1
0
Fork 0
mirror of https://github.com/juce-framework/JUCE.git synced 2026-01-10 23:44:24 +00:00
JUCE/modules/juce_events/interprocess/juce_ChildProcessManager.h

113 lines
4.6 KiB
C++

/*
==============================================================================
This file is part of the JUCE framework.
Copyright (c) Raw Material Software Limited
JUCE is an open source framework subject to commercial or open source
licensing.
By downloading, installing, or using the JUCE framework, or combining the
JUCE framework with any other source code, object code, content or any other
copyrightable work, you agree to the terms of the JUCE End User Licence
Agreement, and all incorporated terms including the JUCE Privacy Policy and
the JUCE Website Terms of Service, as applicable, which will bind you. If you
do not agree to the terms of these agreements, we will not license the JUCE
framework to you, and you must discontinue the installation or download
process and cease use of the JUCE framework.
JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
JUCE Privacy Policy: https://juce.com/juce-privacy-policy
JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/
Or:
You may also use this code under the terms of the AGPLv3:
https://www.gnu.org/licenses/agpl-3.0.en.html
THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.
==============================================================================
*/
namespace juce
{
/** Manages a set of ChildProcesses and periodically checks their return value. Upon completion
it calls listeners added with addChildProcessExitedListener().
This class is mostly aimed for usage on Linux, where terminated child processes are only
cleaned up if their return code is read after termination. In order to ensure this one needs
to call ChildProcess::isFinished() until it returns false or
ChildProcess::waitForProcessToFinish() until it returns true.
This class will keep querying the return code on a Timer thread until the process
terminates. This can be handy if one wants to start and stop multiple ChildProcesses on
Linux that could take a long time to complete.
Since this class uses a Timer to check subprocess status, it's generally only safe to
access the returned ChildProcesses from the message thread.
@see ChildProcessManagerSingleton
@tags{Events}
*/
class JUCE_API ChildProcessManager final : private DeletedAtShutdown
{
public:
/** @cond */
JUCE_DECLARE_SINGLETON_SINGLETHREADED_MINIMAL_INLINE (ChildProcessManager)
/** @endcond */
/** Creates a new ChildProcess and starts it with the provided arguments.
The arguments are the same as the overloads to ChildProcess::start().
The manager will keep the returned ChildProcess object alive until it terminates and its
return value has been queried. Calling ChildProcess::kill() on the returned object will
eventually cause its removal from the ChildProcessManager after it terminates.
*/
template <typename... Args>
std::shared_ptr<ChildProcess> createAndStartManagedChildProcess (Args&&... args)
{
auto p = std::make_shared<ChildProcess>();
if (! p->start (std::forward<Args> (args)...))
return nullptr;
processes.insert (p);
timer.startTimer (1000);
return p;
}
/** Registers a callback function that is called for every ChildProcess that terminated.
This registration is deleted when the returned ErasedScopedGuard is deleted.
*/
auto addChildProcessExitedListener (std::function<void (ChildProcess*)> listener)
{
return listeners.addListener (std::move (listener));
}
/** Returns true if the ChildProcessManager contains any running ChildProcesses that it's
monitoring.
*/
auto hasRunningProcess() const
{
return timer.isTimerRunning();
}
private:
ChildProcessManager() = default;
~ChildProcessManager() override { clearSingletonInstance(); }
void checkProcesses();
std::set<std::shared_ptr<ChildProcess>> processes;
detail::CallbackListenerList<ChildProcess*> listeners;
TimedCallback timer { [this] { checkProcesses(); } };
};
} // namespace juce