generic.h File Reference

Generic (General support functionalities) More...

#include "host.h"
#include "random.h"
#include <stdlib.h>
#include <stddef.h>
#include <time.h>
#include <assert.h>

Macros
#define	VL_VERSION_STRING   "0.9.17"
	Library version string.
#define	VL_ERR_MSG_LEN   1024
	Maximum length (in characters) of an error message.
Common operations
#define	VL_MIN(x, y)   (((x)<(y))?(x):(y))
	Compute the minimum between two values.
#define	VL_MAX(x, y)   (((x)>(y))?(x):(y))
	Compute the maximum between two values.
#define	VL_SHIFT_LEFT(x, n)   (((n)>=0)?((x)<<(n)):((x)>>-(n)))
	Signed left shift operation.

Functions
char const *	vl_get_version_string (void)
	Get VLFeat version string.
char *	vl_configuration_to_string_copy (void)
	Get VLFeat configuration string.
void	vl_set_simd_enabled (vl_bool x)
	Toggle usage of SIMD instructions.
vl_bool	vl_get_simd_enabled (void)
	Are SIMD instructons enabled?
vl_bool	vl_cpu_has_avx (void)
	Check for AVX instruction set.
vl_bool	vl_cpu_has_sse3 (void)
	Check for SSE3 instruction set.
vl_bool	vl_cpu_has_sse2 (void)
	Check for SSE2 instruction set.
vl_size	vl_get_num_cpus (void)
	Get the number of CPU cores of the host.
vl_size	vl_get_max_threads (void)
	Get the maximum number of computational threads.
void	vl_set_num_threads (vl_size n)
	Set the number of threads targeted for parallel computations.
VlRand *	vl_get_rand (void)
	Get the default random number generator.
Memory allocation
void	vl_set_alloc_func (void *(*malloc_func)(size_t), void *(*realloc_func)(void *, size_t), void *(*calloc_func)(size_t, size_t), void(*free_func)(void *))
	Set memory allocation functions.
void *	vl_malloc (size_t n)
	Allocate a memory block.
void *	vl_realloc (void *ptr, size_t n)
	Reallocate a memory block.
void *	vl_calloc (size_t n, size_t size)
	Free and clear a memory block.
void *	vl_memalign (size_t n, size_t size)
void	vl_free (void *ptr)
	Free a memory block.
Measuring time
void	vl_tic (void)
	Reset processor time reference The function resets VLFeat TIC/TOC time reference. There is one such reference per thread.
double	vl_toc (void)
	Get elapsed time since tic.
double	vl_get_cpu_time (void)
	Get processor time.

Type identifiers for atomic data types
#define	VL_TYPE_FLOAT   1
#define	VL_TYPE_DOUBLE   2
#define	VL_TYPE_INT8   3
#define	VL_TYPE_UINT8   4
#define	VL_TYPE_INT16   5
#define	VL_TYPE_UINT16   6
#define	VL_TYPE_INT32   7
#define	VL_TYPE_UINT32   8
#define	VL_TYPE_INT64   9
#define	VL_TYPE_UINT64   10
typedef vl_uint32	vl_type
char const *	vl_get_type_name (vl_type type)
	Get the name of a data type.
vl_size	vl_get_type_size (vl_type type)
	Get data type size.

Error handling
#define	VL_ERR_OK   0
#define	VL_ERR_OVERFLOW   1
#define	VL_ERR_ALLOC   2
#define	VL_ERR_BAD_ARG   3
#define	VL_ERR_IO   4
#define	VL_ERR_EOF   5
#define	VL_ERR_NO_MORE   5
int	vl_get_last_error (void)
	Get the code of the last error.
char const *	vl_get_last_error_message (void)
	Get the last error message.
int	vl_set_last_error (int error, char const *errorMessage,...)
	Set last VLFeat error.

Logging
#define	VL_PRINTF   (*vl_get_printf_func())
	Call user-customizable printf function.
#define	VL_PRINT   (*vl_get_printf_func())
	Same as VL_PRINTF (legacy code)
typedef int(*	printf_func_t )(char const *format,...)
	Customizable printf function pointer type.
void	vl_set_printf_func (printf_func_t printf_func)
	Set the printf function.
printf_func_t	vl_get_printf_func (void)
	Get the printf function.

---

Detailed Description

Author:

Andrea Vedaldi

---

Macro Definition Documentation

#define VL_ERR_ALLOC   2

Resource allocation error

#define VL_ERR_BAD_ARG   3

Bad argument or illegal data error

#define VL_ERR_EOF   5

End-of-file or end-of-sequence error

#define VL_ERR_IO   4

Input/output error

#define VL_ERR_NO_MORE   5

End-of-sequence

Deprecated:

#define VL_ERR_OK   0

No error

#define VL_ERR_OVERFLOW   1

Buffer overflow error

#define VL_MAX	(		x,
			y
	)		(((x)>(y))?(x):(y))

Parameters:

x	value.
y	value.

Returns:

the maximum of x and y.

#define VL_MIN	(		x,
			y
	)		(((x)<(y))?(x):(y))

Parameters:

x	value
y	value

Returns:

the minimum of x and y.

#define VL_PRINTF   (*vl_get_printf_func())

The function calls the user customizable printf.

#define VL_SHIFT_LEFT	(		x,
			n
	)		(((n)>=0)?((x)<<(n)):((x)>>-(n)))

Parameters:

x	value.
n	number of shift positions.

Returns:

x << n . The macro is equivalent to the builtin << operator, but it supports negative shifts too.

#define VL_TYPE_DOUBLE   2

double type

#define VL_TYPE_FLOAT   1

float type

#define VL_TYPE_INT16   5

vl_int16 type

#define VL_TYPE_INT32   7

vl_int32 type

#define VL_TYPE_INT64   9

vl_int64 type

#define VL_TYPE_INT8   3

vl_int8 type

#define VL_TYPE_UINT16   6

vl_uint16 type

#define VL_TYPE_UINT32   8

vl_uint32 type

#define VL_TYPE_UINT64   10

vl_uint64 type

#define VL_TYPE_UINT8   4

vl_uint8 type

---

Function Documentation

void* vl_calloc	(	size_t	n,
		size_t	size
	)

Parameters:

n	number of items to allocate.
size	size in bytes of an item.

Returns:

pointer to the new block.

This function allocates and clears a memory block. The synopsis is the same as the POSIX calloc function.

char* vl_configuration_to_string_copy

(

void

)

Returns:

a new configuration string.

The function returns a new string containing a human readable description of the library configuration.

vl_bool vl_cpu_has_avx

(

void

)

Returns:

true if AVX is present.

vl_bool vl_cpu_has_sse2

(

void

)

Returns:

true if SSE2 is present.

vl_bool vl_cpu_has_sse3

(

void

)

Returns:

true if SSE3 is present.

void vl_free

(

void *

ptr

)

Parameters:

ptr	pointer to the memory block.

This function frees a memory block allocated by vl_malloc, vl_calloc, or vl_realloc. The synopsis is the same as the POSIX malloc function.

double vl_get_cpu_time

(

void

)

Returns:

processor time in seconds.

See also:

vl_tic, vl_toc

int vl_get_last_error

(

void

)

Returns:

error code.

See also:

vl_get_last_error_message.

char const* vl_get_last_error_message

(

void

)

Returns:

pointer to the error message.

See also:

vl_get_last_error.

vl_size vl_get_max_threads

(

void

)

Returns:

number of threads.

See also:

vl_set_num_threads(), Parallel computations

vl_size vl_get_num_cpus

(

void

)

Returns:

number of CPU cores.

printf_func_t vl_get_printf_func

(

void

)

Returns:

printf_func pointer to the printf implementation.

See also:

vl_set_printf_func.

VlRand* vl_get_rand

(

void

)

Returns:

random number generator.

The function returns a pointer to the default random number genrator. There is one such generator per thread.

vl_bool vl_get_simd_enabled

(

void

)

Returns:

true if SIMD instructions are enabled.

char const* vl_get_type_name ( vl_type  type )

inline

Parameters:

type	data type.

Returns:

data name of the data type.

type is one of VL_TYPE_FLOAT, VL_TYPE_DOUBLE, VL_TYPE_INT8, VL_TYPE_INT16, VL_TYPE_INT32, VL_TYPE_INT64, VL_TYPE_UINT8, VL_TYPE_UINT16, VL_TYPE_UINT32, VL_TYPE_UINT64.

vl_size vl_get_type_size ( vl_type  type )

inline

Parameters:

type	data type.

Returns:

size (in byte)

type is one of VL_TYPE_FLOAT, VL_TYPE_DOUBLE, VL_TYPE_INT8, VL_TYPE_INT16, VL_TYPE_INT32, VL_TYPE_INT64, VL_TYPE_UINT8, VL_TYPE_UINT16, VL_TYPE_UINT32, VL_TYPE_UINT64.

char const* vl_get_version_string

(

void

)

Returns:

the library version string.

void* vl_malloc

(

size_t

n

)

Parameters:

n	size in bytes of the new block.

Returns:

pointer to the allocated block.

This function allocates a memory block of the specified size. The synopsis is the same as the POSIX malloc function.

void* vl_realloc	(	void *	ptr,
		size_t	n
	)

Parameters:

ptr	pointer to a memory block previously allocated.
n	size in bytes of the new block.

Returns:

pointer to the new block.

This function reallocates a memory block to change its size. The synopsis is the same as the POSIX realloc function.

void vl_set_alloc_func	(	void *(*)(size_t)	malloc_func,
		void *(*)(void *, size_t)	realloc_func,
		void *(*)(size_t, size_t)	calloc_func,
		void(*)(void *)	free_func
	)

Parameters:

malloc_func	pointer to malloc.
realloc_func	pointer to realloc.
calloc_func	pointer to calloc.
free_func	pointer to free.

int vl_set_last_error	(	int	error,
		char const *	errorMessage,
			...
	)

Parameters:

error	error code.
errorMessage	error message format string.
...	format string arguments.

Returns:

error code.

The function sets the code and optionally the error message of the last encountered error. errorMessage is the message format. It uses the printf convention and is followed by the format arguments. The maximum lenght of the error message is given by VL_ERR_MSG_LEN (longer messages are truncated).

Passing NULL as errorMessage sets the error message to the empty string.

void vl_set_num_threads

(

vl_size

numThreads

)

Parameters:

numThreads

number of threads to use.

See also:

vl_get_max_threads(), Parallel computations

void vl_set_printf_func

(

printf_func_t

printf_func

)

Parameters:

printf_func

pointer to a printf implementation. Set print_func to NULL to disable printf.

void vl_set_simd_enabled

(

vl_bool

x

)

Parameters:

x	true if SIMD instructions are used.

Notice that SIMD instructions are used only if the CPU model supports them. Note alsoc that data alignment may restrict the use of such instructions.

See also:

vl_cpu_has_sse2(), vl_cpu_has_sse3(), etc.

void vl_tic

(

void

)

See also:

vl_get_cpu_time, vl_toc.

double vl_toc

(

void

)

Returns:

elapsed time in seconds.

The function returns the processor time elapsed since vl_tic was called last.

Remarks:

In multi-threaded applications, there is an independent timer for each execution thread.

On UNIX, this function uses the clock() system call. On Windows, it uses the QueryPerformanceCounter() system call, which is more accurate than clock() on this platform.