Add option for link concurrency.

pylib/gyp/generator/ninja.py

 # Copyright (c) 2013 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import collections
 import copy
 import hashlib
 import json
 import multiprocessing
 import os.path
@@ skipping 1564 matching lines @@
 
 def CommandWithWrapper(cmd, wrappers, prog):
   wrapper = wrappers.get(cmd, '')
   if wrapper:
     return wrapper + ' ' + prog
   return prog
 
 
 def GetDefaultConcurrentLinks():
   """Returns a best-guess for a number of concurrent links."""
+  pool_size = os.getenv('GYP_LINK_CONCURRENCY')

[scottmg, 2014/06/05 22:21:45]

i think "int(os.getenv('GYP_LINK_CONCURRENCY', 0))" would be better

[mtklein, 2014/06/05 22:24:51]

No problem!  Do you mean like PS 5?  I was avoiding that because it crashes if
you define GYP_LINK_CONCURRENCY to the empty string, but if that's okay by you
it's okay by me.

+  if pool_size and int(pool_size):
+    return int(pool_size)
+
   if sys.platform in ('win32', 'cygwin'):
     import ctypes
 
     class MEMORYSTATUSEX(ctypes.Structure):
       _fields_ = [
         ("dwLength", ctypes.c_ulong),
         ("dwMemoryLoad", ctypes.c_ulong),
         ("ullTotalPhys", ctypes.c_ulonglong),
         ("ullAvailPhys", ctypes.c_ulonglong),
         ("ullTotalPageFile", ctypes.c_ulonglong),
@@ skipping 609 matching lines @@
           arglists.append(
               (target_list, target_dicts, data, params, config_name))
         pool.map(CallGenerateOutputForConfig, arglists)
       except KeyboardInterrupt, e:
         pool.terminate()
         raise e
     else:
       for config_name in config_names:
         GenerateOutputForConfig(target_list, target_dicts, data, params,
                                 config_name)