Revert changes to parallel processing infrastructure as OS X didn't seem to like the new code.

src/libprs500/parallel.py

@@ -15,9 +15,9 @@
 '''
 Used to run jobs in parallel in separate processes.
 '''
-import re, sys, tempfile, os, cPickle, cStringIO, traceback, atexit, binascii, time
+import re, sys, tempfile, os, cPickle, cStringIO, traceback, atexit, binascii, time, subprocess
 from functools import partial
-from PyQt4.QtCore import QProcess, QIODevice
+
 
 from libprs500.ebooks.lrf.any.convert_from import main as any2lrf
 from libprs500.ebooks.lrf.web.convert_from import main as web2lrf
@@ -53,9 +53,7 @@ class Server(object):
     def __init__(self):
         self.tdir = tempfile.mkdtemp('', '%s_IPC_'%__appname__)
         atexit.register(cleanup, self.tdir)
-        self.stdout = {}
+        self.kill_jobs = [] 
-        self.kill_jobs = []
-        self.detached_jobs = [] 
         
     def kill(self, job_id):
         '''
@@ -67,13 +65,15 @@ class Server(object):
         '''
         Kill process.
         '''
-        if iswindows: # Note that QProcess.kill doesn't actually kill the process on windows
+        if iswindows:
-            process.kill()
+            win32api = __import__('win32api')
-            process.waitForFinished(20)
+            try:
+                win32api.TerminateProcess(int(process.pid), -1)
+            except:
+                pass
         else:
-            # We don't use QProcess.kill as it doesn't seem to work
             import signal
-            os.kill(process.pid(), signal.SIGKILL)
+            os.kill(process.pid, signal.SIGKILL)
             time.sleep(0.05)
         
         
@@ -95,7 +95,6 @@ class Server(object):
         if os.path.exists(job_dir):
             raise ValueError('Cannot run job. The job_id %s has already been used.'%job_id)
         os.mkdir(job_dir)
-        self.stdout[job_id] = cStringIO.StringIO()
         
         job_data = os.path.join(job_dir, 'job_data.pickle')
         cPickle.dump((func, args, kwdargs), open(job_data, 'wb'), -1)
@@ -107,46 +106,36 @@ class Server(object):
                 os.environ['PATH'] += ':'+fd
         cmd = prefix + 'from libprs500.parallel import run_job; run_job(\'%s\')'%binascii.hexlify(job_data)
         
-        p = QProcess()
+        if not monitor:
+            subprocess.Popen([python, '-c', cmd])
+            return
         
-        if monitor:
+        output = open(os.path.join(job_dir, 'output.txt'), 'wb')
-            p.setProcessChannelMode(QProcess.MergedChannels)
+        p = subprocess.Popen([python, '-c', cmd], stdout=output, stderr=output)
-            p.start(python, ['-c', cmd], QIODevice.ReadWrite|QIODevice.Text)                                     
+        while p.returncode is None:
-        else:
-            p.setProcessChannelMode(QProcess.ForwardedChannels)
-            p.start(python, ['-c', cmd])
-            self.detached_jobs.append(p)                        
-            return p.waitForStarted(10000)
-        
-        started = p.waitForStarted(30000) # Wait at most 30 secs
-        if not started:
-            raise RuntimeError('Could not run job: %s %s\nError: '%(func, args, p.errorString()))
-        
-        while p.state() == QProcess.Running:
             if job_id in self.kill_jobs:
                 self._terminate(p)
                 return self.KILL_RESULT, None, None, _('Job killed by user')
-            
+            time.sleep(0.1)
-            if p.waitForReadyRead(100): # Wait 0.1 secs for data to become available
+            p.poll()
-                self.stdout[job_id].write(str(p.read(10))) # Read atmost 10 bytes of data
-             
-             
-        self.stdout[job_id].write(p.readAll())
         
+             
+        output.close()     
         job_result = os.path.join(job_dir, 'job_result.pickle')
         if not os.path.exists(job_result):
             result, exception, traceback = None, ('ParallelRuntimeError', 
                                                   'The worker process died unexpectedly.'), ''
         else:              
             result, exception, traceback = cPickle.load(open(job_result, 'rb'))
-        log = self.stdout[job_id].getvalue()
+        log = open(output.name, 'rb').read()
-        self.stdout.pop(job_id)
+        
         return result, exception, traceback, log
             
     
 def run_job(job_data):
     job_data = binascii.unhexlify(job_data)
-    job_result = os.path.join(os.path.dirname(job_data), 'job_result.pickle')
+    base = os.path.dirname(job_data)
+    job_result = os.path.join(base, 'job_result.pickle')
     func, args, kwdargs = cPickle.load(open(job_data, 'rb'))
     func = PARALLEL_FUNCS[func]
     exception, tb = None, None