The Android SDK has a device emulator. Â I use it in Eclipse with the Android JUnit test framework. Â A few days ago, the emulator refused to start.
From Window -> AVD Manager, I started one of the devices. Â A dialog titled “Starting Android Emulator” came up. Â Inside it, a progress bar ticked off ten seconds. Â Then, nothing. Â This behavior was the same for all my devices, from Android version 1.5 through version 4.0.3.
To see if the problem was related to Eclipse, I started the emulator from the command line. Â To do this, you need the name of the AVD:
android list avd
Using my Android 1.5 virtual device, I tried to start it:
emulator -avd OldAndroid
And the result was “Segmentation fault”. Â I turned on “verbose” and ran again:
emulator -verbose -avd OldAndroid
This prints out what’s happening. Â The last line before the seg fault was: Â “emulator: Initializing hardware OpenGLES emulation support”. Â Next, I tried to see which system call failed:
strace emulator -avd OldAndroid
The last line there is a futex call with operation FUTEX_WAIT and no timeout.  This call was unfinished, resulting in the seg fault.  From the manual page for futex:  “This operation atomically verifies that the futex address uaddr still contains the value val, and sleeps awaiting FUTEX_WAKE on this futex address.”  The address appears in the lines above.
A bug report was filed today about this issue: Â http://code.google.com/p/android/issues/detail?id=34233
Zymurgeek | 21-Jul-12 at 6:11 am | Permalink
Update: I backleveled the android SDK to version 18 (linked in comment #25). The archive contains three directories, but since add-ons and platforms are empty, only replace the tools directory.
This fixed the emulator from the command line, but Eclipse complains ADT requires version 20.
Zymurgeek | 21-Jul-12 at 6:51 am | Permalink
To backlevel a plug-in in Eclipse, you can use Help -> About Eclipse -> Installation Details, select the Installation History tab and select a prior installation. However, the older versions of ADT are no longer in the repository.
As a work-around, download http://dl.google.com/android/ADT-18.0.0.zip. In Eclipse, uninstall ADT with Help -> About Eclipse -> Installation Details -> Installed Software tab . Select all the android version 20 plug-ins and select Uninstall. Restart Eclipse.
Install the zipped plug-in with Help -> Install New Software. Next to “Work with”, select Add. Select Archive and choose your ADT zip file. The rest of the install is straightforward.
Zymurgeek | 01-Feb-13 at 7:58 pm | Permalink
Recently I needed to upgrade the Android SDK Tools, which brought back this bug. Then I discovered I could run with GPU emulation enabled in the AVD, but that caused screen updates to lag horribly. Thanks to an update to the bug report above, I learned that
emulator-armworks. I renamedemulatortoemulator-origand linkedemulator-armtoemulator. After editing my AVDs to disable GPU emulation, everything’s working again.