Add basic interface documentation to RefBase.h.
Much, but not all, of this is cut-and-pasted from an email message
from Mathias Agopian. The rest is reconstructed from the code.
Delete some, now redundant, text from Refbase.cpp, and add a bit
more about the implementation strategy.
Some minor fixes to internal comments.
Bug: 30292291
Change-Id: I56518ae5553bc6de0cc2331778e7fcf2e6c4fd87
The compensating onLastStrongRef call could be made even when there
was no onIncStrongAttempted call to compensate for. This
happened in the OBJECT_LIFETIME_STRONG case when e.g. curCount
was initially zero, but was concurrently incremented by another
thread.
I believe the old code was also incorrect in the
curCount = INITIAL_STRONG_VALUE + 1 case,
which seems to be possible under unlikely conditions.
In that case, I believe the compensating call IS needed.
Thus the condition was also changed.
Bug: 30503444
Change-Id: I44bcbcbb1264e4b52b6d3750dc39b041c4140381
Add some basic tests for RefBase, as well as a more ambitious memory
ordering test.
Add a README.txt with instructions to run the tests.
Comment out a couple of BlobCache tests that failed consistently and
appeared to be incorrect. With that fix, I managed to run
libutils_tests successfully on device.
Bug: 28705989
Change-Id: I8ad29995097a149a0cc38615d6ed37117ec6cb5c
This matches what the Android.mk defined, and should temporarily fix
builds that were broken with:
system/core/libutils/Unicode.cpp:225:12: runtime error: unsigned integer
overflow: 0 - 1 cannot be represented in type 'size_t' (aka 'unsigned
long')
Change-Id: I0363b42fc2d62dfd2d05649c9aa9ef0be573e20a
Add comment that SharedBuffer is deprecated.
Both aref and SharedBuffer had memory ordering bugs. Aref has no
clients.
SharedBuffer had several bugs, which are fixed here:
mRefs was declared neither volatile, not atomic, allowing the
compiler to, for example, reuse a stale previously loaded value.
It used the default android_atomic release memory ordering, which
is insufficient for reference count decrements.
It used an ordinary memory read in onlyOwner() to check whether
an object is safe to deallocate, without any attempt to ensure
memory ordering.
Comments claimed that SharedBuffer was exactly 16 bytes, but
this was neither checked, nor correct on 64-bit platforms.
This turns mRef into a std::atomic and removes the android_atomic
dependency.
Bug: 28826227
Change-Id: I39fa0b4f70ac0471b14ad274806fc4e0c0802e78
Convert to use std::atomic directly.
Consistently use relaxed ordering for increments, release ordering
for decrements, and an added acquire fence when the count goes to
zero.
Fix what looks like another race in attemptIncStrong:
It seems entirely possible that the final adjustment for
INITIAL_STRONG_VALUE would see e.g. INITIAL_STRONG_VALUE + 1,
since we could be running in the middle of another initial
increment.
Attempt to somewhat document what this actually does, and
what's expected from the client. Hide the documentation in
the .cpp file for now.
Remove a confusing redundant test in decWeak. OBJECT_LIFETIME_STRONG
and OBJECT_LIFETIME_WEAK are the only options, in spite of some
of the original comments.
It's conceivable that either of these issues has resulted in
actual crashes, though I would guess the probability is small.
It's hard enough to reason about this code without the bugs.
Bug: 28705989
Change-Id: I4107a56c3fc0fdb7ee17fc8a8f0dd7fb128af9d8
We've removed the Android alarm driver from our supported kernels.
clock_gettime(CLOCK_BOOTTIME) has been a viable option since 2.6.39, so
there's no need for the legacy code path anymore.
We can use this on Linux hosts too, since no one should be building
Android on hosts with kernels that old.
Bug: 28357356
Change-Id: I0aa164383c95e77c53d2c85883d83f85d4abc7b1
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Also cleans up two instances of open() with useless mode params, and
changes a few uses of snprintf to use sizeof(buffer) instead of
hardcoded buffer sizes.
Change-Id: If11591003d910c995e72ad8f75afd072c255a3c5
* Store the output of a length variable in size_t.
* Annotate unsigned constant values as such.
Bug: 27384813
Change-Id: I8504c0a8f5840d4d42e5c0df797a4e5d02d13eb9
This change is a workaround for apps linking
libutils statically and dynamically which causes
them to crash for newer version of Android.
Bug: http://b/27313399
Change-Id: I47ac4146041b6eeef03cb605ea436719d552ec8f
(cherry picked from commit 2c7960c8d9)
Add utility methods that convert String16 and String8 into
std::string.
Also, remove a repeated include of <utils/Unicode.h> in
String16.h, since it is not used in that header file,
and is already included in String16.cpp.
BUG: 27200800
Change-Id: I5238aeb70689499763060a99dff9950fbb7adb3e
TEST: libutils builds successfully.
pid_t is 64-bit in 64-bit mingw, but the windows process/thread
functions return a DWORD(uint32_t). Instead of promoting to a pid_t and
fixing the format strings, just use a uint32_t to store the values.
android_thread_id also cannot be a 64-bit pointer, so for windows just
force it to be a uint32_t.
libutils/ProcessCallStack only works under Linux, since it makes heavy
use of /proc. Don't compile it under Windows or Darwin.
Bug: 26957718
Change-Id: I4e43e7cf18a96f22b3a9a08dbab8c3e960c12930
Arguably we should migrate to std::shared_ptr
but for now make std::vector<sp<>> a bit less
horrible
Change-Id: Ia458a2daff0b656b2f3310b3ea100565ec844c69
FileMaps should be movable, thereby not requiring them to be only used
with a unique_ptr as they currently are.
Change-Id: I0fb8013bf398a2ced5420d85ba888c2a7fc5a496
