+"""Python Daemon Management -- PERF utilities
+
+This module serves two purposes: It has a few utility classes
+for implementing PERF interfaces in common ways, and uses those
+classes to implement some standard PERF objects that can be used by
+PERF clients connecting to any PERF server.
+
+See the documentation for pdm.srv.perf for a description of the
+various PERF interfaces.
+
+It contains two named PERF objects:
+
+ * sysres -- A directory containing the following objects pertaining
+ to the resource usage of the server process:
+ * realtime -- An attribute returning the amount of real time
+ since the PDM module was imported (which likely
+ coincides with the amount of time the server process
+ has been running).
+ * cputime -- An attribute returning the amount of CPU time
+ consumed by the server process (in both user and
+ kernel mode).
+ * utime -- An attribute returning the amount of CPU time the
+ server process has spent in user mode.
+ * stime -- An attribute returning the amount of CPU time the
+ server process has spent in kernel mode.
+ * maxrss -- An attribute returning the largest resident set size
+ the server process has used during its lifetime.
+ * rusage -- An attribute returning the current rusage of the
+ server process.
+* sysinfo -- A directory containing the following objects pertaining
+ to the environment of the server process:
+ * pid -- An attribute returning the PID of the server process.
+ * uname -- An attribute returning the uname information of the
+ system.
+ * hostname -- An attribute returning the hostname of the system.
+ * platform -- An attribute returning the Python build platform.
+"""
+
import os, sys, resource, time, socket, threading
+__all__ = ["attrinfo", "simpleattr", "valueattr", "eventobj",
+ "staticdir", "event", "procevent", "startevent",
+ "finishevent"]
+
class attrinfo(object):
+ """The return value of the `attrinfo' method on `attr' objects as
+ described in pdm.srv.perf.
+
+ Currently contains a single data field, `desc', which should have
+ a human-readable description of the purpose of the attribute.
+ """
def __init__(self, desc = None):
self.desc = desc
return []
class simpleattr(perfobj):
+ """An implementation of the `attr' interface, which is initialized
+ with a function, and returns whatever that function returns when
+ read.
+ """
def __init__(self, func, info = None, *args, **kwargs):
super(simpleattr, self).__init__(*args, **kwargs)
self.func = func
return super(simpleattr, self).pdm_protocols() + ["attr"]
class valueattr(perfobj):
+ """An implementation of the `attr' interface, which is initialized
+ with a single value, and returns that value when read. Subsequent
+ updates to the value are reflected in subsequent reads.
+ """
def __init__(self, init, info = None, *args, **kwargs):
super(valueattr, self).__init__(*args, **kwargs)
self.value = init
def pdm_protocols(self):
return super(valueattr, self).pdm_protocols() + ["attr"]
-
class eventobj(perfobj):
+ """An implementation of the `event' interface. It keeps track of
+ subscribers, and will multiplex any event to all current
+ subscribers when submitted with the `notify' method.
+ """
def __init__(self, *args, **kwargs):
super(eventobj, self).__init__(*args, **kwargs)
self.subscribers = set()
self.subscribers.remove(cb)
def notify(self, event):
+ """Notify all subscribers with the given event object."""
for cb in self.subscribers:
try:
cb(event)
return super(eventobj, self).pdm_protocols() + ["event"]
class staticdir(perfobj):
+ """An implementation of the `dir' interface. Put other PERF
+ objects in it using the normal dict assignment syntax, and it will
+ return them to requesting clients.
+ """
def __init__(self, *args, **kwargs):
super(staticdir, self).__init__(*args, **kwargs)
self.map = {}
return super(staticdir, self).pdm_protocols() + ["dir"]
class event(object):
+ """This class should be subclassed by all event objects sent via
+ the `event' interface. Its main utility is that it keeps track of
+ the time it was created, so that listening clients can precisely
+ measure the time between event notifications.
+
+ Subclasses should make sure to call the __init__ method if they
+ override it.
+ """
def __init__(self):
self.time = time.time()
idlock.release()
class procevent(event):
+ """A subclass of the `event' class meant to group several events
+ related to the same process. Create a new process by creating (a
+ subclass of) the `startevent' class, and subsequent events in the
+ same process by passing that startevent as the `id' parameter.
+
+ It works by having `startevent' allocate a unique ID for each
+ process, and every other procevent initializing from that
+ startevent copying the ID. The data field `id' contains the ID so
+ that it can be compared by clients.
+
+ An example of such a process might be a client connection, where a
+ `startevent' is emitted when a client connects, another subclass
+ of `procevent' emitted when the client runs a command, and a
+ `finishevent' emitted when the connection is closed.
+ """
def __init__(self, id):
super(procevent, self).__init__()
if isinstance(id, procevent):
self.id = id
class startevent(procevent):
+ """A subclass of `procevent'. See its documentation for details."""
def __init__(self):
super(startevent, self).__init__(getprocid())
class finishevent(procevent):
+ """A subclass of `procevent'. Intended to be emitted when a
+ process finishes and terminates. The `aborted' field can be used
+ to indicate whether the process completed successfully, if such a
+ distinction is meaningful. The `start' parameter should be the
+ `startevent' instance used when the process was initiated."""
def __init__(self, start, aborted = False):
super(finishevent, self).__init__(start)
self.aborted = aborted
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