Adds an helper class to shard mspdbsrv.

pylib/gyp/win_tool.py

Index: pylib/gyp/win_tool.py
===================================================================
--- pylib/gyp/win_tool.py	(revision 1796)
+++ pylib/gyp/win_tool.py	(working copy)
@@ -10,12 +10,17 @@
 """
 
 import os
+import re
 import shutil
 import subprocess
 import sys
 
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 
+# A regex matching an argument corresponding to a PDB filename passed as an
+# argument to link.exe.
+_LINK_EXE_PDB_ARG = re.compile('/PDB:(?P<pdb>.+\.exe\.pdb)', re.IGNORECASE)
+_MSPDBSRV_ENDPOINT_ENV_VAR = '_MSPDBSRV_ENDPOINT_'
 
 def main(args):
   executor = WinTool()
@@ -28,6 +33,67 @@
   """This class performs all the Windows tooling steps. The methods can either
   be executed directly, or dispatched from an argument list."""
 
+  class MsPdbSrvHelper(object):
+    """This is an helper class to use a unique instance of mspdbsrv.exe for the
+    linkers linking an .exe target. This helps to reduce the memory pressure one
+    the shared instance of mspdbsrv.exe."""
+
+    def __init__(self, env, args):
+      self.env = env
+      self.args = args
+
+    def __enter__(self):
+      self._MaybeStartMsPdbSrv()
+
+    def __exit__(self, type, value, traceback):
+      if _MSPDBSRV_ENDPOINT_ENV_VAR in self.env:
+        self._StopMsPdbSrv()
+
+    def _MaybeStartMsPdbSrv(self):
+      """Starts an unique instance of mspdbsrv.exe if the given arguments are
+      those of a linker linking a .exe target."""
+      if not os.environ.get('GYP_USE_SEPARATE_MSPDBSRV'):
+        return
+
+      if len(self.args) < 1:
+        raise Exception("Not enough arguments")
+
+      if self.args[0] != 'link.exe':
+        return
+
+      # Checks if this linker produces a PDB for an .exe target. If so use the
+      # name of this PDB to generate an endpoint name for mspdbsrv.exe.
+      endpoint_name = None
+      for arg in self.args:
+        m = _LINK_EXE_PDB_ARG.match(arg)
+        if m:
+          endpoint_name = '%s_%d' % (m.group('pdb'), os.getpid())
+          break
+
+      if endpoint_name is None:
+        return
+
+      # Adds the appropriate environment variable. This will be read by link.exe
+      # to know which instance of mspdbsrv.exe it should connect to (if it's
+      # not set then the default endpoint is used).
+      self.env[_MSPDBSRV_ENDPOINT_ENV_VAR] = endpoint_name
+
+      # Starts the mspdbsrv.exe instance manually. We could specify the endpoint
+      # in the command line but it's redundant with setting it in the
+      # environment block. Starting this process manually allows us to wait for
+      # its completion once the link step is finished. This is required to
+      # respect the dependencies between the different targets.
+      mspdbsrv_args = ('mspdbsrv.exe', '-start', '-spawn')
+      subprocess.Popen(mspdbsrv_args, shell=True, env=self.env)
+
+    def _StopMsPdbSrv(self):
+      """Stop the instance of mspdbsrv.exe that has been started by this
+      helper."""
+      mspdbsrv_stop_args = ('mspdbsrv.exe', '-stop')
+      mspdbsrv_stop_process = subprocess.call(mspdbsrv_stop_args,
+                                              shell=True,
+                                              env=self.env)
+
   def Dispatch(self, args):
     """Dispatches a string command to a method."""
     if len(args) < 1:
@@ -71,13 +137,17 @@
     This happens when there are exports from the dll or exe.
     """
     env = self._GetEnv(arch)
-    popen = subprocess.Popen(args, shell=True, env=env,
-                              stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-    out, _ = popen.communicate()
-    for line in out.splitlines():
-      if not line.startswith('   Creating library '):
-        print line
-    return popen.returncode
+    with WinTool.MsPdbSrvHelper(env, args):
+      link_wrapper = subprocess.Popen(args,

[scottmg, 2013/11/27 20:00:44]

if you want to change this, it shouldn't be "link_wrapper", it's just "link".

[Sébastien Marchand, 2013/11/27 20:29:55]

Done.

+                                      shell=True,
+                                      env=env,
+                                      stdout=subprocess.PIPE,
+                                      stderr=subprocess.STDOUT)
+      out, _ = link_wrapper.communicate()
+      for line in out.splitlines():
+        if not line.startswith('   Creating library '):
+          print line
+    return link_wrapper.returncode
 
   def ExecManifestWrapper(self, arch, *args):
     """Run manifest tool with environment set. Strip out undesirable warning
@@ -168,9 +238,7 @@
     env = self._GetEnv(arch)
     args = open(rspfile).read()
     dir = dir[0] if dir else None
-    popen = subprocess.Popen(args, shell=True, env=env, cwd=dir)
-    popen.wait()
-    return popen.returncode
+    return subprocess.call(args, shell=True, env=env, cwd=dir)
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))