TierEngineMutex Class Reference

TierEngine component for ensuring only one instance of autotier runs for a given run path. More...

#include <mutex.hpp>

Inheritance diagram for TierEngineMutex:

Collaboration diagram for TierEngineMutex:

Public Member Functions
	TierEngineMutex (const fs::path &config_path, const ConfigOverrides &config_overrides)
	Construct a new Tier Engine Mutex object. More...
	~TierEngineMutex (void)
	Destroy the Tier Engine Mutex object, calling unlock_mutex() first. More...
Public Member Functions inherited from TierEngineBase
	TierEngineBase (const fs::path &config_path, const ConfigOverrides &config_overrides)
	Construct a new Tier Engine Base object. More...
virtual	~TierEngineBase (void)
	Destroy the Tier Engine Base object. More...
int	create_run_path (void) const
	Creates path for FIFOs and database, chowning to root:autotier. More...
std::list< Tier > &	get_tiers (void)
	Get reference to the list of tiers.Used in fusePassthrough.cpp to get references to each tier for finding full backend paths. More...
Tier *	tier_lookup (fs::path p)
	Find Tier from path. More...
Tier *	tier_lookup (std::string id)
	Find tier from ID. More...
void	mount_point (const fs::path &mount_point)
	Set the mount_point_ variable. More...
virtual bool	tier (void)
	Virtual tier function to allow other components to call TierEngineTiering::tier(). More...
virtual bool	currently_tiering (void) const

Protected Member Functions
int	lock_mutex (void)
	Opens file at mutex_path such that if the file already exists, opening fails. Uses this as a mutex lock - if the file exists, the critical section is locked. To unlock, delete the file. More...
void	unlock_mutex (void)
	Deletes mutex lock file, unlocking the critical section. More...
Protected Member Functions inherited from TierEngineBase
virtual void	exit (int status) const
	Virtual exit function that can be overridden by other components for cleanup. More...

Protected Attributes
std::mutex	lock_file_mt_
	Used to ensure currently_tiering_ is set atomically with locking the file mutex. More...
Protected Attributes inherited from TierEngineBase
bool	stop_flag_
	Set to false to make thread exit. Used to continue or cancel sleeping after being woken to do ad hoc command work. More...
std::list< Tier >	tiers_
	List of tiers built from configuration file.
Config	config_
	Configuration read from config_file path.
fs::path	run_path_
	Path to mutex lock file, ad hoc FIFO, and database. Defaults to /var/lib/autotier/<hash of config path>, can be overridden in config.
fs::path	mount_point_
	Where autotier filesystem is mounted, set by mount_point().
ConcurrentQueue< AdHoc >	adhoc_work_
std::condition_variable	sleep_cv_
	Condition variable to use wait_until to sleep between tiering, used for the ad hoc server thread or the main thread to wake the tiering thread from sleep. More...
std::shared_ptr< rocksdb::DB >	db_
	Nosql database holding file metadata.

Private Attributes
int	mutex_
	File handle for mutexing tiering of files.

Detailed Description

TierEngine component for ensuring only one instance of autotier runs for a given run path.

Constructor & Destructor Documentation

TierEngineMutex()

TierEngineMutex::TierEngineMutex	(	const fs::path &	config_path,
		const ConfigOverrides &	config_overrides
	)

Construct a new Tier Engine Mutex object.

Parameters

config_path	Path to config file
config_overrides	Config Overrides from main()

~TierEngineMutex()

TierEngineMutex::~TierEngineMutex

(

void

)

Destroy the Tier Engine Mutex object, calling unlock_mutex() first.

Member Function Documentation

lock_mutex()

int TierEngineMutex::lock_mutex ( void  )

protected

Opens file at mutex_path such that if the file already exists, opening fails. Uses this as a mutex lock - if the file exists, the critical section is locked. To unlock, delete the file.

Returns

int 0 if locked, -1 if failed to lock.

unlock_mutex()

void TierEngineMutex::unlock_mutex ( void  )

protected

Deletes mutex lock file, unlocking the critical section.

Member Data Documentation

lock_file_mt_

std::mutex TierEngineMutex::lock_file_mt_

protected

Used to ensure currently_tiering_ is set atomically with locking the file mutex.

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The documentation for this class was generated from the following files:

• src/incl/TierEngine/components/mutex.hpp
• src/impl/autotierfs/TierEngine/components/mutex.cpp