drama::Future< T > Class Template Reference

Detailed Description

template<class T>
class drama::Future< T >

A class which wraps a std::future<T> and provides debugging output to stderr.

The idea of this class is to help debug futures, which can cause unexpected hangs when get() and the destructor are invoked. The later are a particular issue as it may not be apparent when they are being invoked.

By replacing a type of std::future<T> with a drama::Future, you can arrange for debugging information to be output to stderr. Whilst the message output is similar for each such future, a name string can be supplied which allows you to distinguish each future.

A typical approach would replace something like

std::future<bool> myFuture = std::async(...);

with something like

drama::Future<bool> myFuture;
myFuture.SetName("some string...");
myFuture = std::async(...);

By default, any such future results in the messages being output to stderr. Such messages are output if either the global log flag is true, or a local log flag is true. By default, the global log flag is true, and the local is false. but these can be enabled/disabled as required.

The messages are of the form 'drama::Future<%> "%" ...' where the first '' character is replace by typeinfo.name() on the template type. This string is compiler specific, particularly for built-in types. For example, in GCC 4.9, simple built in types use 'b' for bool, 'i' for integer, 'm' for unsigned long. Other compilers will vary. For void, 'void' is output in all cases. The second '' character is replaced by the "name" supplied to the constructor or SetName() method.

Template Parameters

The	type returned by the future.

#include "debugfuture.hh"

Inherits std::future< T >.

Public Member Functions
	Future (const Future &)=delete
	Copy constructor = deleted.
	Future (const std::string &name="unnamed", bool logOn=false) noexcept
	Construct a drama::Future object.
	~Future ()
	Destructor.
T	get ()
	Get value of future.
bool	GetLogState () const
	Return the state of the object specific logging flag.
void	LogOff ()
	Turn logging off.
void	LogOn ()
	Turn logging on.
Future &	operator= (BaseFuture &&rhs) noexcept
	Move assignment operator - source std::future<T>
Future &	operator= (const Future &)=delete
	Assignment operator (non-move) - deleted.
Future &	operator= (Future &&rhs) noexcept
	Move assignment operator.
void	SetName (const std::string &newName)
	Set the name of this object - as used in logging messages.

Static Public Member Functions
static bool	GetGlobalLogState ()
	Return the state of the global logging flag.
static void	GlobalLogOff ()
	Turn logging off - global.
static void	GlobalLogOn ()
	Turn logging on - global.

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

• debugfuture.hh