Guard against threads joining twice.

After a pthread_join() call the handle becomes invalid or could be
recycled by another thread, leading to undefined behavior when
attempting to join it again. Also, on Windows the handle has to be
closed to free it.

Bug b/34883464

Change-Id: Ib20d0539b6b46e331c6378b3a9f0c2a334d34892
Reviewed-by: Alexis H├ętu <>
Reviewed-by: Nicolas Capens <>
Tested-by: Nicolas Capens <>
(cherry picked from commit 3fbe73e77dc48bdb5b53cef15a24e1e8aae48bf5)
2 files changed
tree: e134a06be8a1241d3de24ef30903d8538a4f69dc
  1. .dir-locals.el
  2. .gitignore
  3. AUTHORS.txt
  6. CMakeLists.txt
  9. LICENSE.txt
  11. SwiftShader.sln
  12. docs/
  13. include/
  14. src/
  15. tests/
  16. 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.


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

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:


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.