Source Code for Module VRED_backEnd

 1  ''' 
 2  A class that allows for a dynamic allocation model for VRED 
 3  ''' 
 4  #====================================== 
 5  #  $Revision: #5 $ 
 6  #  $Change: 16930 $ 
 7  #====================================== 
 8   
 9  import os 
10  import sys 
11  import re 
12  import tempfile 
13   
14  import qb.backend.pythonChildBackEnd 
15  import qb.backend.utils as backendUtils 
16   
17   
18 -class VRED_BackEnd(qb.backend.pythonChildBackEnd.PythonChildBackEnd): 
19      """ 
20      A backend for a jobtype that runs an instance of VRED in a child process. 
21   
22      This will allow the VRED session to persist for the duration of the subjob. 
23      """ 
24   
25 -    def getSubprocessArgs(self, port): 
26          """ 
27          Get the arguments to start the child python process. 
28   
29          @param port: the port on which the PyCmdDispatcher's backchannel instance is listening, usually 
30          passed as a parameter to the child_bootstrapper.py script which starts up the pyCmdExecutor 
31          inside child process started by the PyCmdDispatcher 
32   
33          @type port: C{int} 
34   
35          @return: Return a tuple of a list of args to start the python interpreter, 
36          and a list of python commands to initialize the python working environment. 
37           
38          @rtype: C{tuple} C{([childArgs], [pyInitCmds])} 
39          """ 
40          args = [] 
41          if sys.platform != 'win32': 
42              args.extend(['/bin/tcsh', '-c']) 
43   
44          vred_args = self.job['package'].get('vred_args', '') 
45          if vred_args is None: 
46              vred_args = '' 
47   
48          pyCmdLine = '''"%s" %s -postpython "load('%s')"''' % (self.pyExecutable, vred_args, self.childBootstrapper) 
49   
50          args.append(pyCmdLine) 
51   
52          pyInitCmds = [ 
53              'sys.stderr = sys.__stderr__', 
54              'sys.stdout = sys.__stdout__' 
55          ] 
56   
57          return args, pyInitCmds 
58   
59 -    def generateChildBootstrapper(self, port): 
60          """ 
61          @param port: the port on which the PyCmdDispatcher's backchannel instance is listening, usually 
62          passed as a parameter to the child_bootstrapper.py script which starts up the pyCmdExecutor 
63          inside child process started by the PyCmdDispatcher 
64   
65          @type port: C{int} 
66   
67          @return: Return the path to the newly-created file 
68          @rtype: C{str} 
69          """ 
70          tmpdir = tempfile.gettempdir().replace('\\', '/') 
71          this_dir = os.path.dirname(backendUtils.getModulePath()).replace('\\', '/') 
72          template_script = '%s/%s' % (this_dir, 'child_bootstrapper_template.py') 
73   
74          fh = open(template_script, 'r') 
75          bootstrapper_code = fh.readlines() 
76          fh.close() 
77   
78          token = 'PORT_TOKEN' 
79          PORT_TOKEN_RGX = re.compile(token) 
80   
81          for i in range(len(bootstrapper_code)): 
82              line = bootstrapper_code[i] 
83              if line.count(token): 
84                  m = PORT_TOKEN_RGX.search(line) 
85                  if m: 
86                      bootstrapper_code[i] = PORT_TOKEN_RGX.sub(str(port), line) 
87                      break 
88   
89          bootstrapper_file = '%s/bootstrap_%s.%s.py' % (tmpdir, os.environ.get('QBJOBID', 0), os.environ.get('QBSUBID', 0)) 
90   
91          fh = open(bootstrapper_file, 'w') 
92          fh.writelines(bootstrapper_code) 
93          fh.close() 
94   
95          return bootstrapper_file 
96