diff options
| author | Wan-Teh Chang <wtc@google.com> | 2016-12-07 16:16:02 -0800 |
|---|---|---|
| committer | Vittorio Giovara <vittorio.giovara@gmail.com> | 2016-12-08 15:53:58 -0500 |
| commit | 2170017a1cd033b6f28e16476921022712a522d8 (patch) | |
| tree | cfcbe102ef4c0fcddd52e2b51b9fca5a850db146 /libavutil/tests/.gitignore | |
| parent | d5759701a82926059ae3e2530805e900041a5419 (diff) | |
avutil: fix data race in av_get_cpu_flags()
Make the one-time initialization in av_get_cpu_flags() thread-safe. The
static variables |flags|, |cpuflags_mask|, and |checked| in
libavutil/cpu.c are read and written using normal load and store
operations. These are considered as data races. The fix is to use atomic
load and store operations.
Remove the |checked| variable because the invalid value of -1 for
|flags| can be used to indicate the same condition. Rename |flags| to
|cpu_flags| and move it to file scope.
The fix can be verified by running the libavutil/tests/cpu_init.c test
program under ThreadSanitizer:
./configure --toolchain=clang-tsan
make libavutil/tests/cpu_init
libavutil/tests/cpu_init
There should be no warnings from ThreadSanitizer.
Co-author: Dmitry Vyukov of Google, who suggested the data race fix.
Signed-off-by: Wan-Teh Chang <wtc@google.com>
Diffstat (limited to 'libavutil/tests/.gitignore')
| -rw-r--r-- | libavutil/tests/.gitignore | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/libavutil/tests/.gitignore b/libavutil/tests/.gitignore index c4d1d065fb..c8f37a7f90 100644 --- a/libavutil/tests/.gitignore +++ b/libavutil/tests/.gitignore @@ -5,6 +5,7 @@ /base64 /blowfish /cpu +/cpu_init /crc /des /eval |