pipe select test

Author: labath

lldb/unittests/Host/PipeTest.cpp

@@ -11,6 +11,7 @@
 #include "lldb/Host/FileSystem.h"
 #include "lldb/Host/HostInfo.h"
 #include "llvm/Testing/Support/Error.h"
+#include "lldb/Host/Socket.h"
 #include "gtest/gtest.h"
 #include <chrono>
 #include <fcntl.h>
@@ -36,6 +37,36 @@ TEST_F(PipeTest, CreateWithUniqueName) {
                     llvm::Succeeded());
 }
 
+
+TEST_F(PipeTest, select) {
+  ASSERT_THAT_ERROR(Socket::Initialize(), llvm::Succeeded());
+  Pipe pipe;
+  ASSERT_THAT_ERROR(pipe.CreateNew().ToError(), llvm::Succeeded());
+  OVERLAPPED ov = {};
+  HANDLE event = CreateEvent(NULL, true, false, NULL);
+  ASSERT_NE(event, nullptr);
+  ov.hEvent = event;
+  char buffer[1];
+  DWORD bytes_read;
+  BOOL success = ReadFile(pipe.GetReadPipe(), buffer, 0, &bytes_read, &ov);
+  ASSERT_FALSE(success);
+  ASSERT_EQ(GetLastError(), ERROR_IO_PENDING);
+  auto start = std::chrono::system_clock::now();
+  std::future<llvm::Expected<size_t>> future_num_bytes = std::async(
+      std::launch::async, [&] { 
+      std::this_thread::sleep_for(std::chrono::seconds(1));
+      return pipe.Write(".", 1, std::nullopt);
+      });
+  DWORD result = WSAWaitForMultipleEvents(1, &event, false, INFINITE, false);
+  ASSERT_GT(std::chrono::system_clock::now()-start, std::chrono::seconds(1));
+  ASSERT_EQ(result, WSA_WAIT_EVENT_0);
+  ASSERT_TRUE(GetOverlappedResult(pipe.GetReadPipe(), &ov, &bytes_read, false));
+  ASSERT_EQ(bytes_read, 0);
+  ASSERT_THAT_EXPECTED(future_num_bytes.get(), llvm::Succeeded());
+  ASSERT_THAT_EXPECTED(pipe.Read(buffer, 1, std::chrono::seconds(0)), llvm::HasValue(1));
+  ASSERT_EQ(buffer[0], '.');
+}
+
 // Test broken
 #ifndef _WIN32
 TEST_F(PipeTest, OpenAsReader) {