The main theme of this change is encapsulation. This change
preserves all existing functionality but the implementation
is now much cleaner.
Instead of a "database lock", access to the database is treated
as a resource acquisition problem. If a thread's owns a database
connection, then it can access the database; otherwise, it must
acquire a database connection first, and potentially wait for other
threads to give up theirs. The SQLiteConnectionPool encapsulates
the details of how connections are created, configured, acquired,
released and disposed.
One new feature is that SQLiteConnectionPool can make scheduling
decisions about which thread should next acquire a database
connection when there is contention among threads. The factors
considered include wait queue ordering (fairness among peers),
whether the connection is needed for an interactive operation
(unfairness on behalf of the UI), and whether the primary connection
is needed or if any old connection will do. Thus one goal of the
new SQLiteConnectionPool is to improve the utilization of
database connections.
To emulate some quirks of the old "database lock," we introduce
the concept of the primary database connection. The primary
database connection is the one that is typically used to perform
write operations to the database. When a thread holds the primary
database connection, it effectively prevents other threads from
modifying the database (although they can still read). What's
more, those threads will block when they try to acquire the primary
connection, which provides the same kind of mutual exclusion
features that the old "database lock" had. (In truth, we
probably don't need to be requiring use of the primary database
connection in as many places as we do now, but we can seek to refine
that behavior in future patches.)
Another significant change is that native sqlite3_stmt objects
(prepared statements) are fully encapsulated by the SQLiteConnection
object that owns them. This ensures that the connection can
finalize (destroy) all extant statements that belong to a database
connection when the connection is closed. (In the original code,
this was very complicated because the sqlite3_stmt objects were
managed by SQLiteCompiledSql objects which had different lifetime
from the original SQLiteDatabase that created them. Worse, the
SQLiteCompiledSql finalizer method couldn't actually destroy the
sqlite3_stmt objects because it ran on the finalizer thread and
therefore could not guarantee that it could acquire the database
lock in order to do the work. This resulted in some rather
tortured logic involving a list of pending finalizable statements
and a high change of deadlocks or leaks.)
Because sqlite3_stmt objects never escape the confines of the
SQLiteConnection that owns them, we can also greatly simplify
the design of the SQLiteProgram, SQLiteQuery and SQLiteStatement
objects. They no longer have to wrangle a native sqlite3_stmt
object pointer and manage its lifecycle. So now all they do
is hold bind arguments and provide a fancy API.
All of the JNI glue related to managing database connections
and performing transactions is now bound to SQLiteConnection
(rather than being scattered everywhere). This makes sense because
SQLiteConnection owns the native sqlite3 object, so it is the
only class in the system that can interact with the native
SQLite database directly. Encapsulation for the win.
One particularly tricky part of this change is managing the
ownership of SQLiteConnection objects. At any given time,
a SQLiteConnection is either owned by a SQLiteConnectionPool
or by a SQLiteSession. SQLiteConnections should never be leaked,
but we handle that case too (and yell about it with CloseGuard).
A SQLiteSession object is responsible for acquiring and releasing
a SQLiteConnection object on behalf of a single thread as needed.
For example, the session acquires a connection when a transaction
begins and releases it when finished. If the session cannot
acquire a connection immediately, then the requested operation
blocks until a connection becomes available.
SQLiteSessions are thread-local. A SQLiteDatabase assigns a
distinct session to each thread that performs database operations.
This is very very important. First, it prevents two threads
from trying to use the same SQLiteConnection at the same time
(because two threads can't share the same session).
Second, it prevents a single thread from trying to acquire two
SQLiteConnections simultaneously from the same database (because
a single thread can't have two sessions for the same database which,
in addition to being greedy, could result in a deadlock).
There is strict layering between the various database objects,
objects at lower layers are not aware of objects at higher layers.
Moreover, objects at higher layers generally own objects at lower
layers and are responsible for ensuring they are properly disposed
when no longer needed (good for the environment).
API layer: SQLiteDatabase, SQLiteProgram, SQLiteQuery, SQLiteStatement.
Session layer: SQLiteSession.
Connection layer: SQLiteConnectionPool, SQLiteConnection.
Native layer: JNI glue.
By avoiding cyclic dependencies between layers, we make the
architecture much more intelligible, maintainable and robust.
Finally, this change adds a great deal of new debugging information.
It is now possible to view a list of the most recent database
operations including how long they took to run using
"adb shell dumpsys dbinfo". (Because most of the interesting
work happens in SQLiteConnection, it is easy to add debugging
instrumentation to track all database operations in one place.)
Change-Id: Iffb4ce72d8bcf20b4e087d911da6aa84d2f15297
Was int, uint32_t, uint16_t, and uint8_t with 2-bit bitfield.
Also replace 0 by AUDIO_FORMAT_DEFAULT and replace 1 by
AUDIO_FORMAT_PCM_16_BIT.
Change-Id: Ia8804f53f1725669e368857d5bb2044917e17975
- it was a regression introduced into this CL: https://android-git.corp.google.com/g/#/c/154240/5
- basically needed to set the GlyphID encoding to the Skia Paint as we are now using glyphID resulting
from the Harfbuzz shaping
- also define GlyphID encoding as the default on the Paint class
Change-Id: Idb7c2c57ac67595425ce3be9421258962690fcdd
Add the initial support for supporting seperate socket
connections on the p2p interface.
This is the initial change making primary interface connections
work alongside native support for p2p socket connection
Change-Id: I7619715ca75b10afd29af852279fe713331f75e0
- Move all supplicant commands out of jni code in preparation for multi-socket
changes
- Also, clean up some function names to remove the explicit command
Change-Id: Id609ac7df0792fb85b52554d159f22064227c584
o Lots of documentation fixes.
o Add NdefMessage(NdefRecord ... records) ctor
o Add NdefRecord.createMime()
o Add NdefRecord.createExternal()
o Add toString(), equals() and hashCode() implementations
o Deprecate NdefRecord(byte[]) and NdefRecord.toByteArray()
o Remove framework dependency on libnfc_ndef.so
o Remove NfcAdapter.getDefaultAdapter(), its been deprecated a while
next step:
o Attempt to move NdefMessage -> Intent conversion into NDEF, and
make it CTS tested. This will ensure consistent NDEF -> Intent
mapping across all Android devices.
Change-Id: Ifed4910caa9a1d6bad32dbf0a507ab22bca35e22
- force Harfbuzz to shape with the Bengali font
- also fix potential returned NULL value from SkTypeface::CreateFromFile(path)
Change-Id: I25be09d06e449b89bb4a62444e27f77e436b77ba
- normalize (with ICU) each BiDi run before shaping them
We are normalizing by "chuncks" and starting from the end of the string. Each "chunck"
is composed of the main code point and its associated diacritics.
Fix bug #5738435 TextLayoutCache should be able to take care about diacritics during shaping
Change-Id: I7288027a7fa8eafb8b9f38d449625be60214548a
- add the ability to set the vsync delivery rate, when the rate is
set to N>1 (ie: receive every N vsync), SF process' is woken up for
all of vsync, but clients only see the every N events.
- add the concept of one-shot vsync events, with a call-back
to request the next one. currently the call-back is a binder IPC.
Change-Id: I09f71df0b0ba0d88ed997645e2e2497d553c9a1b
If the length is zero, then it will clobber memory at index -1
into the log_clusters array.
Explicitly handle the cases where the entire string or a single
run might have a length of 0.
Bug: 5705479
Change-Id: Ibbd3a4edcb7e1cad09c34091b42bb315776ea558
...Background Replacement on Stingray
This is how I should have done it in the first place. We get the
new surface from the window manager, and then just copy it in to
the constant Surface object we have for the holder.
Change-Id: I537a9e413829a18f689dfb46687014676b27156e
When the emulator is run without '-gpu on', GLES20 isn't supported,
so claiming GLES20Canvas is available will lead to catastrophic
failure. This change makes GLES20Canvas available when compiled in
and either not running on the emulator, or running on the emulator
with native GL acceleration enabled.
Change-Id: I89c944f9e3c9585224f5aa0877335ea48ea4a468
This change simplifies the code associated with receiving input
events from input channels and makes it more robust. It also
does a better job of ensuring that input events are properly
recycled (sometimes we dropped them on the floor).
This change also adds a sequence number to all events, which is
handy for determining whether we are looking at the same event or a
new one, particularly when events are recycled.
Change-Id: I4ebd88f73b5f77f3e150778cd550e7f91956aac2
As it turns out, it used to be possible for there to be multiple
input events simultaneously in flight in an application. Although
it worked, it made it hard to reason about what was going on.
The problem was somewhat exacerbated by the introduction of a
queue of "InputEventMessage" objects as part of an earlier latency
optimization.
This change restores order from chaos and greatly simplifies the
invariants related to input event dispatch within the application.
Change-Id: I6de5fe61c1fe2ac3dd33edf770d949044df8a019
