[Jython-checkins] SF.net SVN: jython:[6208] trunk/jython/Lib/select.py

[<am...@us...>]

Revision: 6208
          http://jython.svn.sourceforge.net/jython/?rev=6208&view=rev
Author:   amak
Date:     2009-04-10 15:36:58 +0000 (Fri, 10 Apr 2009)

Log Message:
-----------
Creating a poll object cache for MS Windows, because of a problem on that platform with creating too many Selectors.
http://bugs.jython.org/issue1291

Modified Paths:
--------------
    trunk/jython/Lib/select.py

Modified: trunk/jython/Lib/select.py
===================================================================
--- trunk/jython/Lib/select.py	2009-04-10 13:45:27 UTC (rev 6207)
+++ trunk/jython/Lib/select.py	2009-04-10 15:36:58 UTC (rev 6208)
@@ -7,10 +7,11 @@
 import java.nio.channels.Selector
 from java.nio.channels.SelectionKey import OP_ACCEPT, OP_CONNECT, OP_WRITE, OP_READ
 
+import errno
+import os
+import Queue
 import socket
 
-import errno
-
 class error(Exception): pass
 
 ALL = None
@@ -144,10 +145,18 @@
         except java.lang.Exception, jlx:
             raise _map_exception(jlx)
 
-    def close(self):
+    def _deregister_all(self):
         try:
             for k in self.selector.keys():
                 k.cancel()
+            # Keys are not actually removed from the selector until the next select operation.
+            self.selector.selectNow()
+        except java.lang.Exception, jlx:
+            raise _map_exception(jlx)
+
+    def close(self):
+        try:
+            self._deregister_all()
             self.selector.close()
         except java.lang.Exception, jlx:
             raise _map_exception(jlx)
@@ -165,10 +174,48 @@
         return 0
     return int(floatvalue * 1000) # Convert to milliseconds
 
+# This cache for poll objects is required because of a bug in java on MS Windows
+# http://bugs.jython.org/issue1291
+
+class poll_object_cache:
+
+    def __init__(self):
+        self.is_windows = os.get_os_type() == 'nt'
+        if self.is_windows:
+            self.poll_object_queue = Queue.Queue()
+        import atexit
+        atexit.register(self.finalize)
+
+    def get_poll_object(self):
+        if not self.is_windows:
+            return poll()
+        try:
+            return self.poll_object_queue.get(False)
+        except Queue.Empty:
+            return poll()
+
+    def release_poll_object(self, pobj):
+        if self.is_windows:
+            pobj._deregister_all()
+            self.poll_object_queue.put(pobj)
+        else:
+            pobj.close()
+
+    def finalize(self):
+        if self.is_windows:
+            while True:
+                try:
+                    p = self.poll_object_queue.get(False)
+                    p.close()
+                except Queue.Empty:
+                    return
+
+_poll_object_cache = poll_object_cache()
+
 def native_select(read_fd_list, write_fd_list, outofband_fd_list, timeout=None):
     timeout = _calcselecttimeoutvalue(timeout)
     # First create a poll object to do the actual watching.
-    pobj = poll()
+    pobj = _poll_object_cache.get_poll_object()
     try:
         registered_for_read = {}
         # Check the read list
@@ -192,10 +239,7 @@
                 write_ready_list.append(fd)
         return read_ready_list, write_ready_list, oob_ready_list
     finally:
-        # Need to close the poll object no matter what happened
-        # If it is left open, it may still have references to sockets
-        # That were registered before any exceptions occurred
-        pobj.close()
+        _poll_object_cache.release_poll_object(pobj)
 
 select = native_select
 


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