1 files changed, 54 insertions, 0 deletions
diff --git a/Help/prop_test/RESOURCE_GROUPS.rst b/Help/prop_test/RESOURCE_GROUPS.rst
new file mode 100644
index 0000000..436451c
--- /dev/null
+++ b/Help/prop_test/RESOURCE_GROUPS.rst
@@ -0,0 +1,54 @@
+RESOURCE_GROUPS
+---------------
+
+Specify resources required by a test, grouped in a way that is meaningful to
+the test.  See :ref:`resource allocation <ctest-resource-allocation>`
+for more information on how this property integrates into the CTest resource
+allocation feature.
+
+The ``RESOURCE_GROUPS`` property is a :ref:`semicolon-separated list <CMake
+Language Lists>` of group descriptions. Each entry consists of an optional
+number of groups using the description followed by a series of resource
+requirements for those groups. These requirements (and the number of groups)
+are separated by commas. The resource requirements consist of the name of a
+resource type, followed by a colon, followed by an unsigned integer
+specifying the number of slots required on one resource of the given type.
+
+The ``RESOURCE_GROUPS`` property tells CTest what resources a test expects
+to use grouped in a way meaningful to the test.  The test itself must read
+the :ref:`environment variables <ctest-resource-environment-variables>` to
+determine which resources have been allocated to each group.  For example,
+each group may correspond to a process the test will spawn when executed.
+
+Consider the following example:
+
+.. code-block:: cmake
+
+  add_test(NAME MyTest COMMAND MyExe)
+  set_property(TEST MyTest PROPERTY RESOURCE_GROUPS
+    "2,gpus:2"
+    "gpus:4,crypto_chips:2")
+
+In this example, there are two group descriptions (implicitly separated by a
+semicolon.) The content of the first description is ``2,gpus:2``. This
+description specifies 2 groups, each of which requires 2 slots from a single
+GPU. The content of the second description is ``gpus:4,crypto_chips:2``. This
+description does not specify a group count, so a default of 1 is assumed.
+This single group requires 4 slots from a single GPU and 2 slots from a
+single cryptography chip. In total, 3 resource groups are specified for this
+test, each with its own unique requirements.
+
+When CTest sets the :ref:`environment variables
+<ctest-resource-environment-variables>` for a test, it assigns a group number
+based on the group description, starting at 0 on the left and the number of
+groups minus 1 on the right. For example, in the example above, the two
+groups in the first description would have IDs of 0 and 1, and the single
+group in the second description would have an ID of 2.
+
+Both the ``RESOURCE_GROUPS`` and :prop_test:`RESOURCE_LOCK` properties serve
+similar purposes, but they are distinct and orthogonal. Resources specified by
+``RESOURCE_GROUPS`` do not affect :prop_test:`RESOURCE_LOCK`, and vice versa.
+Whereas :prop_test:`RESOURCE_LOCK` is a simpler property that is used for
+locking one global resource, ``RESOURCE_GROUPS`` is a more advanced property
+that allows multiple tests to simultaneously use multiple resources of the
+same type, specifying their requirements in a fine-grained manner.