Abstraction layer for process management and multi-threading. More...

Classes
class	BasicSpinLockArray
	An array of light-weight synchronisation primitives (spinlocks). More...

Typedefs
typedef std::atomic_flag	spinlock
	A lightweight synchronization structure.

Functions
void	initialize (int flags)
	Initializes GeogramLib.

void	terminate ()
	Terminates GeogramLib.

void	sleep (index_t microseconds)
	Sleeps for a period of time.

void	show_stats ()
	Displays statistics about the current process.

void	brute_force_kill ()
	Terminates the current process.

index_t	maximum_concurrent_threads ()
	Returns the maximum number of threads that can be running simultaneously.

void	run_threads (ThreadGroup &threads)
	Runs a set of threads simultaneously.

index_t	number_of_cores ()
	Gets the number of available cores.

void	set_thread_manager (ThreadManager *thread_manager)
	Sets the thread manager (internal use).

bool	is_running_threads ()
	Checks whether threads are running.

void	enable_FPE (bool flag)
	Enables/disables floating point exceptions.

bool	FPE_enabled ()
	Gets the status of floating point exceptions.

void	enable_multithreading (bool flag)
	Enables/disables multi-threaded computations Multi-threading can also be configured by setting the value of the property "sys:multithread" with Environment::set_value().

bool	multithreading_enabled ()
	Gets the status of multi-threading.

void	set_max_threads (index_t num_threads)
	Limits the number of concurrent threads to use.

index_t	max_threads ()
	Gets the number of allowed concurrent threads.

void	enable_cancel (bool flag)
	Enables interruption of cancelable tasks.

bool	cancel_enabled ()
	Gets the status of the cancel mode.

size_t	used_memory ()
	Gets the currently used memory.

size_t	max_used_memory ()
	Gets the maximum used memory.

std::string	executable_filename ()
	Gets the full path to the currently running program.

void	print_stack_trace ()
	Prints a stack trace to the standard error.

bool	os_init_threads ()

index_t	os_number_of_cores ()

size_t	os_used_memory ()

size_t	os_max_used_memory ()

bool	os_enable_FPE (bool flag)

bool	os_enable_cancel (bool flag)

void	os_install_signal_handlers ()

std::string	os_executable_filename ()

void	os_brute_force_kill ()

void	os_print_stack_trace ()

void	acquire_spinlock (volatile spinlock &x)
	Loops until `x` is available then reserves it.

void	release_spinlock (volatile spinlock &x)
	Makes `x` available to other threads.

Detailed Description

Abstraction layer for process management and multi-threading.

Typedef Documentation

◆ spinlock

typedef std::atomic_flag GEO::Process::spinlock

A lightweight synchronization structure.

See

Definition at line 149 of file thread_sync.h.

Function Documentation

◆ acquire_spinlock()

void GEO::Process::acquire_spinlock ( volatile spinlock & x )

inline

Loops until x is available then reserves it.

Parameters

[in] x a spinlock

Definition at line 155 of file thread_sync.h.

◆ cancel_enabled()

bool GEO::Process::cancel_enabled ( )

protected

Gets the status of the cancel mode.

Return values

true	if the cancel mode is enabled
false	otherwise

See also: enable_cancel()

◆ enable_cancel()

void GEO::Process::enable_cancel ( bool flag )

protected

Enables interruption of cancelable tasks.

This allows to interrupt cancelable tasks by typing CTRL-C in the terminal. This sets a specific handler on the interrupt signal that calls Progress::cancel() is there is a running cancelable task. If no task is running, the program is interrupted. The cancel mode can also be configured by setting the value of the property "sys:cancel" with Environment::set_value().

Parameters

[in] flag set to true to enable cancel mode, false to disable.

See also: cancel_enabled()

◆ enable_FPE()

void GEO::Process::enable_FPE ( bool flag )

protected

Enables/disables floating point exceptions.

If FPEs are enabled, then floating point exceptions raise a SIGFPE signal, otherwise they generate NaNs. FPEs can also be configured by setting the value of the property "sys:FPE" with Environment::set_value().

Parameters

[in] flag set to true to enable FPEs, false to disable.

See also: FPE_enabled()

◆ enable_multithreading()

void GEO::Process::enable_multithreading ( bool flag )

protected

Enables/disables multi-threaded computations Multi-threading can also be configured by setting the value of the property "sys:multithread" with Environment::set_value().

Parameters

[in] flag set to true to enable multi-threading, false to disable.

See also: multithreading_enabled()

◆ FPE_enabled()

bool GEO::Process::FPE_enabled ( )

protected

Gets the status of floating point exceptions.

Return values

true	if FPE are enabled
false	otherwise

See also: enable_FPE()

◆ initialize()

void GEO::Process::initialize ( int flags )

protected

Initializes GeogramLib.

Parameters

[in] flags the flags passed to GEO::initialize()

This function must be called once before using any functionality of GeogramLib.

◆ is_running_threads()

bool GEO::Process::is_running_threads ( )

protected

Checks whether threads are running.

Return values

true	if concurrent threads are currently running as an effect to Process::run_threads().
false	otherwise.

See also: Process::run_threads()

◆ max_threads()

index_t GEO::Process::max_threads ( )

protected

Gets the number of allowed concurrent threads.

See also: set_max_threads()

◆ max_used_memory()

size_t GEO::Process::max_used_memory ( )

protected

Gets the maximum used memory.

Returns: the maximum used memory in bytes

◆ maximum_concurrent_threads()

index_t GEO::Process::maximum_concurrent_threads ( )

protected

Returns the maximum number of threads that can be running simultaneously.

Return values

The	number of cores if multi-threading is supported
1	otherwise.

◆ multithreading_enabled()

bool GEO::Process::multithreading_enabled ( )

protected

Gets the status of multi-threading.

Return values

true	if multi-threading is enabled
false	otherwise

See also: enable_multithreading()

◆ number_of_cores()

index_t GEO::Process::number_of_cores ( )

protected

Gets the number of available cores.

Returns: The number of available cores including the "virtual ones" if hyper-threading is activated.

◆ release_spinlock()

void GEO::Process::release_spinlock ( volatile spinlock & x )

inline

Makes x available to other threads.

Parameters

[in] x a spinlock

Definition at line 173 of file thread_sync.h.

◆ run_threads()

void GEO::Process::run_threads ( ThreadGroup & threads )

protected

Runs a set of threads simultaneously.

Launches the execution of the threads contained in the vector threads and waits for the completion of all of them.

◆ set_max_threads()

void GEO::Process::set_max_threads ( index_t num_threads )

protected

Limits the number of concurrent threads to use.

The number of threads can also be configured by setting the value of the property "sys:max_threads" with Environment::set_value().

Parameters

[in] num_threads maximum number of threads to use.

See also: max_threads()

◆ set_thread_manager()

void GEO::Process::set_thread_manager ( ThreadManager * thread_manager )

protected

Sets the thread manager (internal use).

This sets the ThreadManager to use for concurrent thread execution. This function is called internally by Process::initialize() and should not be called explicitly.

Note: For internal use only

◆ show_stats()

void GEO::Process::show_stats ( )

protected

Displays statistics about the current process.

Displays the maximum used amount of memory.

◆ sleep()

void GEO::Process::sleep ( index_t microseconds )

protected

Sleeps for a period of time.

Parameters

[in] microseconds the time to sleep, in microseconds.

◆ terminate()

void GEO::Process::terminate ( )

protected

Terminates GeogramLib.

This function is called automatically when the program exits, so it should never be called directly.

◆ used_memory()

size_t GEO::Process::used_memory ( )

protected

Gets the currently used memory.

Returns: the used memory in bytes

Classes

Typedefs

Functions

Detailed Description

Typedef Documentation

◆ spinlock

Function Documentation

◆ acquire_spinlock()

◆ cancel_enabled()

◆ enable_cancel()

◆ enable_FPE()

◆ enable_multithreading()

◆ FPE_enabled()

◆ initialize()

◆ is_running_threads()

◆ max_threads()

◆ max_used_memory()

◆ maximum_concurrent_threads()

◆ multithreading_enabled()

◆ number_of_cores()

◆ release_spinlock()

◆ run_threads()

◆ set_max_threads()

◆ set_thread_manager()

◆ show_stats()

◆ sleep()

◆ terminate()

◆ used_memory()