use the enum module to represent states

[~helmut/onoff.git] / onoff / process.py

diff --git a/onoff/process.py b/onoff/process.py
index aca7c4d..6d738c7 100644 (file)
--- a/onoff/process.py
+++ b/onoff/process.py
@@ -2,93 +2,81 @@ import logging
 import os
 import signal
 
 import os
 import signal
 

-from gi.repository import GObject
-
-from .common import ST_ACTIVE, ST_TRANSITION, OnoffDevice
+from .common import OnoffDevice, OnoffState
+from .gobject import spawn_child

 
 logger = logging.getLogger("onoff.process")
 
 class OnoffProcess(OnoffDevice):
 
 logger = logging.getLogger("onoff.process")
 
 class OnoffProcess(OnoffDevice):

-    def __init__(self, command, start_wait=0, termsig=signal.SIGTERM):
+    """A device that in activated by starting a process and deactivated by
+    killing the process.
+
+    @type pid: int or None
+    @ivar pid: is either None if there is no process or the pid of the
+            spawned process
+    @ivar starting: is either None or a ScheduledFunction representing the
+            callback signalling the end of the activation transition.
+    @type killed: bool
+    @ivar killed: indicates whether the termination signal has been sent
+            to the spawned process.
+    """
+    def __init__(self, command, termsig=signal.SIGTERM):
+        """
+        @type command: [str]
+        @param command: an argument vector to be executed. The first element
+                is used as executable and looked up in $PATH.
+        @param termsig: termination signal to be sent to the process to
+                deactivate it. The process must exit in response to this
+                signal.
+        """

         OnoffDevice.__init__(self)
         self.command = command
         OnoffDevice.__init__(self)
         self.command = command

-        self.start_wait = start_wait

         self.termsig = termsig
         self.termsig = termsig

-        self.desired_state = 0 # bit mask of just ST_ACTIVE
+        self.desired_state = OnoffState.inactive

         self.pid = None
         self.pid = None

-        self.starting = None # timeout event during start
-        self.watch = None # watch event

         self.killed = False
 
     @property
     def state(self):
         self.killed = False
 
     @property
     def state(self):

-        if self.starting or self.killed:
-            return self.desired_state | ST_TRANSITION
+        if self.killed:
+            return self.desired_state | OnoffState.transition

         return self.desired_state
 
     def start_process(self):
         assert self.pid is None
         return self.desired_state
 
     def start_process(self):
         assert self.pid is None

-        assert self.starting is None

         logger.info("starting command %s", " ".join(self.command))
         logger.info("starting command %s", " ".join(self.command))

-        ret = GObject.spawn_async(self.command, flags=GObject.SPAWN_SEARCH_PATH | GObject.SPAWN_DO_NOT_REAP_CHILD)
-        self.pid = ret[0]
-        assert self.pid
+        self.pid = spawn_child(self.command, self.process_died)

         logger.debug("started as pid %d", self.pid)
         logger.debug("started as pid %d", self.pid)

-        self.watch = GObject.child_watch_add(self.pid, self.process_died)
-        self.starting = GObject.timeout_add(1000 * self.start_wait,
-                                            self.process_started)
+        assert self.desired_state == OnoffState.active
+        logger.debug("process started")

         self.changestate(self.state)
 
         self.changestate(self.state)
 

-    def cancel_start_wait(self):
-        if self.starting is None:
-            return
-        logger.debug("cancelling start notification")
-        ret = GObject.source_remove(self.starting)
-        assert ret
-        self.starting = None
-

     def process_died(self, pid, condition):
         assert self.pid == pid
     def process_died(self, pid, condition):
         assert self.pid == pid

-        assert self.watch is not None
-        self.watch = None

         self.pid = None
         self.killed = False
         logger.info("process %d died", pid)
         self.pid = None
         self.killed = False
         logger.info("process %d died", pid)

-        self.cancel_start_wait()
-        if self.desired_state == ST_ACTIVE:
+        if self.desired_state == OnoffState.active:

             self.start_process()
         else:
             self.changestate(self.state)
 
             self.start_process()
         else:
             self.changestate(self.state)
 

-    def process_started(self):
-        assert self.desired_state == ST_ACTIVE
-        assert self.starting is not None
-        self.starting = None
-        logger.debug("process started")
-        self.changestate(self.state)
-
-    def stop_process(self):
-        assert self.pid is not None
-        assert self.watch is not None
-        self.cancel_start_wait()
-        logger.info("killing process %d", self.pid)
-        os.kill(self.pid, self.termsig)
-        self.killed = True
-        self.changestate(self.state)
-

     def activate(self):
     def activate(self):

-        if self.desired_state != ST_ACTIVE:
-            self.desired_state = ST_ACTIVE
+        if self.desired_state != OnoffState.active:
+            self.desired_state = OnoffState.active

             if self.pid is None:
                 self.start_process()
             else:
                 logger.debug("already activated. nothing to do")
 
     def deactivate(self):
             if self.pid is None:
                 self.start_process()
             else:
                 logger.debug("already activated. nothing to do")
 
     def deactivate(self):

-        if self.desired_state != 0:
-            self.desired_state = 0
+        if self.desired_state != OnoffState.inactive:
+            self.desired_state = OnoffState.inactive

             if self.pid is not None and not self.killed:
             if self.pid is not None and not self.killed:

-                self.stop_process()
+                logger.info("killing process %d", self.pid)
+                os.kill(self.pid, self.termsig)
+                self.killed = True
+                self.changestate(self.state)

             else:
                 logger.debug("already deactivated. nothing to do.")
 
             else:
                 logger.debug("already deactivated. nothing to do.")