IssueTracker

This bug has been present since at least 4.0 and seems to be present up to 4.4 which I have been testing on.  After swiping an app away, the foreground service has waitingToKill set to 'remove task'.  The incoming broadcast then makes the service no longer run as foreground then kills it.

I've tracked through this fairly thoroughly I hope.  It seems the bug is in the broadcast code.  If not for that, the service will not be killed.

Swiping an app from the task list calls am.removeTask on the app with the REMOVE_TASK_KILL_PROCESS flag.

https://android.googlesource.com/platform/frameworks/base/+/android-4.4_r1/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
in handleSwipe()
        // Currently, either direction means the same thing, so ignore direction and remove
        // the task.
        final ActivityManager am = (ActivityManager)
                mContext.getSystemService(Context.ACTIVITY_SERVICE);
        if (am != null) {
            am.removeTask(ad.persistentTaskId, ActivityManager.REMOVE_TASK_KILL_PROCESS);


If the task is a foreground service, it ends up getting waitingToKill set with 'remove task'

https://android.googlesource.com/platform/frameworks/base/+/master/services/java/com/android/server/am/ActivityManagerService.java
in cleanUpRemovedTaskLocked() called by removeTask() with the REMOVE_TASK_KILL_PROCESS flag
    private void cleanUpRemovedTaskLocked(TaskRecord tr, int flags) {
        final boolean killProcesses = (flags&ActivityManager.REMOVE_TASK_KILL_PROCESS) != 0;
[...]
        if (killProcesses) {
[...]
            // Kill the running processes.
            for (int i=0; i<procs.size(); i++) {
                ProcessRecord pr = procs.get(i);
                if (pr.setSchedGroup == Process.THREAD_GROUP_BG_NONINTERACTIVE) {
                    Slog.i(TAG, "Killing " + pr.toShortString() + ": remove task");
                    EventLog.writeEvent(EventLogTags.AM_KILL, pr.userId, pr.pid,
                            pr.processName, pr.setAdj, "remove task");
                    pr.killedBackground = true;
                    Process.killProcessQuiet(pr.pid);
                } else {
                    pr.waitingToKill = "remove task";
                }
            }


When receiving a broadcast, the app state is changed to 'broadcast' instead of 'fg-service' by computeOomAdjLocked()

    setIsForeground=false foregroundServices=true forcingToForeground=null
    Proc #20: prcp  F/S/IF trm: 0 6413:com.countercultured.irc/u0a136 (fg-service)

changes to:

    setIsForeground=false foregroundServices=true forcingToForeground=null
    Proc #20: fore  B/S/S  trm: 0 6413:com.countercultured.irc/u0a136 (broadcast)

Then is promptly killed since it is no longer a foreground service.

First character F:  Process.THREAD_GROUP_DEFAULT
First character B:  Process.THREAD_GROUP_BG_NONINTERACTIVE

Second character S: r.foregroundServices == true

Third character IF:  ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND
Third character S:   ActivityManager.PROCESS_STATE_SERVICE

 private final int computeOomAdjLocked(ProcessRecord app, int cachedAdj, ProcessRecord TOP_APP,
            boolean doingAll, long now) {
[...]
        } else if ((queue = isReceivingBroadcast(app)) != null) {
            // An app that is currently receiving a broadcast also
            // counts as being in the foreground for OOM killer purposes.
            // It's placed in a sched group based on the nature of the
            // broadcast as reflected by which queue it's active in.
            adj = ProcessList.FOREGROUND_APP_ADJ;
            schedGroup = (queue == mFgBroadcastQueue)
                    ? Process.THREAD_GROUP_DEFAULT : Process.THREAD_GROUP_BG_NONINTERACTIVE;
            app.adjType = "broadcast";
            procState = ActivityManager.PROCESS_STATE_RECEIVER;


Full dumpsys from before alarm and during

BEFORE:
ACTIVITY MANAGER RUNNING PROCESSES (dumpsys activity processes)
  All known processes:
  *APP* UID 10136 ProcessRecord{65c7df88 1244:com.countercultured.irc/u0a136}
    user #0 uid=10136
    dir=/data/app/com.countercultured.irc-2.apk publicDir=/data/app/com.countercultured.irc-2.apk data=/data/data/com.countercultured.irc
    packageList={com.countercultured.irc}
    compat={480dpi}
    thread=android.app.ApplicationThreadProxy@65ceee30
    pid=1244 starting=false
    lastActivityTime=-7s800ms lastPssTime=-17s326ms nextPssTime=+12s203ms
    adjSeq=133653 lruSeq=0 lastPss=0 lastCachedPss=0
    keeping=true cached=false empty=true
    oom: max=16 curRaw=2 setRaw=2 cur=2 set=2
    curSchedGroup=-1 setSchedGroup=-1 systemNoUi=false trimMemoryLevel=0
    curProcState=3 repProcState=3 pssProcState=-1 setProcState=3 lastStateTime=-7s797ms
    hasShownUi=true pendingUiClean=false hasAboveClient=false
    setIsForeground=false foregroundServices=true forcingToForeground=null
    hasStartedServices=true
    lastRequestedGc=-17s253ms lastLowMemory=-17s253ms reportLowMemory=false
    killedByAm=false waitingToKill=remove task
    Services:
      - ServiceRecord{663ab1d8 u0 com.countercultured.irc/.AlarmService}
      - ServiceRecord{664a8130 u0 com.countercultured.irc/.ServerService}
    Connections:
      - ConnectionRecord{662d0d58 u0 CR com.countercultured.irc/.AlarmService:@65e53448}
    Connected Providers:
      - 6590e6c8/com.android.providers.settings/.SettingsProvider->1244:com.countercultured.irc/u0a136 s1/1 u0/0 +16s148ms
    Receivers:
      - ReceiverList{6601ba00 1244 com.countercultured.irc/10136/u0 remote:65d16a78}
      - ReceiverList{662a2450 1244 com.countercultured.irc/10136/u0 remote:65e29e70}

  Process LRU list (sorted by oom_adj, 33 total, non-act at 5, non-svc at 5):
    Proc # 8: prcp  F/S/IF trm: 0 1244:com.countercultured.irc/u0a136 (fg-service)

  PID mappings:
    PID #1244: ProcessRecord{65c7df88 1244:com.countercultured.irc/u0a136}
  mPreviousProcessVisibleTime: +1d2h23m6s383ms
  mConfigWillChange: false


DURING:
ACTIVITY MANAGER RUNNING PROCESSES (dumpsys activity processes)
  All known processes:
  *APP* UID 10136 ProcessRecord{65c7df88 1244:com.countercultured.irc/u0a136}
    user #0 uid=10136
    dir=/data/app/com.countercultured.irc-2.apk publicDir=/data/app/com.countercultured.irc-2.apk data=/data/data/com.countercultured.irc
    packageList={com.countercultured.irc}
    compat={480dpi}
    thread=android.app.ApplicationThreadProxy@65ceee30
    pid=1244 starting=false
    lastActivityTime=-7s830ms lastPssTime=-17s356ms nextPssTime=+19s994ms
    adjSeq=133655 lruSeq=0 lastPss=0 lastCachedPss=0
    keeping=true cached=false empty=false
    oom: max=16 curRaw=0 setRaw=0 cur=0 set=0
    curSchedGroup=0 setSchedGroup=0 systemNoUi=false trimMemoryLevel=0
    curProcState=7 repProcState=7 pssProcState=-1 setProcState=7 lastStateTime=-6ms
    hasShownUi=true pendingUiClean=false hasAboveClient=false
    setIsForeground=false foregroundServices=true forcingToForeground=null
    hasStartedServices=true
    lastRequestedGc=-17s283ms lastLowMemory=-17s283ms reportLowMemory=false
    killedByAm=true waitingToKill=remove task
    Services:
      - ServiceRecord{663ab1d8 u0 com.countercultured.irc/.AlarmService}
      - ServiceRecord{664a8130 u0 com.countercultured.irc/.ServerService}
    Connections:
      - ConnectionRecord{662d0d58 u0 CR com.countercultured.irc/.AlarmService:@65e53448}
    Connected Providers:
      - 6590e6c8/com.android.providers.settings/.SettingsProvider->1244:com.countercultured.irc/u0a136 s1/1 u0/0 +16s179ms
    curReceiver=BroadcastRecord{65f930f0 u-1 com.countercultured.irc.ALARM_ACTION}
    Receivers:
      - ReceiverList{6601ba00 1244 com.countercultured.irc/10136/u0 remote:65d16a78}
      - ReceiverList{662a2450 1244 com.countercultured.irc/10136/u0 remote:65e29e70}

  Process LRU list (sorted by oom_adj, 33 total, non-act at 5, non-svc at 5):
    Proc # 8: fore  B/S/S  trm: 0 1244:com.countercultured.irc/u0a136 (broadcast)

  PID mappings:
    PID #1244: ProcessRecord{65c7df88 1244:com.countercultured.irc/u0a136}
  mPreviousProcessVisibleTime: +1d2h23m6s383ms
  mConfigWillChange: false