The atomic operations exported by the platform's C library do not
provide full memory barriers. This can result in incorrect results
when NDK machine code linked against them runs on multi-core devices.
While the bug has been fixed in the platform, this NDK header change
ensures that any source code that includes <sys/atomics.h> will end
up using a correct implementation of these functions, based on the
corresponding GCC builtins.
These builtins always provide a full barrier and have reasonable
performance. Application developers who depend on <sys/atomics.h>
should recompile their unmodified sources against this version
of the NDK as soon as possible.
This commit removes duplication of system headers per platform, i.e. remove
copies of common headers like <stdlib.h> from arch-arm/usr/include and arch-x86/usr/include
and move them to a common include directory. More specifically:
- common headers: android-N/arch-A/usr/include --> android-N/include
- arch-specific headers: android-N/arch-A/usr-include --> android-N/arch-A/include
- arch-specific libs: android-N/arch-A/usr/lib --> android-N/arch-A/lib
Change-Id: Ifdba5038d108901931f3e3a7c14ebe6270d2d276
NOTE: This also contains careful separation of API-level-specific headers.
For example, platforms/android-5/include/pthread.h contains new function
declarations that are not available when using platforms/android-3/include/pthread.h
NOTE: The NDK's build-platforms.sh script has been updated to understand the new
layout. This change in develeopment/ndk does not change the layout of
platform files under $NDK/platforms after build-platforms.sh is called.
