Mojo: Abstract out write/writev vs send/sendmsg (for Unix domain sockets).

mojo/embedder/platform_channel_pair_posix_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/embedder/platform_channel_pair.h"
 
 #include <errno.h>
 #include <signal.h>
 #include <sys/socket.h>
 #include <sys/types.h>
+#include <sys/uio.h>
 #include <unistd.h>
 
 #include "base/logging.h"
 #include "base/macros.h"
-#include "build/build_config.h"
+#include "mojo/embedder/platform_channel_utils_posix.h"
 #include "mojo/embedder/scoped_platform_handle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace embedder {
 namespace {
 
 class PlatformChannelPairPosixTest : public testing::Test {
  public:
   PlatformChannelPairPosixTest() {}
@@ skipping 37 matching lines @@
             read(server_handle.get().fd, buffer, sizeof(buffer)));
   EXPECT_STREQ(kHello, buffer);
 
   // Try reading again.
   ssize_t result = read(server_handle.get().fd, buffer, sizeof(buffer));
   // We should probably get zero (for "end of file"), but -1 would also be okay.
   EXPECT_TRUE(result == 0 || result == -1);
   if (result == -1)
     PLOG(WARNING) << "read (expected 0 for EOF)";
 
-  // However, |write()|/|send()| should fail outright.
-  // On Mac, |SIGPIPE| needs to be suppressed on the socket itself and we can
-  // use |write()|/|writev()|. On Linux, we have to suppress it by using
-  // |send()|/|sendmsg()| with |MSG_NOSIGNAL|.
-#if defined(OS_MACOSX)
-  result = write(server_handle.get().fd, kHello, sizeof(kHello));
-#else
-  result = send(server_handle.get().fd, kHello, sizeof(kHello), MSG_NOSIGNAL);
-#endif
+  // Test our replacement for |write()|/|send()|.
+  result = PlatformChannelWrite(server_handle.get(), kHello, sizeof(kHello));
   EXPECT_EQ(-1, result);
   if (errno != EPIPE)
     PLOG(WARNING) << "write (expected EPIPE)";
+
+  // Test our replacement for |writev()|/|sendv()|.
+  struct iovec iov[2] = {
+    { const_cast<char*>(kHello), sizeof(kHello) },
+    { const_cast<char*>(kHello), sizeof(kHello) }
+  };
+  result = PlatformChannelWritev(server_handle.get(), iov, 2);
+  EXPECT_EQ(-1, result);
+  if (errno != EPIPE)
+    PLOG(WARNING) << "write (expected EPIPE)";
 }
 
 }  // namespace
 }  // namespace embedder
 }  // namespace mojo