adb: win32: fix shutdown deadlock

adb can hang at shutdown due to a deadlock relating to WSACleanup().
This works around the issue by not calling WSACleanup() which shouldn't
be done anyway since threads aren't done using Winsock at shutdown.

A quick way to reproduce the original problem is to run many instances
of adb, many of which will call exit() soon:

  for /l %i in (1,1,20) do @start adb nodaemon server

You may have to boost the 20 to 200, or set ADB_TRACE=1 or use Windows
10 instead of Windows 7, to affect the timing, but eventually there
should be hung adb processes with that repro.

A more complete fix to prevent problems like this from occuring in the
future, would be to additionally do the following:

- Investigate all static destructors that are called when exit() is
  called.

- If they don't do anything important, switch all calls to exit() to
  instead call _exit() and then ban exit() from being called.

Change-Id: Id1be3bf0053809a45f2eca4461e4c35b5ef9388d
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
1 file changed