✨ Expose QDMI device queue depth

CHANGELOG.md

@@ -12,6 +12,8 @@ releases may include breaking changes.
 
 ### Added
 
+- ✨ Expose the optional QDMI device queue depth through the C++ and Python
+  FoMaC APIs ([#2010]) ([**@burgholzer**])
 - ✨ Add PennyLane support for gate-based QDMI devices ([#2005])
   ([**@burgholzer**])
 - ✨ Integrate QDMI devices as MLIR compiler targets across C++, Python, and
@@ -720,6 +722,7 @@ for previous changelogs._
 
 <!-- PR links -->
 
+[#2010]: https://github.com/munich-quantum-toolkit/core/pull/2010
 [#2007]: https://github.com/munich-quantum-toolkit/core/pull/2007
 [#2006]: https://github.com/munich-quantum-toolkit/core/pull/2006
 [#2005]: https://github.com/munich-quantum-toolkit/core/pull/2005

bindings/fomac/fomac.cpp

@@ -389,6 +389,9 @@ when the custom slot is unsupported.)pb");
   device.def("needs_calibration", &fomac::Device::getNeedsCalibration,
              "Returns whether the device needs calibration.");
 
+  device.def("queue_depth", &fomac::Device::getQueueDepth,
+             "Returns the current queue depth, or None if unavailable.");
+
   device.def("length_unit", &fomac::Device::getLengthUnit,
              "Returns the unit of length used by the device.");
 

cmake/ExternalDependencies.cmake

@@ -89,11 +89,11 @@ if(BUILD_MQT_CORE_TESTS)
 endif()
 
 # cmake-format: off
-set(QDMI_MINIMUM_VERSION 1.3.2
+set(QDMI_MINIMUM_VERSION 1.3.3
         CACHE STRING "Minimum QDMI version")
-set(QDMI_VERSION 1.3.2
+set(QDMI_VERSION 1.3.3
         CACHE STRING "QDMI version")
-set(QDMI_REV "d05a0b418f42e54e9585d2e00af8ce23e745fd83" # v1.3.2
+set(QDMI_REV "684aae5a959d63e3affb9428df2c4a0187bdb624" # QDMI PR #486
         CACHE STRING "QDMI identifier (tag, branch or commit hash)")
 set(QDMI_REPO_OWNER "Munich-Quantum-Software-Stack"
         CACHE STRING "QDMI repository owner (change when using a fork)")

include/mqt-core/fomac/FoMaC.hpp

@@ -470,6 +470,9 @@ class Device {
   /// @see QDMI_DEVICE_PROPERTY_NEEDSCALIBRATION
   [[nodiscard]] std::optional<size_t> getNeedsCalibration() const;
 
+  /// @see QDMI_DEVICE_PROPERTY_QUEUEDEPTH
+  [[nodiscard]] std::optional<size_t> getQueueDepth() const;
+
   /// @see QDMI_DEVICE_PROPERTY_LENGTHUNIT
   [[nodiscard]] std::optional<std::string> getLengthUnit() const;
 

include/mqt-core/qdmi/common/Common.hpp

@@ -390,6 +390,8 @@ constexpr auto toString(const QDMI_Device_Property prop) -> const char* {
     return "SUPPORTED PROGRAM FORMATS";
   case QDMI_DEVICE_PROPERTY_CHILDDEVICES:
     return "CHILD DEVICES";
+  case QDMI_DEVICE_PROPERTY_QUEUEDEPTH:
+    return "QUEUE DEPTH";
   case QDMI_DEVICE_PROPERTY_MAX:
     return "MAX";
   case QDMI_DEVICE_PROPERTY_CUSTOM1:

python/mqt/core/fomac.pyi

@@ -297,6 +297,9 @@ class Device:
     def needs_calibration(self) -> int | None:
         """Returns whether the device needs calibration."""
 
+    def queue_depth(self) -> int | None:
+        """Returns the current queue depth, or None if unavailable."""
+
     def length_unit(self) -> str | None:
         """Returns the unit of length used by the device."""
 

src/fomac/FoMaC.cpp

@@ -275,6 +275,10 @@ std::optional<size_t> Device::getNeedsCalibration() const {
       QDMI_DEVICE_PROPERTY_NEEDSCALIBRATION);
 }
 
+std::optional<size_t> Device::getQueueDepth() const {
+  return queryProperty<std::optional<size_t>>(QDMI_DEVICE_PROPERTY_QUEUEDEPTH);
+}
+
 std::optional<std::string> Device::getLengthUnit() const {
   return queryProperty<std::optional<std::string>>(
       QDMI_DEVICE_PROPERTY_LENGTHUNIT);

test/fomac/test_fomac.cpp

@@ -348,6 +348,7 @@ TEST(FoMaCTest, DevicePropertyToString) {
                "SUPPORTED PROGRAM FORMATS");
   EXPECT_STREQ(qdmi::toString(QDMI_DEVICE_PROPERTY_CHILDDEVICES),
                "CHILD DEVICES");
+  EXPECT_STREQ(qdmi::toString(QDMI_DEVICE_PROPERTY_QUEUEDEPTH), "QUEUE DEPTH");
   EXPECT_STREQ(qdmi::toString(QDMI_DEVICE_PROPERTY_MAX), "MAX");
   EXPECT_STREQ(qdmi::toString(QDMI_DEVICE_PROPERTY_CUSTOM1), "CUSTOM1");
   EXPECT_STREQ(qdmi::toString(QDMI_DEVICE_PROPERTY_CUSTOM2), "CUSTOM2");
@@ -423,6 +424,10 @@ TEST_P(DeviceTest, NeedsCalibration) {
   EXPECT_NO_THROW(std::ignore = device.getNeedsCalibration());
 }
 
+TEST_F(DDSimulatorDeviceTest, QueueDepthIsUnavailable) {
+  EXPECT_EQ(device.getQueueDepth(), std::nullopt);
+}
+
 TEST_P(DeviceTest, LengthUnit) {
   EXPECT_NO_THROW(std::ignore = device.getLengthUnit());
 }

test/python/fomac/test_fomac.py

@@ -169,6 +169,14 @@ def test_device_needs_calibration(device: Device) -> None:
         assert isinstance(needs_cal, int)
 
 
+def test_device_queue_depth(device: Device) -> None:
+    """Test that the optional device queue depth is a non-negative integer."""
+    queue_depth = device.queue_depth()
+    if queue_depth is not None:
+        assert isinstance(queue_depth, int)
+        assert queue_depth >= 0
+
+
 def test_device_length_unit(device: Device) -> None:
     """Test that the device length unit is a non-empty string."""
     lu = device.length_unit()