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
We comment out the names of the parameters we're intentionally
not using.
(cherrypick of 44a0eb4d8cdf4ab881f5d5a1acc1155266a46f6a.)
Change-Id: I0a92d9200ca26cdc4700d2ff9e3ab33c102520d5
I'll come back and remove klog_init when I've removed other calls to it.
Change-Id: Iad7fd26d853b4ddc54e9abd44516b6f138cbbfcb
Test: booted N9, looked at "adb shell dmesg" output.
The <hardware/qemu_pipe.h> header isn't related to any loadable
hardware module, this patch thus relocates it to <system/qemu_pipe.h>
which is a much more logical location.
Note the following changes:
- The pipe name must begin with the 'pipe:' prefix to avoid an
un-necessary snprintf() and buffer copy.
- Does not probe for the obsolete /dev/goldfish_pipe device, i.e.
only use /dev/qemu_pipe instead.
- Use QEMU_PIPE_DEBUG() instead of D() as the debugging macro.
+ Update ADB to use the newest <system/qemu_pipe.h>
+ Add qemu_pipe_frame_send() and qemu_pipe_frame_recv() utility
functions which replace the obsolete qemud_channel_send() and
qemud_channel_recv() from the defunct <hardware/qemud.h>
header.
BUG=25875346
Change-Id: Ic290a5b79d466c2af64b49bd9134643277c11bfd
If the underlying local map changes, it's possible for multiple
threads to try and modify the map data associated with the UnwindLocalMap
object. Add a lock when generating the local map to avoid this problem.
In addition, add a read lock whenever any caller gets the maps iterator.
Updated all iterator callers to make this lock.
Bug: 29387050
Change-Id: Ie34822c3d8fd3bdb3dd126aeeb399969c36508c1
clang doesn't do the frontend inlining/dead code elimination needed for
the fortified implementation to work. Therefore, turn it off.
Bug: http://b/28381737
Change-Id: Ie8dd970e3908b1daaa587ad2bd041e8f6e2089db
am: 6a29fe931d
* commit '6a29fe931d9fd3bf7f2aad3713dc70c080970763':
Add utility to prepare files in a similar way to directories
Change-Id: I288024d55e8cead1c902950938b03bfa8dcc3df3
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
(cherry picked from commit 3e4c076ef2)
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
(cherry picked from commit e263e6c633)
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
