Miscellaneous utilities. More...

#include <util.h>

Classes
struct	os
	OS dedicated utilities. More...

Static Public Member Functions
static handle_type	guess_handle (handle_category category) noexcept
	Gets the type of the handle given a category.

static handle_type	guess_handle (file_handle file) noexcept
	Gets the type of the stream to be used with the given descriptor.

static std::vector< cpu_info >	cpu () noexcept
	Gets information about the CPUs on the system.

static std::vector< interface_address >	interface_addresses () noexcept
	Gets a set of descriptors of all the available interfaces.

static std::string	index_to_name (unsigned int index) noexcept
	IPv6-capable implementation of if_indextoname.

static std::string	index_to_iid (unsigned int index) noexcept
	Retrieves a network interface identifier.

static bool	replace_allocator (malloc_func_type malloc_func, realloc_func_type realloc_func, calloc_func_type calloc_func, free_func_type free_func) noexcept
	Override the use of some standard library’s functions.

static std::array< double, 3 >	load_average () noexcept
	Gets the load average.

static char **	setup_args (int argc, char **argv)
	Store the program arguments.

static std::string	process_title ()
	Gets the title of the current process.

static bool	process_title (const std::string &title)
	Sets the current process title.

static uint64_t	total_memory () noexcept
	Gets memory information (in bytes).

static uint64_t	constrained_memory () noexcept
	Gets the amount of memory available to the process (in bytes).

static uint64_t	available_memory () noexcept
	Gets the amount of free memory still available to the process.

static double	uptime () noexcept
	Gets the current system uptime.

static resource_usage	rusage () noexcept
	Gets the resource usage measures for the current process.

static timespec64	gettime (clock_id source) noexcept
	Gets the current system time from a high-resolution clock source.

static uint64_t	hrtime () noexcept
	Gets the current high-resolution real time.

static std::string	path () noexcept
	Gets the executable path.

static std::string	cwd () noexcept
	Gets the current working directory.

static bool	chdir (const std::string &dir) noexcept
	Changes the current working directory.

static timeval64	time_of_day () noexcept
	Cross-platform implementation of `gettimeofday`

static void	sleep (unsigned int msec) noexcept
	Causes the calling thread to sleep for a while.

static unsigned int	available_parallelism () noexcept
	Returns an estimate of the amount of parallelism a program should use (always a non-zero value).

Detailed Description

Miscellaneous utilities.

Miscellaneous functions that don’t really belong to any other class.

Definition at line 288 of file util.h.

Member Function Documentation

◆ available_memory()

static uint64_t uvw::utilities::available_memory ( )

staticnoexcept

Gets the amount of free memory still available to the process.

Returns: Amount of free memory still available to the process (in bytes).

◆ available_parallelism()

static unsigned int uvw::utilities::available_parallelism ( )

staticnoexcept

Returns an estimate of the amount of parallelism a program should use (always a non-zero value).

Returns: Estimate of the amount of parallelism a program should use.

◆ chdir()

static bool uvw::utilities::chdir ( const std::string & dir )

staticnoexcept

Changes the current working directory.

Parameters

dir	The working directory to be set.

Returns: True in case of success, false otherwise.

◆ constrained_memory()

static uint64_t uvw::utilities::constrained_memory ( )

staticnoexcept

Gets the amount of memory available to the process (in bytes).

Gets the amount of memory available to the process based on limits imposed by the OS. If there is no such constraint, or the constraint is unknown, 0 is returned.
Note that it is not unusual for this value to be less than or greater than totalMemory.

Returns: Amount of memory available to the process.

◆ cpu()

static std::vector< cpu_info > uvw::utilities::cpu ( )

staticnoexcept

Gets information about the CPUs on the system.

This function can be used to query the underlying system and get a set of descriptors of all the available CPUs.

Returns: A set of descriptors of all the available CPUs.

◆ cwd()

static std::string uvw::utilities::cwd ( )

staticnoexcept

Gets the current working directory.

Returns: The current working directory, an empty string in case of errors.

◆ gettime()

static timespec64 uvw::utilities::gettime ( clock_id source )

staticnoexcept

Gets the current system time from a high-resolution clock source.

Parameters

source Clock source, either real-time or monotonic.

Returns: Current system time from the given high-resolution clock source.

◆ guess_handle() [1/2]

static handle_type uvw::utilities::guess_handle ( file_handle file )

staticnoexcept

Gets the type of the stream to be used with the given descriptor.

Returns the type of stream that should be used with a given file descriptor.
Usually this will be used during initialization to guess the type of the stdio streams.

Parameters

file	A valid descriptor.

Returns: One of the following types:

handle_type::UNKNOWN
handle_type::PIPE
handle_type::TCP
handle_type::TTY
handle_type::UDP
handle_type::FILE

◆ guess_handle() [2/2]

static handle_type uvw::utilities::guess_handle ( handle_category category )

staticnoexcept

Gets the type of the handle given a category.

Parameters

category A properly initialized handle category.

Returns: The actual type of the handle as defined by handle_type

◆ hrtime()

static uint64_t uvw::utilities::hrtime ( )

staticnoexcept

Gets the current high-resolution real time.

The time is expressed in nanoseconds. It is relative to an arbitrary time in the past. It is not related to the time of the day and therefore not subject to clock drift. The primary use is for measuring performance between interval.

Returns: The current high-resolution real time.

◆ index_to_iid()

static std::string uvw::utilities::index_to_iid ( unsigned int index )

staticnoexcept

Retrieves a network interface identifier.

See the official documentation for further details.

Parameters

index Network interface index.

Returns: Network interface identifier.

◆ index_to_name()

static std::string uvw::utilities::index_to_name ( unsigned int index )

staticnoexcept

IPv6-capable implementation of if_indextoname.

Mapping between network interface names and indexes.

See the official documentation for further details.

Parameters

index Network interface index.

Returns: Network interface name.

◆ interface_addresses()

static std::vector< interface_address > uvw::utilities::interface_addresses ( )

staticnoexcept

Gets a set of descriptors of all the available interfaces.

This function can be used to query the underlying system and get a set of descriptors of all the available interfaces, either internal or not.

Returns: A set of descriptors of all the available interfaces.

◆ load_average()

static std::array< double, 3 > uvw::utilities::load_average ( )

staticnoexcept

Gets the load average.

Returns: [0,0,0] on Windows (not available), the load average otherwise.

◆ path()

static std::string uvw::utilities::path ( )

staticnoexcept

Gets the executable path.

Returns: The executable path, an empty string in case of errors.

◆ process_title() [1/2]

static std::string uvw::utilities::process_title ( )

static

Gets the title of the current process.

Returns: The process title.

◆ process_title() [2/2]

static bool uvw::utilities::process_title ( const std::string & title )

static

Sets the current process title.

Parameters

title The process title to be set.

Returns: True in case of success, false otherwise.

◆ replace_allocator()

static bool uvw::utilities::replace_allocator	(	malloc_func_type	malloc_func,
		realloc_func_type	realloc_func,
		calloc_func_type	calloc_func,
		free_func_type	free_func
	)

staticnoexcept

Override the use of some standard library’s functions.

Override the use of the standard library’s memory allocation functions.
This method must be invoked before any other uvw function is called or after all resources have been freed and thus the underlying library doesn’t reference any allocated memory chunk.

If any of the function pointers is null, the invokation will fail.

Note: There is no protection against changing the allocator multiple times. If the user changes it they are responsible for making sure the allocator is changed while no memory was allocated with the previous allocator, or that they are compatible.

Parameters

malloc_func	Replacement function for malloc.
realloc_func	Replacement function for realloc.
calloc_func	Replacement function for calloc.
free_func	Replacement function for free.

Returns: True in case of success, false otherwise.

◆ rusage()

static resource_usage uvw::utilities::rusage ( )

staticnoexcept

Gets the resource usage measures for the current process.

Returns: Resource usage measures, zeroes-filled object in case of errors.

◆ setup_args()

static char ** uvw::utilities::setup_args	(	int	argc,
		char **	argv
	)

static

Store the program arguments.

Required for getting / setting the process title.

Returns: Arguments that haven't been consumed internally.

◆ sleep()

static void uvw::utilities::sleep ( unsigned int msec )

staticnoexcept

Causes the calling thread to sleep for a while.

Parameters

msec	Number of milliseconds to sleep.

◆ time_of_day()

static timeval64 uvw::utilities::time_of_day ( )

staticnoexcept

Cross-platform implementation of gettimeofday

Returns: The current time.

◆ total_memory()

static uint64_t uvw::utilities::total_memory ( )

staticnoexcept

Gets memory information (in bytes).

Returns: Memory information.

◆ uptime()

static double uvw::utilities::uptime ( )

staticnoexcept

Gets the current system uptime.

Returns: The current system uptime or 0 in case of errors.

The documentation for this struct was generated from the following file:

src/uvw/util.h

Classes

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ available_memory()

◆ available_parallelism()

◆ chdir()

◆ constrained_memory()

◆ cpu()

◆ cwd()

◆ gettime()

◆ guess_handle() [1/2]

◆ guess_handle() [2/2]

◆ hrtime()

◆ index_to_iid()

◆ index_to_name()

◆ interface_addresses()

◆ load_average()

◆ path()

◆ process_title() [1/2]

◆ process_title() [2/2]

◆ replace_allocator()

◆ rusage()

◆ setup_args()

◆ sleep()

◆ time_of_day()

◆ total_memory()

◆ uptime()