concurrent.futures.process.BrokenProcessPool eseguendo QuantumProgram di qiskit-sdk

Petar

7 anni fa

Soluzione: il codice eseguito in Python deve essere protetto, o meglio “guarded”, ciò significa che il QuantumProgram deve essere eseguito dentro ad un’istruzione if __name__ == “__main__”

Compilando il programma nell’esempio nel qiskit-sdk-py si incorre nel seguente errore durante l’esecuzione:

Traceback (most recent call last):
  File "C:\Users\....\...\first.py", line 35, in <module>
    print(result.get_data("bell"))
  File "D:\Python36\lib\site-packages\qiskit\_result.py", line 204, in get_data
    raise exception
  File "D:\Python36\lib\site-packages\qiskit\_jobprocessor.py", line 99, in _job_done_callback
    result = future.result()
  File "D:\Python36\lib\concurrent\futures\_base.py", line 425, in result
    return self.__get_result()
  File "D:\Python36\lib\concurrent\futures\_base.py", line 384, in __get_result
    raise self._exception
concurrent.futures.process.BrokenProcessPool: A process in the process pool was terminated abruptly while the future was running or pending.

Traceback (most recent call last):

File "C:\Users\....\...\first.py", line 35, in <module>

print(result.get_data("bell"))

File "D:\Python36\lib\site-packages\qiskit\_result.py", line 204, in get_data

raise exception

File "D:\Python36\lib\site-packages\qiskit\_jobprocessor.py", line 99, in _job_done_callback

result = future.result()

File "D:\Python36\lib\concurrent\futures\_base.py", line 425, in result

return self.__get_result()

File "D:\Python36\lib\concurrent\futures\_base.py", line 384, in __get_result

raise self._exception

concurrent.futures.process.BrokenProcessPool: A process in the process pool was terminated abruptly while the future was running or pending.

Questo accade perché si tentano di avviare delle biforcazioni del processo originale senza aver utilizzato un idioma appropriato per il modulo. Per correggere il problema è sufficiente reimpostare il codice eseguibile in questo modo:

from qiskit import QuantumProgram, QISKitError, RegisterSizeError

# Create a QuantumProgram object instance.
Q_program = QuantumProgram()

if __name__ == "__main__":
    backend = 'local_qasm_simulator'
    try:
        # Create a Quantum Register called "qr" with 2 qubits.
        qr = Q_program.create_quantum_register("qr", 2)
        # Create a Classical Register called "cr" with 2 bits.
        cr = Q_program.create_classical_register("cr", 2)
        # Create a Quantum Circuit called "qc" involving the Quantum Register "qr"
        # and the Classical Register "cr".
        qc = Q_program.create_circuit("bell", [qr], [cr])

        # Add the H gate in the Qubit 0, putting this qubit in superposition.
        qc.h(qr[0])
        # Add the CX gate on control qubit 0 and target qubit 1, putting 
        # the qubits in a Bell state
        qc.cx(qr[0], qr[1])

        # Add a Measure gate to see the state.
        qc.measure(qr, cr)

        # Compile and execute the Quantum Program in the local_qasm_simulator.
        result = Q_program.execute(["bell"], backend=backend, shots=1024, seed=1)

        # Show the results.
        print(result)
        print(result.get_data("bell"))

    except QISKitError as ex:
        print('There was an error in the circuit!. Error = {}'.format(ex))
    except RegisterSizeError as ex:
        print('Error in the number of registers!. Error = {}'.format(ex))

from qiskit import QuantumProgram, QISKitError, RegisterSizeError

# Create a QuantumProgram object instance.

Q_program = QuantumProgram()

if __name__ == "__main__":

backend = 'local_qasm_simulator'

try:

# Create a Quantum Register called "qr" with 2 qubits.

qr = Q_program.create_quantum_register("qr", 2)

# Create a Classical Register called "cr" with 2 bits.

cr = Q_program.create_classical_register("cr", 2)

# Create a Quantum Circuit called "qc" involving the Quantum Register "qr"

# and the Classical Register "cr".

qc = Q_program.create_circuit("bell", [qr], [cr])

# Add the H gate in the Qubit 0, putting this qubit in superposition.

qc.h(qr[0])

# Add the CX gate on control qubit 0 and target qubit 1, putting

# the qubits in a Bell state

qc.cx(qr[0], qr[1])

# Add a Measure gate to see the state.

qc.measure(qr, cr)

# Compile and execute the Quantum Program in the local_qasm_simulator.

result = Q_program.execute(["bell"], backend=backend, shots=1024, seed=1)

# Show the results.

print(result)

print(result.get_data("bell"))

except QISKitError as ex:

print('There was an error in the circuit!. Error = {}'.format(ex))

except RegisterSizeError as ex:

print('Error in the number of registers!. Error = {}'.format(ex))

Ambiente di prova:

Version used: Python 3.6.3 (v3.6.3:2c5fed8, Oct 3 2017, 18:11:49) [MSC v.1900 64 bit (AMD64)] on win32
Environment name and version (e.g. Python 3.6.1): Python 3.6.3
Operating System and version: Microsoft Windows 10 Pro 10.0.16299 build 16299

Pubblicato originariamente su Github.

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