tty: use blocking mode on OS X

Makefile

@@ -118,7 +118,7 @@ test: all
 	$(MAKE) build-addons
 	$(MAKE) cctest
 	$(PYTHON) tools/test.py --mode=release -J \
-		addon doctool known_issues message parallel sequential
+		addon doctool known_issues message pseudo-tty parallel sequential
 	$(MAKE) lint
 
 test-parallel: all
@@ -183,7 +183,8 @@ test-all-valgrind: test-build
 test-ci: | build-addons
 	$(PYTHON) tools/test.py $(PARALLEL_ARGS) -p tap --logfile test.tap \
 		--mode=release --flaky-tests=$(FLAKY_TESTS) \
-		$(TEST_CI_ARGS) addons doctool known_issues message parallel sequential
+		$(TEST_CI_ARGS) addons doctool known_issues message pseudo-tty parallel \
+		sequential
 
 test-release: test-build
 	$(PYTHON) tools/test.py --mode=release

doc/api/console.md

@@ -53,11 +53,15 @@ duplicate the browser's functionality exactly.
 
 ## Asynchronous vs Synchronous Consoles
 
-The console functions are asynchronous unless the destination is a file.
+The console functions are usually asynchronous unless the destination is a file.
 Disks are fast and operating systems normally employ write-back caching;
 it should be a very rare occurrence indeed that a write blocks, but it
 is possible.
 
+Additionally, console functions are blocking when outputting to TTYs
+(terminals) on OS X as a workaround for the OS's very small, 1kb buffer size.
+This is to prevent interleaving between `stdout` and `stderr`.
+
 ## Class: Console
 
 <!--type=class-->

doc/api/process.md

@@ -833,7 +833,8 @@ if (someConditionNotMet()) {
 ```
 
 The reason this is problematic is because writes to `process.stdout` in Node.js
-are *non-blocking* and may occur over multiple ticks of the Node.js event loop.
+are usually *non-blocking* and may occur over multiple ticks of the Node.js
+event loop.
 Calling `process.exit()`, however, forces the process to exit *before* those
 additional writes to `stdout` can be performed.
 
@@ -1367,6 +1368,10 @@ event and that writes can block when output is redirected to a file (although
 disks are fast and operating systems normally employ write-back caching so it
 should be a very rare occurrence indeed.)
 
+Additionally, `process.stderr` and `process.stdout` are blocking when outputting
+to TTYs (terminals) on OS X as a workaround for the OS's very small, 1kb
+buffer size. This is to prevent interleaving between `stdout` and `stderr`.
+
 ## process.stdin
 
 A `Readable Stream` for stdin (on fd `0`).
@@ -1417,6 +1422,10 @@ event and that writes can block when output is redirected to a file (although
 disks are fast and operating systems normally employ write-back caching so it
 should be a very rare occurrence indeed.)
 
+Additionally, `process.stderr` and `process.stdout` are blocking when outputting
+to TTYs (terminals) on OS X as a workaround for the OS's very small, 1kb
+buffer size. This is to prevent interleaving between `stdout` and `stderr`.
+
 To check if Node.js is being run in a TTY context, read the `isTTY` property
 on `process.stderr`, `process.stdout`, or `process.stdin`:
 

lib/tty.js

@@ -48,6 +48,13 @@ function WriteStream(fd) {
     writable: true
   });
 
+  // Prevents interleaved stdout/stderr output in OS X terminals.
+  // As noted in the following reference, local TTYs tend to be quite fast and
+  // this behaviour has become expected due historical functionality on OS X,
+  // even though it was originally intended to change in v1.0.2 (Libuv 1.2.1).
+  // Ref: https://github.com/nodejs/node/pull/1771#issuecomment-119351671
+  if (process.platform === 'darwin') this._handle.setBlocking(true);
+
   var winSize = [];
   var err = this._handle.getWindowSize(winSize);
   if (!err) {

test/pseudo-tty/no_dropped_stdio.js

@@ -0,0 +1,15 @@
+// https://github.com/nodejs/node/issues/6456#issuecomment-219320599
+// https://gist.github.com/isaacs/1495b91ec66b21d30b10572d72ad2cdd
+'use strict';
+require('../common');
+
+// 1000 bytes wrapped at 50 columns
+// \n turns into a double-byte character
+// (48 + {2}) * 20 = 1000
+var out = ('o'.repeat(48) + '\n').repeat(20);
+// Add the remaining 24 bytes and terminate with an 'O'.
+// This results in 1025 bytes, just enough to overflow the 1kb OS X TTY buffer.
+out += 'o'.repeat(24) + 'O';
+
+process.stdout.write(out);
+process.exit(0);

test/pseudo-tty/no_dropped_stdio.out

@@ -0,0 +1,21 @@
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+ooooooooooooooooooooooooO

test/pseudo-tty/no_interleaved_stdio.js

@@ -0,0 +1,17 @@
+// https://github.com/nodejs/node/issues/6456#issuecomment-219320599
+// https://gist.github.com/isaacs/1495b91ec66b21d30b10572d72ad2cdd
+'use strict';
+require('../common');
+
+// 1000 bytes wrapped at 50 columns
+// \n turns into a double-byte character
+// (48 + {2}) * 20 = 1000
+var out = ('o'.repeat(48) + '\n').repeat(20);
+// Add the remaining 24 bytes and terminate with an 'O'.
+// This results in 1025 bytes, just enough to overflow the 1kb OS X TTY buffer.
+out += 'o'.repeat(24) + 'O';
+
+const err = '__This is some stderr__';
+
+process.stdout.write(out);
+process.stderr.write(err);

test/pseudo-tty/no_interleaved_stdio.out

@@ -0,0 +1,21 @@
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+oooooooooooooooooooooooooooooooooooooooooooooooo
+ooooooooooooooooooooooooO__This is some stderr__

test/pseudo-tty/testcfg.py

@@ -0,0 +1,161 @@
+# Copyright 2008 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import test
+import os
+from os.path import join, exists, basename, isdir
+import re
+import utils
+
+FLAGS_PATTERN = re.compile(r"//\s+Flags:(.*)")
+
+class TTYTestCase(test.TestCase):
+
+  def __init__(self, path, file, expected, arch, mode, context, config):
+    super(TTYTestCase, self).__init__(context, path, arch, mode)
+    self.file = file
+    self.expected = expected
+    self.config = config
+    self.arch = arch
+    self.mode = mode
+
+  def IgnoreLine(self, str):
+    """Ignore empty lines and valgrind output."""
+    if not str.strip(): return True
+    else: return str.startswith('==') or str.startswith('**')
+
+  def IsFailureOutput(self, output):
+    f = file(self.expected)
+    # Convert output lines to regexps that we can match
+    env = { 'basename': basename(self.file) }
+    patterns = [ ]
+    for line in f:
+      if not line.strip():
+        continue
+      pattern = re.escape(line.rstrip() % env)
+      pattern = pattern.replace('\\*', '.*')
+      pattern = '^%s$' % pattern
+      patterns.append(pattern)
+    # Compare actual output with the expected
+    raw_lines = (output.stdout + output.stderr).split('\n')
+    outlines = [ s.strip() for s in raw_lines if not self.IgnoreLine(s) ]
+    if len(outlines) != len(patterns):
+      print "length differs."
+      print "expect=%d" % len(patterns)
+      print "actual=%d" % len(outlines)
+      print "patterns:"
+      for i in xrange(len(patterns)):
+        print "pattern = %s" % patterns[i]
+      print "outlines:"
+      for i in xrange(len(outlines)):
+        print "outline = %s" % outlines[i]
+      return True
+    for i in xrange(len(patterns)):
+      if not re.match(patterns[i], outlines[i]):
+        print "match failed"
+        print "line=%d" % i
+        print "expect=%s" % patterns[i]
+        print "actual=%s" % outlines[i]
+        return True
+    return False
+
+  def GetLabel(self):
+    return "%s %s" % (self.mode, self.GetName())
+
+  def GetName(self):
+    return self.path[-1]
+
+  def GetCommand(self):
+    result = [self.config.context.GetVm(self.arch, self.mode)]
+    source = open(self.file).read()
+    flags_match = FLAGS_PATTERN.search(source)
+    if flags_match:
+      result += flags_match.group(1).strip().split()
+    result.append(self.file)
+    return result
+
+  def GetSource(self):
+    return (open(self.file).read()
+          + "\n--- expected output ---\n"
+          + open(self.expected).read())
+
+  def RunCommand(self, command, env):
+    full_command = self.context.processor(command)
+    output = test.Execute(full_command,
+                     self.context,
+                     self.context.GetTimeout(self.mode),
+                     env,
+                     True)
+    self.Cleanup()
+    return test.TestOutput(self,
+                      full_command,
+                      output,
+                      self.context.store_unexpected_output)
+
+
+class TTYTestConfiguration(test.TestConfiguration):
+
+  def __init__(self, context, root):
+    super(TTYTestConfiguration, self).__init__(context, root)
+
+  def Ls(self, path):
+    if isdir(path):
+        return [f[:-3] for f in os.listdir(path) if f.endswith('.js')]
+    else:
+        return []
+
+  def ListTests(self, current_path, path, arch, mode):
+    all_tests = [current_path + [t] for t in self.Ls(self.root)]
+    result = []
+    # Skip these tests on Windows, as pseudo terminals are not available
+    if utils.IsWindows():
+      print ("Skipping pseudo-tty tests, as pseudo terminals are not available"
+             " on Windows.")
+      return result
+    for test in all_tests:
+      if self.Contains(path, test):
+        file_prefix = join(self.root, reduce(join, test[1:], ""))
+        file_path = file_prefix + ".js"
+        output_path = file_prefix + ".out"
+        if not exists(output_path):
+          print "Could not find %s" % output_path
+          continue
+        result.append(TTYTestCase(test, file_path, output_path,
+                                      arch, mode, self.context, self))
+    return result
+
+  def GetBuildRequirements(self):
+    return ['sample', 'sample=shell']
+
+  def GetTestStatus(self, sections, defs):
+    status_file = join(self.root, 'message.status')
+    if exists(status_file):
+      test.ReadConfigurationInto(status_file, sections, defs)
+
+
+def GetConfiguration(context, root):
+  return TTYTestConfiguration(context, root)