93e72b695e
The libcamera internal headers are located in src/libcamera/include/. The directory is added to the compiler headers search path with a meson include_directories() directive, and internal headers are included with (e.g. for the internal semaphore.h header) #include "semaphore.h" All was well, until libcxx decided to implement the C++20 synchronization library. The __threading_support header gained a #include <semaphore.h> to include the pthread's semaphore support. As include_directories() adds src/libcamera/include/ to the compiler search path with -I, the internal semaphore.h is included instead of the pthread version. Needless to say, the compiler isn't happy. Three options have been considered to fix this issue: - Use -iquote instead of -I. The -iquote option instructs gcc to only consider the header search path for headers included with the "" version. Meson unfortunately doesn't support this option. - Rename the internal semaphore.h header. This was deemed to be the beginning of a long whack-a-mole game, where namespace clashes with system libraries would appear over time (possibly dependent on particular system configurations) and would need to be constantly fixed. - Move the internal headers to another directory to create a unique namespace through path components. This causes lots of churn in all the existing source files through the all project. The first option would be best, but isn't available to us due to missing support in meson. Even if -iquote support was added, we would need to fix the problem before a new version of meson containing the required support would be released. The third option is thus the only practical solution available. Bite the bullet, and do it, moving headers to include/libcamera/internal/. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Jacopo Mondi <jacopo@jmondi.org>
111 lines
3.3 KiB
C++
111 lines
3.3 KiB
C++
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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/*
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* Copyright (C) 2019, Google Inc.
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*
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* bound_method.cpp - Method bind and invocation
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*/
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#include <libcamera/bound_method.h>
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#include "libcamera/internal/message.h"
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#include "libcamera/internal/semaphore.h"
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#include "libcamera/internal/thread.h"
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/**
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* \file bound_method.h
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* \brief Method bind and invocation
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*/
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namespace libcamera {
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/**
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* \enum ConnectionType
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* \brief Connection type for asynchronous communication
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*
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* This enumeration describes the possible types of asynchronous communication
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* between a sender and a receiver. It applies to Signal::emit() and
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* Object::invokeMethod().
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*
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* \var ConnectionType::ConnectionTypeAuto
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* \brief If the sender and the receiver live in the same thread,
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* ConnectionTypeDirect is used. Otherwise ConnectionTypeQueued is used.
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*
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* \var ConnectionType::ConnectionTypeDirect
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* \brief The receiver is invoked immediately and synchronously in the sender's
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* thread.
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*
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* \var ConnectionType::ConnectionTypeQueued
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* \brief The receiver is invoked asynchronously
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*
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* Invoke the receiver asynchronously in its thread when control returns to the
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* thread's event loop. The sender proceeds without waiting for the invocation
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* to complete.
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*
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* \var ConnectionType::ConnectionTypeBlocking
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* \brief The receiver is invoked synchronously
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*
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* If the sender and the receiver live in the same thread, this is equivalent to
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* ConnectionTypeDirect. Otherwise, the receiver is invoked asynchronously in
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* its thread when control returns to the thread's event loop. The sender
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* blocks until the receiver signals the completion of the invocation.
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*/
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/**
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* \brief Invoke the bound method with packed arguments
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* \param[in] pack Packed arguments
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* \param[in] deleteMethod True to delete \a this bound method instance when
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* method invocation completes
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*
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* The bound method stores its return value, if any, in the arguments \a pack.
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* For direct and blocking invocations, this is performed synchronously, and
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* the return value contained in the pack may be used. For queued invocations,
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* the return value is stored at an undefined point of time and shall thus not
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* be used by the caller.
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*
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* \return True if the return value contained in the \a pack may be used by the
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* caller, false otherwise
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*/
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bool BoundMethodBase::activatePack(std::shared_ptr<BoundMethodPackBase> pack,
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bool deleteMethod)
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{
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ConnectionType type = connectionType_;
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if (type == ConnectionTypeAuto) {
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if (Thread::current() == object_->thread())
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type = ConnectionTypeDirect;
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else
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type = ConnectionTypeQueued;
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} else if (type == ConnectionTypeBlocking) {
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if (Thread::current() == object_->thread())
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type = ConnectionTypeDirect;
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}
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switch (type) {
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case ConnectionTypeDirect:
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default:
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invokePack(pack.get());
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if (deleteMethod)
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delete this;
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return true;
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case ConnectionTypeQueued: {
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std::unique_ptr<Message> msg =
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std::make_unique<InvokeMessage>(this, pack, nullptr, deleteMethod);
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object_->postMessage(std::move(msg));
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return false;
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}
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case ConnectionTypeBlocking: {
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Semaphore semaphore;
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std::unique_ptr<Message> msg =
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std::make_unique<InvokeMessage>(this, pack, &semaphore, deleteMethod);
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object_->postMessage(std::move(msg));
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semaphore.acquire();
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return true;
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}
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}
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}
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} /* namespace libcamera */
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