Source Code for Module util.jvm

 1  ''' 
 2  Created on 22 Jun 2012 
 3   
 4  @author: Eleftherios Avramidis 
 5  ''' 
 6  import subprocess 
 7  import time 
 8  import os 
 9   
10 -def get_libs(): 
11      """ 
12      Return libs directory and files that need to be included in the java classpath 
13      @return: file patter and directories to be included in the java classpath 
14      @rtype: list(str) 
15      """ 
16      path = os.path.abspath(__file__) 
17      components = path.split(os.sep) 
18      rootpath = os.path.join(os.sep, *components[:-3]) 
19      libpath = os.path.join(rootpath, "lib") 
20      libpath_all = os.path.join(libpath, "*")     
21      libs = [libpath, libpath_all] 
22      return libs 
23   
24 -class JVM(object): 
25      ''' 
26      A wrapper for the Py4J server of Java Virtual Machine, so that java libraries can be accessed via Py4J.  
27      @ivar jvm: The object of the wrapped Java Virtual Machine process 
28      @ivar socket_no: The socket that the Java Server is responding to Py4J requests  
29      @ivar pid: The system process id of the Java Server  
30      ''' 
31   
32 -    def __init__(self, java_classpath): 
33          ''' 
34          Star running java 
35          ''' 
36              
37          #java_classpath.extend(get_libs()) 
38          java_classpath = get_libs() 
39          path = os.path.abspath(__file__) 
40          #java_classpath.append(os.path.dirname(path)) 
41           
42          classpath = ":".join(java_classpath) 
43          print "classpath = ", classpath 
44   
45          #since code ships without compiled java, we run this command to make sure that the necessary java .class file is ready 
46          #commenting out as it is better handled by bash script in /lib 
47          #try: 
48          #    subprocess.check_call(["javac", "-classpath", classpath, "%s/JavaServer.java" % os.path.dirname(path) ]) 
49          #except: 
50          #    pass 
51           
52          # prepare and run Java server 
53          #cmd = "java -cp %s:%s:%s JavaServer" % (berkeley_parser_jar, py4j_jar, dir_path)         
54          cmd = ["java", "-cp", classpath, "JavaServer" ] 
55          print cmd 
56          cmd = " ".join(cmd) 
57           
58          self.jvm = subprocess.Popen(cmd, shell=True, bufsize=0, stdout=subprocess.PIPE) #shell=True, 
59          time.sleep(3) 
60          self.jvm.stdout.flush() 
61          self.socket_no = int(self.jvm.stdout.readline().strip()) 
62          self.pid = self.jvm.pid 
63           
64 -    def terminate(self): 
65          """ 
66          Stop the Java Server 
67          """ 
68          self.jvm.terminate() 
69       
70       
71 -    def __del__(self): 
72          """ 
73          Stop the Java Server if the object stops existing 
74          """ 
75          try: 
76              self.jvm.terminate() 
77          except: 
78              pass 
79