SocketService Class Reference

The SocketService is a thread pool object that is meant to service attached socket ports. More...

#include <socketport.h>

Inheritance diagram for SocketService:

Collaboration diagram for SocketService:

Public Types
enum	Throw { throwNothing, throwObject, throwException }
	How to raise error. More...
typedef enum Thread::Throw	Throw
	How to raise error. More...
enum	Cancel {   cancelInitial =0, cancelDeferred =1, cancelImmediate, cancelDisabled,   cancelManual, cancelDefault =cancelDeferred }
	How work cancellation. More...
typedef enum Thread::Cancel	Cancel
	How work cancellation. More...
enum	Suspend { suspendEnable, suspendDisable }
	How work suspend. More...
typedef enum Thread::Suspend	Suspend
	How work suspend. More...

Public Member Functions
void	update (unsigned char flag=0xff)
	Notify service thread that a port has been added or removed, or a timer changed, so that a new schedule can be computed for expiring attached ports. More...
	SocketService (int pri=0, size_t stack=0, const char *id=NULL)
	Create a service thread for attaching socket ports. More...
virtual	~SocketService ()
	Terminate the thread pool and eliminate any attached socket ports. More...
int	getCount (void) const
	Get current reference count. More...
int	start (Semaphore *start=0)
	When a new thread is created, it does not begin immediate execution. More...
int	detach (Semaphore *start=0)
	Start a new thread as "detached". More...
Thread *	getParent (void)
	Gets the pointer to the Thread class which created the current thread object. More...
void	suspend (void)
	Suspends execution of the selected thread. More...
void	resume (void)
	Resumes execution of the selected thread. More...
Cancel	getCancel (void)
	Used to retrieve the cancellation mode in effect for the selected thread. More...
bool	isRunning (void) const
	Verifies if the thread is still running or has already been terminated but not yet deleted. More...
bool	isDetached (void) const
	Check if this thread is detached. More...
void	join (void)
	Blocking call which unlocks when thread terminates. More...
bool	isThread (void) const
	Tests to see if the current execution context is the same as the specified thread object. More...
cctid_t	getId (void) const
	Get system thread numeric identifier. More...
const char *	getName (void) const
	Get the name string for this thread, to use in debug messages. More...

Static Public Member Functions
static Thread *	get (void)
static void	setStack (size_t size=0)
	Set base stack limit before manual stack sizes have effect. More...
static void	sleep (timeout_t msec)
	A thread-safe sleep call. More...
static void	yield (void)
	Yields the current thread's CPU time slice to allow another thread to begin immediate execution. More...
static Throw	getException (void)
	Get exception mode of the current thread. More...
static void	setException (Throw mode)
	Set exception mode of the current thread. More...
static Cancel	enterCancel (void)
	This is used to help build wrapper functions in libraries around system calls that should behave as cancellation points but don't. More...
static void	exitCancel (Cancel cancel)
	This is used to restore a cancel block. More...

Protected Member Functions
virtual void	onUpdate (unsigned char buf)
	Handles all requests other than "termination". More...
virtual void	onEvent (void)
	Called once each time the service thread is rescheduled. More...
virtual void	onCallback (SocketPort *port)
	Called for each port that is being processed in response to an event. More...
void	setName (const char *text)
	Set the name of the current thread. More...
virtual void	final (void)
	A thread that is self terminating, either by invoking exit() or leaving it's run(), will have this method called. More...
virtual void	initial (void)
	The initial method is called by a newly created thread when it starts execution. More...
virtual void *	getExtended (void)
	Since getParent() and getThread() only refer to an object of the Thread "base" type, this virtual method can be replaced in a derived class with something that returns data specific to the derived class that can still be accessed through the pointer returned by getParent() and getThread(). More...
virtual void	notify (Thread *)
	When a thread terminates, it now sends a notification message to the parent thread which created it. More...
void	exit (void)
	Used to properly exit from a Thread derived run() or initial() method. More...
void	sync (void)
	Used to wait for a join or cancel, in place of explicit exit. More...
bool	testCancel (void)
	test a cancellation point for deferred thread cancellation. More...
void	setCancel (Cancel mode)
	Sets thread cancellation mode. More...
void	setSuspend (Suspend mode)
	Sets the thread's ability to be suspended from execution. More...
void	terminate (void)
	Used by another thread to terminate the current thread. More...
void	clrParent (void)
	clear parent thread relationship. More...

Private Member Functions
void	attach (SocketPort *port)
	Attach a new socket port to this service thread. More...
void	detach (SocketPort *port)
	Detach a socket port from this service thread. More...
void	run (void)
	The service thread itself. More...
void	nameMutex (const char *name)
	Enable setting of mutex name for deadlock debug. More...
void	enterMutex (void)
	Entering a Mutex locks the mutex for the current thread. More...
void	enter (void)
	Future abi will use enter/leave/test members. More...
void	leave (void)
	Future abi will use enter/leave/test members. More...
bool	test (void)
	Future abi will use enter/leave/test members. More...
bool	tryEnterMutex (void)
	Tries to lock the mutex for the current thread. More...
void	leaveMutex (void)
	Leaving a mutex frees that mutex for use by another thread. More...

Static Private Member Functions
static void	setDebug (bool mode)
	Enable or disable deadlock debugging. More...

Private Attributes
fd_set	connect
int	iosync [2]
int	hiwater
int volatile	count
SocketPort *volatile	first
SocketPort *volatile *	last

Friends
class	SocketPort

Detailed Description

The SocketService is a thread pool object that is meant to service attached socket ports.

Multiple pool objects may be created and multiple socket ports may be attached to the same thread of execution. This allows one to balance threads and sockets they service rather than either using a single thread for all connections or a seperate thread for each connection. Features can be added through supported virtual methods.

Author

David Sugar dyfet.nosp@m.@ost.nosp@m.el.co.nosp@m.m Thread pool service object for socket ports.

Definition at line 288 of file socketport.h.

Member Typedef Documentation

typedef enum Thread::Cancel Thread::Cancel

inherited

How work cancellation.

typedef enum Thread::Suspend Thread::Suspend

inherited

How work suspend.

typedef enum Thread::Throw Thread::Throw

inherited

How to raise error.

Member Enumeration Documentation

enum Thread::Cancel

inherited

How work cancellation.

Enumerator
cancelInitial	used internally, do not use
cancelDeferred	exit thread on cancellation pointsuch as yield
cancelImmediate	exit befor cancellation
cancelDisabled	ignore cancellation
cancelManual	unimplemented (working in progress) Todo: implement
cancelDefault	default you should use this for compatibility instead of deferred

Definition at line 1108 of file thread.h.

enum Thread::Suspend

inherited

How work suspend.

Enumerator
suspendEnable	suspend enabled
suspendDisable	suspend disabled, Suspend do nothing

Definition at line 1122 of file thread.h.

enum Thread::Throw

inherited

How to raise error.

Enumerator
throwNothing	continue without throwing error
throwObject	throw object that cause error (throw this)
throwException	throw an object relative to error

Definition at line 1099 of file thread.h.

Constructor & Destructor Documentation

SocketService::SocketService	(	int	pri = 0,
		size_t	stack = 0,
		const char *	id = NULL
	)

Create a service thread for attaching socket ports.

The thread begins execution with the first attached socket.

Parameters

pri	of this thread to run under.
stack	stack size.
id	thread ID.

virtual SocketService::~SocketService ( )

virtual

Terminate the thread pool and eliminate any attached socket ports.

Member Function Documentation

void SocketService::attach ( SocketPort *  port )

private

Attach a new socket port to this service thread.

Parameters

port	of SocketPort derived object to attach.

void Thread::clrParent ( void  )

inlineprotectedinherited

clear parent thread relationship.

Definition at line 1295 of file thread.h.

void SocketService::detach ( SocketPort *  port )

private

Detach a socket port from this service thread.

Parameters

port	of SocketPort derived object to remove.

int Thread::detach ( Semaphore *  start = 0 )

inherited

Start a new thread as "detached".

This is an alternative start() method that resolves some issues with later glibc implimentations which incorrectly impliment self-detach.

Returns

error code if execution fails.

Parameters

start

optional starting semaphore to alternately use.

void Mutex::enter ( void  )

inlineinherited

Future abi will use enter/leave/test members.

Definition at line 263 of file thread.h.

static Cancel Thread::enterCancel ( void  )

staticinherited

This is used to help build wrapper functions in libraries around system calls that should behave as cancellation points but don't.

Returns

saved cancel type.

void Mutex::enterMutex ( void  )

inherited

Entering a Mutex locks the mutex for the current thread.

This also can be done using the ENTER_CRITICAL macro or by using the ++ operator on a mutex.

See Also

leaveMutex

void Thread::exit ( void  )

protectedinherited

Used to properly exit from a Thread derived run() or initial() method.

Terminates execution of the current thread and calls the derived classes final() method.

static void Thread::exitCancel ( Cancel  cancel )

staticinherited

This is used to restore a cancel block.

Parameters

cancel

type that was saved.

virtual void Thread::final ( void  )

protectedvirtualinherited

A thread that is self terminating, either by invoking exit() or leaving it's run(), will have this method called.

It can be used to self delete the current object assuming the object was created with new on the heap rather than stack local, hence one may often see final defined as "delete this" in a derived thread class. A final method, while running, cannot be terminated or cancelled by another thread. Final is called for all cancellation type (even immediate).

You can safe delete thread ("delete this") class on final, but you should exit ASAP (or do not try to call CommonC++ methods...)

Note

A thread cannot delete its own context or join itself. To make a thread that is a self running object that self-deletes, one has to detach the thread by using detach() instead of start().

See Also

exit

run

Reimplemented in ThreadQueue.

static Thread* Thread::get ( void  )

staticinherited

Cancel Thread::getCancel ( void  )

inlineinherited

Used to retrieve the cancellation mode in effect for the selected thread.

Returns

cancellation mode constant.

Definition at line 1419 of file thread.h.

int SocketService::getCount ( void  ) const

inline

Get current reference count.

This can be used when selecting the least used service handler from a pool.

Returns

count of active ports.

Definition at line 382 of file socketport.h.

static Throw Thread::getException ( void  )

staticinherited

Get exception mode of the current thread.

Returns

exception mode.

virtual void* Thread::getExtended ( void  )

protectedvirtualinherited

Since getParent() and getThread() only refer to an object of the Thread "base" type, this virtual method can be replaced in a derived class with something that returns data specific to the derived class that can still be accessed through the pointer returned by getParent() and getThread().

Returns

pointer to derived class specific data.

cctid_t Thread::getId ( void  ) const

inherited

Get system thread numeric identifier.

Returns

numeric identifier of this thread.

const char* Thread::getName ( void  ) const

inlineinherited

Get the name string for this thread, to use in debug messages.

Returns

debug name.

Definition at line 1463 of file thread.h.

Thread* Thread::getParent ( void  )

inlineinherited

Gets the pointer to the Thread class which created the current thread object.

Returns

a Thread *, or "(Thread *)this" if no parent.

Definition at line 1397 of file thread.h.

virtual void Thread::initial ( void  )

protectedvirtualinherited

The initial method is called by a newly created thread when it starts execution.

This method is ran with deferred cancellation disabled by default. The Initial method is given a separate handler so that it can create temporary objects on it's own stack frame, rather than having objects created on run() that are only needed by startup and yet continue to consume stack space.

See Also

run

final

Reimplemented in TCPSession, and UnixSession.

bool Thread::isDetached ( void  ) const

inherited

Check if this thread is detached.

Returns

true if the thread is detached.

bool Thread::isRunning ( void  ) const

inherited

Verifies if the thread is still running or has already been terminated but not yet deleted.

Returns

true if the thread is still executing.

bool Thread::isThread ( void  ) const

inherited

Tests to see if the current execution context is the same as the specified thread object.

Returns

true if the current context is this object.

void Thread::join ( void  )

inherited

Blocking call which unlocks when thread terminates.

void Mutex::leave ( void  )

inlineinherited

Future abi will use enter/leave/test members.

Definition at line 269 of file thread.h.

void Mutex::leaveMutex ( void  )

inherited

Leaving a mutex frees that mutex for use by another thread.

If the mutex has been entered (invoked) multiple times (recursivily) by the same thread, then it will need to be exited the same number of instances before it is free for re-use. This operation can also be done using the LEAVE_CRITICAL macro or by the – operator on a mutex.

See Also

enterMutex

void Mutex::nameMutex ( const char *  name )

inlineinherited

Enable setting of mutex name for deadlock debug.

Parameters

name	for mutex.

Definition at line 248 of file thread.h.

virtual void Thread::notify ( Thread *  )

protectedvirtualinherited

When a thread terminates, it now sends a notification message to the parent thread which created it.

The actual use of this notification is left to be defined in a derived class.

Parameters

-	the thread that has terminated.

virtual void SocketService::onCallback ( SocketPort *  port )

protectedvirtual

Called for each port that is being processed in response to an event.

This can be used to add additional notification options during callback in combination with update().

Parameters

port	SocketPort who's callback events are being evaluated.

virtual void SocketService::onEvent ( void  )

protectedvirtual

Called once each time the service thread is rescheduled.

This is called after the mutex is locked and can be used to slip in additional processing.

virtual void SocketService::onUpdate ( unsigned char  buf )

protectedvirtual

Handles all requests other than "termination".

Parameters

buf	request id as posted from update().

void Thread::resume ( void  )

inherited

Resumes execution of the selected thread.

void SocketService::run ( void  )

privatevirtual

The service thread itself.

Implements Thread.

void Thread::setCancel ( Cancel  mode )

protectedinherited

Sets thread cancellation mode.

Threads can either be set immune to termination (cancelDisabled), can be set to terminate when reaching specific "thread cancellation points" (cancelDeferred) or immediately when Terminate is requested (cancelImmediate).

Parameters

mode	for cancellation of the current thread.

static void Mutex::setDebug ( bool  mode )

inlinestaticinherited

Enable or disable deadlock debugging.

Parameters

mode	debug mode.

Definition at line 240 of file thread.h.

static void Thread::setException ( Throw  mode )

staticinherited

Set exception mode of the current thread.

Returns

exception mode.

void Thread::setName ( const char *  text )

protectedinherited

Set the name of the current thread.

If the name is passed as NULL, then the default name is set (usually object pointer).

Parameters

text	name to use.

static void Thread::setStack ( size_t  size = 0 )

inlinestaticinherited

Set base stack limit before manual stack sizes have effect.

Parameters

size	stack size to set, or use 0 to clear autostack.

Definition at line 1347 of file thread.h.

void Thread::setSuspend ( Suspend  mode )

protectedinherited

Sets the thread's ability to be suspended from execution.

The thread may either have suspend enabled (suspendEnable) or disabled (suspendDisable).

Parameters

mode	for suspend.

static void Thread::sleep ( timeout_t  msec )

staticinherited

A thread-safe sleep call.

On most Posix systems, "sleep()" is implimented with SIGALRM making it unusable from multipe threads. Pthread libraries often define an alternate "sleep" handler such as usleep(), nanosleep(), or nap(), that is thread safe, and also offers a higher timer resolution.

Parameters

msec	timeout in milliseconds.

int Thread::start ( Semaphore *  start = 0 )

inherited

When a new thread is created, it does not begin immediate execution.

This is because the derived class virtual tables are not properly loaded at the time the C++ object is created within the constructor itself, at least in some compiler/system combinations. The thread can either be told to wait for an external semaphore, or it can be started directly after the constructor completes by calling the start() method.

Returns

error code if execution fails.

Parameters

start

optional starting semaphore to alternately use.

void Thread::suspend ( void  )

inherited

Suspends execution of the selected thread.

Pthreads do not normally support suspendable threads, so the behavior is simulated with signals. On systems such as Linux that define threads as processes, SIGSTOP and SIGCONT may be used.

void Thread::sync ( void  )

protectedinherited

Used to wait for a join or cancel, in place of explicit exit.

void Thread::terminate ( void  )

protectedinherited

Used by another thread to terminate the current thread.

Termination actually occurs based on the current setCancel() mode. When the current thread does terminate, control is returned to the requesting thread. terminate() should always be called at the start of any destructor of a class derived from Thread to assure the remaining part of the destructor is called without the thread still executing.

bool Mutex::test ( void  )

inlineinherited

Future abi will use enter/leave/test members.

Returns

true if entered.

Definition at line 277 of file thread.h.

bool Thread::testCancel ( void  )

protectedinherited

test a cancellation point for deferred thread cancellation.

bool Mutex::tryEnterMutex ( void  )

inherited

Tries to lock the mutex for the current thread.

Behaves like enterMutex , except that it doesn't block the calling thread if the mutex is already locked by another thread.

Returns

true if locking the mutex was succesful otherwise false

See Also

enterMutex

leaveMutex

void SocketService::update

(

unsigned char

flag = 0xff

)

Notify service thread that a port has been added or removed, or a timer changed, so that a new schedule can be computed for expiring attached ports.

A "0" is used to terminate the service thread, and additional values can be specified which will be "caught" in the onUpdate() handler.

Parameters

flag	update flag value.

static void Thread::yield ( void  )

staticinherited

Yields the current thread's CPU time slice to allow another thread to begin immediate execution.

Friends And Related Function Documentation

friend class SocketPort

friend

Definition at line 321 of file socketport.h.

Field Documentation

fd_set SocketService::connect

private

Definition at line 292 of file socketport.h.

int volatile SocketService::count

private

Definition at line 300 of file socketport.h.

SocketPort* volatile SocketService::first

private

Definition at line 301 of file socketport.h.

int SocketService::hiwater

private

Definition at line 294 of file socketport.h.

int SocketService::iosync[2]

private

Definition at line 293 of file socketport.h.

SocketPort* volatile * SocketService::last

private

Definition at line 301 of file socketport.h.

---

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

• socketport.h