qcodes.utils.threading

class qcodes.utils.threading.RespondingThread(target: Callable[[...], qcodes.utils.threading.T], args: Sequence[Any] = (), kwargs: Optional[Dict[str, Any]] = None, *args2: Any, **kwargs2: Any)[source]

Bases: threading.Thread

Thread subclass for parallelizing execution. Behaves like a regular thread but returns a value from target, and propagates exceptions back to the main thread when this value is collected.

The output method joins the thread, then checks for errors and returns the output value.

so, if you have a function f where f(1, 2, a=3) == 4, then:

>>> thread = RespondingThread(target=f, args=(1, 2), kwargs={'a': 3})
>>> thread.start()
>>> # do other things while this is running
>>> out = thread.output()  # out is 4

This constructor should always be called with keyword arguments. Arguments are:

group should be None; reserved for future extension when a ThreadGroup class is implemented.

target is the callable object to be invoked by the run() method. Defaults to None, meaning nothing is called.

name is the thread name. By default, a unique name is constructed of the form “Thread-N” where N is a small decimal number.

args is the argument tuple for the target invocation. Defaults to ().

kwargs is a dictionary of keyword arguments for the target invocation. Defaults to {}.

If a subclass overrides the constructor, it must make sure to invoke the base class constructor (Thread.__init__()) before doing anything else to the thread.

run() None[source]

Method representing the thread’s activity.

You may override this method in a subclass. The standard run() method invokes the callable object passed to the object’s constructor as the target argument, if any, with sequential and keyword arguments taken from the args and kwargs arguments, respectively.

output(timeout: Optional[float] = None) Optional[qcodes.utils.threading.T][source]
property daemon

A boolean value indicating whether this thread is a daemon thread.

This must be set before start() is called, otherwise RuntimeError is raised. Its initial value is inherited from the creating thread; the main thread is not a daemon thread and therefore all threads created in the main thread default to daemon = False.

The entire Python program exits when only daemon threads are left.

getName()
property ident

Thread identifier of this thread or None if it has not been started.

This is a nonzero integer. See the get_ident() function. Thread identifiers may be recycled when a thread exits and another thread is created. The identifier is available even after the thread has exited.

isAlive()

Return whether the thread is alive.

This method is deprecated, use is_alive() instead.

isDaemon()
is_alive()

Return whether the thread is alive.

This method returns True just before the run() method starts until just after the run() method terminates. The module function enumerate() returns a list of all alive threads.

join(timeout=None)

Wait until the thread terminates.

This blocks the calling thread until the thread whose join() method is called terminates – either normally or through an unhandled exception or until the optional timeout occurs.

When the timeout argument is present and not None, it should be a floating point number specifying a timeout for the operation in seconds (or fractions thereof). As join() always returns None, you must call is_alive() after join() to decide whether a timeout happened – if the thread is still alive, the join() call timed out.

When the timeout argument is not present or None, the operation will block until the thread terminates.

A thread can be join()ed many times.

join() raises a RuntimeError if an attempt is made to join the current thread as that would cause a deadlock. It is also an error to join() a thread before it has been started and attempts to do so raises the same exception.

property name

A string used for identification purposes only.

It has no semantics. Multiple threads may be given the same name. The initial name is set by the constructor.

setDaemon(daemonic)
setName(name)
start()

Start the thread’s activity.

It must be called at most once per thread object. It arranges for the object’s run() method to be invoked in a separate thread of control.

This method will raise a RuntimeError if called more than once on the same thread object.

class qcodes.utils.threading.SequentialParamsCaller(*args, **kwds)[source]

Bases: qcodes.utils.threading._ParamsCallerProtocol

class qcodes.utils.threading.ThreadPoolParamsCaller(*args, **kwds)[source]

Bases: qcodes.utils.threading._ParamsCallerProtocol

Context manager for calling given parameters in a thread pool. Note that parameters that have the same underlying instrument will be called in the same thread.

Usage:

...
with ThreadPoolParamsCaller(p1, p2, ...) as pool_caller:
    ...
    output = pool_caller()
    ...
    # Output can be passed directly into DataSaver.add_result:
    # datasaver.add_result(*output)
    ...
...
Parameters
  • param_meas – parameter or a callable without arguments

  • max_workers – number of worker threads to create in the pool; if None, the number of worker threads will be equal to the number of unique “underlying instruments”

__call__() List[Tuple[Union[qcodes.instrument.parameter._BaseParameter, str], Union[str, complex, numpy.integer, numpy.floating, numpy.complexfloating, numpy.ndarray, Sequence[Union[str, complex, numpy.integer, numpy.floating, numpy.complexfloating]]]]][source]

Call parameters in the thread pool and return (param, value) tuples.

qcodes.utils.threading.call_params_threaded(param_meas: Sequence[Union[qcodes.instrument.parameter._BaseParameter, Callable[[], None]]]) List[Tuple[Union[qcodes.instrument.parameter._BaseParameter, str], Union[str, complex, numpy.integer, numpy.floating, numpy.complexfloating, numpy.ndarray, Sequence[Union[str, complex, numpy.integer, numpy.floating, numpy.complexfloating]]]]][source]

Function to create threads per instrument for the given set of measurement parameters.

Parameters

param_meas – a Sequence of measurement parameters

qcodes.utils.threading.process_params_meas(param_meas: Sequence[Union[qcodes.instrument.parameter._BaseParameter, Callable[[], None]]], use_threads: Optional[bool] = None) List[Tuple[Union[qcodes.instrument.parameter._BaseParameter, str], Union[str, complex, numpy.integer, numpy.floating, numpy.complexfloating, numpy.ndarray, Sequence[Union[str, complex, numpy.integer, numpy.floating, numpy.complexfloating]]]]][source]
qcodes.utils.threading.thread_map(callables: Sequence[Callable[[...], qcodes.utils.threading.T]], args: Optional[Sequence[Sequence[Any]]] = None, kwargs: Optional[Sequence[Dict[str, Any]]] = None) List[Optional[qcodes.utils.threading.T]][source]

Evaluate a sequence of callables in separate threads, returning a list of their return values.

Parameters
  • callables – A sequence of callables.

  • args (Optional) – A sequence of sequences containing the positional arguments for each callable.

  • kwargs (Optional) – A sequence of dicts containing the keyword arguments for each callable.