Background
==========
On Windows, if you run "adb shell exit" in a loop in two windows,
eventually the adb client will be unable to connect to the adb server. I
think connect() is returning WSAEADDRINUSE: "Only one usage of each
socket address (protocol/network address/port) is normally permitted.
(10048)". The Windows System Event Log may also show Event 4227, Tcpip.
Netstat output is filled with:
# for the adb server
TCP 127.0.0.1:5037 127.0.0.1:65523 TIME_WAIT
# for the adb client
TCP 127.0.0.1:65523 127.0.0.1:5037 TIME_WAIT
The error probably means that the client is running out of free
address:port pairs.
The first netstat line is unavoidable, but the second line exists
because the adb client is not waiting for orderly/graceful shutdown of
the socket, and that is apparently required on Windows to get rid of the
second line. For more info, see
https://github.com/CompareAndSwap/SocketCloseTest .
This is exacerbated by the fact that "adb shell exit" makes 4 socket
connections to the adb server: 1) host:version, 2) host:features, 3)
host:version (again), 4) shell:exit. Also exacerbating is the fact that
the adb protocol is length-prefixed so the client typically does not
have to 'read() until zero' which effectively waits for orderly/graceful
shutdown.
The Fix
=======
Introduce a function, ReadOrderlyShutdown(), that should be called in
the adb client to wait for the server to close its socket, before
closing the client socket.
I reviewed all code where the adb client makes a connection to the adb
server and added ReadOrderlyShutdown() when it made sense. I wasn't able
to add it to the following:
* interactive_shell: this doesn't matter because this is interactive and
thus can't be run fast enough to use up ports.
* adb sideload: I couldn't get enough test coverage and I don't think
this is being called frequently enough to be a problem.
* send_shell_command, backup, adb_connect_command, adb shell, adb
exec-out, install_multiple_app, adb_send_emulator_command: These
already wait for server socket shutdown since they already call
recv() until zero.
* restore, adb exec-in: protocol design can't have the server close
first.
* adb start-server: no fd is actually returned
* create_local_service_socket, local_connect_arbitrary_ports,
connect_device: probably called rarely enough not to be a problem.
Also in this change
===================
* Clarify comments in when adb_shutdown() is called before exit().
* add some missing adb_close() in adb sideload.
* Fixup error handling and comments in adb_send_emulator_command().
* Make SyncConnection::SendQuit return a success boolean.
* Add unittest for adb emu kill command. This gets code coverage over
this very careful piece of code.
Change-Id: Iad0b1336f5b74186af2cd35f7ea827d0fa77a17c
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
adb.cpp: launch_server() has a long comment about how
stdin/stdout/stderr handles have to be made non-inheritable to prevent
hangs in callers to adb.exe.
It would be disastrous to do this wrong, and I've modified this code, so
here's a unittest to verify that I'm doing it right.
The test also runs fine on unix.
Change-Id: I3672c3066bc7498635c19212f9e5c50757942439
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
This is mostly just the AdbWrapper that we used in our tests, but I've
cleaned up the API to be a little more Pythonic (mostly in the sense
that commands are passed as lists rather than strings that are
shlex.split() by the shell command), and implemented the workaround
error checking for adb shell.
Move the tests up a directory. Having them buried a level down has
only been annoying.
There are now two files containing Python tests. test_device.py
contains tests specifically checking the AndroidDevice API, and
test_adb.py checks the ADB client program. To run both, use
python -m unittest discover [-v]
Change-Id: Ibd158c528d31126a5b048bd00bc93039dbc468bc
