Add an implementation of base::SyncSocket::Peek for posix platforms. Also

update the unit test to test the result.
TEST=ipc_tests/sync_socket_unittest.cc

Review URL: http://codereview.chromium.org/468023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33944 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 12 insertions, 5 deletions

diff --git a/base/sync_socket_posix.cc b/base/sync_socket_posix.cc
index 5390c7d..194c0bc 100644
--- a/base/sync_socket_posix.cc
+++ b/base/sync_socket_posix.cc
@@ -8,6 +8,7 @@
 #include <limits.h>
 #include <stdio.h>
 #include <sys/types.h>
+#include <sys/ioctl.h>
 #include <sys/socket.h>
 
 #include "base/atomicops.h"
@@ -98,10 +99,13 @@ size_t SyncSocket::Receive(void* buffer, size_t length) {
   }
 }
 
-// TODO(port). Some kind of select?
 size_t SyncSocket::Peek() {
-  NOTIMPLEMENTED();
-  return 0;
+  int number_chars;
+  if (-1 == ioctl(handle_, FIONREAD, &number_chars)) {
+    // If there is an error in ioctl, signal that the channel would block.
+    return 0;
+  }
+  return (size_t) number_chars;
 }
 
 }  // namespace base
diff --git a/ipc/sync_socket_unittest.cc b/ipc/sync_socket_unittest.cc
index 7710c09..c33d99a 100644
--- a/ipc/sync_socket_unittest.cc
+++ b/ipc/sync_socket_unittest.cc
@@ -189,14 +189,14 @@ class SyncSocketClientListener : public IPC::Channel::Listener {
   // string as was written on the SyncSocket.  These are compared
   // and a shutdown message is sent back to the server.
   void OnMsgClassResponse(const std::string& str) {
-#if defined(OS_WIN)
     // We rely on the order of sync_socket.Send() and chan_->Send() in
     // the SyncSocketServerListener object.
     EXPECT_EQ(kHelloStringLength, socket_->Peek());
-#endif
     char buf[kHelloStringLength];
     socket_->Receive(static_cast<void*>(buf), kHelloStringLength);
     EXPECT_EQ(strcmp(str.c_str(), buf), 0);
+    // After receiving from the socket there should be no bytes left.
+    EXPECT_EQ(0, socket_->Peek());
     IPC::Message* msg = new MsgClassShutdown();
     EXPECT_NE(msg, reinterpret_cast<IPC::Message*>(NULL));
     EXPECT_TRUE(chan_->Send(msg));
@@ -221,6 +221,9 @@ TEST_F(SyncSocketTest, SanityTest) {
   // Create a pair of SyncSockets.
   base::SyncSocket* pair[2];
   base::SyncSocket::CreatePair(pair);
+  // Immediately after creation there should be no pending bytes.
+  EXPECT_EQ(0, pair[0]->Peek());
+  EXPECT_EQ(0, pair[1]->Peek());
   base::SyncSocket::Handle target_handle;
   // Connect the channel and listener.
   ASSERT_TRUE(chan.Connect());