This change fixes race conditions that occur very regularly when
content providers are accessed from multiple threads at the same
time.
When a content provider is not already in the application's cache,
the application needs to ask the ActivityManager to obtain it.
Meanwhile, another thread can come along and do the same thing.
This can cause problems because the application attempts to
install two copies of the provider and the reference counts
and other bookkeeping can get muddled.
Similarly, there are races between releasing the last reference
to a content provider and acquiring the content provider. It's
possible for one thread to snatch the content provider from the
jaws of death. We need to handle this explicitly to ensure that
the content provider does not accidentally get released right
after it was acquired by the other thread.
This change ensures that the reference count bookkeeping and
provider map are maintained in parallel while holding the same lock.
Previously because the lock was dropped and reacquired in the
middle of acquisition and removal, it was possible for a
content provider with a zero reference count to be returned
to the application. Likewise, it was possible for a content
provider with a non-zero reference count to be disposed!
This change also performs compensatory actions when races are
detected to ensure that the necessary invariants are maintained
throughout. In particular, it ensures that the application
drops a duplicate reference to a content provider when no
longer needed.
Another way to solve this problem would be to explicitly prevent
the races from happening in the first place by maintaining a
table of content providers that are in the process of being
acquired. The first thread to attempt to acquire the provider
would store a record. The next thread would find the record
and block until the first thread was finished. I chose not
to implement the code in that manner because we would still
have needed to perform compensatory actions in the case where
the same provider binder has multiple logical names. Also,
it could cause deadlocks if the attempt to acquire
a content provider were re-entrant for some bizarre reason.
Bug: 5547357
Change-Id: I2ad39a8acc30aaf7ae5354decd0a0a41e9b9c3da
The existing action bar overlay decor layouts hit a case in
RelativeLayout that causes two measure passes for the main content. As
this can be expensive, stick the bar and the content overlay into
their own sub-layout and switch things to use a FrameLayout at the top
level instead.
Be explicit about the layout_width/height on ActionBar-containing
decor layouts as the older decor layouts are.
Change-Id: I4330f0f25841dd8058b94a320f93bf67fb56bf17
This updated tablet layouts to support showing album art and transport
control views in PIN, pattern and password screens of lock screen.
It also allows the addition of a background protect asset and
the ability to show the system wallpaper on layouts that define a
transport_bg_protect view.
Also updated layout to use new ICS-style buttons on lock screen and
fixed bug with "forgot pattern" button where we were showing the
emergency call icon.
To avoid problems with leading ones in the mono-space clock font,
we now right-justify status text on tablet and remove the AM/PM
indicator.
Status font size adjusted by UX.
Added background protection drop shadow to transport control.
Fixed portrait mode to be right-justified when transport is showing.
Change-Id: I790292fc39f4588f87adc9d9241706817ae6baab
Use const references to keys and values where appropriate to avoid
copying them unnecessarily.
Deleted some dead code.
Simplified a few pieces that were doing unnecessary redundant work.
Change-Id: Ib2145b7094a40db2d679e05dafe050fe1e87b846
Traceview showed approximately 10% of total parse time inside the
synthetic 'trampoline' methods generated to provide inner classes
with access to their outer class's private fields. The bottleneck
in this particular case is in XmlBlock and its inner class Parser.
Making the bottlneck outer-class members and methods package-scope
instead of private removes that 10% overhead being spent within
these access trampolines.
Traceview tends to overemphasize the significance of very small
methods such as these trampolines. That said, the measured speed
gain on the ParseLargeXmlResFg op due to this patch is between
5% and 6%.
Change-Id: Ia0e3ae5408d1f9992b46e6e30dd2407090379b07
We were not passing the length of the UTF-16 string to
String16::setTo. As a result, it was copying the contents of
the text up to the first null it found.
First problem, these strings are not typically null terminated!
Second problem, if the string contained a null character, then
we might truncate it. However, we only truncated the string
when the copy constructor was invoked (say, when we called
get() on the cache) but not in internalTextCopy() (before
adding the key to the cache).
As a result of the second problem, we would first search
the cache for a key that matched a partially copied truncated
string (potentially reading uninitialized memory that followed it).
Finding none, we would add the entry to the cache using
the correct key.
If the cache already had a value associated with the correct key,
then the put would fail, returning false. Charging ever onwards,
we would add the size of the entry to the cache size.
Proceeding in this manner, it was possible for the cache to
believe it had less remaining space than it really did. At that
point, it was possible for the cache to evict all entries and
yet still not think it had room to add a new one, so it would
continue trying to make space indefinitely.
Bug: 5576812
Change-Id: I05251594f6b2da0a5dc09f7200f04fe9100ec766
Revert "Fix bug #5387832 [UI/Visual] Address of the website is not displayed properly(second line of the address is partly shown)"
This reverts commit caa8c06de5
