The various atomic operations are declared as inline in the header files
to cut the function call overhead. However, the plain inline keyword is
just a suggestion to the compiler which makes its own decision on whether
to inline them or not. Worst, if they are not inlined, the
-fvisibility-inlines-hidden compiler flag will render them as hidden
symbols in the object file. If they are picked up by the linker over the
ones supplied in libcutils.so the following warning will be reported:
warning: hidden symbol 'android_atomic_inc' in foo.o is referenced by
DSO bar.so
One way is to add __attribute__((visibility("default"))) to those inline
functions to suppress the linker warnings. A better way is to force
inlining as with this patch.
Change-Id: Ie4fcfdfaaf06f42d351619a0d89671a9df15ca2f
This change moves the ARM definitions into GCC extended inline
assembler. In addition, the same set of x86 definitions are now
shared among all x86 targets.
Change-Id: I6e5aa3a413d0af2acbe5d32994983d35a01fdcb3
Added new atomic functions, renamed some old ones. Some #defines have
been added for backward compatibility.
Merged the pre- and post-ARMv6 implementations into a single file.
Renamed the semi-private __android_membar_full_smp to USE_SCREAMING_CAPS
since that's more appropriate for a macro.
Added lots of comments.
Note Mac OS X primitives have not been tested.
Change-Id: If827260750aeb61ad5c2b760e30658e29dbb26f2
Added atomic-inline.h. Added a platform-specific memory barrier call
there.
Added android_atomic_acquire_cmpxchg() and android_atomic_release_store().
Not tested on Mac OS X or SH.
Added memory barrier calls to linux-x86 atomics. Mac OS X has barrier
functions already. sh isn't really SMP-ready. linux-arm needs work
(to be done in a separate change).
Updated the makefile to make the SMP state visible to the code here.
Note that host binaries are NOT built with SMP enabled; while our hosts
are very likely SMP, it's not worth figuring out e.g. whether it's okay
to use the SSE2 mfence instruction or have to use something else. We
haven't had barriers enabled in host tools before, so there's probably
no need to stat now.
Removed quasiatomic 64-bit calls (now part of Dalvik).
Change-Id: I49e5e6c8abe70f304cdedb9d7b8e6e65f8925815
Ben Cheng