drm_hwcomposer: Tracking of the DRM FB objects using RAII
DRM framebuffer objects must be kept registered in DRM/KMS
while used for scanning-out (After atomic commit applied
for processing by display controller and until next atomic
commit is applied for processing).
Existing logic for tracking current state is overcomplicated and
needs to be redesigned. Also further developing of drm_hwc will
require migration to asynchronous atomic commit, so additional
asynchronous FB cleanup logic must be created.
Buffer caching logic will also benefit from this.
With the RAII all further changes will be less painful and more robust.
By this commit I also renamed DrmGenericImporter to DrmFbImporter:
'Fb' word is present in most of existing composers (android and linux)
so it will be easier to compare different implementations.
Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
diff --git a/drm/DrmFbImporter.h b/drm/DrmFbImporter.h
new file mode 100644
index 0000000..167aa60
--- /dev/null
+++ b/drm/DrmFbImporter.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef DRM_DRMFBIMPORTER_H_
+#define DRM_DRMFBIMPORTER_H_
+
+#include <drm/drm_fourcc.h>
+#include <hardware/gralloc.h>
+
+#include <array>
+#include <map>
+
+#include "drm/DrmDevice.h"
+#include "drmhwcgralloc.h"
+
+#ifndef DRM_FORMAT_INVALID
+#define DRM_FORMAT_INVALID 0
+#endif
+
+using GemHandle = uint32_t;
+
+namespace android {
+
+class DrmFbIdHandle {
+ public:
+ static auto CreateInstance(hwc_drm_bo_t *bo, GemHandle first_gem_handle,
+ const std::shared_ptr<DrmDevice> &drm)
+ -> std::shared_ptr<DrmFbIdHandle>;
+
+ ~DrmFbIdHandle();
+ DrmFbIdHandle(DrmFbIdHandle &&) = delete;
+ DrmFbIdHandle(const DrmFbIdHandle &) = delete;
+ auto operator=(const DrmFbIdHandle &) = delete;
+ auto operator=(DrmFbIdHandle &&) = delete;
+
+ auto GetFbId [[nodiscard]] () const -> uint32_t {
+ return fb_id_;
+ }
+
+ private:
+ explicit DrmFbIdHandle(std::shared_ptr<DrmDevice> drm)
+ : drm_(std::move(drm)){};
+
+ const std::shared_ptr<DrmDevice> drm_;
+
+ uint32_t fb_id_{};
+ std::array<GemHandle, HWC_DRM_BO_MAX_PLANES> gem_handles_{};
+};
+
+class DrmFbImporter {
+ public:
+ explicit DrmFbImporter(std::shared_ptr<DrmDevice> drm)
+ : drm_(std::move(drm)){};
+ ~DrmFbImporter() = default;
+ DrmFbImporter(const DrmFbImporter &) = delete;
+ DrmFbImporter(DrmFbImporter &&) = delete;
+ auto operator=(const DrmFbImporter &) = delete;
+ auto operator=(DrmFbImporter &&) = delete;
+
+ auto GetOrCreateFbId(hwc_drm_bo_t *bo) -> std::shared_ptr<DrmFbIdHandle>;
+
+ private:
+ void CleanupEmptyCacheElements() {
+ for (auto it = drm_fb_id_handle_cache_.begin();
+ it != drm_fb_id_handle_cache_.end();) {
+ if (it->second.expired()) {
+ it = drm_fb_id_handle_cache_.erase(it);
+ } else {
+ ++it;
+ }
+ }
+ }
+
+ const std::shared_ptr<DrmDevice> drm_;
+
+ std::map<GemHandle, std::weak_ptr<DrmFbIdHandle>> drm_fb_id_handle_cache_;
+};
+
+} // namespace android
+
+#endif