Class ARMPrintf

  • public final class ARMPrintf
    extends java.lang.Object
    Native bindings to the arm_printf extension.

    This extension enables the device side printf built in function for OpenCL C versions prior to 1.2. It also extends the cl_context_properties enumeration to allow a user defined printf callback and/or printf buffer size.

    The printf built in function should be used for debugging purposes only and may have a significant negative impact on the performance of an OpenCL application.

    • Field Detail


        public static final int CL_PRINTF_CALLBACK_ARM
        Accepted by the properties argument to CreateContext.

        Property value: void printf_callback(const char *buffer, size_t len, size_t complete, void *user_data)

        Specifies a pointer to function to be invoked when printf data is available. Upon invocation the arguments are set to the following values.

        • buffer is a pointer to a character array of size len created by printf.
        • len is the number of new characters in buffer.
        • complete is set to a non zero value if there is no more data in the device's printf buffer.
        • user_data is the user_data parameter specified to CreateContext.

        If this property is not specified, no callback will be registered and any printf output from a kernel will be discarded.

        See Also:
        Constant Field Values

        public static final int CL_PRINTF_BUFFERSIZE_ARM
        Accepted by the properties argument to CreateContext.

        Property value: size_t

        Specifies the size of printf buffer allocations to use within the driver. A printf buffer is allocated per device per context, within a context the buffer will be shared between kernels executing on a device. The implementation is free to round up or ignore this value.

        If this property is not specified an implementation defined default size will be chosen. For OpenCL driver versions prior to OpenCL 1.2 this value will be 1 MiB. For driver versions of OpenCL 1.2 or greater this value is defined by the DEVICE_PRINTF_BUFFER_SIZE parameter name for GetDeviceInfo.

        See Also:
        Constant Field Values