NaCl SDK: Nicer error message for httpd start.

If creating the HTTPServer fails, today an exception is thrown, saying
that httpd isn't defined. This can happen if a user accidentally tries
to start multiple httpd.py processes.

After this patch, we get a more descriptive error message when failing:
$ ./httpd.py
Error creating HTTPServer: [Errno 98] Address already in use

Traceback (most recent call last):
  File "./httpd.py", line 306, in <module>
    sys.exit(main(sys.argv[1:]))
  File "./httpd.py", line 298, in main
    options.test_mode)
  File "./httpd.py", line 176, in __init__
    raise Exception('Unable to launch HTTP server.')
Exception: Unable to launch HTTP server.

BUG=


Review URL: https://chromiumcodereview.appspot.com/11421033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@169153 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 6 insertions, 0 deletions

diff --git a/native_client_sdk/src/tools/httpd.py b/native_client_sdk/src/tools/httpd.py
index 8057f91..8735e49 100755
--- a/native_client_sdk/src/tools/httpd.py
+++ b/native_client_sdk/src/tools/httpd.py
@@ -10,6 +10,7 @@ import multiprocessing
 import optparse
 import os
 import SimpleHTTPServer  # pylint: disable=W0611
+import socket
 import sys
 import time
 import urlparse
@@ -252,6 +253,11 @@ def _HTTPServerProcess(conn, dirname, port, server_kwargs):
     os.chdir(dirname)
     httpd = PluggableHTTPServer(('', port), PluggableHTTPRequestHandler,
                                 **server_kwargs)
+  except socket.error as e:
+    sys.stderr.write('Error creating HTTPServer: %s\n' % e)
+    sys.exit(1)
+
+  try:
     conn.send(httpd.server_address[1])  # the chosen port number
     httpd.timeout = 0.5  # seconds
     while httpd.running: