llnl · adayton1 · Mar 4, 2024 · Mar 4, 2024 · Jun 4, 2026
diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
@@ -114,6 +114,7 @@ The format of this file is based on [Keep a Changelog](http://keepachangelog.com
 ### Changed
 - Moved installed CMake targets from share/chai/cmake to lib/cmake/chai to be consistent with other libraries in the RAJA Portability Suite
 - Improved dependency handling during the build of CHAI and when it is imported into another library/application
+- Renamed CMake option CHAI\_DISABLE\_RM to CHAI\_ENABLE\_MANAGER
 - Removed ArrayManager::enableDeviceSynchronization and ArrayManager::disableDeviceSynchronization. Instead, use the environment variables for device synchronization after all kernels (e.g. CUDA\_LAUNCH\_BLOCKING or HIP\_LAUNCH\_BLOCKING)
 
 ### Fixed

diff --git a/cmake/SetupChaiOptions.cmake b/cmake/SetupChaiOptions.cmake
@@ -9,8 +9,8 @@ option(CHAI_ENABLE_GPU_SIMULATION_MODE "Enable GPU Simulation Mode" Off)
 option(CHAI_ENABLE_OPENMP "Enable OpenMP" Off)
 option(CHAI_ENABLE_MPI "Enable MPI (for umpire replay only)" Off)
 
-option(CHAI_DISABLE_RM "Make ManagedArray a thin wrapper" Off)
-mark_as_advanced(CHAI_DISABLE_RM)
+option(CHAI_ENABLE_MANAGER "Use the ArrayManager" On)
+mark_as_advanced(CHAI_ENABLE_MANAGER)
 
 option(CHAI_ENABLE_UM "Use CUDA unified (managed) memory" Off)
 option(CHAI_THIN_GPU_ALLOCATE "Single memory space model" Off)
@@ -42,6 +42,6 @@ if (CHAI_ENABLE_UM AND NOT ENABLE_CUDA AND NOT CHAI_THIN_GPU_ALLOCATE)
   message(FATAL_ERROR "Option CHAI_ENABLE_UM requires ENABLE_CUDA or CHAI_THIN_GPU_ALLOCATE")
 endif()
 
-if (CHAI_THIN_GPU_ALLOCATE AND NOT CHAI_DISABLE_RM)
-  message(FATAL_ERROR "Option CHAI_THIN_GPU_ALLOCATE requires CHAI_DISABLE_RM")
+if (CHAI_THIN_GPU_ALLOCATE AND CHAI_ENABLE_MANAGER)
+  message(FATAL_ERROR "Option CHAI_THIN_GPU_ALLOCATE=On requires CHAI_ENABLE_MANAGER=Off")
 endif()
diff --git a/docs/sphinx/advanced_configuration.rst b/docs/sphinx/advanced_configuration.rst
@@ -25,7 +25,7 @@ Here is a summary of the configuration options, their default value, and meaning
       ENABLE_HIP                   Off      Enable HIP support.
       CHAI_ENABLE_GPU_SIMULATION_MODE   Off      Simulates GPU execution.
       CHAI_ENABLE_UM                    Off      Enable support for CUDA Unified Memory.
-      CHAI_DISABLE_RM                   Off      Disable the ArrayManager and make ManagedArray a thin wrapper around a pointer.
+      CHAI_ENABLE_MANAGER          On       Enable the ArrayManager.
       ENABLE_TESTS                 On       Build test executables.
       ENABLE_BENCHMARKS            On       Build benchmark programs.
       ===========================  ======== ===============================================================================
@@ -51,10 +51,11 @@ These arguments are explained in more detail below:
   not manually copy data. Data movement in this case is handled by the CUDA
   driver and runtime.
 
-* CHAI_DISABLE_RM
-  This option will remove all usage of the ``ArrayManager`` class and let the
-  ``ManagedArray`` objects function as thin wrappers around a raw pointer. This
-  option can be used with CPU-only allocations, or with CUDA Unified Memory.
+* CHAI_ENABLE_MANAGER
+  This option enables usage of the ``ArrayManager`` class. Turning it off lets
+  the ``ManagedArray`` objects function as thin wrappers around a raw pointer.
+  The thin wrapper version can be used with CPU-only allocations, unified
+  memory, or with architectures using a single memory space.
 
 * ENABLE_TESTS
   This option controls whether or not test executables will be built.

diff --git a/src/chai/CMakeLists.txt b/src/chai/CMakeLists.txt
@@ -26,7 +26,7 @@ set (chai_headers
 set (chai_sources
   ArrayManager.cpp)
 
-if(CHAI_DISABLE_RM)
+if(NOT CHAI_ENABLE_MANAGER)
   set(chai_headers
     ${chai_headers}
     ManagedArray_thin.inl)

diff --git a/src/chai/ChaiMacros.hpp b/src/chai/ChaiMacros.hpp
@@ -90,7 +90,7 @@
 
 #define CHAI_UNUSED_ARG(X)
 
-#if !defined(CHAI_DISABLE_RM)
+#if defined(CHAI_ENABLE_MANAGER)
 
 #define CHAI_LOG(level, msg) \
   UMPIRE_LOG(level, msg);

diff --git a/src/chai/ManagedArray.hpp b/src/chai/ManagedArray.hpp
@@ -311,7 +311,7 @@ class ManagedArray : public CHAICopyable
    */
   CHAI_HOST_DEVICE void set(size_t i, T val) const;
 
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
   /*!
    * \brief Assign a user-defined callback triggerd upon memory migration.
    *
@@ -369,7 +369,7 @@ class ManagedArray : public CHAICopyable
     m_pointer_record = other.m_pointer_record;
     m_allocator_id = other.m_allocator_id;
     m_is_slice = other.m_is_slice;
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
 #if !defined(CHAI_DEVICE_COMPILE)
   // if we can, ensure elems is based off the pointer_record size out of paranoia
   if (m_pointer_record != nullptr && !m_is_slice) {
@@ -388,7 +388,7 @@ class ManagedArray : public CHAICopyable
 private:
   // The following are only used by ManagedArray.inl, but for template
   // shenanigan reasons need to be defined here.
-#if !defined(CHAI_DISABLE_RM)
+#if defined(CHAI_ENABLE_MANAGER)
   // if T is a CHAICopyable, then it is important to initialize all the
   // elements with default constructors, since it is extremely easy to
   // trigger a moveInnerImpl, which expects inner values to be initialized.
@@ -483,7 +483,7 @@ ManagedArray<T> makeManagedArray(T* data,
                                  ExecutionSpace space,
                                  bool owned)
 {
-#if !defined(CHAI_DISABLE_RM)
+#if defined(CHAI_ENABLE_MANAGER)
   ArrayManager* manager = ArrayManager::getInstance();
 
   // First, try and find an existing PointerRecord for the pointer
@@ -573,9 +573,9 @@ CHAI_INLINE CHAI_HOST_DEVICE ManagedArray<T> ManagedArray<T>::slice( size_t offs
 
 }  // end of namespace chai
 
-#if defined(CHAI_DISABLE_RM)
-#include "chai/ManagedArray_thin.inl"
-#else
+#if defined(CHAI_ENABLE_MANAGER)
 #include "chai/ManagedArray.inl"
+#else
+#include "chai/ManagedArray_thin.inl"
 #endif
 #endif  // CHAI_ManagedArray_HPP
diff --git a/src/chai/config.hpp.in b/src/chai/config.hpp.in
@@ -9,7 +9,7 @@
 
 #cmakedefine CHAI_ENABLE_CUDA 
 #cmakedefine CHAI_ENABLE_HIP 
-#cmakedefine CHAI_DISABLE_RM
+#cmakedefine CHAI_ENABLE_MANAGER
 #cmakedefine CHAI_THIN_GPU_ALLOCATE
 #cmakedefine CHAI_ENABLE_UM
 #cmakedefine CHAI_DEBUG

diff --git a/src/chai/managed_ptr.hpp b/src/chai/managed_ptr.hpp
@@ -11,7 +11,7 @@
 
 #if defined(CHAI_ENABLE_MANAGED_PTR)
 
-#if !defined(CHAI_DISABLE_RM) || defined(CHAI_THIN_GPU_ALLOCATE)
+#if defined(CHAI_ENABLE_MANAGER) || defined(CHAI_THIN_GPU_ALLOCATE)
 #include "chai/ArrayManager.hpp"
 #endif
 
@@ -630,7 +630,7 @@ namespace chai {
          ///    with the ACTION_MOVE event.
          ///
          CHAI_HOST void move() const {
-#if !defined(CHAI_DISABLE_RM)
+#if defined(CHAI_ENABLE_MANAGER)
             if (m_pointer_record) {
                ExecutionSpace newSpace = ArrayManager::getInstance()->getExecutionSpace();
 
@@ -1085,7 +1085,7 @@ CHAI_HOST ManagedArrayOfManagedPtrUnpacker<T> unpack(const chai::ManagedArray<ch
    template <typename T,
              typename... Args>
    CHAI_HOST T* make_on_host(Args&&... args) {
-#if !defined(CHAI_DISABLE_RM)
+#if defined(CHAI_ENABLE_MANAGER)
       // Get the ArrayManager and save the current execution space
       chai::ArrayManager* arrayManager = chai::ArrayManager::getInstance();
       ExecutionSpace currentSpace = arrayManager->getExecutionSpace();
@@ -1098,7 +1098,7 @@ CHAI_HOST ManagedArrayOfManagedPtrUnpacker<T> unpack(const chai::ManagedArray<ch
       // Create on the host
       T* cpuPointer = new T(detail::processArguments(args)...);
 
-#if !defined(CHAI_DISABLE_RM)
+#if defined(CHAI_ENABLE_MANAGER)
       // Set the execution space back to the previous value
       arrayManager->setExecutionSpace(currentSpace);
 #endif
@@ -1133,7 +1133,7 @@ CHAI_HOST ManagedArrayOfManagedPtrUnpacker<T> unpack(const chai::ManagedArray<ch
    template <typename T,
              typename... Args>
    CHAI_HOST T* make_on_device(Args... args) {
-#if !defined(CHAI_DISABLE_RM)
+#if defined(CHAI_ENABLE_MANAGER)
       // Get the ArrayManager and save the current execution space
       chai::ArrayManager* arrayManager = chai::ArrayManager::getInstance();
       ExecutionSpace currentSpace = arrayManager->getExecutionSpace();
@@ -1171,7 +1171,7 @@ CHAI_HOST ManagedArrayOfManagedPtrUnpacker<T> unpack(const chai::ManagedArray<ch
       free(cpuBuffer);
       gpuFree(gpuBuffer);
 
-#if !defined(CHAI_DISABLE_RM)
+#if defined(CHAI_ENABLE_MANAGER)
       // Set the execution space back to the previous value
       arrayManager->setExecutionSpace(currentSpace);
 #endif

diff --git a/tests/integration/managed_array_tests.cpp b/tests/integration/managed_array_tests.cpp
@@ -30,7 +30,7 @@
 #define device_assert(EXP) assert(EXP)
 #endif
 
-#ifdef CHAI_DISABLE_RM
+#if !defined(CHAI_ENABLE_MANAGER)
 #define assert_empty_map(IGNORED)
 #else
 #define assert_empty_map(IGNORED) ASSERT_EQ(chai::ArrayManager::getInstance()->getPointerMap().size(),0)
@@ -54,7 +54,7 @@ TEST(ManagedArray, SetOnHost)
   assert_empty_map(true);
 }
 
-#if (!defined(CHAI_DISABLE_RM))
+#if defined(CHAI_ENABLE_MANAGER)
 TEST(ManagedArray, Const)
 {
   chai::ManagedArray<float> array(10);
@@ -168,7 +168,7 @@ TEST(ManagedArray, ArrayOfSlices) {
   assert_empty_map(true);
 }
 
-#if (!defined(CHAI_DISABLE_RM))
+#if defined(CHAI_ENABLE_MANAGER)
 TEST(ManagedArray, PickHostFromHostConst) {
   chai::ManagedArray<int> array(10);
 
@@ -213,7 +213,7 @@ TEST(ManagedArray, SetHostToHost)
 
 
 #if defined(CHAI_ENABLE_UM)
-#if (!defined(CHAI_DISABLE_RM))
+#if defined(CHAI_ENABLE_MANAGER)
 TEST(ManagedArray, PickHostFromHostConstUM) {
   chai::ManagedArray<int> array(10, chai::UM);
 
@@ -293,7 +293,7 @@ GPU_TEST(ManagedArray, PickHostFromDeviceUM)
   assert_empty_map(true);
 }
 
-#if (!defined(CHAI_DISABLE_RM))
+#if defined(CHAI_ENABLE_MANAGER)
 GPU_TEST(ManagedArray, PickHostFromDeviceConstUM) {
   chai::ManagedArray<int> array(10, chai::UM);
 
@@ -348,7 +348,7 @@ GPU_TEST(ManagedArray, PickandSetSliceDeviceToDeviceUM) {
 }
 #endif
 
-#if (!defined(CHAI_DISABLE_RM))
+#if defined(CHAI_ENABLE_MANAGER)
 GPU_TEST(ManagedArray, PickandSetDeviceToDevice)
 {
   chai::ManagedArray<int> array1(10);
@@ -748,7 +748,7 @@ TEST(ManagedArray, ExternalUnownedFromManagedArray)
 }
 
 #if defined(CHAI_ENABLE_CUDA) || defined(CHAI_ENABLE_HIP)
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
 GPU_TEST(ManagedArray, ExternalUnownedMoveToGPU)
 {
   float data[20];
@@ -794,7 +794,7 @@ TEST(ManagedArray, data)
 }
 
 #if defined(CHAI_ENABLE_CUDA) || defined(CHAI_ENABLE_HIP)
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
 GPU_TEST(ManagedArray, dataGPU)
 {
   // Initialize
@@ -891,7 +891,7 @@ TEST(ManagedArray, cdata)
 }
 
 #if defined(CHAI_ENABLE_CUDA) || defined(CHAI_ENABLE_HIP)
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
 GPU_TEST(ManagedArray, cdataGPU)
 {
   // Initialize
@@ -1022,7 +1022,7 @@ TEST(ManagedArray, Reset)
 }
 
 #if defined(CHAI_ENABLE_CUDA) || defined(CHAI_ENABLE_HIP)
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
 GPU_TEST(ManagedArray, ResetDevice)
 {
   chai::ManagedArray<float> array(20);
@@ -1043,7 +1043,7 @@ GPU_TEST(ManagedArray, ResetDevice)
 
 
 #if defined(CHAI_ENABLE_CUDA) || defined(CHAI_ENABLE_HIP)
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
 GPU_TEST(ManagedArray, UserCallback)
 {
   int num_h2d = 0;
@@ -1427,7 +1427,7 @@ GPU_TEST(ManagedArray, DeviceInitializedNestedArrays)
 
 
 #if defined(CHAI_ENABLE_CUDA) || defined(CHAI_ENABLE_HIP)
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
 GPU_TEST(ManagedArray, Move)
 {
   chai::ManagedArray<float> array(10, chai::GPU);
@@ -1700,7 +1700,7 @@ GPU_TEST(ManagedArray, MoveInnerToDeviceAgain)
   outerArray.free();
   assert_empty_map(true);
 }
-#endif  // CHAI_DISABLE_RM
+#endif  // defined(CHAI_ENABLE_MANAGER)
 #endif  // defined(CHAI_ENABLE_CUDA) || defined(CHAI_ENABLE_HIP)
 
 TEST(ManagedArray, Clone)

diff --git a/tests/unit/array_manager_unit_tests.cpp b/tests/unit/array_manager_unit_tests.cpp
@@ -16,7 +16,7 @@ TEST(ArrayManager, Constructor)
   ASSERT_NE(rm, nullptr);
 }
 
-#ifndef CHAI_DISABLE_RM
+#if defined(CHAI_ENABLE_MANAGER)
 
 TEST(ArrayManager, getPointerMap)
 {
@@ -183,4 +183,4 @@ TEST(ArrayManager, controlGlobalCallback)
   ASSERT_TRUE(callbacksAreOn);
 }
 
-#endif // !CHAI_DISABLE_RM
+#endif // defined(CHAI_ENABLE_MANAGER)