipe->shouldSetSocketOpt = 0;
-    }
-#endif
-
     for (; buff < buffEnd; buff++)
         count += buff->size;
 
@@ -480,7 +465,22 @@ openglesPipe_init( void* hwpipe, void* _looper, const char* args )
     /* For now, simply connect through tcp */
     snprintf(temp, sizeof temp, "%d", DEFAULT_OPENGLES_PORT);
     pipe = (NetPipe *)netPipe_initTcp(hwpipe, _looper, temp);
-    pipe->shouldSetSocketOpt = 1;
+
+    // Disable TCP nagle algorithm to improve throughput of small packets
+    socket_set_nodelay(pipe->io->fd);
+
+    // On Win32, adjust buffer sizes
+#ifdef _WIN32
+    {
+        int sndbuf = 128 * 1024;
+        int len = sizeof(sndbuf);
+        if (setsockopt(pipe->io->fd, SOL_SOCKET, SO_SNDBUF,
+                       (char*)&sndbuf, len) == SOCKET_ERROR) {
+            D("Failed to set SO_SNDBUF to %d error=0x%x\n",
+               sndbuf, WSAGetLastError());
+        }
+    }
+#endif /* _WIN32 */
 
     return pipe;
 }