Multiprocess / RemoteGraphicsView now works in Windows

Bugfix in GraphicsItem.pixelVectors
Fixes for PySide and Python3

examples/multiprocess.py

@@ -8,32 +8,32 @@ import time
 
 
 
-print "\n=================\nStart Process"
+print("\n=================\nStart Process")
 proc = mp.Process()
 import os
-print "parent:", os.getpid(), "child:", proc.proc.pid
+print("parent:", os.getpid(), "child:", proc.proc.pid)
-print "started"
+print("started")
 rnp = proc._import('numpy')
 arr = rnp.array([1,2,3,4])
-print repr(arr)
+print(repr(arr))
-print str(arr)
+print(str(arr))
-print "return value:", repr(arr.mean(_returnType='value'))
+print("return value:", repr(arr.mean(_returnType='value')))
-print "return proxy:", repr(arr.mean(_returnType='proxy'))
+print( "return proxy:", repr(arr.mean(_returnType='proxy')))
-print "return auto: ", repr(arr.mean(_returnType='auto'))
+print( "return auto: ", repr(arr.mean(_returnType='auto')))
 proc.join()
-print "process finished"
+print( "process finished")
 
 
 
-print "\n=================\nStart ForkedProcess"
+print( "\n=================\nStart ForkedProcess")
 proc = mp.ForkedProcess()
 rnp = proc._import('numpy')
 arr = rnp.array([1,2,3,4])
-print repr(arr)
+print( repr(arr))
-print str(arr)
+print( str(arr))
-print repr(arr.mean())
+print( repr(arr.mean()))
 proc.join()
-print "process finished"
+print( "process finished")
 
 
 
@@ -42,10 +42,10 @@ import pyqtgraph as pg
 from pyqtgraph.Qt import QtCore, QtGui
 app = pg.QtGui.QApplication([])
 
-print "\n=================\nStart QtProcess"
+print( "\n=================\nStart QtProcess")
 import sys
 if (sys.flags.interactive != 1):
-    print "   (not interactive; remote process will exit immediately.)"
+    print( "   (not interactive; remote process will exit immediately.)")
 proc = mp.QtProcess()
 d1 = proc.transfer(np.random.normal(size=1000))
 d2 = proc.transfer(np.random.normal(size=1000))

examples/parallelize.py

@@ -5,7 +5,7 @@ import pyqtgraph.multiprocess as mp
 import pyqtgraph as pg
 import time
 
-print "\n=================\nParallelize"
+print( "\n=================\nParallelize")
 
 ## Do a simple task: 
 ##   for x in range(N):
@@ -36,7 +36,7 @@ with pg.ProgressDialog('processing serially..', maximum=len(tasks)) as dlg:
         dlg += 1
         if dlg.wasCanceled():
             raise Exception('processing canceled')
-print "Serial time: %0.2f" % (time.time() - start)
+print( "Serial time: %0.2f" % (time.time() - start))
 
 ### Use parallelize, but force a single worker
 ### (this simulates the behavior seen on windows, which lacks os.fork)
@@ -47,8 +47,8 @@ with mp.Parallelize(enumerate(tasks), results=results2, workers=1, progressDialo
         for j in xrange(size):
             tot += j * x
         tasker.results[i] = tot
-print "\nParallel time, 1 worker: %0.2f" % (time.time() - start)
+print( "\nParallel time, 1 worker: %0.2f" % (time.time() - start))
-print "Results match serial:   ", results2 == results
+print( "Results match serial:  %s" % str(results2 == results))
 
 ### Use parallelize with multiple workers
 start = time.time()
@@ -58,6 +58,6 @@ with mp.Parallelize(enumerate(tasks), results=results3, progressDialog='processi
         for j in xrange(size):
             tot += j * x
         tasker.results[i] = tot
-print "\nParallel time, %d workers: %0.2f" % (mp.Parallelize.suggestedWorkerCount(), time.time() - start)
+print( "\nParallel time, %d workers: %0.2f" % (mp.Parallelize.suggestedWorkerCount(), time.time() - start))
-print "Results match serial:      ", results3 == results
+print( "Results match serial:      %s" % str(results3 == results))
 

pyqtgraph/__init__.py

@@ -4,7 +4,7 @@ PyQtGraph - Scientific Graphics and GUI Library for Python
 www.pyqtgraph.org
 """
 
-__version__ = None
+__version__ = '0.9.5'
 
 ### import all the goodies and add some helper functions for easy CLI use
 
@@ -16,6 +16,9 @@ from .Qt import QtGui
 #if QtGui.QApplication.instance() is None:
     #app = QtGui.QApplication([])
 
+import numpy  ## pyqtgraph requires numpy
+              ## (import here to avoid massive error dump later on if numpy is not available)
+
 import os, sys
 
 ## check python version
@@ -49,6 +52,8 @@ CONFIG_OPTIONS = {
     'background': (0, 0, 0),        ## default background for GraphicsWidget
     'antialias': False,
     'editorCommand': None,  ## command used to invoke code editor from ConsoleWidgets
+    'useWeave': True,       ## Use weave to speed up some operations, if it is available
+    'weaveDebug': False,    ## Print full error message if weave compile fails
 } 
 
 

pyqtgraph/debug.py

@@ -393,7 +393,7 @@ class Profiler:
         if self.delayed:
             self.msgs.append(msg2)
         else:
-            print msg2
+            print(msg2)
         self.t0 = ptime.time()
         self.t1 = self.t0
     
@@ -410,7 +410,7 @@ class Profiler:
         if self.delayed:
             self.msgs.append(msg2)
         else:
-            print msg2
+            print(msg2)
         self.t1 = ptime.time()  ## don't measure time it took to print
         
     def finish(self, msg=None):
@@ -425,10 +425,10 @@ class Profiler:
             self.msgs.append(msg)
             if self.depth == 0:
                 for line in self.msgs:
-                    print line
+                    print(line)
                 Profiler.msgs = []
         else:
-            print msg
+            print(msg)
         Profiler.depth = self.depth
         self.finished = True
         

pyqtgraph/exporters/SVGExporter.py

@@ -220,7 +220,7 @@ def _generateItemSvg(item, nodes=None, root=None):
         ## get list of sub-groups
         g2 = [n for n in g1.childNodes if isinstance(n, xml.Element) and n.tagName == 'g']
     except:
-        print doc.toxml()
+        print(doc.toxml())
         raise
 
 

pyqtgraph/flowchart/library/Data.py

@@ -236,7 +236,7 @@ class EvalNode(Node):
             text = fn + "\n".join(["    "+l for l in str(self.text.toPlainText()).split('\n')]) + run
             exec(text)
         except:
-            print "Error processing node:", self.name()
+            print("Error processing node: %s" % self.name())
             raise
         return output
         

pyqtgraph/functions.py

@@ -23,6 +23,7 @@ SI_PREFIXES_ASCII = 'yzafpnum kMGTPEZY'
 
 
 from .Qt import QtGui, QtCore, USE_PYSIDE
+from pyqtgraph import getConfigOption
 import numpy as np
 import decimal, re
 import ctypes
@@ -30,9 +31,10 @@ import ctypes
 try:
     import scipy.ndimage
     HAVE_SCIPY = True
+    WEAVE_DEBUG = getConfigOption('weaveDebug')
     try:
         import scipy.weave
-        USE_WEAVE = True
+        USE_WEAVE = getConfigOption('useWeave')
     except:
         USE_WEAVE = False
 except ImportError:
@@ -631,6 +633,7 @@ def rescaleData(data, scale, offset, dtype=None):
         data = newData.reshape(data.shape)
     except:
         if USE_WEAVE:
+            if WEAVE_DEBUG:
                 debug.printExc("Error; disabling weave.")
             USE_WEAVE = False
         
@@ -795,7 +798,7 @@ def makeARGB(data, lut=None, levels=None, scale=None, useRGBA=False):
             if levels.shape != (data.shape[-1], 2):
                 raise Exception('levels must have shape (data.shape[-1], 2)')
         else:
-            print levels
+            print(levels)
             raise Exception("levels argument must be 1D or 2D.")
         #levels = np.array(levels)
         #if levels.shape == (2,):
@@ -1257,7 +1260,7 @@ def isocurve(data, level, connected=False, extendToEdge=False, path=False):
         points[b[1]].append([b,a])
 
     ## rearrange into chains
-    for k in points.keys():
+    for k in list(points.keys()):
         try:
             chains = points[k]
         except KeyError:   ## already used this point elsewhere

pyqtgraph/graphicsItems/GraphicsItem.py

@@ -4,7 +4,7 @@ from pyqtgraph.Point import Point
 import pyqtgraph.functions as fn
 import weakref
 from pyqtgraph.pgcollections import OrderedDict
-import operator
+import operator, sys
 
 class FiniteCache(OrderedDict):
     """Caches a finite number of objects, removing
@@ -17,7 +17,7 @@ class FiniteCache(OrderedDict):
         self.pop(item, None) # make sure item is added to end
         OrderedDict.__setitem__(self, item, val) 
         while len(self) > self._length:
-            del self[self.keys()[0]]
+            del self[list(self.keys())[0]]
         
     def __getitem__(self, item):
         val = dict.__getitem__(self, item)
@@ -197,14 +197,14 @@ class GraphicsItem(object):
         
         ## check local cache
         if direction is None and dt == self._pixelVectorCache[0]:
-            return self._pixelVectorCache[1]
+            return tuple(map(Point, self._pixelVectorCache[1]))  ## return a *copy*
         
         ## check global cache
         key = (dt.m11(), dt.m21(), dt.m31(), dt.m12(), dt.m22(), dt.m32(), dt.m31(), dt.m32())
         pv = self._pixelVectorGlobalCache.get(key, None)
         if pv is not None:
             self._pixelVectorCache = [dt, pv]
-            return pv
+            return tuple(map(Point,pv))  ## return a *copy*
         
         
         if direction is None:

pyqtgraph/graphicsItems/ROI.py

@@ -1783,8 +1783,7 @@ class LineSegmentROI(ROI):
         dh = h2-h1
         if dh.length() == 0:
             return p
-        pxv = self.pixelVectors(h2-h1)[1]
+        pxv = self.pixelVectors(dh)[1]
-        
         if pxv is None:
             return p
             
@@ -1809,7 +1808,7 @@ class LineSegmentROI(ROI):
         for i in range(len(imgPts)-1):
             d = Point(imgPts[i+1] - imgPts[i])
             o = Point(imgPts[i])
-            r = fn.affineSlice(data, shape=(int(d.length()),), vectors=[d.norm()], origin=o, axes=axes, order=1)
+            r = fn.affineSlice(data, shape=(int(d.length()),), vectors=[Point(d.norm())], origin=o, axes=axes, order=1)
             rgns.append(r)
             
         return np.concatenate(rgns, axis=axes[0])

pyqtgraph/graphicsItems/ScatterPlotItem.py

@@ -41,7 +41,7 @@ def drawSymbol(painter, symbol, size, pen, brush):
     if isinstance(symbol, basestring):
         symbol = Symbols[symbol]
     if np.isscalar(symbol):
-        symbol = Symbols.values()[symbol % len(Symbols)]
+        symbol = list(Symbols.values())[symbol % len(Symbols)]
     painter.drawPath(symbol)
 
     

pyqtgraph/graphicsItems/ViewBox/ViewBox.py

@@ -1198,7 +1198,7 @@ class ViewBox(GraphicsWidget):
         if ViewBox is None:     ## can happen as python is shutting down
             return
         ## Called with ID and name of view (the view itself is no longer available)
-        for v in ViewBox.AllViews.keys():
+        for v in list(ViewBox.AllViews.keys()):
             if id(v) == vid:
                 ViewBox.AllViews.pop(v)
                 break

pyqtgraph/multiprocess/bootstrap.py

@@ -2,15 +2,23 @@
 import sys, pickle, os
 
 if __name__ == '__main__':
+    if hasattr(os, 'setpgrp'):
         os.setpgrp()  ## prevents signals (notably keyboard interrupt) being forwarded from parent to this process
-    name, port, authkey, targetStr, path = pickle.load(sys.stdin)
+    if sys.version[0] == '3':
+        name, port, authkey, ppid, targetStr, path, pyside = pickle.load(sys.stdin.buffer)        
+    else:
+        name, port, authkey, ppid, targetStr, path, pyside = pickle.load(sys.stdin)
+    #print "key:",  ' '.join([str(ord(x)) for x in authkey])
     if path is not None:
         ## rewrite sys.path without assigning a new object--no idea who already has a reference to the existing list.
         while len(sys.path) > 0:
             sys.path.pop()
         sys.path.extend(path)
+        
+    if pyside:
+        import PySide
     #import pyqtgraph
     #import pyqtgraph.multiprocess.processes
     target = pickle.loads(targetStr)  ## unpickling the target should import everything we need
-    target(name, port, authkey)
+    target(name, port, authkey, ppid)
     sys.exit(0)

pyqtgraph/multiprocess/parallelizer.py

@@ -1,6 +1,6 @@
 import os, sys, time, multiprocessing, re
-from processes import ForkedProcess
+from .processes import ForkedProcess
-from remoteproxy import ClosedError
+from .remoteproxy import ClosedError
 
 class CanceledError(Exception):
     """Raised when the progress dialog is canceled during a processing operation."""
@@ -19,7 +19,7 @@ class Parallelize(object):
         for task in tasks:
             result = processTask(task)
             results.append(result)
-        print results
+        print(results)
         
         
         ## Here is the parallelized version:
@@ -30,7 +30,7 @@ class Parallelize(object):
             for task in tasker:
                 result = processTask(task)
                 tasker.results.append(result)
-        print results
+        print(results)
         
         
     The only major caveat is that *result* in the example above must be picklable,

pyqtgraph/multiprocess/processes.py

@@ -1,7 +1,11 @@
-from remoteproxy import RemoteEventHandler, ClosedError, NoResultError, LocalObjectProxy, ObjectProxy
+from .remoteproxy import RemoteEventHandler, ClosedError, NoResultError, LocalObjectProxy, ObjectProxy
 import subprocess, atexit, os, sys, time, random, socket, signal
-import cPickle as pickle
 import multiprocessing.connection
+from pyqtgraph.Qt import USE_PYSIDE
+try:
+    import cPickle as pickle
+except ImportError:
+    import pickle
 
 __all__ = ['Process', 'QtProcess', 'ForkedProcess', 'ClosedError', 'NoResultError']
 
@@ -54,12 +58,13 @@ class Process(RemoteEventHandler):
             executable = sys.executable
         
         ## random authentication key
-        authkey = ''.join([chr(random.getrandbits(7)) for i in range(20)])
+        authkey = os.urandom(20)
-        
+        #print "key:", ' '.join([str(ord(x)) for x in authkey])
         ## Listen for connection from remote process (and find free port number)
         port = 10000
         while True:
             try:
+                ## hmac authentication appears to be broken on windows (says AuthenticationError: digest received was wrong)
                 l = multiprocessing.connection.Listener(('localhost', int(port)), authkey=authkey)
                 break
             except socket.error as ex:
@@ -73,7 +78,11 @@ class Process(RemoteEventHandler):
         self.proc = subprocess.Popen((executable, bootstrap), stdin=subprocess.PIPE)
         targetStr = pickle.dumps(target)  ## double-pickle target so that child has a chance to 
                                           ## set its sys.path properly before unpickling the target
-        pickle.dump((name+'_child', port, authkey, targetStr, sysPath), self.proc.stdin)
+        pid = os.getpid() # we must sent pid to child because windows does not have getppid
+        pyside = USE_PYSIDE
+        
+        ## Send everything the remote process needs to start correctly
+        pickle.dump((name+'_child', port, authkey, pid, targetStr, sysPath, pyside), self.proc.stdin)
         self.proc.stdin.close()
         
         ## open connection for remote process
@@ -92,10 +101,11 @@ class Process(RemoteEventHandler):
                 time.sleep(0.05)
         
         
-def startEventLoop(name, port, authkey):
+def startEventLoop(name, port, authkey, ppid):
     conn = multiprocessing.connection.Client(('localhost', int(port)), authkey=authkey)
     global HANDLER
-    HANDLER = RemoteEventHandler(conn, name, os.getppid())
+    #ppid = 0 if not hasattr(os, 'getppid') else os.getppid()
+    HANDLER = RemoteEventHandler(conn, name, ppid)
     while True:
         try:
             HANDLER.processRequests()  # exception raised when the loop should exit
@@ -161,6 +171,7 @@ class ForkedProcess(RemoteEventHandler):
                 proxyId = LocalObjectProxy.registerObject(v)
                 proxyIDs[k] = proxyId
         
+        ppid = os.getpid()  # write this down now; windows doesn't have getppid
         pid = os.fork()
         if pid == 0:
             self.isParent = False
@@ -200,9 +211,9 @@ class ForkedProcess(RemoteEventHandler):
                 if 'random' in sys.modules:
                     sys.modules['random'].seed(os.getpid() ^ int(time.time()*10000%10000))
             
-            RemoteEventHandler.__init__(self, remoteConn, name+'_child', pid=os.getppid())
+            #ppid = 0 if not hasattr(os, 'getppid') else os.getppid()
+            RemoteEventHandler.__init__(self, remoteConn, name+'_child', pid=ppid)
             
-            ppid = os.getppid()
             self.forkedProxies = {}
             for name, proxyId in proxyIDs.iteritems():
                 self.forkedProxies[name] = ObjectProxy(ppid, proxyId=proxyId, typeStr=repr(preProxy[name]))
@@ -228,7 +239,7 @@ class ForkedProcess(RemoteEventHandler):
             except ClosedError:
                 break
             except:
-                print "Error occurred in forked event loop:"
+                print("Error occurred in forked event loop:")
                 sys.excepthook(*sys.exc_info())
         sys.exit(0)
         
@@ -293,7 +304,7 @@ class QtProcess(Process):
         btn.show()
         
         def slot():
-            print 'slot invoked on parent process'
+            print('slot invoked on parent process')
         btn.clicked.connect(proxy(slot))   # be sure to send a proxy of the slot
     """
     
@@ -318,7 +329,7 @@ class QtProcess(Process):
         except ClosedError:
             self.timer.stop()
     
-def startQtEventLoop(name, port, authkey):
+def startQtEventLoop(name, port, authkey, ppid):
     conn = multiprocessing.connection.Client(('localhost', int(port)), authkey=authkey)
     from pyqtgraph.Qt import QtGui, QtCore
     #from PyQt4 import QtGui, QtCore
@@ -330,7 +341,8 @@ def startQtEventLoop(name, port, authkey):
                                               ## until it is explicitly closed by the parent process.
     
     global HANDLER
-    HANDLER = RemoteQtEventHandler(conn, name, os.getppid())
+    #ppid = 0 if not hasattr(os, 'getppid') else os.getppid()
+    HANDLER = RemoteQtEventHandler(conn, name, ppid)
     HANDLER.startEventTimer()
     app.exec_()
 

pyqtgraph/multiprocess/remoteproxy.py

@@ -1,6 +1,11 @@
-import os, __builtin__, time, sys, traceback, weakref
+import os, time, sys, traceback, weakref
-import cPickle as pickle
 import numpy as np
+try:
+    import __builtin__ as builtins
+    import cPickle as pickle
+except ImportError:
+    import builtins
+    import pickle
 
 class ClosedError(Exception):
     """Raised when an event handler receives a request to close the connection
@@ -68,7 +73,7 @@ class RemoteEventHandler(object):
         try:
             return cls.handlers[pid]
         except:
-            print pid, cls.handlers
+            print(pid, cls.handlers)
             raise
     
     def getProxyOption(self, opt):
@@ -103,7 +108,7 @@ class RemoteEventHandler(object):
                 else:
                     raise
             except:
-                print "Error in process %s" % self.name
+                print("Error in process %s" % self.name)
                 sys.excepthook(*sys.exc_info())
                 
         return numProcessed
@@ -181,7 +186,7 @@ class RemoteEventHandler(object):
             elif cmd == 'import':
                 name = opts['module']
                 fromlist = opts.get('fromlist', [])
-                mod = __builtin__.__import__(name, fromlist=fromlist)
+                mod = builtins.__import__(name, fromlist=fromlist)
                 
                 if len(fromlist) == 0:
                     parts = name.lstrip('.').split('.')
@@ -239,7 +244,7 @@ class RemoteEventHandler(object):
         self.send(request='result', reqId=reqId, callSync='off', opts=dict(result=result))
     
     def replyError(self, reqId, *exc):
-        print "error:", self.name, reqId, exc[1]
+        print("error: %s %s %s" % (self.name, str(reqId), str(exc[1])))
         excStr = traceback.format_exception(*exc)
         try:
             self.send(request='error', reqId=reqId, callSync='off', opts=dict(exception=exc[1], excString=excStr))
@@ -352,9 +357,9 @@ class RemoteEventHandler(object):
         try:
             optStr = pickle.dumps(opts)
         except:
-            print "====  Error pickling this object:  ===="
+            print("====  Error pickling this object:  ====")
-            print opts
+            print(opts)
-            print "======================================="
+            print("=======================================")
             raise
         
         nByteMsgs = 0
@@ -404,12 +409,12 @@ class RemoteEventHandler(object):
             #print ''.join(result)
             exc, excStr = result
             if exc is not None:
-                print "===== Remote process raised exception on request: ====="
+                print("===== Remote process raised exception on request: =====")
-                print ''.join(excStr)
+                print(''.join(excStr))
-                print "===== Local Traceback to request follows: ====="
+                print("===== Local Traceback to request follows: =====")
                 raise exc
             else:
-                print ''.join(excStr)
+                print(''.join(excStr))
                 raise Exception("Error getting result. See above for exception from remote process.")
                 
         else:
@@ -535,7 +540,7 @@ class Request(object):
                     raise ClosedError()
                 time.sleep(0.005)
                 if timeout >= 0 and time.time() - start > timeout:
-                    print "Request timed out:", self.description
+                    print("Request timed out: %s" % self.description)
                     import traceback
                     traceback.print_stack()
                     raise NoResultError()

pyqtgraph/opengl/glInfo.py

@@ -6,10 +6,10 @@ class GLTest(QtOpenGL.QGLWidget):
     def __init__(self):
         QtOpenGL.QGLWidget.__init__(self)
         self.makeCurrent()
-        print "GL version:", glGetString(GL_VERSION)
+        print("GL version:" + glGetString(GL_VERSION))
-        print "MAX_TEXTURE_SIZE:", glGetIntegerv(GL_MAX_TEXTURE_SIZE)
+        print("MAX_TEXTURE_SIZE: %d" % glGetIntegerv(GL_MAX_TEXTURE_SIZE))
-        print "MAX_3D_TEXTURE_SIZE:", glGetIntegerv(GL_MAX_3D_TEXTURE_SIZE)
+        print("MAX_3D_TEXTURE_SIZE: %d" % glGetIntegerv(GL_MAX_3D_TEXTURE_SIZE))
-        print "Extensions:", glGetString(GL_EXTENSIONS)
+        print("Extensions: " + glGetString(GL_EXTENSIONS))
 
 GLTest()
 

pyqtgraph/reload.py

@@ -267,14 +267,14 @@ class A(object):
         object.__init__(self)
         self.msg = msg
     def fn(self, pfx = ""):
-        print pfx+"A class:", self.__class__, id(self.__class__)
+        print(pfx+"A class: %%s %%s" %% (str(self.__class__), str(id(self.__class__))))
-        print pfx+"  %%s: %d" %% self.msg
+        print(pfx+"  %%s: %d" %% self.msg)
 
 class B(A):
     def fn(self, pfx=""):
-        print pfx+"B class:", self.__class__, id(self.__class__)
+        print(pfx+"B class:", self.__class__, id(self.__class__))
-        print pfx+"  %%s: %d" %% self.msg
+        print(pfx+"  %%s: %d" %% self.msg)
-        print pfx+"  calling superclass.. (%%s)" %% id(A) 
+        print(pfx+"  calling superclass.. (%%s)" %% id(A) )
         A.fn(self, "  ")
 """
 
@@ -294,7 +294,7 @@ class C(A):
         A.__init__(self, msg + "(init from C)")
         
 def fn():
-    print "fn: %s"
+    print("fn: %s")
 """ 
 
     open(modFile1, 'w').write(modCode1%(1,1))

pyqtgraph/widgets/RemoteGraphicsView.py

@@ -3,7 +3,7 @@ import pyqtgraph.multiprocess as mp
 import pyqtgraph as pg
 from .GraphicsView import GraphicsView
 import numpy as np
-import mmap, tempfile, ctypes, atexit
+import mmap, tempfile, ctypes, atexit, sys, random
 
 __all__ = ['RemoteGraphicsView']
 
@@ -27,13 +27,15 @@ class RemoteGraphicsView(QtGui.QWidget):
         rpgRemote = self._proc._import('pyqtgraph.widgets.RemoteGraphicsView')
         self._view = rpgRemote.Renderer(*args, **kwds)
         self._view._setProxyOptions(deferGetattr=True)
-        self.setFocusPolicy(self._view.focusPolicy())
+        self.setFocusPolicy(QtCore.Qt.FocusPolicy(self._view.focusPolicy()))
         self.setSizePolicy(QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Expanding)
         self.setMouseTracking(True)
-        
+        self.shm = None
         shmFileName = self._view.shmFileName()
+        if 'win' in sys.platform:
+            self.shmtag = shmFileName
+        else:
             self.shmFile = open(shmFileName, 'r')
-        self.shm = mmap.mmap(self.shmFile.fileno(), mmap.PAGESIZE, mmap.MAP_SHARED, mmap.PROT_READ)
         
         self._view.sceneRendered.connect(mp.proxy(self.remoteSceneChanged)) #, callSync='off'))
                                                                             ## Note: we need synchronous signals
@@ -53,10 +55,15 @@ class RemoteGraphicsView(QtGui.QWidget):
         return QtCore.QSize(*self._sizeHint)
         
     def remoteSceneChanged(self, data):
-        w, h, size = data
+        w, h, size, newfile = data
         #self._sizeHint = (whint, hhint)
-        if self.shm.size != size:
+        if self.shm is None or self.shm.size != size:
+            if self.shm is not None:
                 self.shm.close()
+            if 'win' in sys.platform:
+                self.shmtag = newfile   ## on windows, we create a new tag for every resize
+                self.shm = mmap.mmap(-1, size, self.shmtag) ## can't use tmpfile on windows because the file can only be opened once.
+            else:
                 self.shm = mmap.mmap(self.shmFile.fileno(), size, mmap.MAP_SHARED, mmap.PROT_READ)
         self.shm.seek(0)
         self._img = QtGui.QImage(self.shm.read(w*h*4), w, h, QtGui.QImage.Format_ARGB32)
@@ -112,11 +119,12 @@ class Renderer(GraphicsView):
     
     def __init__(self, *args, **kwds):
         ## Create shared memory for rendered image
-        #fd = os.open('/tmp/mmaptest', os.O_CREAT | os.O_TRUNC | os.O_RDWR)
+        if 'win' in sys.platform:
-        #os.write(fd, '\x00' * mmap.PAGESIZE)
+            self.shmtag = "pyqtgraph_shmem_" + ''.join([chr((random.getrandbits(20)%25) + 97) for i in range(20)])
+            self.shm = mmap.mmap(-1, mmap.PAGESIZE, self.shmtag) # use anonymous mmap on windows
+        else:
             self.shmFile = tempfile.NamedTemporaryFile(prefix='pyqtgraph_shmem_')
             self.shmFile.write('\x00' * mmap.PAGESIZE)
-        #fh.flush()
             fd = self.shmFile.fileno()
             self.shm = mmap.mmap(fd, mmap.PAGESIZE, mmap.MAP_SHARED, mmap.PROT_WRITE)
         atexit.register(self.close)
@@ -130,9 +138,13 @@ class Renderer(GraphicsView):
         
     def close(self):
         self.shm.close()
+        if 'win' not in sys.platform:
             self.shmFile.close()
         
     def shmFileName(self):
+        if 'win' in sys.platform:
+            return self.shmtag
+        else:
             return self.shmFile.name
         
     def update(self):
@@ -152,6 +164,13 @@ class Renderer(GraphicsView):
                 return
             size = self.width() * self.height() * 4
             if size > self.shm.size():
+                if 'win' in sys.platform:
+                    ## windows says "WindowsError: [Error 87] the parameter is incorrect" if we try to resize the mmap
+                    self.shm.close()
+                    ## it also says (sometimes) 'access is denied' if we try to reuse the tag.
+                    self.shmtag = "pyqtgraph_shmem_" + ''.join([chr((random.getrandbits(20)%25) + 97) for i in range(20)])
+                    self.shm = mmap.mmap(-1, size, self.shmtag)
+                else:
                     self.shm.resize(size)
             address = ctypes.addressof(ctypes.c_char.from_buffer(self.shm, 0))
             
@@ -161,7 +180,7 @@ class Renderer(GraphicsView):
             p = QtGui.QPainter(self.img)
             self.render(p, self.viewRect(), self.rect())
             p.end()
-            self.sceneRendered.emit((self.width(), self.height(), self.shm.size()))
+            self.sceneRendered.emit((self.width(), self.height(), self.shm.size(), self.shmFileName()))
 
     def mousePressEvent(self, typ, pos, gpos, btn, btns, mods):
         typ = QtCore.QEvent.Type(typ)