Select Git revision
ring_types.h
-
Adrien Béraud authored
* rename namespace from ring to jami * rename logs methods from RING_* to JAMI_* * rename RING_VIDEO to ENABLE_VIDEO Change-Id: Ic98498652d7059fafe58a96220d565bcdfa53658
Adrien Béraud authored* rename namespace from ring to jami * rename logs methods from RING_* to JAMI_* * rename RING_VIDEO to ENABLE_VIDEO Change-Id: Ic98498652d7059fafe58a96220d565bcdfa53658
Code owners
Assign users and groups as approvers for specific file changes. Learn more.
ring_types.h 2.54 KiB
/*
* Copyright (C) 2004-2019 Savoir-faire Linux Inc.
*
* Author: Tristan Matthews <tristan.matthews@savoirfairelinux.com>
* Author: Adrien Béraud <adrien.beraud@savoirfairelinux.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef RING_TYPES_H_
#define RING_TYPES_H_
#include <type_traits>
#include <memory>
#include <mutex>
#include <cstddef> // for size_t
#include <ciso646> // fix windows compiler bug
namespace jami {
typedef int16_t AudioSample;
static constexpr size_t SIZEBUF = 16000; /** About 62.5ms of buffering at 48kHz */
/**
* This meta-function is used to enable a template overload
* only if given class T is a base of class U
*/
template <class T, class U>
using enable_if_base_of = typename std::enable_if<std::is_base_of<T, U>::value, T>::type;
/**
* Return a shared pointer on an auto-generated global instance of class T.
* This instance is created only at usage and destroyed when not,
* as we keep only a weak reference on it.
* But when created it's always the same object until all holders release
* their sharing.
* An optional MaxRespawn positive integer can be given to limit the number
* of time the object can be created (i.e. different instance).
* Any negative values (default) block this effect (unlimited respawn).
* This function is thread-safe.
*/
template <class T, signed MaxRespawn=-1>
std::shared_ptr<T>
getGlobalInstance()
{
static std::recursive_mutex mutex; // recursive as instance calls recursively
static std::weak_ptr<T> wlink;
std::unique_lock<std::recursive_mutex> lock(mutex);
if (wlink.expired()) {
static signed counter {MaxRespawn};
if (not counter)
return nullptr;
auto link = std::make_shared<T>();
wlink = link;
if (counter > 0)
--counter;
return link;
}
return wlink.lock();
}
} // namespace jami
#endif // RING_TYPES_H_