Jinoh Kang : gdiplus: Replace GpImage's busy flag with SRWLOCK.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 72c0c88f2a5c9b52bb01f7981c0894a47efa55f3
URL:    https://gitlab.winehq.org/wine/wine/-/commit/72c0c88f2a5c9b52bb01f7981c0894a...

Author: Jinoh Kang <jinoh.kang.kr(a)gmail.com>
Date:   Sat Oct 22 21:25:37 2022 +0900

gdiplus: Replace GpImage's busy flag with SRWLOCK.

Today, the image_unlock() helper function has a data race due to
non-atomic write to GpImage's 'busy' flag which is accessible by other
threads.  Also, it lacks a release fence, which means that other threads
can observe the unlocked (busy = 0) state too early when the current
thread unlocks the image; specifically, the write to the 'busy' field of
the GpImage can be reordered before the last read/write to any other
fields of the same GpImage.

Fix this by replacing the 'busy' field of GpImage with SRWLOCK.

---

 dlls/gdiplus/gdiplus_private.h | 13 ++++----
 dlls/gdiplus/image.c           | 67 +++++++++++++++++++-----------------------
 2 files changed, 36 insertions(+), 44 deletions(-)