fix(avplayer): close safely from event callbacks

[Ondra97]

What

Closing an AvPlayer from its event callback tried to join the controller thread that was running that callback. std::thread::join throws for a self-join, terminating the process during destruction.

When the controller closes its own player, detach that thread and retain a closure marker independently of the player. After the callback returns, the loop reads that marker and exits before accessing the destroyed player's locks or event queue. Closure from another thread still joins the controller normally.

The regression closes from the ready callback and the end-of-playback stop callback, creates a replacement player inside each callback, and checks that media allocations are released. It reuses the existing generated movie fixture and runs separately from the playback suite.

Tested

Windows 11 Pro 10.0.26300, supported WinLibs GCC 15.2.0, Release, main e34c47921.

• The new callback-close case fails on main with a std::system_error from self-joining in the player destructor. With the fix it passes three consecutive runs (2.44 s total); the final test dispatcher layout also passes (0.88 s).
• The existing guest_avplayer playback suite passes (4.16 s). Full default Windows build, conventions and whitespace checks pass.
• Reviewed fix(avplayer): defer loop warnings until frame delivery #5846 and fix(avplayer): keep handed-out video frames until later frames are handed out #1601, which change source buffering and the shared movie fixture, and separated the test dispatch insertion from fix(avplayer): defer loop warnings until frame delivery #5846. Neither implements callback closure. The repository overlap checker reports no conflicts in the shared-file inventory.
• Linux and retail-title runs were not performed locally. No performance claim.

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw; no silent stubs added
• No notes, investigation files or images added to the repository
• New third-party code is a submodule built from source; none added
• Generic behaviour, not specific to one title
• Depends on: none
• Unblocks: none
• GPUs tested: n/a
• AI-assisted: yes, Codex

Full platform runtime CI requires a write-access collaborator to dispatch it under repository policy.

[github-actions]

Other open pull requests touch the same code. Merging one will break the other, or both implement the same thing. If this one builds on them, list them in Depends on.

Pull request	Conflicting files (lines on main)	Same exports	Same new files
PR 5995	core/libs/prx/libSceAvPlayer/CMakeLists.txt L13, L18-19

Some comparisons could not be completed because a pull request conflicts with the base branch. Review these shared files manually before concluding that there is no overlap.

Pull request	Shared files not compared
PR 1601	core/libs/tests/GuestAvPlayer.cpp
PR 6044	core/libs/prx/libSceAvPlayer/CMakeLists.txt core/libs/tests/GuestAvPlayer.cpp

[jotitadev]

Linux run (Ubuntu 26.04, Intel i7-8700, GCC 15.2, full build, non-GPU tests), head 5474b7756 merged onto main 44df21632.

• Builds; guest_avplayer and the new guest_avplayer_callback_close pass.
• With AvPlayer.hpp/Player.cpp from main: guest_avplayer_callback_close aborts with std::system_error / Resource deadlock avoided (glibc's EDEADLK for the self-join), the Linux counterpart of the Windows failure in the description. guest_avplayer still passes.

Non-GPU suite (ctest -E "^agc"): same result as main; only file_writer_binary and file_writer_text fail, and they fail on main too on this machine (Ubuntu 26.04 coreutils).

Written with AI assistance (Claude Code). I ran the builds and tests above on my machine.

[adriadam10]

Checked on Linux: build and ctest of AvPlayer/libs (34 tests) pass; with AvPlayer.hpp/Player.cpp reverted, guest_avplayer_callback_close fails, so it exercises the fix. The detached controller only touches the shared closed flag after the callback returns, and the flag outlives the player via the lambda capture. Matches jotitadev's Linux run. Merging.