[NaCl SDK] nacl_io: implement set/getsockopt for TCP_NODELAY.

native_client_sdk/src/libraries/nacl_io/mount_node_tcp.cc

Index: native_client_sdk/src/libraries/nacl_io/mount_node_tcp.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/mount_node_tcp.cc b/native_client_sdk/src/libraries/nacl_io/mount_node_tcp.cc
index e13809d14fc1c3413460fd40ef0d62b066e35041..48a719e9d288b7a299c84af6e2f33f91bb6d881c 100644
--- a/native_client_sdk/src/libraries/nacl_io/mount_node_tcp.cc
+++ b/native_client_sdk/src/libraries/nacl_io/mount_node_tcp.cc
@@ -272,13 +272,15 @@ class TCPConnectWork : public MountStream::Work {
 
 MountNodeTCP::MountNodeTCP(Mount* mount)
     : MountNodeSocket(mount),
-      emitter_(new EventEmitterTCP(kDefaultFifoSize, kDefaultFifoSize)) {
+      emitter_(new EventEmitterTCP(kDefaultFifoSize, kDefaultFifoSize)),
+      tcp_nodelay_(false) {
   emitter_->AttachStream(this);
 }
 
 MountNodeTCP::MountNodeTCP(Mount* mount, PP_Resource socket)
     : MountNodeSocket(mount, socket),
-      emitter_(new EventEmitterTCP(kDefaultFifoSize, kDefaultFifoSize)) {
+      emitter_(new EventEmitterTCP(kDefaultFifoSize, kDefaultFifoSize)),
+      tcp_nodelay_(false) {
   emitter_->AttachStream(this);
 }
 
@@ -320,6 +322,48 @@ void MountNodeTCP::SetError_Locked(int pp_error_num) {
   emitter_->SetError_Locked();
 }
 
+Error MountNodeTCP::GetSockOpt(int lvl,
+                               int optname,
+                               void* optval,
+                               socklen_t* len) {
+  if (lvl == IPPROTO_TCP && optname == TCP_NODELAY) {
+    int value = tcp_nodelay_;
+    socklen_t value_len = sizeof(value);
+    int copy_bytes = std::min(value_len, *len);
+    memcpy(optval, &value, copy_bytes);
+    *len = value_len;
+    return 0;
+  }
+
+  return MountNodeSocket::GetSockOpt(lvl, optname, optval, len);
+}
+
+
+Error MountNodeTCP::SetNoDelay() {

[binji, 2013/12/02 20:55:32]

should this be called SetNoDelay_Locked? Or does it work properly without
holding the lock?

[Sam Clegg, 2013/12/02 22:55:44]

Done.

+  if (!IsConnected())
+    return 0;
+
+  int32_t error = TCPInterface()->SetOption(socket_resource_,
+      PP_TCPSOCKET_OPTION_NO_DELAY,
+      PP_MakeBool(tcp_nodelay_ ? PP_TRUE : PP_FALSE),
+      PP_BlockUntilComplete());
+  return PPErrorToErrno(error);
+}
+
+Error MountNodeTCP::SetSockOpt(int lvl,
+                               int optname,
+                               const void* optval,
+                               socklen_t len) {
+  if (lvl == IPPROTO_TCP && optname == TCP_NODELAY) {
+    if (len < sizeof(int))
+      return EINVAL;
+    tcp_nodelay_ = *static_cast<const int*>(optval) ? true : false;

[binji, 2013/12/02 20:55:32]

nit: I'd prefer

*static_cast<const int*>(optval) != 0

here instead

[Sam Clegg, 2013/12/02 22:55:44]

Done.

+    return SetNoDelay();
+  }
+
+  return MountNodeSocket::SetSockOpt(lvl, optname, optval, len);
+}
+
 void MountNodeTCP::QueueAccept() {
   MountStream::Work* work = new TCPAcceptWork(mount_stream(), emitter_);
   mount_stream()->EnqueueWork(work);
@@ -464,6 +508,10 @@ void MountNodeTCP::ConnectDone_Locked() {
 
   emitter_->ConnectDone_Locked();
 
+  // The NODELAY option cannot be set in PPAPI before the socket
+  // is connected, but setsockopt() might have already set it.
+  SetNoDelay();
+
   // Begin the input pump
   QueueInput();
 }