| 1 | // Copyright (C) 2024 The Qt Company Ltd. |
|---|---|
| 2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
| 3 | |
| 4 | #include "qrhivaluemapper_p.h" |
| 5 | |
| 6 | #include <qmutex.h> |
| 7 | #include <rhi/qrhi.h> |
| 8 | #include <q20vector.h> |
| 9 | |
| 10 | #include <vector> |
| 11 | |
| 12 | QT_BEGIN_NAMESPACE |
| 13 | |
| 14 | // ensures thread-safe access to rhi cleanup handlers |
| 15 | class QRhiCallback::Manager : public std::enable_shared_from_this<Manager> |
| 16 | { |
| 17 | using CallbackList = std::vector<std::weak_ptr<QRhiCallback>>; |
| 18 | struct CallbacksItem |
| 19 | { |
| 20 | CallbackList callbacks; |
| 21 | size_t lastValidCallbackCount = 1u; |
| 22 | |
| 23 | void addCallback(const std::weak_ptr<QRhiCallback> &cb) |
| 24 | { |
| 25 | Q_ASSERT(!cb.expired()); |
| 26 | |
| 27 | // check periodically to ensure avg O(1) |
| 28 | if (callbacks.size() > lastValidCallbackCount * 2) { |
| 29 | q20::erase_if(c&: callbacks, pred: [](const auto &cb) { |
| 30 | return cb.expired(); |
| 31 | }); |
| 32 | lastValidCallbackCount = callbacks.size() + 1; |
| 33 | } |
| 34 | |
| 35 | callbacks.push_back(x: cb); |
| 36 | } |
| 37 | }; |
| 38 | |
| 39 | public: |
| 40 | void registerCallback(QRhi &rhi, const std::weak_ptr<QRhiCallback> &cb) |
| 41 | { |
| 42 | QMutexLocker locker(&m_mutex); |
| 43 | auto [rhiIt, added] = m_rhiToCallbackItems.try_emplace(k: &rhi, args: CallbacksItem{}); |
| 44 | if (added) |
| 45 | rhi.addCleanupCallback(callback: [instance = shared_from_this()](QRhi *rhi) { |
| 46 | for (auto &weakCb : instance->extractCallbacks(rhi)) |
| 47 | if (auto cb = weakCb.lock()) |
| 48 | cb->onRhiCleanup(rhi&: *rhi); // run outside the global mutex |
| 49 | }); |
| 50 | |
| 51 | rhiIt->second.addCallback(cb); |
| 52 | } |
| 53 | |
| 54 | private: |
| 55 | CallbackList extractCallbacks(QRhi *rhi) |
| 56 | { |
| 57 | QMutexLocker locker(&m_mutex); |
| 58 | auto it = m_rhiToCallbackItems.find(x: rhi); |
| 59 | Q_ASSERT(it != m_rhiToCallbackItems.end()); |
| 60 | |
| 61 | CallbackList result = std::move(it->second.callbacks); |
| 62 | m_rhiToCallbackItems.erase(position: it); |
| 63 | return result; |
| 64 | } |
| 65 | |
| 66 | private: |
| 67 | std::unordered_map<QRhi *, CallbacksItem> m_rhiToCallbackItems; |
| 68 | QBasicMutex m_mutex; |
| 69 | }; |
| 70 | |
| 71 | Q_GLOBAL_STATIC(std::shared_ptr<QRhiCallback::Manager>, rhiCallbacksStorage, |
| 72 | std::make_shared<QRhiCallback::Manager>()); |
| 73 | |
| 74 | QRhiCallback::QRhiCallback() : m_manager(*rhiCallbacksStorage) { } |
| 75 | |
| 76 | QRhiCallback::~QRhiCallback() = default; // must be out-of-line |
| 77 | |
| 78 | void QRhiCallback::registerCallback(QRhi &rhi) |
| 79 | { |
| 80 | m_manager->registerCallback(rhi, cb: weak_from_this()); |
| 81 | } |
| 82 | |
| 83 | QT_END_NAMESPACE |
| 84 |