Move ExecutionQueue and WorkItem to gclient_utils.py

gclient.py

Index: gclient.py
diff --git a/gclient.py b/gclient.py
index 741d3ebfa2e071211c3b089638016d084a240155..aa80b8660a56a65927c6750f756f0319821129f0 100644
--- a/gclient.py
+++ b/gclient.py
@@ -59,7 +59,6 @@ import pprint
 import re
 import subprocess
 import sys
-import threading
 import urlparse
 import urllib
 
@@ -80,110 +79,6 @@ def attr(attr, data):
 
 ## GClient implementation.
 
-class WorkItem(object):
-  """One work item."""
-  requirements = []
-  name = None
-
-  def run(self):
-    pass
-
-
-class ExecutionQueue(object):
-  """Dependencies sometime needs to be run out of order due to From() keyword.
-
-  This class manages that all the required dependencies are run before running
-  each one.
-
-  Methods of this class are multithread safe.
-  """
-  def __init__(self, progress):
-    self.lock = threading.Lock()
-    # List of Dependency.
-    self.queued = []
-    # List of strings representing each Dependency.name that was run.
-    self.ran = []
-    # List of items currently running.
-    self.running = []
-    self.progress = progress
-    if self.progress:
-      self.progress.update()
-
-  def enqueue(self, d):
-    """Enqueue one Dependency to be executed later once its requirements are
-    satisfied.
-    """
-    assert isinstance(d, WorkItem)
-    try:
-      self.lock.acquire()
-      self.queued.append(d)
-      total = len(self.queued) + len(self.ran) + len(self.running)
-    finally:
-      self.lock.release()
-    if self.progress:
-      self.progress._total = total + 1
-      self.progress.update(0)
-
-  def flush(self, *args, **kwargs):
-    """Runs all enqueued items until all are executed."""
-    while self._run_one_item(*args, **kwargs):
-      pass
-    queued = []
-    running = []
-    try:
-      self.lock.acquire()
-      if self.queued:
-        queued = self.queued
-        self.queued = []
-      if self.running:
-        running = self.running
-        self.running = []
-    finally:
-      self.lock.release()
-    if self.progress:
-      self.progress.end()
-    if queued:
-      raise gclient_utils.Error('Entries still queued: %s' % str(queued))
-    if running:
-      raise gclient_utils.Error('Entries still queued: %s' % str(running))
-
-  def _run_one_item(self, *args, **kwargs):
-    """Removes one item from the queue that has all its requirements completed
-    and execute it.
-
-    Returns False if no item could be run.
-    """
-    i = 0
-    d = None
-    try:
-      self.lock.acquire()
-      while i != len(self.queued) and not d:
-        d = self.queued.pop(i)
-        for r in d.requirements:
-          if not r in self.ran:
-            self.queued.insert(i, d)
-            d = None
-            break
-        i += 1
-      if not d:
-        return False
-      self.running.append(d)
-    finally:
-      self.lock.release()
-    d.run(*args, **kwargs)
-    try:
-      self.lock.acquire()
-      # TODO(maruel): http://crbug.com/51711
-      #assert not d.name in self.ran
-      if not d.name in self.ran:
-        self.ran.append(d.name)
-      self.running.remove(d)
-      if self.progress:
-        self.progress.update(1)
-    finally:
-      self.lock.release()
-    return True
-
 
 class GClientKeywords(object):
   class FromImpl(object):
@@ -239,7 +134,7 @@ class GClientKeywords(object):
       raise gclient_utils.Error("Var is not defined: %s" % var_name)
 
 
-class Dependency(GClientKeywords, WorkItem):
+class Dependency(GClientKeywords, gclient_utils.WorkItem):
   """Object that represents a dependency checkout."""
   DEPS_FILE = 'DEPS'
 
@@ -815,7 +710,7 @@ solutions = [
     pm = None
     if command == 'update' and not self._options.verbose:
       pm = Progress('Syncing projects', 1)
-    work_queue = ExecutionQueue(pm)
+    work_queue = gclient_utils.ExecutionQueue(pm)
     for s in self.dependencies:
       work_queue.enqueue(s)
     work_queue.flush(self._options, revision_overrides, command, args,
@@ -860,7 +755,7 @@ solutions = [
     if not self.dependencies:
       raise gclient_utils.Error('No solution specified')
     # Load all the settings.
-    work_queue = ExecutionQueue(None)
+    work_queue = gclient_utils.ExecutionQueue(None)
     for s in self.dependencies:
       work_queue.enqueue(s)
     work_queue.flush(self._options, {}, None, [], work_queue)