Initalization and Information ============================= .. highlight:: cpp .. index:: gpu::getCudaEnabledDeviceCount gpu::getCudaEnabledDeviceCount ---------------------------------- .. cpp:function:: int gpu::getCudaEnabledDeviceCount() Returns number of CUDA-enabled devices installed. It is to be used before any other GPU functions calls. If OpenCV is compiled without GPU support this function returns 0. .. index:: gpu::setDevice gpu::setDevice ------------------ .. cpp:function:: void gpu::setDevice(int device) Sets device and initializes it for the current thread. Call of this function can be omitted, but in this case a default device will be initialized on fist GPU usage. :param device: index of GPU device in system starting with 0. .. index:: gpu::getDevice gpu::getDevice ------------------ .. cpp:function:: int gpu::getDevice() Returns the current device index, which was set by :cpp:func:`gpu::setDevice` or initialized by default. .. index:: gpu::GpuFeature gpu::GpuFeature --------------- .. c:type:: gpu::GpuFeature GPU compute features. :: enum GpuFeature { COMPUTE_10, COMPUTE_11, COMPUTE_12, COMPUTE_13, COMPUTE_20, COMPUTE_21, ATOMICS, NATIVE_DOUBLE }; .. index:: gpu::DeviceInfo gpu::DeviceInfo --------------- .. cpp:class:: gpu::DeviceInfo This class provides functionality for querying the specified GPU properties. :: class DeviceInfo { public: DeviceInfo(); DeviceInfo(int device_id); string name() const; int majorVersion() const; int minorVersion() const; int multiProcessorCount() const; size_t freeMemory() const; size_t totalMemory() const; bool supports(GpuFeature feature) const; bool isCompatible() const; }; .. index:: gpu::DeviceInfo::DeviceInfo gpu::DeviceInfo::DeviceInfo ------------------------------- .. cpp:function:: gpu::DeviceInfo::DeviceInfo() .. cpp:function:: gpu::DeviceInfo::DeviceInfo(int device_id) Constructs :cpp:class:`gpu::DeviceInfo` object for the specified device. If ``device_id`` parameter is missed it constructs object for the current device. :param device_id: Index of the GPU device in system starting with 0. .. index:: gpu::DeviceInfo::name gpu::DeviceInfo::name ------------------------- .. cpp:function:: string gpu::DeviceInfo::name() Returns the device name. .. index:: gpu::DeviceInfo::majorVersion gpu::DeviceInfo::majorVersion --------------------------------- .. cpp:function:: int gpu::DeviceInfo::majorVersion() Returns the major compute capability version. .. index:: gpu::DeviceInfo::minorVersion gpu::DeviceInfo::minorVersion --------------------------------- .. cpp:function:: int gpu::DeviceInfo::minorVersion() Returns the minor compute capability version. .. index:: gpu::DeviceInfo::multiProcessorCount gpu::DeviceInfo::multiProcessorCount ---------------------------------------- .. cpp:function:: int gpu::DeviceInfo::multiProcessorCount() Returns the number of streaming multiprocessors. .. index:: gpu::DeviceInfo::freeMemory gpu::DeviceInfo::freeMemory ------------------------------- .. cpp:function:: size_t gpu::DeviceInfo::freeMemory() Returns the amount of free memory in bytes. .. index:: gpu::DeviceInfo::totalMemory gpu::DeviceInfo::totalMemory -------------------------------- .. cpp:function:: size_t gpu::DeviceInfo::totalMemory() Returns the amount of total memory in bytes. .. index:: gpu::DeviceInfo::supports gpu::DeviceInfo::supports ----------------------------- .. cpp:function:: bool gpu::DeviceInfo::supports(GpuFeature feature) Returns true if the device has the given GPU feature, otherwise false. :param feature: Feature to be checked. See :c:type:`gpu::GpuFeature`. .. index:: gpu::DeviceInfo::isCompatible gpu::DeviceInfo::isCompatible --------------------------------- .. cpp:function:: bool gpu::DeviceInfo::isCompatible() Returns true if the GPU module can be run on the specified device, otherwise false. .. index:: gpu::TargetArchs gpu::TargetArchs ---------------- .. c:type:: gpu::TargetArchs This class provides functionality (as set of static methods) for checking which NVIDIA card architectures the GPU module was built for. The following method checks whether the module was built with the support of the given feature: .. cpp:function:: static bool gpu::TargetArchs::builtWith(GpuFeature feature) :param feature: Feature to be checked. See :c:type:`gpu::GpuFeature`. There are a set of methods for checking whether the module contains intermediate (PTX) or binary GPU code for the given architecture(s): .. cpp:function:: static bool gpu::TargetArchs::has(int major, int minor) .. cpp:function:: static bool gpu::TargetArchs::hasPtx(int major, int minor) .. cpp:function:: static bool gpu::TargetArchs::hasBin(int major, int minor) .. cpp:function:: static bool gpu::TargetArchs::hasEqualOrLessPtx(int major, int minor) .. cpp:function:: static bool gpu::TargetArchs::hasEqualOrGreater(int major, int minor) .. cpp:function:: static bool gpu::TargetArchs::hasEqualOrGreaterPtx(int major, int minor) .. cpp:function:: static bool gpu::TargetArchs::hasEqualOrGreaterBin(int major, int minor) :param major: Major compute capability version. :param minor: Minor compute capability version. According to the CUDA C Programming Guide Version 3.2: "PTX code produced for some specific compute capability can always be compiled to binary code of greater or equal compute capability". .. index:: gpu::MultiGpuManager gpu::MultiGpuManager -------------------- .. c:type:: gpu::MultiGpuManager Provides functionality for working with many GPUs. :: class MultiGpuManager { public: MultiGpuManager(); ~MultiGpuManager(); // Must be called before any other GPU calls void init(); // Makes the given GPU active void gpuOn(int gpu_id); // Finishes the piece of work on the current GPU void gpuOff(); static const int BAD_GPU_ID; }; .. index:: gpu::MultiGpuManager::MultiGpuManager gpu::MultiGpuManager::MultiGpuManager ---------------------------------------- .. cpp:function:: gpu::MultiGpuManager::MultiGpuManager() Creates multi GPU manager, but doesn't initialize it. .. index:: gpu::MultiGpuManager::~MultiGpuManager gpu::MultiGpuManager::~MultiGpuManager ---------------------------------------- .. cpp:function:: gpu::MultiGpuManager::~MultiGpuManager() Releases multi GPU manager. .. index:: gpu::MultiGpuManager::init gpu::MultiGpuManager::init ---------------------------------------- .. cpp:function:: void gpu::MultiGpuManager::init() Initializes multi GPU manager. .. index:: gpu::MultiGpuManager::gpuOn gpu::MultiGpuManager::gpuOn ---------------------------------------- .. cpp:function:: void gpu::MultiGpuManager::gpuOn(int gpu_id) Makes the given GPU active. :param gpu_id: Index of the GPU device in system starting with 0. .. index:: gpu::MultiGpuManager::gpuOff gpu::MultiGpuManager::gpuOff ---------------------------------------- .. cpp:function:: void gpu::MultiGpuManager::gpuOff() Finishes the piece of work on the current GPU.