Fence Class Reference

#include <fence.h>

Inheritance diagram for Fence:

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Public Member Functions
	Fence ()
void	Enter ()
void	Leave ()
void	Close ()
void	Drain ()
void	Open ()

Private Member Functions
	FRIEND_TEST (T_Fence, Basics)

Private Attributes
atomic_int64	counter_
atomic_int32	blocking_

Static Private Attributes
static const unsigned	kBusyWaitBackoffMs = 100

Additional Inherited Members
Protected Member Functions inherited from SingleCopy
	SingleCopy ()

Detailed Description

This file is part of the CernVM File System. A Fence can be used to protect critical regions where blocking is a very rare operation. When the Fence is not blocked, entering and leaving a critical region requires only a 1-2 atomic operations. In order to block the fence, no new threads can enter a critical region. When all entered regions are left, the fence is blocked. Waiting is done through slow busy wait.

Definition at line 25 of file fence.h.

Constructor & Destructor Documentation

Fence::Fence ( )

inline

Definition at line 29 of file fence.h.

Member Function Documentation

void Fence::Close ( )

inline

Definition at line 45 of file fence.h.

Referenced by loader::Reload().

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void Fence::Drain ( )

inline

Close and let live critical regions exit

Definition at line 52 of file fence.h.

Referenced by loader::Reload(), and FuseRemounter::TryFinish().

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void Fence::Enter ( )

inline

Definition at line 34 of file fence.h.

Referenced by cvmfs::cvmfs_forget(), cvmfs::cvmfs_getattr(), cvmfs::cvmfs_getxattr(), cvmfs::cvmfs_listxattr(), cvmfs::cvmfs_lookup(), cvmfs::cvmfs_open(), cvmfs::cvmfs_opendir(), cvmfs::cvmfs_readlink(), cvmfs::cvmfs_statfs(), cvmfs::Evict(), and cvmfs::Pin().

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Fence::FRIEND_TEST ( T_Fence  , Basics    )

private

void Fence::Leave ( )

inline

Definition at line 41 of file fence.h.

Referenced by cvmfs::cvmfs_forget(), cvmfs::cvmfs_getattr(), cvmfs::cvmfs_getxattr(), cvmfs::cvmfs_listxattr(), cvmfs::cvmfs_lookup(), cvmfs::cvmfs_open(), cvmfs::cvmfs_opendir(), cvmfs::cvmfs_readlink(), cvmfs::cvmfs_statfs(), cvmfs::Evict(), and cvmfs::Pin().

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void Fence::Open ( )

inline

Definition at line 59 of file fence.h.

Referenced by loader::Reload(), and FuseRemounter::TryFinish().

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Member Data Documentation

atomic_int32 Fence::blocking_

private

A boolean that indicates if the fence is blocked.

Definition at line 74 of file fence.h.

atomic_int64 Fence::counter_

private

Number of active critical regions.

Definition at line 69 of file fence.h.

const unsigned Fence::kBusyWaitBackoffMs = 100

staticprivate

Definition at line 64 of file fence.h.

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

• /home/sftnight/jenkins/workspace/CvmfsDoxygen/label/docker-x86_64/cvmfs/cvmfs/fence.h