DPCTLDeviceMgr_GetPositionInDevices(DRef, device_mask) added

This function is more general that DPCTL_GetRelativeId(DRef).
The latter corresponds to DPCTLDeviceMgr_GetPositionInDevices(DRef,
 DPCTLDevice_GetBackend(DRef) | DPCTLDevice_GetDeviceType(DRef));

The function can be used to generate filter selector based on a
pattern, expressed by device_mask (any backend, given type), or
(any backend, any type), or (given backend, given type).

Author: oleksandr-pavlyk

dpctl-capi/include/dpctl_sycl_device_manager.h

@@ -76,6 +76,26 @@ DPCTL_API
 __dpctl_give DPCTLDeviceVectorRef
 DPCTLDeviceMgr_GetDevices(int device_identifier);
 
+/*!
+ * @brief Returns an index on the given device in the vector returned by
+ * #DPCTLDeviceMgr_GetDevices if found, -1 otherwise.
+ *
+ * The device_identifier can be a combination of #DPCTLSyclBackendType and
+ * #DPCTLSyclDeviceType bit flags. The function returns all devices that
+ * match the specified bit flags.
+ *
+ * @param    DRef              A #DPCTLSyclDeviceRef opaque pointer.
+ * @param    device_identifier A bitflag that can be any combination of
+ *                             #DPCTLSyclBackendType and #DPCTLSyclDeviceType
+ *                             enum values.
+ * @return   If found, returns the position of the given device in the
+ * vector that would be returned by #DPCTLDeviceMgr_GetDevices if called
+ * with the same device_identifier argument.
+ */
+DPCTL_API
+int DPCTLDeviceMgr_GetPositionInDevices(__dpctl_keep DPCTLSyclDeviceRef DRef,
+                                        int device_identifier);
+
 /*!
  * @brief If the DPCTLSyclDeviceRef argument is a root device, then this
  * function returns a cached default SYCL context for that device.

dpctl-capi/source/dpctl_sycl_device_manager.cpp

@@ -164,6 +164,35 @@ DPCTLDeviceMgr_GetDevices(int device_identifier)
     return wrap(Devices);
 }
 
+int DPCTLDeviceMgr_GetPositionInDevices(__dpctl_keep DPCTLSyclDeviceRef DRef,
+                                        int device_identifier)
+{
+    constexpr int not_found = -1;
+    if (!DRef) {
+        return not_found;
+    }
+
+    const auto &root_devices = device::get_devices();
+    default_selector mRanker;
+    int index = not_found;
+    auto reference_device = *(unwrap(DRef));
+
+    for (const auto &root_device : root_devices) {
+        if (mRanker(root_device) < 0)
+            continue;
+        auto Bty(DPCTL_SyclBackendToDPCTLBackendType(
+            root_device.get_platform().get_backend()));
+        auto Dty(DPCTL_SyclDeviceTypeToDPCTLDeviceType(
+            root_device.get_info<info::device::device_type>()));
+        if ((device_identifier & Bty) && (device_identifier & Dty)) {
+            ++index;
+            if (root_device == reference_device)
+                return index;
+        }
+    }
+    return not_found;
+}
+
 /*!
  * Returns the number of available devices for a specific backend and device
  * type combination.

dpctl-capi/tests/test_sycl_device_manager.cpp

@@ -146,12 +146,12 @@ struct TestDPCTLGetDevicesOrdering : public ::testing::TestWithParam<int>
 {
     DPCTLDeviceVectorRef DV = nullptr;
     size_t nDevices = 0;
+    int device_type_mask;
 
     TestDPCTLGetDevicesOrdering()
     {
-        const int device_type_mask =
-            (GetParam() & DPCTLSyclDeviceType::DPCTL_ALL) |
-            DPCTLSyclBackendType::DPCTL_ALL_BACKENDS;
+        device_type_mask = (GetParam() & DPCTLSyclDeviceType::DPCTL_ALL) |
+                           DPCTLSyclBackendType::DPCTL_ALL_BACKENDS;
         EXPECT_NO_FATAL_FAILURE(
             DV = DPCTLDeviceMgr_GetDevices(device_type_mask));
         EXPECT_TRUE(DV != nullptr);
@@ -179,6 +179,7 @@ TEST_P(TestDPCTLGetDevicesOrdering, ChkConsistencyWithFilterSelector)
         std::string fs_device_type, fs;
         DPCTLSyclDeviceRef DRef = nullptr, D0Ref = nullptr;
         DPCTLSyclDeviceSelectorRef DSRef = nullptr;
+        int j = -1;
         EXPECT_NO_FATAL_FAILURE(DRef = DPCTLDeviceVector_GetAt(DV, i));
         EXPECT_NO_FATAL_FAILURE(Dty = DPCTLDevice_GetDeviceType(DRef));
         EXPECT_NO_FATAL_FAILURE(
@@ -189,6 +190,10 @@ TEST_P(TestDPCTLGetDevicesOrdering, ChkConsistencyWithFilterSelector)
         EXPECT_NO_FATAL_FAILURE(D0Ref = DPCTLDevice_CreateFromSelector(DSRef));
         EXPECT_NO_FATAL_FAILURE(DPCTLDeviceSelector_Delete(DSRef));
         EXPECT_TRUE(DPCTLDevice_AreEq(DRef, D0Ref));
+        EXPECT_NO_FATAL_FAILURE(
+            j = DPCTLDeviceMgr_GetPositionInDevices(DRef, device_type_mask));
+        EXPECT_TRUE(j >= 0);
+        EXPECT_TRUE(i == static_cast<decltype(i)>(j));
         EXPECT_NO_FATAL_FAILURE(DPCTLDevice_Delete(D0Ref));
         EXPECT_NO_FATAL_FAILURE(DPCTLDevice_Delete(DRef));
     }