Do not submit this patch before the one that modifies the Android emulator to
work-around a weird ARMv7 emulation issue. This is done to temporarily re-allow
the -user builds needed for QA.
This is required to work-around some corny bugs in ARMv7 emulation.
The emulation itself is required to run the dex pre-optimization pass
for -user builds.
372 MB/s for large transfers, 440 MB/s for smaller ones down to 1KB. 130 MB/s for very small transfers ( < 32 bytes )
Performance is similar with non-congruent buffers.
For performance reasons, we don't call the kernel helper. Instead, we directly
access the TLS register on ARMv6 and higher. For ARMv5TE, keep using the hard-coded
address populated by the kernel on each task switch.
NOTE: Since we don't call the kernel helper, this must precisely match your
kernel configuration. This is controlled by setting the ARCH_ARM_HAVE_TLS_REGISTER
variable to 'true' in your board configuration file.
The problem was due to the fact that, in the case of dynamic executables,
the dynamic linker calls the DT_PREINIT_ARRAY, DT_INIT and DT_INIT_ARRAY
constructors when loading shared libraries and dynamic executables,
*before* calling the executable's entry point (i.e. arch-$ARCH/bionic/crtbegin_dynamic.c)
which in turns call __libc_init() in libc.so, as defined by bionic/libc_init_dynamic.c
The latter did call these constructors array again, mistakenly.
The patch also updates the documentation of many related functions.
Also adds a new section to linker/README.TXT explaining restrictions on
C library usage.
The patch has been tested on a Dream for stability issues with
proprietary blobs:
- H264 decoding works
- Camera + Video recording works
- GPS works
- Sensors work
The tests in system/extra/tests/bionic/libc/common/test_static_cpp_mutex.cpp has been
run and shows the static C++ constructor being called only once.
