lsst.ctrl.pool.pool.ReductionThread Class Reference

Inheritance diagram for lsst.ctrl.pool.pool.ReductionThread:

Public Member Functions
def	__init__ (self, reducer, initial=None, sleep=0.1)
	Constructor. More...
def	run (self)
def	add (self, data)
def	join (self)

Detailed Description

Thread to do reduction of results

"A thread?", you say. "What about the python GIL?"
Well, because we 'sleep' when there's no immediate response from the
slaves, that gives the thread a chance to fire; and threads are easier
to manage (e.g., shared memory) than a process.

Definition at line 420 of file pool.py.

Constructor & Destructor Documentation

__init__()

def lsst.ctrl.pool.pool.ReductionThread.__init__	(		self,
			reducer,
			initial = None,
			sleep = 0.1
	)

Constructor.

    The 'reducer' should take two values and return a single
    (reduced) value.

    @param reducer  Function that does the reducing
    @param initial  Initial value for reduction, or None
    @param sleep  Time to sleep when there's nothing to do (sec)

Definition at line 428 of file pool.py.

    def __init__(self, reducer, initial=None, sleep=0.1):
        """!Constructor
 
        The 'reducer' should take two values and return a single
        (reduced) value.
 
        @param reducer  Function that does the reducing
        @param initial  Initial value for reduction, or None
        @param sleep  Time to sleep when there's nothing to do (sec)
        """
        threading.Thread.__init__(self, name="reducer")
        self._queue = []  # Queue of stuff to be reduced
        self._lock = threading.Lock()  # Lock for the queue
        self._reducer = reducer
        self._sleep = sleep
        self._result = initial  # Final result
        self._done = threading.Event()  # Signal that everything is done
 

Member Function Documentation

add()

def lsst.ctrl.pool.pool.ReductionThread.add	(		self,
			data
	)

Add data to the queue to be reduced

Definition at line 470 of file pool.py.

    def add(self, data):
        """Add data to the queue to be reduced"""
        with self._lock:
            self._queue.append(data)
 

join()

def lsst.ctrl.pool.pool.ReductionThread.join

(

self

)

Complete the thread

Unlike Thread.join (which always returns 'None'), we return the result
we calculated.

Definition at line 475 of file pool.py.

    def join(self):
        """Complete the thread
 
        Unlike Thread.join (which always returns 'None'), we return the result
        we calculated.
        """
        self._done.set()
        threading.Thread.join(self)
        return self._result
 
 

run()

def lsst.ctrl.pool.pool.ReductionThread.run

(

self

)

Do the work

Thread entry point, called by Thread.start

Definition at line 459 of file pool.py.

    def run(self):
        """Do the work
 
        Thread entry point, called by Thread.start
        """
        while True:
            self._doReduce()
            if self._done.wait(self._sleep):
                self._doReduce()
                return
 

---

The documentation for this class was generated from the following file:

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/ctrl_pool/22.0.1-2-g92698f7+9f079a9461/python/lsst/ctrl/pool/pool.py