Adds get_composite_devices method to dpctl.SyclPlatform

This method is only applicable for level_zero backend, returning an empty list for all other backend types

Author: ndgrigorian

dpctl/_backend.pxd

@@ -316,6 +316,8 @@ cdef extern from "syclinterface/dpctl_sycl_platform_interface.h":
         const DPCTLSyclPlatformRef)
     cdef DPCTLDeviceVectorRef DPCTLPlatform_GetDevices(
         const DPCTLSyclPlatformRef PRef, _device_type DTy)
+    cdef DPCTLDeviceVectorRef DPCTLPlatform_GetCompositeDevices(
+        const DPCTLSyclPlatformRef PRef)
 
 
 cdef extern from "syclinterface/dpctl_sycl_context_interface.h":

dpctl/_sycl_platform.pyx

@@ -37,6 +37,7 @@ from ._backend cimport (  # noqa: E211
     DPCTLPlatform_CreateFromSelector,
     DPCTLPlatform_Delete,
     DPCTLPlatform_GetBackend,
+    DPCTLPlatform_GetCompositeDevices,
     DPCTLPlatform_GetDefaultContext,
     DPCTLPlatform_GetDevices,
     DPCTLPlatform_GetName,
@@ -447,6 +448,41 @@ cdef class SyclPlatform(_SyclPlatform):
 
         return devices
 
+    def get_composite_devices(self):
+        """
+        Returns the list of composite :class:`dpctl.SyclDevice` objects
+        associated with :class:`dpctl.SyclPlatform` instance.
+
+        Returns:
+            list:
+                A :obj:`list` of composite :class:`dpctl.SyclDevice` objects
+                that belong to this platform.
+
+        Raises:
+            TypeError:
+                If `device_type` is not a str or :class:`dpctl.device_type`
+                enum.
+            ValueError:
+                If the ``DPCTLPlatform_GetCompositeDevices`` call returned
+                ``NULL`` instead of a ``DPCTLDeviceVectorRef`` object.
+        """
+        cdef DPCTLDeviceVectorRef DVRef = NULL
+        cdef size_t num_devs
+        cdef size_t i
+        cdef DPCTLSyclDeviceRef DRef
+
+        DVRef = DPCTLPlatform_GetCompositeDevices(self.get_platform_ref())
+        if (DVRef is NULL):
+            raise ValueError("Internal error: NULL device vector encountered")
+        num_devs = DPCTLDeviceVector_Size(DVRef)
+        composite_devices = []
+        for i in range(num_devs):
+            DRef = DPCTLDeviceVector_GetAt(DVRef, i)
+            composite_devices.append(SyclDevice._create(DRef))
+        DPCTLDeviceVector_Delete(DVRef)
+
+        return composite_devices
+
 
 def lsplatform(verbosity=0):
     """

libsyclinterface/include/syclinterface/dpctl_sycl_platform_interface.h

@@ -193,4 +193,17 @@ __dpctl_give DPCTLDeviceVectorRef
 DPCTLPlatform_GetDevices(__dpctl_keep const DPCTLSyclPlatformRef PRef,
                          DPCTLSyclDeviceType DTy);
 
+/*!
+ * @brief Returns a vector of composite devices associated with sycl::platform
+ * referenced by DPCTLSyclPlatformRef object.
+ *
+ * @param    PRef           The DPCTLSyclPlatformRef pointer.
+ * @return   A DPCTLDeviceVectorRef with composite devices associated with
+ * given PRef.
+ * @ingroup PlatformInterface
+ */
+DPCTL_API
+__dpctl_give DPCTLDeviceVectorRef
+DPCTLPlatform_GetCompositeDevices(__dpctl_keep const DPCTLSyclPlatformRef PRef);
+
 DPCTL_C_EXTERN_C_END

libsyclinterface/source/dpctl_sycl_platform_interface.cpp

@@ -313,3 +313,39 @@ DPCTLPlatform_GetDevices(__dpctl_keep const DPCTLSyclPlatformRef PRef,
         return nullptr;
     }
 }
+
+__dpctl_give DPCTLDeviceVectorRef
+DPCTLPlatform_GetCompositeDevices(__dpctl_keep const DPCTLSyclPlatformRef PRef)
+{
+    auto P = unwrap<platform>(PRef);
+    if (!P) {
+        error_handler("Cannot retrieve composite devices from "
+                      "DPCTLSyclPlatformRef as input is a nullptr.",
+                      __FILE__, __func__, __LINE__);
+        return nullptr;
+    }
+
+    using vecTy = std::vector<DPCTLSyclDeviceRef>;
+    vecTy *DevicesVectorPtr = nullptr;
+    try {
+        DevicesVectorPtr = new vecTy();
+    } catch (std::exception const &e) {
+        delete DevicesVectorPtr;
+        error_handler(e, __FILE__, __func__, __LINE__);
+        return nullptr;
+    }
+
+    try {
+        auto composite_devices = P->ext_oneapi_get_composite_devices();
+        DevicesVectorPtr->reserve(composite_devices.size());
+        for (const auto &Dev : composite_devices) {
+            DevicesVectorPtr->emplace_back(
+                wrap<device>(new device(std::move(Dev))));
+        }
+        return wrap<vecTy>(DevicesVectorPtr);
+    } catch (std::exception const &e) {
+        delete DevicesVectorPtr;
+        error_handler(e, __FILE__, __func__, __LINE__);
+        return nullptr;
+    }
+}