Changeset 1533

Timestamp:

04/23/08 11:10:07 (2 years ago)

Author:

JensDiemer

Message:

subprocess with timeout without threading

Files:

• CodeSnippets/subprocess2.py (modified) (3 diffs)

CodeSnippets/subprocess2.py

@@ -6 +6 @@
     ~~~~~~~~~~~~~~~~~~~~~~~
 
+    http://www.python-forum.de/topic-14301.html
+    http://www.python-forum.de/post-23692.html#23692
+
+    Use some parts from the user 'droptix':
+        http://www.python-forum.de/post-96180.html#96180
 """
 
@@ -13 +18 @@
 
 
-import os, subprocess, threading, signal
+import os, sys, subprocess, signal, time
 
-KILL_SIGNAL = signal.SIGKILL
+if sys.platform == "win32":
+    import win32api
+    import win32con
+    import win32process
+    #FIRST_SIGNAL = win32con.CTRL_C_EVENT
+    FIRST_SIGNAL = win32con.CTRL_BREAK_EVENT
+else:
+    import signal
+    FIRST_SIGNAL = signal.SIGTERM # 15
+    SECOND_SIGNAL = signal.SIGKILL # 9
 
-class subprocess2(threading.Thread):
+DEFAULT_TIMEOUT = 5
+DEFAULT_WAIT_TIME = 0.25
+
+
+
+class Subprocess2(object):
     """
-    subprocess with a timeout
-
-    Note: os.kill() doesn't exist under Windows!
+    subprocess with timeout
     """
     def __init__(self, *args, **kwags):
-        self.killed = None
+        self.killed = False
+        self.kill_count = 0
 
-        self.timeout = kwags.pop("timeout", 5)
+        self.timeout = kwags.pop("timeout", DEFAULT_TIMEOUT)
+        self.wait_time = kwags.pop("wait_time", DEFAULT_WAIT_TIME)
+        self.debug = kwags.pop("debug", False)
 
-        self.args = args
-        self.kwags = kwags
+        self.start_time = time.time()
+        self.process = subprocess.Popen(*args, **kwags)
+        self.wait_loop()
 
-        threading.Thread.__init__(self)
+    def wait_loop(self):
+        """
+        Sleep and check if the subprocess is ended, if not terminate it.
+        """
+        while True:
+            time.sleep(self.wait_time)
+            returncode = self.process.poll()
+            if self.debug: print "debug: returncode:", returncode
+            if returncode != None:
+                if self.debug: print "debug: process is terminated"
+                return
+            if time.time() - self.start_time >= self.timeout:
+                if self.debug: print "debug: timeout arrived"
+                self.killed = True
+                self.kill_count += 1
+                try:
+                    if sys.platform == "win32":
+                        self.win32_kill()
+                        return # We can only directly terminat the process
+                    else:
+                        self.os_kill()
+                finally:
+                    if self.kill_count >= 2:
+                        return
 
-        self.start()
-        self.join(self.timeout)
-        self.stop()
 
-    def run(self):
+    def win32_kill(self):
         """
-        start child process and wait for terminate
+        terminate the subprocess under windows
         """
-        self.process = subprocess.Popen(*self.args, **self.kwags)
-        self.process.wait()
-        if self.killed == None:
-            # The process terminate and was not killed in the past
-            self.killed = False
+        if self.debug: print "debug: terminal process"
+        h = win32api.OpenProcess(
+            win32con.PROCESS_ALL_ACCESS, False,
+            self.process.pid
+        )
+        handle = h.handle
+        win32process.TerminateProcess(handle, 1)
 
-    def stop(self):
+    def os_kill(self):
         """
-        kill the child process if it's not terminated in the past
+        terminate the subporocess using os.kill()
         """
-        if self.killed == False:
-            # process is terminate
-            return
+        if self.kill_count == 1:
+            if self.debug: print "debug: kill with FIRST_SIGNAL"
+            kill_signal = FIRST_SIGNAL
         else:
-            # kill a running process
-            self.killed = True
-            os.kill(self.process.pid, KILL_SIGNAL)
+            if self.debug: print "debug: kill with SECOND_SIGNAL"
+            kill_signal = SECOND_SIGNAL
+
+        os.kill(self.process.pid, kill_signal)
+
 
 
 if __name__ == "__main__":
     print "try 'ls'..."
-    p = subprocess2("ls",
+    p = Subprocess2("ls",
         stdout=subprocess.PIPE,
-        shell=True, timeout = 1
+        shell=True, timeout = 1, debug = True
     )
     print "returncode:", p.process.returncode
@@ -73 +118 @@
 
     print "start the python interpreter..."
-    p = subprocess2("python",
+    p = Subprocess2("python",
         stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-        shell=True, timeout = 1
+        shell=True, timeout = 1, debug = True
     )
     print "returncode:", p.process.returncode