fix: StateVector shouldn't be a supported pragma for DM simulator

src/braket/simulator_v2/base_simulator_v2.py

@@ -3,7 +3,6 @@
 from collections.abc import Sequence
 from typing import Any, Optional, Union
 
-import juliacall
 import numpy as np
 from braket.default_simulator.result_types import TargetedResultType
 from braket.default_simulator.simulator import BaseLocalSimulator
@@ -100,7 +99,7 @@ def run_jaqcd(
         translated_ir, qubit_count = self._jaqcd_to_jl(circuit_ir, shots)
         try:
             r = jl.simulate(self._device, translated_ir, qubit_count, shots)
-        except juliacall.JuliaError as e:
+        except JuliaError as e:
             _handle_julia_error(e)
         r.additionalMetadata.action = circuit_ir
         r = _result_value_to_ndarray(r)
@@ -158,7 +157,7 @@ def run_openqasm(
         """
         try:
             r = jl.simulate(self._device, self._openqasm_to_jl(openqasm_ir), shots)
-        except juliacall.JuliaError as e:
+        except JuliaError as e:
             _handle_julia_error(e)
         r.additionalMetadata.action = openqasm_ir
         # attach the result types
@@ -209,7 +208,7 @@ def run_multiple(
                 shots=shots,
                 inputs=inputs,
             )
-        except juliacall.JuliaError as e:
+        except JuliaError as e:
             _handle_julia_error(e)
 
         for r_ix, result in enumerate(results):

src/braket/simulator_v2/density_matrix_simulator_v2.py

@@ -115,7 +115,6 @@ def properties(self) -> GateModelSimulatorDeviceCapabilities:
                         ],
                         "supportedPragmas": [
                             "braket_unitary_matrix",
-                            "braket_result_type_state_vector",
                             "braket_result_type_density_matrix",
                             "braket_result_type_sample",
                             "braket_result_type_expectation",

src/braket/simulator_v2/julia_import.py

@@ -1,42 +1,34 @@
 import os
-import sys
 import warnings
 
+import juliacall
+
 # Check if JuliaCall is already loaded, and if so, warn the user
 # about the relevant environment variables. If not loaded,
 # set up sensible defaults.
-if "juliacall" in sys.modules:
+# Required to avoid segfaults (https://juliapy.github.io/PythonCall.jl/dev/faq/)
+if os.environ.get("PYTHON_JULIACALL_HANDLE_SIGNALS", "yes") != "yes":
     warnings.warn(
-        "`juliacall` module has already been imported. "
-        + "Make sure that you have set the environment variable "
-        + "`PYTHON_JULIACALL_HANDLE_SIGNALS=yes` to avoid segfaults. "
+        "`PYTHON_JULIACALL_HANDLE_SIGNALS` environment variable "
+        + "is set to something other than 'yes' or ''. "
+        + "You will experience segfaults if running with Julia multithreading."
     )
-else:
-    # Required to avoid segfaults (https://juliapy.github.io/PythonCall.jl/dev/faq/)
-    if os.environ.get("PYTHON_JULIACALL_HANDLE_SIGNALS", "yes") != "yes":
-        warnings.warn(
-            "`PYTHON_JULIACALL_HANDLE_SIGNALS` environment variable "
-            + "is set to something other than 'yes' or ''. "
-            + "You will experience segfaults if running with Julia multithreading."
-        )
-
-    if os.environ.get("PYTHON_JULIACALL_THREADS", "auto") != "auto":
-        warnings.warn(
-            "`PYTHON_JULIACALL_THREADS` environment variable is set to "
-            + "something other than `auto`, so `amazon-braket-simulator-v2` "
-            + "was not able to set it."
-        )
 
-    for k, default in (
-        ("PYTHON_JULIACALL_HANDLE_SIGNALS", "yes"),
-        ("PYTHON_JULIACALL_THREADS", "auto"),
-        ("PYTHON_JULIACALL_OPTLEVEL", "3"),
-        # let the user's Conda/Pip handle installing things
-        ("JULIA_CONDAPKG_BACKEND", "Null"),
-    ):
-        os.environ[k] = os.environ.get(k, default)
+if os.environ.get("PYTHON_JULIACALL_THREADS", "auto") != "auto":
+    warnings.warn(
+        "`PYTHON_JULIACALL_THREADS` environment variable is set to "
+        + "something other than `auto`, so `amazon-braket-simulator-v2` "
+        + "was not able to set it."
+    )
 
-import juliacall
+for k, default in (
+    ("PYTHON_JULIACALL_HANDLE_SIGNALS", "yes"),
+    ("PYTHON_JULIACALL_THREADS", "auto"),
+    ("PYTHON_JULIACALL_OPTLEVEL", "3"),
+    # let the user's Conda/Pip handle installing things
+    ("JULIA_CONDAPKG_BACKEND", "Null"),
+):
+    os.environ[k] = os.environ.get(k, default)
 
 jl = juliacall.Base.Module()
 

test/unit_tests/braket/simulator_v2/test_density_matrix_simulator_v2.py

@@ -267,7 +267,6 @@ def test_properties():
                     ],
                     "supportedPragmas": [
                         "braket_unitary_matrix",
-                        "braket_result_type_state_vector",
                         "braket_result_type_density_matrix",
                         "braket_result_type_sample",
                         "braket_result_type_expectation",

test/unit_tests/braket/simulator_v2/test_state_vector_simulator_v2.py

@@ -85,7 +85,6 @@ def test_simulator_run_grcs_16(grcs_16_qubit, batch_size):
     if isinstance(grcs_16_qubit.circuit_ir, JaqcdProgram):
         result = simulator.run(
             grcs_16_qubit.circuit_ir,
-            qubit_count=16,
             shots=0,
             batch_size=batch_size,
         )
@@ -102,9 +101,7 @@ def test_simulator_run_bell_pair(bell_ir, batch_size, caplog):
     simulator = StateVectorSimulator()
     shots_count = 10000
     if isinstance(bell_ir, JaqcdProgram):
-        result = simulator.run(
-            bell_ir, qubit_count=2, shots=shots_count, batch_size=batch_size
-        )
+        result = simulator.run(bell_ir, shots=shots_count, batch_size=batch_size)
     else:
         result = simulator.run(bell_ir, shots=shots_count, batch_size=batch_size)
 
@@ -729,7 +726,6 @@ def test_simulator_identity(caplog):
         if isinstance(program, JaqcdProgram):
             result = simulator.run(
                 program,
-                qubit_count=2,
                 shots=shots_count,
             )
         else:
@@ -756,7 +752,7 @@ def test_simulator_instructions_not_supported(circuit_noise):
     )
     with pytest.raises(TypeError, match=no_noise):
         if isinstance(circuit_noise, JaqcdProgram):
-            simulator.run(circuit_noise, qubit_count=2, shots=0)
+            simulator.run(circuit_noise, shots=0)
         else:
             simulator.run(circuit_noise, shots=0)
 
@@ -765,7 +761,7 @@ def test_simulator_run_no_results_no_shots(bell_ir):
     simulator = StateVectorSimulator()
     with pytest.raises(ValueError):
         if isinstance(bell_ir, JaqcdProgram):
-            simulator.run(bell_ir, qubit_count=2, shots=0)
+            simulator.run(bell_ir, shots=0)
         else:
             simulator.run(bell_ir, shots=0)
 
@@ -788,7 +784,7 @@ def test_simulator_run_amplitude_shots():
         """
     )
     with pytest.raises(ValueError):
-        simulator.run(jaqcd, qubit_count=2, shots=100)
+        simulator.run(jaqcd, shots=100)
     with pytest.raises(ValueError):
         simulator.run(qasm, shots=100)
 
@@ -838,7 +834,7 @@ def test_simulator_run_statevector_shots():
         """
     )
     with pytest.raises(ValueError):
-        simulator.run(jaqcd, qubit_count=2, shots=100)
+        simulator.run(jaqcd, shots=100)
     with pytest.raises(ValueError):
         simulator.run(qasm, shots=100)
 
@@ -871,7 +867,7 @@ def test_simulator_run_result_types_shots(caplog):
         """
     )
     shots_count = 100
-    jaqcd_result = simulator.run(jaqcd, qubit_count=2, shots=shots_count)
+    jaqcd_result = simulator.run(jaqcd, shots=shots_count)
     qasm_result = simulator.run(qasm, shots=shots_count)
     for result in jaqcd_result, qasm_result:
         assert all([len(measurement) == 2] for measurement in result.measurements)
@@ -911,7 +907,7 @@ def test_simulator_run_result_types_shots_basis_rotation_gates(caplog):
         """
     )
     shots_count = 1000
-    jaqcd_result = simulator.run(jaqcd, qubit_count=2, shots=shots_count)
+    jaqcd_result = simulator.run(jaqcd, shots=shots_count)
     qasm_result = simulator.run(qasm, shots=shots_count)
     for result in jaqcd_result, qasm_result:
         assert all([len(measurement) == 2] for measurement in result.measurements)
@@ -941,7 +937,7 @@ def test_simulator_run_result_types_shots_basis_rotation_gates_value_error():
             )
         )
         shots_count = 1000
-        simulator.run(ir, qubit_count=2, shots=shots_count)
+        simulator.run(ir, shots=shots_count)
 
 
 @pytest.mark.parametrize(
@@ -1031,7 +1027,7 @@ def test_simulator_run_observable_references_invalid_qubit(ir, qubit_count):
     shots_count = 0
     if isinstance(ir, JaqcdProgram):
         with pytest.raises(ValueError):
-            simulator.run(ir, qubit_count=qubit_count, shots=shots_count)
+            simulator.run(ir, shots=shots_count)
     else:
         # index error since you're indexing from a logical qubit
         with pytest.raises(IndexError):
@@ -1046,7 +1042,7 @@ def test_simulator_bell_pair_result_types(
     simulator = StateVectorSimulator()
     ir = bell_ir_with_result(targets)
     if isinstance(ir, JaqcdProgram):
-        result = simulator.run(ir, qubit_count=2, shots=0, batch_size=batch_size)
+        result = simulator.run(ir, shots=0, batch_size=batch_size)
     else:
         result = simulator.run(ir, shots=0, batch_size=batch_size)
     assert len(result.resultTypes) == 2
@@ -1082,7 +1078,7 @@ def test_simulator_fails_samples_0_shots():
         """
     )
     with pytest.raises(ValueError):
-        simulator.run(jaqcd, qubit_count=1, shots=0)
+        simulator.run(jaqcd, shots=0)
     with pytest.raises(ValueError):
         simulator.run(qasm, shots=0)
 
@@ -1161,7 +1157,7 @@ def test_simulator_valid_observables(result_types, expected):
             }
         )
     )
-    result = simulator.run(prog, qubit_count=2, shots=0)
+    result = simulator.run(prog, shots=0)
     for i in range(len(result_types)):
         assert np.allclose(result.resultTypes[i].value, expected[i])
 
@@ -1482,7 +1478,7 @@ def test_simulator_analytic_value_type(jaqcd_string, oq3_pragma, jaqcd_type):
         #pragma braket result {oq3_pragma}
         """
     )
-    result = simulator.run(jaqcd, qubit_count=2, shots=0)
+    result = simulator.run(jaqcd, shots=0)
     assert result.resultTypes[0].type == jaqcd_type
     assert isinstance(result.resultTypes[0].value, np.ndarray)
     result = simulator.run(qasm, shots=0)
@@ -1568,12 +1564,29 @@ def test_noncontiguous_qubits_jaqcd_multiple_targets():
         "results": [{"type": "expectation", "observable": ["z"], "targets": [4]}],
     }
     prg = JaqcdProgram.parse_raw(json.dumps(jaqcd_program))
-    result = StateVectorSimulator().run(prg, qubit_count=2, shots=0)
+    result = StateVectorSimulator().run(prg, shots=0)
 
     assert result.measuredQubits == [0, 1]
     assert result.resultTypes[0].value == -1
 
 
+def test_run_multiple_single_circuit():
+    payload = [
+        OpenQASMProgram(
+            source="""
+            OPENQASM 3.0;
+            bit[1] b;
+            qubit[1] q;
+            h q[0];
+            #pragma braket result state_vector
+            """
+        )
+    ]
+    simulator = StateVectorSimulator()
+    results = simulator.run_multiple(payload, shots=0)
+    assert np.allclose(results[0].resultTypes[0].value, np.array([1, 1]) / np.sqrt(2))
+
+
 def test_run_multiple():
     payloads = [
         OpenQASMProgram(