Fix potential data race in mutex lock implementation.

Writing or reading an ordinary volatile boolean does not provide memory
ordering guarantees. Use atomic<bool> with release and acquire semantics
instead. On x86 this should have no impact on the generated code, since
it architecturally offers strong memory ordering guarantees.

Bug chromium:710753

Change-Id: I5aa2a6eeecfcd691a0aa8d06fd067f9d59ab13c3
Reviewed-by: Corentin Wallez <>
Reviewed-by: Nicolas Capens <>
Tested-by: Nicolas Capens <>
1 file changed
tree: 2e0f7452bd19881895b2c9220a3c4902958267d3
  1. .dir-locals.el
  2. .gitignore
  3. .gitmodules
  4. AUTHORS.txt
  7. CMakeLists.txt
  10. DEPS
  11. LICENSE.txt
  12. OWNERS
  15. README.version
  16. SwiftShader.sln
  17. docs/
  18. include/
  19. src/
  20. tests/
  21. third_party/



SwiftShader is a high-performance CPU-based implementation of the OpenGL ES and Direct3D 9 graphics APIs12. Its goal is to provide hardware independence for advanced 3D graphics.


The SwiftShader libraries act as drop-in replacements for graphics drivers.

On Windows, most applications can be made to use SwiftShader's DLLs by placing them in the same folder as the executable. On Linux, the LD_LIBRARY_PATH environment variable or -rpath linker option can be used to direct applications to search for shared libraries in the indicated directory first.

Prebuilt binaries can be found at:


See CONTRIBUTING.txt for important contributing requirements.

The canonical repository for SwiftShader is hosted at:

All changes must be reviewed and approved in the Gerrit review tool at:

Authenticate your account here:

All changes require a Change-ID tag in the commit message. A commit hook may be used to add this tag automatically, and can be found at: To clone the repository and install the commit hook in one go:

git clone && (cd SwiftShader && curl -Lo `git rev-parse --git-dir`/hooks/commit-msg ; chmod +x `git rev-parse --git-dir`/hooks/commit-msg)

Changes are uploaded to Gerrit by performing:

git push origin HEAD:refs/for/master


See docs/


Public mailing list:

Bug tracker:


The SwiftShader project is licensed under the Apache License Version 2.0. You can find a copy of it in LICENSE.txt.

Files in the third_party folder are subject to their respective license.

Authors and Contributors

The legal authors for copyright purposes are listed in AUTHORS.txt.

CONTRIBUTORS.txt contains a list of names of individuals who have contributed to SwiftShader. If you‘re not on the list, but you’ve signed the Google CLA and have contributed more than a formatting change, feel free to request to be added.


  1. Trademarks are the property of their respective owners.
  2. We do not claim official conformance with any graphics APIs at this moment.
  3. This is not an official Google product.