opencv/modules/gpu/doc/initalization_and_information.rst
2013-06-10 15:52:01 +04:00

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Initalization and Information
=============================
.. highlight:: cpp
gpu::getCudaEnabledDeviceCount
------------------------------
Returns the number of installed CUDA-enabled devices.
.. ocv:function:: int gpu::getCudaEnabledDeviceCount()
Use this function before any other GPU functions calls. If OpenCV is compiled without GPU support, this function returns 0.
gpu::setDevice
--------------
Sets a device and initializes it for the current thread.
.. ocv:function:: void gpu::setDevice(int device)
:param device: System index of a GPU device starting with 0.
If the call of this function is omitted, a default device is initialized at the fist GPU usage.
gpu::getDevice
--------------
Returns the current device index set by :ocv:func:`gpu::setDevice` or initialized by default.
.. ocv:function:: int gpu::getDevice()
gpu::resetDevice
----------------
Explicitly destroys and cleans up all resources associated with the current device in the current process.
.. ocv:function:: void gpu::resetDevice()
Any subsequent API call to this device will reinitialize the device.
gpu::FeatureSet
---------------
Enumeration providing GPU computing features.
.. ocv:enum:: gpu::FeatureSet
.. ocv:emember:: FEATURE_SET_COMPUTE_10
.. ocv:emember:: FEATURE_SET_COMPUTE_11
.. ocv:emember:: FEATURE_SET_COMPUTE_12
.. ocv:emember:: FEATURE_SET_COMPUTE_13
.. ocv:emember:: FEATURE_SET_COMPUTE_20
.. ocv:emember:: FEATURE_SET_COMPUTE_21
.. ocv:emember:: GLOBAL_ATOMICS
.. ocv:emember:: SHARED_ATOMICS
.. ocv:emember:: NATIVE_DOUBLE
gpu::TargetArchs
----------------
.. ocv:class:: gpu::TargetArchs
Class providing a set of static methods to check what NVIDIA* card architecture the GPU module was built for.
The following method checks whether the module was built with the support of the given feature:
.. ocv:function:: static bool gpu::TargetArchs::builtWith( FeatureSet feature_set )
:param feature_set: Features to be checked. See :ocv:enum:`gpu::FeatureSet`.
There is a set of methods to check whether the module contains intermediate (PTX) or binary GPU code for the given architecture(s):
.. ocv:function:: static bool gpu::TargetArchs::has(int major, int minor)
.. ocv:function:: static bool gpu::TargetArchs::hasPtx(int major, int minor)
.. ocv:function:: static bool gpu::TargetArchs::hasBin(int major, int minor)
.. ocv:function:: static bool gpu::TargetArchs::hasEqualOrLessPtx(int major, int minor)
.. ocv:function:: static bool gpu::TargetArchs::hasEqualOrGreater(int major, int minor)
.. ocv:function:: static bool gpu::TargetArchs::hasEqualOrGreaterPtx(int major, int minor)
.. ocv: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".
gpu::DeviceInfo
---------------
.. ocv:class:: gpu::DeviceInfo
Class providing functionality for querying the specified GPU properties. ::
class CV_EXPORTS DeviceInfo
{
public:
//! creates DeviceInfo object for the current GPU
DeviceInfo();
//! creates DeviceInfo object for the given GPU
DeviceInfo(int device_id);
//! ASCII string identifying device
const char* name() const;
//! global memory available on device in bytes
size_t totalGlobalMem() const;
//! shared memory available per block in bytes
size_t sharedMemPerBlock() const;
//! 32-bit registers available per block
int regsPerBlock() const;
//! warp size in threads
int warpSize() const;
//! maximum pitch in bytes allowed by memory copies
size_t memPitch() const;
//! maximum number of threads per block
int maxThreadsPerBlock() const;
//! maximum size of each dimension of a block
Vec3i maxThreadsDim() const;
//! maximum size of each dimension of a grid
Vec3i maxGridSize() const;
//! clock frequency in kilohertz
int clockRate() const;
//! constant memory available on device in bytes
size_t totalConstMem() const;
//! major compute capability
int major() const;
//! minor compute capability
int minor() const;
//! alignment requirement for textures
size_t textureAlignment() const;
//! pitch alignment requirement for texture references bound to pitched memory
size_t texturePitchAlignment() const;
//! number of multiprocessors on device
int multiProcessorCount() const;
//! specified whether there is a run time limit on kernels
bool kernelExecTimeoutEnabled() const;
//! device is integrated as opposed to discrete
bool integrated() const;
//! device can map host memory with cudaHostAlloc/cudaHostGetDevicePointer
bool canMapHostMemory() const;
enum ComputeMode
{
ComputeModeDefault, /**< default compute mode (Multiple threads can use ::cudaSetDevice() with this device) */
ComputeModeExclusive, /**< compute-exclusive-thread mode (Only one thread in one process will be able to use ::cudaSetDevice() with this device) */
ComputeModeProhibited, /**< compute-prohibited mode (No threads can use ::cudaSetDevice() with this device) */
ComputeModeExclusiveProcess /**< compute-exclusive-process mode (Many threads in one process will be able to use ::cudaSetDevice() with this device) */
};
//! compute mode
ComputeMode computeMode() const;
//! maximum 1D texture size
int maxTexture1D() const;
//! maximum 1D mipmapped texture size
int maxTexture1DMipmap() const;
//! maximum size for 1D textures bound to linear memory
int maxTexture1DLinear() const;
//! maximum 2D texture dimensions
Vec2i maxTexture2D() const;
//! maximum 2D mipmapped texture dimensions
Vec2i maxTexture2DMipmap() const;
//! maximum dimensions (width, height, pitch) for 2D textures bound to pitched memory
Vec3i maxTexture2DLinear() const;
//! maximum 2D texture dimensions if texture gather operations have to be performed
Vec2i maxTexture2DGather() const;
//! maximum 3D texture dimensions
Vec3i maxTexture3D() const;
//! maximum Cubemap texture dimensions
int maxTextureCubemap() const;
//! maximum 1D layered texture dimensions
Vec2i maxTexture1DLayered() const;
//! maximum 2D layered texture dimensions
Vec3i maxTexture2DLayered() const;
//! maximum Cubemap layered texture dimensions
Vec2i maxTextureCubemapLayered() const;
//! maximum 1D surface size
int maxSurface1D() const;
//! maximum 2D surface dimensions
Vec2i maxSurface2D() const;
//! maximum 3D surface dimensions
Vec3i maxSurface3D() const;
//! maximum 1D layered surface dimensions
Vec2i maxSurface1DLayered() const;
//! maximum 2D layered surface dimensions
Vec3i maxSurface2DLayered() const;
//! maximum Cubemap surface dimensions
int maxSurfaceCubemap() const;
//! maximum Cubemap layered surface dimensions
Vec2i maxSurfaceCubemapLayered() const;
//! alignment requirements for surfaces
size_t surfaceAlignment() const;
//! device can possibly execute multiple kernels concurrently
bool concurrentKernels() const;
//! device has ECC support enabled
bool ECCEnabled() const;
//! PCI bus ID of the device
int pciBusID() const;
//! PCI device ID of the device
int pciDeviceID() const;
//! PCI domain ID of the device
int pciDomainID() const;
//! true if device is a Tesla device using TCC driver, false otherwise
bool tccDriver() const;
//! number of asynchronous engines
int asyncEngineCount() const;
//! device shares a unified address space with the host
bool unifiedAddressing() const;
//! peak memory clock frequency in kilohertz
int memoryClockRate() const;
//! global memory bus width in bits
int memoryBusWidth() const;
//! size of L2 cache in bytes
int l2CacheSize() const;
//! maximum resident threads per multiprocessor
int maxThreadsPerMultiProcessor() const;
//! gets free and total device memory
void queryMemory(size_t& totalMemory, size_t& freeMemory) const;
size_t freeMemory() const;
size_t totalMemory() const;
//! checks whether device supports the given feature
bool supports(FeatureSet feature_set) const;
//! checks whether the GPU module can be run on the given device
bool isCompatible() const;
};
gpu::DeviceInfo::DeviceInfo
---------------------------
The constructors.
.. ocv:function:: gpu::DeviceInfo::DeviceInfo()
.. ocv:function:: gpu::DeviceInfo::DeviceInfo(int device_id)
:param device_id: System index of the GPU device starting with 0.
Constructs the ``DeviceInfo`` object for the specified device. If ``device_id`` parameter is missed, it constructs an object for the current device.
gpu::DeviceInfo::name
---------------------
Returns the device name.
.. ocv:function:: const char* gpu::DeviceInfo::name() const
gpu::DeviceInfo::major
----------------------
Returns the major compute capability version.
.. ocv:function:: int gpu::DeviceInfo::major()
gpu::DeviceInfo::minor
----------------------
Returns the minor compute capability version.
.. ocv:function:: int gpu::DeviceInfo::minor()
gpu::DeviceInfo::freeMemory
---------------------------
Returns the amount of free memory in bytes.
.. ocv:function:: size_t gpu::DeviceInfo::freeMemory()
gpu::DeviceInfo::totalMemory
----------------------------
Returns the amount of total memory in bytes.
.. ocv:function:: size_t gpu::DeviceInfo::totalMemory()
gpu::DeviceInfo::supports
-------------------------
Provides information on GPU feature support.
.. ocv:function:: bool gpu::DeviceInfo::supports(FeatureSet feature_set) const
:param feature_set: Features to be checked. See :ocv:enum:`gpu::FeatureSet`.
This function returns ``true`` if the device has the specified GPU feature. Otherwise, it returns ``false`` .
gpu::DeviceInfo::isCompatible
-----------------------------
Checks the GPU module and device compatibility.
.. ocv:function:: bool gpu::DeviceInfo::isCompatible()
This function returns ``true`` if the GPU module can be run on the specified device. Otherwise, it returns ``false`` .
gpu::DeviceInfo::deviceID
-------------------------
Returns system index of the GPU device starting with 0.
.. ocv:function:: int gpu::DeviceInfo::deviceID()