PosixThread Class Reference

#include <thread.h>

Inheritance diagram for PosixThread:

Collaboration diagram for PosixThread:

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
	PosixThread (int pri=0, size_t stack=0)
void	signalThread (int signo)
	Delivers a Posix signal to the current thread. 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 void	sigInstall (int signo)
	Install a signal handler for use by threads and the OnSignal() event notification handler. More...
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
void	signalParent (signo_t signo)
	In the Posix version of Common C++, this can be used to send a signal into the parent thread of the current object. More...
void	signalMain (signo_t signo)
	In the Posix version of Common C++, this can be used to send a signal into the main application thread. More...
virtual void	onTimer (void)
	A derivable method to call when a SIGALRM is being delivered to a specific thread. More...
virtual void	onHangup (void)
	A derived method to handle hangup events being delivered to a specific thread. More...
virtual void	onException (void)
	A derived method to call when a SIGABRT is being delivered to a specific thread. More...
virtual void	onDisconnect (void)
	A derived method to call when a SIGPIPE is being delivered to a specific thread. More...
virtual void	onPolling (void)
	A derived method to handle asynchronous I/O requests delivered to the specified thread. More...
virtual void	onSignal (int)
	A derivable method to call for delivering a signal event to a specified thread. More...
void	setTimer (timeout_t timer, bool periodic=false)
	Used to specify a timeout event that can be delivered to the current thread via SIGALRM. More...
timeout_t	getTimer (void) const
	Gets the time remaining for the current threads timer before it expires. More...
void	endTimer (void)
	Terminates the timer before the timeout period has expired. More...
void	setSignal (int signo, bool active)
	Used to enable or disable a signal within the current thread. More...
pthread_attr_t *	getPthreadAttrPtr (void)
	Access to pthread_attr structure this allows setting/modifying pthread attributes not covered in the platform independant Thread constructor, e.g. More...
pthread_t	getPthreadId (void)
	Get pthread_t of underlying posix thread (useful for debugging/logging) More...
void	setName (const char *text)
	Set the name of the current thread. More...
virtual void	run (void)=0
	All threads execute by deriving the Run method of 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...

Static Private Member Functions
static void	signalThread (Thread *th, signo_t signo)

Private Attributes
time_t	_alarm

Static Private Attributes
static PosixThread *	_timer
static Mutex	_arm

Friends
class	ThreadImpl
class	Thread

Detailed Description

Definition at line 1537 of file thread.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

PosixThread::PosixThread	(	int	pri = 0,
		size_t	stack = 0
	)

Member Function Documentation

void Thread::clrParent ( void  )

inlineprotectedinherited

clear parent thread relationship.

Definition at line 1295 of file thread.h.

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 PosixThread::endTimer ( void  )

protected

Terminates the timer before the timeout period has expired.

This prevents the timer from sending it's SIGALRM and makes the timer available to other threads.

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 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.

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.

pthread_attr_t* PosixThread::getPthreadAttrPtr ( void  )

protected

Access to pthread_attr structure this allows setting/modifying pthread attributes not covered in the platform independant Thread constructor, e.g.

contention scope or scheduling policy

pthread_t PosixThread::getPthreadId ( void  )

protected

Get pthread_t of underlying posix thread (useful for debugging/logging)

timeout_t PosixThread::getTimer ( void  ) const

protected

Gets the time remaining for the current threads timer before it expires.

Returns

time remaining before timer expires in milliseconds.

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.

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 PosixThread::onDisconnect ( void  )

protectedvirtual

A derived method to call when a SIGPIPE is being delivered to a specific thread.

virtual void PosixThread::onException ( void  )

protectedvirtual

A derived method to call when a SIGABRT is being delivered to a specific thread.

virtual void PosixThread::onHangup ( void  )

protectedvirtual

A derived method to handle hangup events being delivered to a specific thread.

virtual void PosixThread::onPolling ( void  )

protectedvirtual

A derived method to handle asynchronous I/O requests delivered to the specified thread.

virtual void PosixThread::onSignal ( int  )

protectedvirtual

A derivable method to call for delivering a signal event to a specified thread.

Parameters

-	posix signal id.

virtual void PosixThread::onTimer ( void  )

protectedvirtual

A derivable method to call when a SIGALRM is being delivered to a specific thread.

void Thread::resume ( void  )

inherited

Resumes execution of the selected thread.

virtual void Thread::run ( void  )

protectedpure virtualinherited

All threads execute by deriving the Run method of Thread.

This method is called after Initial to begin normal operation of the thread. If the method terminates, then the thread will also terminate after notifying it's parent and calling it's Final() method.

See Also

Initial

Implemented in SerialService, SingleThreadRTPSession< RTPDataChannel, RTCPChannel, ServiceQueue >, SocketService, ThreadQueue, and SingleRTPSessionPool.

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 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.

void PosixThread::setSignal ( int  signo, bool  active  )

protected

Used to enable or disable a signal within the current thread.

Parameters

signo	posix signal id.
active	set to true to enable.

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.

void PosixThread::setTimer ( timeout_t  timer, bool  periodic = false  )

protected

Used to specify a timeout event that can be delivered to the current thread via SIGALRM.

When the timer expires, the onTimer() method is called for the thread. At present, only one thread timer can be active at any given time. On some operating systems (including Linux) a timer can be active on each thread.

Parameters

timer	timeout in milliseconds.
periodic	should the timer be periodic.

Note

currently, periodic timers are only available on systems with a working setitimer call.

static void PosixThread::sigInstall ( int  signo )

static

Install a signal handler for use by threads and the OnSignal() event notification handler.

Parameters

signo

posix signal id.

void PosixThread::signalMain ( signo_t  signo )

inlineprotected

In the Posix version of Common C++, this can be used to send a signal into the main application thread.

Parameters

signo

a posix signal id.

Definition at line 1569 of file thread.h.

void PosixThread::signalParent ( signo_t  signo )

inlineprotected

In the Posix version of Common C++, this can be used to send a signal into the parent thread of the current object.

Parameters

signo

a posix signal id.

Definition at line 1560 of file thread.h.

static void PosixThread::signalThread ( Thread *  th, signo_t  signo  )

staticprivate

void PosixThread::signalThread ( int  signo )

inline

Delivers a Posix signal to the current thread.

Parameters

signo

a posix signal id.

Definition at line 1680 of file thread.h.

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 Thread::testCancel ( void  )

protectedinherited

test a cancellation point for deferred thread cancellation.

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 Thread

friend

Definition at line 1543 of file thread.h.

friend class ThreadImpl

friend

Definition at line 1542 of file thread.h.

Field Documentation

time_t PosixThread::_alarm

private

Definition at line 1550 of file thread.h.

Mutex PosixThread::_arm

staticprivate

Definition at line 1547 of file thread.h.

PosixThread* PosixThread::_timer

staticprivate

Definition at line 1546 of file thread.h.

---

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

• thread.h