Description:

This class provides a limited (minimal) abstraction of C++ type std::thread. As elaborated in the module's documentation, this class is not considered full featured but - as of today- is meant for simple use cases only.

For general information of multi-threading support provided by ALib, please consult the ALib Module Threads - Programmer's Manual.

Friends

function bootstrap function shutdown

See also: For this class, a pretty printer for the GNU debugger is provided.

Definition at line 124 of file thread.inl.

Inheritance diagram for alib::threads::Thread:

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Collaboration diagram for alib::threads::Thread:

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Public Type Index:
enum class	State { Unstarted = 0 , Started = 1 , Running = 2 , Done = 3 , Terminated = 4 }

Public Static Method Index:
static ALIB_DLL Thread *	Get (std::thread::id nativeID)

static Thread *	GetCurrent ()

static ALIB_DLL Thread *	GetMain ()

static void	Sleep (const Ticks::Duration &duration)

static void	Sleep (const Ticks::Duration::TDuration &duration)

static void	SleepMicros (int64_t microseconds)

static void	SleepMillis (int milliseconds)

static void	SleepNanos (int64_t nanoseconds)

static void	SleepUntil (const Ticks &time)

static void	YieldToSystem ()

Public Method Index:
	Thread (const character *pName=A_CHAR(""))

	Thread (const Thread &)=delete
	Deleted copy constructor.

ALIB_DLL	Thread (Runnable target, const character pName=A_CHAR(""))

virtual	~Thread () override

ThreadID	GetID () const

virtual const character *	GetName () const

std::thread::id	GetNativeID () const

State	GetState ()

bool	IsAlive ()

virtual ALIB_DLL void	Join ()

virtual void	Run () override

virtual void	SetName (const character *newName)

virtual ALIB_DLL void	Start ()

Public Method Index: inherited from alib::threads::Runnable
virtual	~Runnable ()
	Virtual destructor.

Protected Field Index:
std::thread *	c11Thread =nullptr
	The internal C++ thread object.

ThreadID	id =0
	The id of the thread.

const character *	name =nullptr
	The name of the thread.

std::thread::id	nativeID
	The internal C++ thread id.

Runnable *	runnable =nullptr
	The runnable to execute.

State	state = State::Unstarted
	Internal flag to indicate if the thread is alive.

Protected Method Index:
ALIB_DLL void	destruct ()

Enumeration Details:

◆ State

enum class alib::threads::Thread::State

strong

States that follow lifecycle of the thread. The states are accessible with method GetState.

Enumerator
Unstarted	Not started, and no call to Start was performed, yet. This is the state after construction of an instance.
Started	Method Start was invoked but not running, yet.
Running	The thread's Run method is currently processed.
Done	The run method is processed, and the thread is ready to be terminated.
Terminated	The thread is terminated.

Definition at line 136 of file thread.inl.

Field Details:

◆ c11Thread

std::thread* alib::threads::Thread::c11Thread =nullptr

protected

The internal C++ thread object.

Definition at line 153 of file thread.inl.

◆ id

ThreadID alib::threads::Thread::id =0

protected

The id of the thread.

Definition at line 162 of file thread.inl.

◆ name

const character* alib::threads::Thread::name =nullptr

protected

The name of the thread.

Definition at line 165 of file thread.inl.

◆ nativeID

std::thread::id alib::threads::Thread::nativeID

protected

The internal C++ thread id.

Definition at line 156 of file thread.inl.

◆ runnable

Runnable* alib::threads::Thread::runnable =nullptr

protected

The runnable to execute.

Definition at line 159 of file thread.inl.

◆ state

State alib::threads::Thread::state = State::Unstarted

protected

Internal flag to indicate if the thread is alive.

Definition at line 168 of file thread.inl.

Constructor(s) / Destructor Details:

◆ Thread() [1/2]

alib::threads::Thread::Thread ( const character * pName = A_CHAR("") )

inline

Constructor without a parameter specifying a Runnable. Such thread will not execute any code unless a specialized class is derived that overrides virtual method Run.

Parameters

pName (Optional) The designated name of the thread. If the name provided is, empty the name of the thread will be set to match a string representation of the thread id.

Definition at line 181 of file thread.inl.

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◆ Thread() [2/2]

alib::threads::Thread::Thread	(	Runnable *	target,
		const character *	pName = A_CHAR("") )

Constructor with the provision of a Runnable 'target'. The Run method of target will be executed upon thread start (unless this class implements an own Run() method which overrides this behavior.

Parameters

target	The target to execute when the thread runs.
pName	(Optional) The designated name of the thread. If the name provided is empty, the name of the thread will be set to match a string representation of the thread id.

Definition at line 221 of file thread.cpp.

◆ ~Thread()

virtual alib::threads::Thread::~Thread ( )

inlineoverridevirtual

Before destruction, Join has to be called. The destructor blocks if the thread was started and is still running. Blocking lasts until the thread's end of execution.

Definition at line 196 of file thread.inl.

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Method Details:

◆ destruct()

void alib::threads::Thread::destruct ( )

protected

For reasons currently not understood, MSVC does not allow a direct implementation of the virtual destructor. Only when moving the implementation to this dedicated helper method, the linker does not complain about a missing vtable.

Definition at line 229 of file thread.cpp.

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◆ Get()

Thread * alib::threads::Thread::Get ( std::thread::id nativeID )

static

Static method that returns an object representing the thread identified by the given system ID nativeID. nullptr is returned only if:

parameter nativeID is nulled, or
during bootstrapping of ALib, which multithreaded applications have to perform before starting threads, nullptr might be returned as well.

In any other situations, either,

nativeID is received from a thread that was started using this class Thread, then a pointer to that instance is returned, or
the thread was started without the use of ALib, then an instance of this class is created (once) and registered.

Parameters

nativeID The C++ Standard Libraray identifier.

Returns: A pointer to the instance associated with the native thread ID.

Definition at line 329 of file thread.cpp.

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◆ GetCurrent()

Thread * alib::threads::Thread::GetCurrent ( )

inlinestatic

Static method that returns an object representing the thread that invoked this call. If no instance of class Thread was created for the current thread, yet, then one with a negative ID is created, indicating that this thread was not created by ALib.

Once a Thread was created, a pointer to this instance stored in the thread_local namespace variable THIS_THREAD is returned. Thus, this method is very fast from, starting with the second invocation.

Note: For technical reasons, under WindowsOS and DLL compilation, this method is not inlined, but implemented using the macro ALIB_DLL.

Returns: A pointer to the current thread.

Definition at line 300 of file thread.inl.

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◆ GetID()

ThreadID alib::threads::Thread::GetID ( ) const

inline

Returns the id of this Thread. Systems threads have IDs below 0, ALIB generated threads have positive IDs and start with 1.

Returns: The ALib id of the thread.

Definition at line 227 of file thread.inl.

◆ GetMain()

Thread * alib::threads::Thread::GetMain ( )

static

Static method that returns the thread that initialized the library. Such thread is supposedly the "main" thread, as bootstrapping usually is performed by the process before any other threads are started.

Returns: A pointer to the main thread.

Definition at line 328 of file thread.cpp.

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◆ GetName()

virtual const character * alib::threads::Thread::GetName ( ) const

inlinevirtual

Returns the name of the thread. An ALib thread can have any name that is given to it and such name can be changed any time. In fact, names are for debugging and logging purposes only.

Returns: Returns the name of the thread.

Reimplemented in alib::threadmodel::DedicatedWorker.

Definition at line 241 of file thread.inl.

◆ GetNativeID()

std::thread::id alib::threads::Thread::GetNativeID ( ) const

inline

Returns the id of this Thread. Systems threads have IDs below 0, ALIB generated threads have positive IDs and start with 1.

Returns: The ALib id of the thread.

Definition at line 233 of file thread.inl.

◆ GetState()

State alib::threads::Thread::GetState ( )

inline

Returns the state of the thread. The states are given in enumeration State and during the lifecycle of the thread, the state transitions from State::Unstarted to State::Terminated.

Note: For system threads (the thread that executed function main thread and those not created using ALib thread features) State::Running is returned. For those, it can't be determined if the thread is stared, alive or not.

Returns: The current state within the thread's lifecycle.

Definition at line 258 of file thread.inl.

◆ IsAlive()

bool alib::threads::Thread::IsAlive ( )

inline

A shortcut to GetState().first == State::Started || GetState().first == State::Running.

Returns: true if the current state of the thread is State::Running.

Definition at line 265 of file thread.inl.

◆ Join()

void alib::threads::Thread::Join ( )

virtual

Terminates a thread using std::join(). When this method is called, the thread should be in state State::Done, which is the case after method Run has exited. Otherwise, a warning is raised.

Definition at line 251 of file thread.cpp.

◆ Run()

virtual void alib::threads::Thread::Run ( )

inlineoverridevirtual

If we have a runnable, its run() method is executed. Otherwise nothing is done.

Hence, to have the thread execute something, either a Runnable has to be provided or a derived version of this class replaces this method.

Implements alib::threads::Runnable.

Reimplemented in alib::threadmodel::DedicatedWorker, and alib::threadmodel::Trigger.

Definition at line 217 of file thread.inl.

◆ SetName()

virtual void alib::threads::Thread::SetName ( const character * newName )

inlinevirtual

Sets the name of the thread. An ALib thread can have any name that is given to it and such name can be changed any time. Thread names are meant for debugging and logging purposes only.

Parameters

newName The name that the Thread should hold.

Definition at line 247 of file thread.inl.

◆ Sleep() [1/2]

void alib::threads::Thread::Sleep ( const Ticks::Duration & duration )

inlinestatic

Suspends the current thread by calling std::this_thread::sleep_for.

See also: Variants SleepUntil, SleepMicros, SleepMillis and SleepNanos.

Parameters

duration Sleep duration.

Definition at line 365 of file thread.inl.

◆ Sleep() [2/2]

void alib::threads::Thread::Sleep ( const Ticks::Duration::TDuration & duration )

inlinestatic

Suspends the current thread by calling std::this_thread::sleep_for.

See also: Variants SleepUntil, SleepMicros, SleepMillis and SleepNanos.

Parameters

duration Sleep duration.

Definition at line 371 of file thread.inl.

◆ SleepMicros()

void alib::threads::Thread::SleepMicros ( int64_t microseconds )

inlinestatic

Suspends the current thread by calling std::this_thread::sleep_for.

See also: Variants SleepMillis, SleepNanos, Sleep and SleepUntil

Parameters

microseconds Sleep time in microseconds.

Definition at line 353 of file thread.inl.

◆ SleepMillis()

void alib::threads::Thread::SleepMillis ( int milliseconds )

inlinestatic

Suspends the current thread by calling std::this_thread::sleep_for.

See also: Variants SleepMicros, SleepNanos, Sleep and SleepUntil

Parameters

milliseconds Sleep time in milliseconds.

Definition at line 346 of file thread.inl.

◆ SleepNanos()

void alib::threads::Thread::SleepNanos ( int64_t nanoseconds )

inlinestatic

Suspends the current thread by calling std::this_thread::sleep_for.

See also: Variants SleepMicros, SleepMillis, Sleep and SleepUntil

Parameters

nanoseconds Sleep time in nanoseconds.

Definition at line 359 of file thread.inl.

◆ SleepUntil()

void alib::threads::Thread::SleepUntil ( const Ticks & time )

inlinestatic

Suspends the current thread by calling std::this_thread::sleep_for.

See also: Variants Sleep, SleepMicros, SleepMillis and SleepNanos

Parameters

time	Sleep duration.

Definition at line 377 of file thread.inl.

◆ Start()

void alib::threads::Thread::Start ( )

virtual

Starts the execution of the thread. Method Run is invoked by the new system thread, which - if not overwritten - invokes the method Runnable::Run. Of course, this method immediately returns, and after invocation, method IsAlive will usually return true (unless the executed thread is not finished already).

Reimplemented in alib::threadmodel::Trigger.

Definition at line 296 of file thread.cpp.

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◆ YieldToSystem()

void alib::threads::Thread::YieldToSystem ( )

inlinestatic

Proactively offers the system to suspend the current thread. Invokes std::this_thread::yield.

Note: Must not be named 'Yield', because this is a macro name with MSVC.

Definition at line 341 of file thread.inl.

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

Description:

Friends

Public Type Index:

Public Static Method Index:

Public Method Index:

Protected Field Index:

Protected Method Index:

Enumeration Details:

◆ State

Field Details:

◆ c11Thread

◆ id

◆ name

◆ nativeID

◆ runnable

◆ state

Constructor(s) / Destructor Details:

◆ Thread() [1/2]

◆ Thread() [2/2]

◆ ~Thread()

Method Details:

◆ destruct()

◆ Get()

◆ GetCurrent()

◆ GetID()

◆ GetMain()

◆ GetName()

◆ GetNativeID()

◆ GetState()

◆ IsAlive()

◆ Join()

◆ Run()

◆ SetName()

◆ Sleep() [1/2]

◆ Sleep() [2/2]

◆ SleepMicros()

◆ SleepMillis()

◆ SleepNanos()

◆ SleepUntil()

◆ Start()

◆ YieldToSystem()