Make std* blocking file-descriptors.

runtime/bin/file_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "bin/file.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 20 matching lines @@
   void set_fd(int fd) { fd_ = fd; }
 
  private:
   int fd_;
 
   DISALLOW_COPY_AND_ASSIGN(FileHandle);
 };
 
 
 File::~File() {
-  // Close the file (unless it's a standard stream).
-  if (handle_->fd() > STDERR_FILENO) {
-    Close();
-  }
+  Close();
   delete handle_;
 }
 
 
 void File::Close() {
   ASSERT(handle_->fd() >= 0);
-  int err = TEMP_FAILURE_RETRY_BLOCK_SIGNALS(close(handle_->fd()));
-  if (err != 0) {
-    const int kBufferSize = 1024;
-    char error_buf[kBufferSize];
-    Log::PrintErr("%s\n", strerror_r(errno, error_buf, kBufferSize));
+  if (handle_->fd() == STDOUT_FILENO) {

[Søren Gjesse, 2014/02/07 11:05:11]

Why is stderr not handled here as well?

[Anders Johnsen, 2014/02/14 08:43:28]

It's only to work around print printing to file/socket, that's reusing the
stdout fd.

+    // If stdout, redirect fd to /dev/null.
+    int null_fd = TEMP_FAILURE_RETRY(open("/dev/null", O_WRONLY));
+    ASSERT(null_fd >= 0);

[Søren Gjesse, 2014/02/07 11:05:11]

So this will still affect "printf debugging".

[Anders Johnsen, 2014/02/14 08:43:28]

Yes, intentionally. :)

+    VOID_TEMP_FAILURE_RETRY(dup2(null_fd, STDOUT_FILENO));

[Søren Gjesse, 2014/02/07 11:05:11]

Use handle_->fd() instead of STDOUT_FILENO here.

[Ivan Posva, 2014/02/11 04:08:37]

I am wondering whether we should have duped the stdout and stderr fds at the
beginning when opening them from dart:io.

[Anders Johnsen, 2014/02/14 08:43:28]

Done.

[Anders Johnsen, 2014/02/14 08:43:28]

That would still have given us this scenario where stdout.close and print can do
bad things. Note that the fact that we can close stdout is a feature.

+    VOID_TEMP_FAILURE_RETRY(close(null_fd));
+  } else {
+    int err = TEMP_FAILURE_RETRY_BLOCK_SIGNALS(close(handle_->fd()));
+    if (err != 0) {
+      const int kBufferSize = 1024;
+      char error_buf[kBufferSize];
+      Log::PrintErr("%s\n", strerror_r(errno, error_buf, kBufferSize));
+    }
   }
   handle_->set_fd(kClosedFd);
 }
 
 
 bool File::IsClosed() {
   return handle_->fd() == kClosedFd;
 }
 
 
@@ skipping 351 matching lines @@
   return (file_1_info.st_ino == file_2_info.st_ino &&
           file_1_info.st_dev == file_2_info.st_dev) ?
       File::kIdentical :
       File::kDifferent;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)