Issue #14087: multiprocessing: add Condition.wait_for(). Patch by sbt.

2 files changed, 38 insertions, 0 deletions

diff --git a/Lib/multiprocessing/managers.py b/Lib/multiprocessing/managers.py
index eaf912c..d1c9d45 100644
--- a/Lib/multiprocessing/managers.py
+++ b/Lib/multiprocessing/managers.py
@@ -48,6 +48,7 @@ from traceback import format_exc
 from multiprocessing import Process, current_process, active_children, Pool, util, connection
 from multiprocessing.process import AuthenticationString
 from multiprocessing.forking import exit, Popen, ForkingPickler
+from time import time as _time
 
 #
 # Register some things for pickling
@@ -996,6 +997,24 @@ class ConditionProxy(AcquirerProxy):
         return self._callmethod('notify')
     def notify_all(self):
         return self._callmethod('notify_all')
+    def wait_for(self, predicate, timeout=None):
+        result = predicate()
+        if result:
+            return result
+        if timeout is not None:
+            endtime = _time() + timeout
+        else:
+            endtime = None
+            waittime = None
+        while not result:
+            if endtime is not None:
+                waittime = endtime - _time()
+                if waittime <= 0:
+                    break
+            self.wait(waittime)
+            result = predicate()
+        return result
+
 
 class EventProxy(BaseProxy):
     _exposed_ = ('is_set', 'set', 'clear', 'wait')
diff --git a/Lib/multiprocessing/synchronize.py b/Lib/multiprocessing/synchronize.py
index e35bbff..532ac5c 100644
--- a/Lib/multiprocessing/synchronize.py
+++ b/Lib/multiprocessing/synchronize.py
@@ -43,6 +43,7 @@ import _multiprocessing
 from multiprocessing.process import current_process
 from multiprocessing.util import register_after_fork, debug
 from multiprocessing.forking import assert_spawning, Popen
+from time import time as _time
 
 # Try to import the mp.synchronize module cleanly, if it fails
 # raise ImportError for platforms lacking a working sem_open implementation.
@@ -290,6 +291,24 @@ class Condition(object):
             while self._wait_semaphore.acquire(False):
                 pass
 
+    def wait_for(self, predicate, timeout=None):
+        result = predicate()
+        if result:
+            return result
+        if timeout is not None:
+            endtime = _time() + timeout
+        else:
+            endtime = None
+            waittime = None
+        while not result:
+            if endtime is not None:
+                waittime = endtime - _time()
+                if waittime <= 0:
+                    break
+            self.wait(waittime)
+            result = predicate()
+        return result
+
 #
 # Event
 #