A wrapper for replicating nodes in different threads to produce more responsive workers in multithreaded applications. More...

#include <VFS_threadpool.h>

Inheritance diagram for VFS_threadpool:

Public Types
enum	mode { roundrobin = 0 , available }
	A pool will distribute requests based on a mode. More...

Public Slots
virtual void	executeRequest (VFS_request *t) override
	A dummy entry to override VFS_node::executeRequest() More...

virtual void	subtreeRequest (VFS_request *t) override
	A dummy entry to override VFS_node::subtreeRequest() More...

Public Slots inherited from VFS_node
virtual void	applyDiff (VFS_request *r)
	Apply a diff received via subscription. More...

virtual void	executeRequest (VFS_request *t)
	Based on the VFS_request::requestType, execute the function associated with an operation. More...

void	notifySubscribers (VFS_node origin, VFS_request t)
	Propagate a diff to subscribers. More...

virtual void	receiveResponse (VFS_request *t)
	Once a VFS_request has been completed, a response will be issued back to its _origin. More...

void	remove (bool andDelete)
	Remove a child node. More...

virtual void	remove (VFS_node node=nullptr, QString name=nullptr, QString user="server")
	Remove a child node from this node. More...

virtual void	subtreeRequest (VFS_request *t)
	find() the target of a VFS_request, and execute the request More...

virtual void	unsubscribeAll (VFS_node *n)
	Remove all references to a subscriber from this node. More...

Public Member Functions
Q_INVOKABLE	VFS_threadpool (uint count, VFS_threadpool::mode mode, QDomElement nodeConfig, QVariantMap env, bool printConfig=false)
	VFS_threadpool constructor. More...

virtual	~VFS_threadpool () override
	VFS_threadpool destructor. More...

virtual VFS_node *	find (VFS_request *r) override
	Distribute requests to children based on `_mode`. More...

virtual bool	isContainer () override
	A threadpool is always a container. More...

Public Member Functions inherited from VFS_node
Q_INVOKABLE	VFS_node ()
	The VFS_node constructor will add its instance to the VFS_node::__allNodes global node registry, observing thread safety rules. More...

virtual	~VFS_node ()
	VFS_node destructor. More...

virtual VFS_node *	append (QString name, VFS_node *node, bool containerCheck=true, QString user="server")
	Append a VFS_node as a child of this node. More...

QString	className ()
	Return the class name of a node. More...

virtual VFS_request *	createRequest (VFS_request::requestType type, QString path, QString user="unknown", QJsonDocument data=QJsonDocument(), QJsonObject metadata=QJsonObject(), bool dontDelete=false)
	Create a new VFS_request with this object as _origin. More...

VFS_node *	find (QString path)
	Find a node by string path. More...

VFS_node *	findChildWithName (QString name)
	Check if a child with a given name exists. More...

virtual VFS_node *	mount ()
	Mount this node. More...

virtual QString	reportDetails ()
	Additional details for a generated report. More...

QString	uniqueChildName (QString name)
	Generate a unique child name. More...

virtual VFS_node *	unmount ()
	Unmount this node. More...

virtual bool	validChildName (QString name)
	Check if a node name is valid. More...

Static Public Attributes
static const QStringList	modeStrings { "roundrobin", "available" }
	string names of each mode for the config file More...

Protected Attributes
uint	_count
	The replication count. More...

uint	_index
	The current index for roundrobin requests. More...

VFS_threadpool::mode	_mode
	The distribution mode. More...

Protected Attributes inherited from VFS_node
VFS_children	_children
	This node's children. More...

QMutex	_lock
	A recursive mutex that is local to this node. More...

VFS_subscriptionType	_subscribers
	This node's subscribers. These subscribers will receive diff notifications. More...

Additional Inherited Members
Signals inherited from VFS_node
void	diff (VFS_node origin, VFS_request t)
	Emit a diff, which will trigger notifySubscribers() for a mounted node. More...

void	finished (bool andDelete=false)
	Emitted if a thread fails to create its node, or a node is rm()'d, or any other reason a node has completed its lifecycle. It is deleted if `andDelete==true`. More...

void	mounted ()
	Emitted when a node is mount()ed. More...

void	unmounted (VFS_node *self)
	Emitted when a node is unmount()ed. More...

Static Public Member Functions inherited from VFS_node
static bool	__isNode (VFS_node *)
	Check to see if a node is in the global registry. More...

static QString	code (QString nodename, QString libname, QString &error)
	Fetch code or any other resource from a node. More...

Protected Member Functions inherited from VFS_node
virtual void	aclDefaults (VFS_request *r)
	Return default values and features associated wth this node. More...

void	addACLDefault (QJsonObject &acl, bool value, QString description="")
	Add a default value to the acl object. More...

void	addACLFeature (QJsonObject &acl, QString feature, bool value, QString description="")
	Add a feature to the acl object. More...

void	addACLFeatureGroup (QJsonObject &acl, QString feature, QString group, bool value)
	Add a feature group to the acl object. More...

void	addACLFeatureUser (QJsonObject &acl, QString feature, QString user, bool value)
	Add a feature user to the acl object. More...

void	addACLGroup (QJsonObject &acl, QString group, bool value)
	Add a group to the acl object. More...

void	addACLUser (QJsonObject &acl, QString user, bool value)
	Add a user to the acl object. More...

virtual QByteArray	icon ()
	Fetch the icon for a node. More...

virtual void	issueRequest (VFS_node target, VFS_request t)
	Issue a VFS_request to its target. More...

virtual void	issueRequest (VFS_request *t)
	A convenience function. More...

virtual void	issueResponse (VFS_request *t)
	Once a request has been completed, issue a response. More...

virtual void	ls (VFS_request *r)
	List the contents of this node. More...

virtual void	metadata (VFS_request *r)
	Fetch the metadata of this node. More...

virtual void	read (VFS_request *r)
	Return the data contents of this node, or if it's a container call ls() More...

virtual void	releaseLock (VFS_request *r)
	Release a lock on this node. More...

virtual void	report (VFS_request *r)
	Report debugging information about the current state of this node. More...

virtual void	requestLock (VFS_request *r)
	Request a lock on this node. More...

virtual void	rm (VFS_request *r)
	Remove a child entry from a node, or the node itself. More...

virtual void	submit (VFS_request *r)
	Submit a diff to a node. More...

virtual void	subscribe (VFS_request *r)
	Add an entry to this node's _subscription list. More...

virtual void	unsubscribe (VFS_request *r)
	Remove an entry from this node's _subscription list. More...

virtual void	unsubscribePath (QString path)
	Unsubscribe all references to a subpath. More...

virtual void	write (VFS_request *r)
	Write data to this node. More...

Detailed Description

A wrapper for replicating nodes in different threads to produce more responsive workers in multithreaded applications.

Any group of nodes can be placed in a threadpool. The threadpool will replicate the group against the threads value provided. Because of this, special care must be taken to ensure that the replicated nodes are not expected to be unique or stateful.

For instance, a series of read-only VFS_HD nodes make sense for this purpose, as multithreaded disk reads may make more sense than a blocking single-threaded one. However, each VFS_HD node will maintain its own cache and therefore a write to a threadpool-ed VFS_HD node will be unpredictable when under load.

The threadpool will proxy VFS_requests to its children based on its distribution mode:

Roundrobin - Incoming requests will revolve through children.
Available - Incoming requests will be queued on the child with the fewest pending requests.

Note: That the actual number of threads created will depend on the nodes being created. If 5 children are on separate threads and the pool has a count of 5, 25 new threads will be created.

See also: VFS_creator::constructNode; VFS_thread; XML Config File(s)

Definition at line 9 of file VFS_threadpool.h.

Member Enumeration Documentation

◆ mode

enum VFS_threadpool::mode

A pool will distribute requests based on a mode.

Enumerator
roundrobin	roundrobin mode will cycle through children
available	available mode will use the child with the fewest outstanding requests

Definition at line 16 of file VFS_threadpool.h.

Constructor & Destructor Documentation

◆ VFS_threadpool()

VFS_threadpool::VFS_threadpool	(	uint	count,
		VFS_threadpool::mode	mode,
		QDomElement	nodeConfig,
		QVariantMap	env,
		bool	printConfig = `false`
	)

explicit

VFS_threadpool constructor.

Parameters

count	The number of threads to create
mode	The distribution mode for this pool
nodeConfig	An XML specification for nodes to replicate
env	The current environment
printConfig	A debug setting passed during creation of threads

Creates a series of _thread nodes based on incoming config data. The new threads are named based on the node type, node name and thread index, which is useful in debuggers like gdb.

Definition at line 49 of file VFS_threadpool.cpp.

◆ ~VFS_threadpool()

VFS_threadpool::~VFS_threadpool ( )

overridevirtual

VFS_threadpool destructor.

Definition at line 77 of file VFS_threadpool.cpp.

Member Function Documentation

◆ executeRequest

void VFS_threadpool::executeRequest ( VFS_request * t )

overridevirtualslot

A dummy entry to override VFS_node::executeRequest()

Parameters

t	The VFS_request object

This is a dummy entry to catch errors. In pactice it should never be called. If a warning is issued it means that some node has received a pointer to this node, which it should never have.

Definition at line 156 of file VFS_threadpool.cpp.

◆ find()

VFS_node * VFS_threadpool::find ( VFS_request * r )

overridevirtual

Distribute requests to children based on _mode.

Parameters

r	The VFS_request object

Returns: The result of a selected child's VFS_node::find()

This method will use _mode to determine which child path to follow for requests.

See also: VFS_threadpool

Reimplemented from VFS_node.

Definition at line 103 of file VFS_threadpool.cpp.

◆ isContainer()

bool VFS_threadpool::isContainer ( )

overridevirtual

A threadpool is always a container.

Returns: true

Reimplemented from VFS_node.

Definition at line 87 of file VFS_threadpool.cpp.

◆ subtreeRequest

void VFS_threadpool::subtreeRequest ( VFS_request * t )

overridevirtualslot

A dummy entry to override VFS_node::subtreeRequest()

Parameters

t	The VFS_request object

This is a dummy entry to catch errors. In pactice it should never be called. If a warning is issued it means that some node has received a pointer to this node, which it should never have.

Definition at line 140 of file VFS_threadpool.cpp.

Member Data Documentation

◆ _count

uint VFS_threadpool::_count

protected

The replication count.

Definition at line 34 of file VFS_threadpool.h.

◆ _index

uint VFS_threadpool::_index

protected

The current index for roundrobin requests.

Definition at line 35 of file VFS_threadpool.h.

◆ _mode

VFS_threadpool::mode VFS_threadpool::_mode

protected

The distribution mode.

Definition at line 36 of file VFS_threadpool.h.

◆ modeStrings

const QStringList VFS_threadpool::modeStrings { "roundrobin", "available" }

static

string names of each mode for the config file

Definition at line 22 of file VFS_threadpool.h.

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

Public Types

Public Slots

Public Member Functions

Static Public Attributes

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ mode

Constructor & Destructor Documentation

◆ VFS_threadpool()

◆ ~VFS_threadpool()

Member Function Documentation

◆ executeRequest

◆ find()

◆ isContainer()

◆ subtreeRequest

Member Data Documentation

◆ _count

◆ _index

◆ _mode

◆ modeStrings