my_system.cc File Reference

Functions to retrieve system information like total physical memory and total number of logical CPUs adhering to limits set by cgroups. More...

#include <cassert>
#include <cstdint>
#include <optional>
#include <thread>
#include "my_config.h"
#include "my_system_api/my_system_api.h"
#include "mysql/components/library_mysys/my_system.h"
#include <unistd.h>

Namespaces
namespace	anonymous_namespace{my_system.cc}

Functions
bool	anonymous_namespace{my_system.cc}::string_to_bool (const std::string &input)
std::optional< ulonglong >	anonymous_namespace{my_system.cc}::string_to_ull (const std::string &input)
bool	has_container_resource_limits ()
	Determines if container configurations has set resource limits. More...
bool	init_container_aware (const std::string &is_container_aware) noexcept
	Overloaded function for easy use. More...
bool	init_container_aware (const bool is_container_aware) noexcept
	Determine if resource limits set by container must be respected and checks the correctness of the configurations. More...
void	deinit_container_aware () noexcept
	Release internal state and deinitialize container awareness. More...
static uint64_t	total_physical_memory () noexcept
	Get the total physical memory accessible to the server. More...
bool	init_my_physical_memory (const std::string &memory)
	Overloaded function for easy use. More...
bool	init_my_physical_memory (ulonglong memory)
	Initialize the my_physical_memory function using server_memory option. More...
uint64_t	my_physical_memory () noexcept
	Determine the total physical memory available in bytes. More...
uint32_t	my_num_vcpus () noexcept
	Determine the total number of logical CPUs available. More...

Variables
bool *	anonymous_namespace{my_system.cc}::should_use_container_config = nullptr
ulonglong	anonymous_namespace{my_system.cc}::configured_memory {0}

Detailed Description

Functions to retrieve system information like total physical memory and total number of logical CPUs adhering to limits set by cgroups.

Function Documentation

deinit_container_aware()

void deinit_container_aware ( )

noexcept

Release internal state and deinitialize container awareness.

has_container_resource_limits()

bool has_container_resource_limits

(

)

Determines if container configurations has set resource limits.

Returns

true if container configuration resource limits

init_container_aware() [1/2]

bool init_container_aware ( const bool  is_container_aware )

noexcept

Determine if resource limits set by container must be respected and checks the correctness of the configurations.

Initializes internal state with input

Parameters

[in]

is_container_aware

true if container config must be respected

Returns

true if container configurations are correct, false otherwise

init_container_aware() [2/2]

bool init_container_aware ( const std::string &  is_container_aware )

noexcept

Overloaded function for easy use.

Parameters

[in]

is_container_aware

string considered to be true if "ON", false otherwise

Returns

true if container configurations are correct, false otherwise

init_my_physical_memory() [1/2]

bool init_my_physical_memory

(

const std::string &

memory

)

Overloaded function for easy use.

Parameters

[in]

memory

string containing value of server_memory

Returns

true on success, false if input memory value is invalid

init_my_physical_memory() [2/2]

bool init_my_physical_memory

(

ulonglong

memory

)

Initialize the my_physical_memory function using server_memory option.

Parameters

[in]

memory

Value of the server_memory startup option

Note

The input value of 0 indicates no limits, and underlying container/host configuration must be used

Returns

true on success, false if input memory value is invalid

my_num_vcpus()

uint32_t my_num_vcpus ( )

noexcept

Determine the total number of logical CPUs available.

If process is running within a container, the number of logical CPUs is the maximum limit set for the container. If the process is not running in a container then it uses the appropriate system APIs to determine the number of logical CPUs.

If the API is unable to determine the number of logical CPUs, then it returns 0.

Note

: The container set limits are calculated from the CFS quota and period as quota/period and is round down. A limit of 0.5 will return the value 0 and is treated as though no limits are set.

Returns

number of logical CPUs or 0

my_physical_memory()

uint64_t my_physical_memory ( )

noexcept

Determine the total physical memory available in bytes.

If process is running within a container, then memory available is the maximum limit set for the container. If the process is not running in a container then it uses the appropriate system APIs to determine the available memory.

If the API is unable to determine the available memory, then it returns 0.

Returns

physical memory in bytes or 0

total_physical_memory()

static uint64_t total_physical_memory ( )

inlinestaticnoexcept

Get the total physical memory accessible to the server.

Tries to read cgroup limits first. If failed or no limits were found, then tries to read from the system using corresponding system APIs.

Returns

total physical memory available to the server, or 0 on failure