services/core/java/com/android/server/os/SchedulingPolicyService.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2012 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.server.os;

 import android.content.pm.PackageManager;
 import android.os.Binder;
 import android.os.IBinder;
 import android.os.ISchedulingPolicyService;
 import android.os.Process;
 import android.util.Log;

 import com.android.server.SystemServerInitThreadPool;

 /**
  * The implementation of the scheduling policy service interface.
  *
  * @hide
  */
 public class SchedulingPolicyService extends ISchedulingPolicyService.Stub {

     private static final String TAG = "SchedulingPolicyService";

     // Minimum and maximum values allowed for requestPriority parameter prio
     private static final int PRIORITY_MIN = 1;
     private static final int PRIORITY_MAX = 3;

     private static final String[] MEDIA_PROCESS_NAMES = new String[] {
             "media.swcodec", // /apex/com.android.media.swcodec/bin/mediaswcodec
     };
     private final IBinder.DeathRecipient mDeathRecipient = new IBinder.DeathRecipient() {
         @Override
         public void binderDied() {
             requestCpusetBoost(false /*enable*/, null /*client*/);
         }
     };
     // Current process that received a cpuset boost
     private int mBoostedPid = -1;
     // Current client registered to the death recipient
     private IBinder mClient;

     public SchedulingPolicyService() {
         // system_server (our host) could have crashed before. The app may not survive
         // it, but mediaserver/media.codec could have, and mediaserver probably tried
         // to disable the boost while we were dead.
         // We do a restore of media.codec to default cpuset upon service restart to
         // catch this case. We can't leave media.codec in boosted state, because we've
         // lost the death recipient of mClient from mediaserver after the restart,
         // if mediaserver dies in the future we won't have a notification to reset.
         // (Note that if mediaserver thinks we're in boosted state before the crash,
         // the state could go out of sync temporarily until mediaserver enables/disable
         // boost next time, but this won't be a big issue.)
         SystemServerInitThreadPool.submit(() -> {
             synchronized (mDeathRecipient) {
                 // only do this if we haven't already got a request to boost.
                 if (mBoostedPid == -1) {
                     int[] nativePids = Process.getPidsForCommands(MEDIA_PROCESS_NAMES);
                     if (nativePids != null && nativePids.length == 1) {
                         mBoostedPid = nativePids[0];
                         disableCpusetBoost(nativePids[0]);
                     }
                 }
             }
         }, TAG + ".<init>");
     }

     // TODO(b/35196900) We should pass the period in time units, rather
     // than a fixed priority number.
     public int requestPriority(int pid, int tid, int prio, boolean isForApp) {
         //Log.i(TAG, "requestPriority(pid=" + pid + ", tid=" + tid + ", prio=" + prio + ")");

         // Verify that the caller uid is permitted, priority is in range,
         // and that the callback thread specified by app belongs to the app that
         // called mediaserver or audioserver.
         // Once we've verified that the caller uid is permitted, we can trust the pid but
         // we can't trust the tid.  No need to explicitly check for pid == 0 || tid == 0,
         // since if not the case then the getThreadGroupLeader() test will also fail.
         if (!isPermitted() || prio < PRIORITY_MIN ||
                 prio > PRIORITY_MAX || Process.getThreadGroupLeader(tid) != pid) {
            return PackageManager.PERMISSION_DENIED;
         }
         // If the calling UID is audio server, and this call is not for an app,
         // then it must be for the audio HAL. Validate the UID of the thread.
         if (Binder.getCallingUid() == Process.AUDIOSERVER_UID && !isForApp
                 && Process.getUidForPid(tid) != Process.AUDIOSERVER_UID) {
             return PackageManager.PERMISSION_DENIED;
         }
         if (Binder.getCallingUid() != Process.BLUETOOTH_UID) {
             try {
                 // make good use of our CAP_SYS_NICE capability
                 Process.setThreadGroup(tid, !isForApp ?
                   Process.THREAD_GROUP_AUDIO_SYS : Process.THREAD_GROUP_RT_APP);
             } catch (RuntimeException e) {
                 Log.e(TAG, "Failed setThreadGroup: " + e);
                 return PackageManager.PERMISSION_DENIED;
            }
         }
         try {
             // must be in this order or it fails the schedulability constraint
             Process.setThreadScheduler(tid, Process.SCHED_FIFO | Process.SCHED_RESET_ON_FORK,
                                        prio);
         } catch (RuntimeException e) {
             Log.e(TAG, "Failed setThreadScheduler: " + e);
             return PackageManager.PERMISSION_DENIED;
         }
         return PackageManager.PERMISSION_GRANTED;
     }

     // Request to move media.codec process between SP_FOREGROUND and SP_TOP_APP.
     public int requestCpusetBoost(boolean enable, IBinder client) {
         // Can only allow mediaserver to call this.
         if (Binder.getCallingPid() != Process.myPid() &&
                 Binder.getCallingUid() != Process.MEDIA_UID) {
             return PackageManager.PERMISSION_DENIED;
         }

         int[] nativePids = Process.getPidsForCommands(MEDIA_PROCESS_NAMES);
         if (nativePids == null || nativePids.length != 1) {
             Log.e(TAG, "requestCpusetBoost: can't find media.codec process");
             return PackageManager.PERMISSION_DENIED;
         }

         synchronized (mDeathRecipient) {
             if (enable) {
                 return enableCpusetBoost(nativePids[0], client);
             } else {
                 return disableCpusetBoost(nativePids[0]);
             }
         }
     }

     private int enableCpusetBoost(int pid, IBinder client) {
         if (mBoostedPid == pid) {
             return PackageManager.PERMISSION_GRANTED;
         }

         // The mediacodec process has changed, clean up the old pid and
         // client before we boost the new process, so that the state
         // is left clean if things go wrong.
         mBoostedPid = -1;
         if (mClient != null) {
             try {
                 mClient.unlinkToDeath(mDeathRecipient, 0);
             } catch (Exception e) {
             } finally {
                 mClient = null;
             }
         }

         try {
             client.linkToDeath(mDeathRecipient, 0);

             Log.i(TAG, "Moving " + pid + " to group " + Process.THREAD_GROUP_TOP_APP);
             Process.setProcessGroup(pid, Process.THREAD_GROUP_TOP_APP);

             mBoostedPid = pid;
             mClient = client;

             return PackageManager.PERMISSION_GRANTED;
         } catch (Exception e) {
             Log.e(TAG, "Failed enableCpusetBoost: " + e);
             try {
                 // unlink if things go wrong and don't crash.
                 client.unlinkToDeath(mDeathRecipient, 0);
             } catch (Exception e1) {}
         }

         return PackageManager.PERMISSION_DENIED;
     }

     private int disableCpusetBoost(int pid) {
         int boostedPid = mBoostedPid;

         // Clean up states first.
         mBoostedPid = -1;
         if (mClient != null) {
             try {
                 mClient.unlinkToDeath(mDeathRecipient, 0);
             } catch (Exception e) {
             } finally {
                 mClient = null;
             }
         }

         // Try restore the old thread group, no need to fail as the
         // mediacodec process could be dead just now.
         if (boostedPid == pid) {
             try {
                 Log.i(TAG, "Moving " + pid + " back to group default");
                 Process.setProcessGroup(pid, Process.THREAD_GROUP_DEFAULT);
             } catch (Exception e) {
                 Log.w(TAG, "Couldn't move pid " + pid + " back to group default");
             }
         }

         return PackageManager.PERMISSION_GRANTED;
     }

     private boolean isPermitted() {
         // schedulerservice hidl
         if (Binder.getCallingPid() == Process.myPid()) {
             return true;
         }

         switch (Binder.getCallingUid()) {
         case Process.AUDIOSERVER_UID:  // fastcapture, fastmixer
         case Process.CAMERASERVER_UID: // camera high frame rate recording
         case Process.BLUETOOTH_UID:    // Bluetooth audio playback
         case Process.PHONE_UID:        // phone call
             return true;
         default:
             return false;
         }
     }
 }
	/*
	* Copyright (C) 2012 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.server.os;

	import android.content.pm.PackageManager;
	import android.os.Binder;
	import android.os.IBinder;
	import android.os.ISchedulingPolicyService;
	import android.os.Process;
	import android.util.Log;

	import com.android.server.SystemServerInitThreadPool;

	/**
	* The implementation of the scheduling policy service interface.
	*
	* @hide
	*/
	public class SchedulingPolicyService extends ISchedulingPolicyService.Stub {

	private static final String TAG = "SchedulingPolicyService";

	// Minimum and maximum values allowed for requestPriority parameter prio
	private static final int PRIORITY_MIN = 1;
	private static final int PRIORITY_MAX = 3;

	private static final String[] MEDIA_PROCESS_NAMES = new String[] {
	"media.swcodec", // /apex/com.android.media.swcodec/bin/mediaswcodec
	};
	private final IBinder.DeathRecipient mDeathRecipient = new IBinder.DeathRecipient() {
	@Override
	public void binderDied() {
	requestCpusetBoost(false /enable/, null /client/);
	}
	};
	// Current process that received a cpuset boost
	private int mBoostedPid = -1;
	// Current client registered to the death recipient
	private IBinder mClient;

	public SchedulingPolicyService() {
	// system_server (our host) could have crashed before. The app may not survive
	// it, but mediaserver/media.codec could have, and mediaserver probably tried
	// to disable the boost while we were dead.
	// We do a restore of media.codec to default cpuset upon service restart to
	// catch this case. We can't leave media.codec in boosted state, because we've
	// lost the death recipient of mClient from mediaserver after the restart,
	// if mediaserver dies in the future we won't have a notification to reset.
	// (Note that if mediaserver thinks we're in boosted state before the crash,
	// the state could go out of sync temporarily until mediaserver enables/disable
	// boost next time, but this won't be a big issue.)
	SystemServerInitThreadPool.submit(() -> {
	synchronized (mDeathRecipient) {
	// only do this if we haven't already got a request to boost.
	if (mBoostedPid == -1) {
	int[] nativePids = Process.getPidsForCommands(MEDIA_PROCESS_NAMES);
	if (nativePids != null && nativePids.length == 1) {
	mBoostedPid = nativePids[0];
	disableCpusetBoost(nativePids[0]);
	}
	}
	}
	}, TAG + ".<init>");
	}

	// TODO(b/35196900) We should pass the period in time units, rather
	// than a fixed priority number.
	public int requestPriority(int pid, int tid, int prio, boolean isForApp) {
	//Log.i(TAG, "requestPriority(pid=" + pid + ", tid=" + tid + ", prio=" + prio + ")");

	// Verify that the caller uid is permitted, priority is in range,
	// and that the callback thread specified by app belongs to the app that
	// called mediaserver or audioserver.
	// Once we've verified that the caller uid is permitted, we can trust the pid but
	// we can't trust the tid. No need to explicitly check for pid == 0 \|\| tid == 0,
	// since if not the case then the getThreadGroupLeader() test will also fail.
	if (!isPermitted() \|\| prio < PRIORITY_MIN \|\|
	prio > PRIORITY_MAX \|\| Process.getThreadGroupLeader(tid) != pid) {
	return PackageManager.PERMISSION_DENIED;
	}
	// If the calling UID is audio server, and this call is not for an app,
	// then it must be for the audio HAL. Validate the UID of the thread.
	if (Binder.getCallingUid() == Process.AUDIOSERVER_UID && !isForApp
	&& Process.getUidForPid(tid) != Process.AUDIOSERVER_UID) {
	return PackageManager.PERMISSION_DENIED;
	}
	if (Binder.getCallingUid() != Process.BLUETOOTH_UID) {
	try {
	// make good use of our CAP_SYS_NICE capability
	Process.setThreadGroup(tid, !isForApp ?
	Process.THREAD_GROUP_AUDIO_SYS : Process.THREAD_GROUP_RT_APP);
	} catch (RuntimeException e) {
	Log.e(TAG, "Failed setThreadGroup: " + e);
	return PackageManager.PERMISSION_DENIED;
	}
	}
	try {
	// must be in this order or it fails the schedulability constraint
	Process.setThreadScheduler(tid, Process.SCHED_FIFO \| Process.SCHED_RESET_ON_FORK,
	prio);
	} catch (RuntimeException e) {
	Log.e(TAG, "Failed setThreadScheduler: " + e);
	return PackageManager.PERMISSION_DENIED;
	}
	return PackageManager.PERMISSION_GRANTED;
	}

	// Request to move media.codec process between SP_FOREGROUND and SP_TOP_APP.
	public int requestCpusetBoost(boolean enable, IBinder client) {
	// Can only allow mediaserver to call this.
	if (Binder.getCallingPid() != Process.myPid() &&
	Binder.getCallingUid() != Process.MEDIA_UID) {
	return PackageManager.PERMISSION_DENIED;
	}

	int[] nativePids = Process.getPidsForCommands(MEDIA_PROCESS_NAMES);
	if (nativePids == null \|\| nativePids.length != 1) {
	Log.e(TAG, "requestCpusetBoost: can't find media.codec process");
	return PackageManager.PERMISSION_DENIED;
	}

	synchronized (mDeathRecipient) {
	if (enable) {
	return enableCpusetBoost(nativePids[0], client);
	} else {
	return disableCpusetBoost(nativePids[0]);
	}
	}
	}

	private int enableCpusetBoost(int pid, IBinder client) {
	if (mBoostedPid == pid) {
	return PackageManager.PERMISSION_GRANTED;
	}

	// The mediacodec process has changed, clean up the old pid and
	// client before we boost the new process, so that the state
	// is left clean if things go wrong.
	mBoostedPid = -1;
	if (mClient != null) {
	try {
	mClient.unlinkToDeath(mDeathRecipient, 0);
	} catch (Exception e) {
	} finally {
	mClient = null;
	}
	}

	try {
	client.linkToDeath(mDeathRecipient, 0);

	Log.i(TAG, "Moving " + pid + " to group " + Process.THREAD_GROUP_TOP_APP);
	Process.setProcessGroup(pid, Process.THREAD_GROUP_TOP_APP);

	mBoostedPid = pid;
	mClient = client;

	return PackageManager.PERMISSION_GRANTED;
	} catch (Exception e) {
	Log.e(TAG, "Failed enableCpusetBoost: " + e);
	try {
	// unlink if things go wrong and don't crash.
	client.unlinkToDeath(mDeathRecipient, 0);
	} catch (Exception e1) {}
	}

	return PackageManager.PERMISSION_DENIED;
	}

	private int disableCpusetBoost(int pid) {
	int boostedPid = mBoostedPid;

	// Clean up states first.
	mBoostedPid = -1;
	if (mClient != null) {
	try {
	mClient.unlinkToDeath(mDeathRecipient, 0);
	} catch (Exception e) {
	} finally {
	mClient = null;
	}
	}

	// Try restore the old thread group, no need to fail as the
	// mediacodec process could be dead just now.
	if (boostedPid == pid) {
	try {
	Log.i(TAG, "Moving " + pid + " back to group default");
	Process.setProcessGroup(pid, Process.THREAD_GROUP_DEFAULT);
	} catch (Exception e) {
	Log.w(TAG, "Couldn't move pid " + pid + " back to group default");
	}
	}

	return PackageManager.PERMISSION_GRANTED;
	}

	private boolean isPermitted() {
	// schedulerservice hidl
	if (Binder.getCallingPid() == Process.myPid()) {
	return true;
	}

	switch (Binder.getCallingUid()) {
	case Process.AUDIOSERVER_UID: // fastcapture, fastmixer
	case Process.CAMERASERVER_UID: // camera high frame rate recording
	case Process.BLUETOOTH_UID: // Bluetooth audio playback
	case Process.PHONE_UID: // phone call
	return true;
	default:
	return false;
	}
	}
	}