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>
Call getaddrinfo() for connecting to IPv6 destinations.
Winsock APIs do not set errno. WSAGetLastError() returns Winsock errors
that are more numerous than BSD sockets, so it really doesn't make sense
to map those to BSD socket errors. Plus, even if we did that, the
Windows C Runtime (that mingw binaries use) has a strerror() that does
not recognize BSD socket error codes.
The solution is to wrap the various libcutils socket_* APIs with
sysdeps.h network_* APIs. For POSIX, the network_* APIs just call
strerror(). For Windows, they call SystemErrorCodeToString() (adapted
from Chromium).
Also in this change:
- Various other code was modified to return errors in a std::string*
argument, to be able to surface the error string to the end-user.
- Improved error checking and use of D() to log Winsock errors for
improved debuggability.
- For sysdeps_win32.cpp, added unique_fh class that works like
std::unique_ptr, for calling _fh_close().
- Fix win32 adb_socketpair() setting of errno in error case.
- Improve _socket_set_errno() D() logging to reduce confusion. Map
a few extra error codes.
- Move adb_shutdown() lower in sysdeps_win32.cpp so it can call
_socket_set_errno().
- Move network_connect() from adb_utils.cpp to sysdeps.h.
- Merge socket_loopback_server() and socket_inaddr_any_server() into
_network_server() since most of the code was identical.
Change-Id: I945f36870f320578b3a11ba093852ba6f7b93400
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
The adb emu command was never working because the socket connection to
the emulator was closed without reading all of the data that the
emulator sent. On Windows, this caused the emulator's recv() call to
error-out, so it never got the command that was sent.
Before settling on this fix, I also experimented changing the arguments
to the socket shutdown() call and that didn't seem to help. I also tried
removing the call to shutdown() and that didn't help. So that should
rule out shutdown() as the problem. One experiment that helped was
delaying before calling adb_close(), but that is of course fragile and
doesn't address the real issue, which is not closing the socket until
the commands have been read.
https://code.google.com/p/android/issues/detail?id=21021
Change-Id: I8fa4d740a2faa2c9922ec50792e16564a94f6eed
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
I keep trying to clean things up and needing std::strings. Might as
well just do this now.
usb_linux_client.c is going to stay as C because GCC isn't smart
enough to deal with the designated initializers it uses (though for
some reason it is in C mode).
The Darwin files are staying as C because I don't have a way to test
that they build.
The Windows files are staying as C because while I can actually build
for them, it's slow and painful.
Change-Id: I75367d29205a9049d34460032b3bb36384f43941