[NFC][SYCL] Change context_impl::getDevices to return devices_range (#19456)

`devices_range` helper was added in
intel/llvm#19405 to facilitate ongoing
refactoring of using more raw ptr/ref to `*_impl` objects.

Also update some of the callsites that can use that instead of more
expensive `get_info<info::context::devices>()`.

Author: aelovikov-intel

sycl/source/detail/context_impl.hpp

@@ -130,9 +130,7 @@ class context_impl : public std::enable_shared_from_this<context_impl> {
   /// \return an instance of raw UR context handle.
   const ur_context_handle_t &getHandleRef() const;
 
-  /// Unlike `get_info<info::context::devices>', this function returns a
-  /// reference.
-  const std::vector<device> &getDevices() const { return MDevices; }
+  devices_range getDevices() const { return MDevices; }
 
   using CachedLibProgramsT =
       std::map<std::pair<DeviceLibExt, ur_device_handle_t>,

sycl/source/detail/device_global_map_entry.cpp

@@ -104,7 +104,7 @@ DeviceGlobalMapEntry::getOrAllocateDeviceGlobalUSM(const context &Context) {
          "USM allocations should not be acquired for device_global with "
          "device_image_scope property.");
   context_impl &CtxImpl = *getSyclObjImpl(Context);
-  device_impl &DevImpl = *getSyclObjImpl(CtxImpl.getDevices().front());
+  device_impl &DevImpl = CtxImpl.getDevices().front();
   std::lock_guard<std::mutex> Lock(MDeviceToUSMPtrMapMutex);
 
   auto DGUSMPtr = MDeviceToUSMPtrMap.find({&DevImpl, &CtxImpl});
@@ -153,9 +153,8 @@ DeviceGlobalMapEntry::getOrAllocateDeviceGlobalUSM(const context &Context) {
 void DeviceGlobalMapEntry::removeAssociatedResources(
     const context_impl *CtxImpl) {
   std::lock_guard<std::mutex> Lock{MDeviceToUSMPtrMapMutex};
-  for (device Device : CtxImpl->getDevices()) {
-    auto USMPtrIt =
-        MDeviceToUSMPtrMap.find({getSyclObjImpl(Device).get(), CtxImpl});
+  for (device_impl &Device : CtxImpl->getDevices()) {
+    auto USMPtrIt = MDeviceToUSMPtrMap.find({&Device, CtxImpl});
     if (USMPtrIt != MDeviceToUSMPtrMap.end()) {
       DeviceGlobalUSMMem &USMMem = USMPtrIt->second;
       detail::usm::freeInternal(USMMem.MPtr, CtxImpl);

sycl/source/detail/helpers.hpp

@@ -102,6 +102,10 @@ template <typename iterator> class iterator_range {
   iterator_range(IterTy Begin, IterTy End, size_t Size)
       : Begin(Begin), End(End), Size(Size) {}
 
+  iterator_range()
+      : iterator_range(static_cast<value_type *>(nullptr),
+                       static_cast<value_type *>(nullptr), 0) {}
+
   template <typename ContainerTy>
   iterator_range(const ContainerTy &Container)
       : iterator_range(Container.begin(), Container.end(), Container.size()) {}

sycl/source/detail/image_impl.cpp

@@ -23,12 +23,11 @@ uint8_t GImageStreamID;
 #endif
 
 template <typename Param>
-static bool checkImageValueRange(const std::vector<device> &Devices,
-                                 const size_t Value) {
-  return Value >= 1 && std::all_of(Devices.cbegin(), Devices.cend(),
-                                   [Value](const device &Dev) {
-                                     return Value <= Dev.get_info<Param>();
-                                   });
+static bool checkImageValueRange(devices_range Devices, const size_t Value) {
+  return Value >= 1 &&
+         std::all_of(Devices.begin(), Devices.end(), [Value](device_impl &Dev) {
+           return Value <= Dev.get_info<Param>();
+         });
 }
 
 template <typename T, typename... Args> static bool checkAnyImpl(T) {
@@ -345,46 +344,47 @@ void *image_impl::allocateMem(context_impl *Context, bool InitFromUserData,
 
 bool image_impl::checkImageDesc(const ur_image_desc_t &Desc,
                                 context_impl *Context, void *UserPtr) {
+  devices_range Devices = Context ? Context->getDevices() : devices_range{};
   if (checkAny(Desc.type, UR_MEM_TYPE_IMAGE1D, UR_MEM_TYPE_IMAGE1D_ARRAY,
                UR_MEM_TYPE_IMAGE2D_ARRAY, UR_MEM_TYPE_IMAGE2D) &&
-      !checkImageValueRange<info::device::image2d_max_width>(
-          getDevices(Context), Desc.width))
+      !checkImageValueRange<info::device::image2d_max_width>(Devices,
+                                                             Desc.width))
     throw exception(make_error_code(errc::invalid),
                     "For a 1D/2D image/image array, the width must be a Value "
                     ">= 1 and <= info::device::image2d_max_width");
 
   if (checkAny(Desc.type, UR_MEM_TYPE_IMAGE3D) &&
-      !checkImageValueRange<info::device::image3d_max_width>(
-          getDevices(Context), Desc.width))
+      !checkImageValueRange<info::device::image3d_max_width>(Devices,
+                                                             Desc.width))
     throw exception(make_error_code(errc::invalid),
                     "For a 3D image, the width must be a Value >= 1 and <= "
                     "info::device::image3d_max_width");
 
   if (checkAny(Desc.type, UR_MEM_TYPE_IMAGE2D, UR_MEM_TYPE_IMAGE2D_ARRAY) &&
-      !checkImageValueRange<info::device::image2d_max_height>(
-          getDevices(Context), Desc.height))
+      !checkImageValueRange<info::device::image2d_max_height>(Devices,
+                                                              Desc.height))
     throw exception(make_error_code(errc::invalid),
                     "For a 2D image or image array, the height must be a Value "
                     ">= 1 and <= info::device::image2d_max_height");
 
   if (checkAny(Desc.type, UR_MEM_TYPE_IMAGE3D) &&
-      !checkImageValueRange<info::device::image3d_max_height>(
-          getDevices(Context), Desc.height))
+      !checkImageValueRange<info::device::image3d_max_height>(Devices,
+                                                              Desc.height))
     throw exception(make_error_code(errc::invalid),
                     "For a 3D image, the heightmust be a Value >= 1 and <= "
                     "info::device::image3d_max_height");
 
   if (checkAny(Desc.type, UR_MEM_TYPE_IMAGE3D) &&
-      !checkImageValueRange<info::device::image3d_max_depth>(
-          getDevices(Context), Desc.depth))
+      !checkImageValueRange<info::device::image3d_max_depth>(Devices,
+                                                             Desc.depth))
     throw exception(make_error_code(errc::invalid),
                     "For a 3D image, the depth must be a Value >= 1 and <= "
                     "info::device::image2d_max_depth");
 
   if (checkAny(Desc.type, UR_MEM_TYPE_IMAGE1D_ARRAY,
                UR_MEM_TYPE_IMAGE2D_ARRAY) &&
-      !checkImageValueRange<info::device::image_max_array_size>(
-          getDevices(Context), Desc.arraySize))
+      !checkImageValueRange<info::device::image_max_array_size>(Devices,
+                                                                Desc.arraySize))
     throw exception(make_error_code(errc::invalid),
                     "For a 1D and 2D image array, the array_size must be a "
                     "Value >= 1 and <= info::device::image_max_array_size.");
@@ -451,12 +451,6 @@ bool image_impl::checkImageFormat(const ur_image_format_t &Format,
   return true;
 }
 
-std::vector<device> image_impl::getDevices(context_impl *Context) {
-  if (!Context)
-    return {};
-  return Context->get_info<info::context::devices>();
-}
-
 void image_impl::sampledImageConstructorNotification(
     const detail::code_location &CodeLoc, void *UserObj, const void *HostObj,
     uint32_t Dim, size_t Range[3], image_format Format,

sycl/source/detail/image_impl.hpp

@@ -35,6 +35,7 @@ class accessor;
 class handler;
 
 namespace detail {
+class devices_range;
 
 // utility functions and typedefs for image_impl
 using image_allocator = aligned_allocator<byte>;
@@ -297,8 +298,6 @@ class image_impl final : public SYCLMemObjT {
   void unsampledImageDestructorNotification(void *UserObj);
 
 private:
-  std::vector<device> getDevices(context_impl *Context);
-
   ur_mem_type_t getImageType() {
     if (MDimensions == 1)
       return (MIsArrayImage ? UR_MEM_TYPE_IMAGE1D_ARRAY : UR_MEM_TYPE_IMAGE1D);

sycl/source/detail/program_manager/program_manager.cpp

@@ -124,10 +124,10 @@ static bool isDeviceBinaryTypeSupported(context_impl &ContextImpl,
   if (ContextBackend == backend::ext_oneapi_cuda)
     return false;
 
-  const std::vector<device> &Devices = ContextImpl.getDevices();
+  devices_range Devices = ContextImpl.getDevices();
 
   // Program type is SPIR-V, so we need a device compiler to do JIT.
-  for (const device &D : Devices) {
+  for (device_impl &D : Devices) {
     if (!D.get_info<info::device::is_compiler_available>())
       return false;
   }
@@ -143,7 +143,7 @@ static bool isDeviceBinaryTypeSupported(context_impl &ContextImpl,
       return true;
   }
 
-  for (const device &D : Devices) {
+  for (device_impl &D : Devices) {
     // We need cl_khr_il_program extension to be present
     // and we can call clCreateProgramWithILKHR using the extension
     std::vector<std::string> Extensions =

sycl/source/detail/scheduler/graph_builder.cpp

@@ -213,10 +213,9 @@ Scheduler::GraphBuilder::getOrInsertMemObjRecord(queue_impl *Queue,
     // which means that there is already an allocation(cl_mem) in some context.
     // Registering this allocation in the SYCL graph.
 
-    std::vector<sycl::device> Devices =
-        InteropCtxPtr->get_info<info::context::devices>();
-    assert(Devices.size() != 0);
-    device_impl &Dev = *detail::getSyclObjImpl(Devices[0]);
+    devices_range Devices = InteropCtxPtr->getDevices();
+    assert(!Devices.empty());
+    device_impl &Dev = Devices.front();
 
     // Since all the Scheduler commands require queue but we have only context
     // here, we need to create a dummy queue bound to the context and one of the
@@ -675,7 +674,7 @@ static bool checkHostUnifiedMemory(context_impl *Ctx) {
   if (Ctx == nullptr)
     return true;
 
-  for (const device &Device : Ctx->getDevices()) {
+  for (device_impl &Device : Ctx->getDevices()) {
     if (!Device.get_info<info::device::host_unified_memory>())
       return false;
   }

sycl/source/detail/usm/usm_impl.cpp

@@ -581,13 +581,13 @@ device get_pointer_device(const void *Ptr, const context &Ctxt) {
 
   // Check if ptr is a host allocation
   if (get_pointer_type(Ptr, Ctxt) == alloc::host) {
-    auto Devs = detail::getSyclObjImpl(Ctxt)->getDevices();
+    detail::devices_range Devs = detail::getSyclObjImpl(Ctxt)->getDevices();
     if (Devs.size() == 0)
       throw exception(make_error_code(errc::invalid),
                       "No devices in passed context!");
 
     // Just return the first device in the context
-    return Devs[0];
+    return detail::createSyclObjFromImpl<device>(Devs.front());
   }
 
   ur_device_handle_t DeviceId;