unix-adapter: Accommodate partial write calls, if it happens somehow.

Maybe this can happen?  I don't know.

src/unix-adapter/OutputHandler.cc

@@ -30,6 +30,7 @@
 
 #include "../shared/DebugClient.h"
 #include "Event.h"
+#include "Util.h"
 #include "WakeupFd.h"
 
 OutputHandler::OutputHandler(HANDLE winpty, WakeupFd &completionWakeup) :
@@ -100,18 +101,7 @@ void OutputHandler::threadProc() {
             }
             break;
         }
-        // I don't know if this write can be interrupted or not, but handle it
-        // just in case.
-        int written;
-        do {
-            written = write(STDOUT_FILENO, &buffer[0], numRead);
-        } while (written == -1 && errno == EINTR);
-        if (numRead != static_cast<DWORD>(written)) {
-            trace("OutputHandler: write failed: "
-                "errno=%d numRead=%u written=%d",
-                errno,
-                static_cast<unsigned int>(numRead),
-                written);
+        if (!writeAll(STDOUT_FILENO, &buffer[0], numRead)) {
             break;
         }
     }

src/unix-adapter/Util.cc

@@ -0,0 +1,59 @@
+// Copyright (c) 2015 Ryan Prichard
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+
+#include "Util.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../shared/DebugClient.h"
+
+// Write the entire buffer, restarting it as necessary.
+bool writeAll(int fd, const void *buffer, size_t size) {
+    size_t written = 0;
+    while (written < size) {
+        int ret = write(fd,
+                        reinterpret_cast<const char*>(buffer) + written,
+                        size - written);
+        if (ret == -1 && errno == EINTR) {
+            continue;
+        }
+        if (ret <= 0) {
+            trace("write failed: "
+                "fd=%d errno=%d size=%u written=%d ret=%d",
+                fd,
+                errno,
+                static_cast<unsigned int>(size),
+                static_cast<unsigned int>(written),
+                ret);
+            return false;
+        }
+        assert(static_cast<size_t>(ret) <= size - written);
+        written += ret;
+    }
+    assert(written == size);
+    return true;
+}
+
+bool writeStr(int fd, const char *str) {
+    return writeAll(fd, str, strlen(str));
+}

src/unix-adapter/Util.h

@@ -0,0 +1,29 @@
+// Copyright (c) 2015 Ryan Prichard
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+
+#ifndef UNIX_ADAPTER_UTIL_H
+#define UNIX_ADAPTER_UTIL_H
+
+#include <stdlib.h>
+
+bool writeAll(int fd, const void *buffer, size_t size);
+bool writeStr(int fd, const char *str);
+
+#endif // UNIX_ADAPTER_UTIL_H

src/unix-adapter/subdir.mk

@@ -23,6 +23,7 @@ ALL_TARGETS += build/$(UNIX_ADAPTER_EXE)
 UNIX_ADAPTER_OBJECTS = \
 	build/unix/unix-adapter/InputHandler.o \
 	build/unix/unix-adapter/OutputHandler.o \
+	build/unix/unix-adapter/Util.o \
 	build/unix/unix-adapter/WakeupFd.o \
 	build/unix/unix-adapter/main.o \
 	build/unix/shared/DebugClient.o \