107b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten/* 207b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * Copyright (C) 2012 The Android Open Source Project 307b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * 407b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * Licensed under the Apache License, Version 2.0 (the "License"); 507b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * you may not use this file except in compliance with the License. 607b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * You may obtain a copy of the License at 707b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * 807b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * http://www.apache.org/licenses/LICENSE-2.0 907b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * 1007b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * Unless required by applicable law or agreed to in writing, software 1107b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * distributed under the License is distributed on an "AS IS" BASIS, 1207b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1307b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * See the License for the specific language governing permissions and 1407b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * limitations under the License. 1507b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten */ 1607b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 1707b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kastenpackage android.os; 1807b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 1907b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kastenimport android.content.Context; 2007b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kastenimport android.content.pm.PackageManager; 2107b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kastenimport android.os.Binder; 2207b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kastenimport android.os.Process; 2307b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kastenimport android.util.Log; 2407b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 2507b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten/** 2607b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * The implementation of the scheduling policy service interface. 2707b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * 2807b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten * @hide 2907b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten */ 3007b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kastenpublic class SchedulingPolicyService extends ISchedulingPolicyService.Stub { 3107b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 3207b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten private static final String TAG = "SchedulingPolicyService"; 3307b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 3407b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten // Minimum and maximum values allowed for requestPriority parameter prio 3507b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten private static final int PRIORITY_MIN = 1; 36430c25428a351bbf3d02b152050c7403457875e2Glenn Kasten private static final int PRIORITY_MAX = 3; 3707b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 3807b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten public SchedulingPolicyService() { 3907b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten } 4007b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 4107b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten public int requestPriority(int pid, int tid, int prio) { 4207b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten //Log.i(TAG, "requestPriority(pid=" + pid + ", tid=" + tid + ", prio=" + prio + ")"); 4307b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 4407b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten // Verify that caller is mediaserver, priority is in range, and that the 4507b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten // callback thread specified by app belongs to the app that called mediaserver. 4607b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten // Once we've verified that the caller is mediaserver, we can trust the pid but 4707b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten // we can't trust the tid. No need to explicitly check for pid == 0 || tid == 0, 4807b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten // since if not the case then the getThreadGroupLeader() test will also fail. 4907b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten if (Binder.getCallingUid() != Process.MEDIA_UID || prio < PRIORITY_MIN || 5007b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten prio > PRIORITY_MAX || Process.getThreadGroupLeader(tid) != pid) { 5107b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten return PackageManager.PERMISSION_DENIED; 5207b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten } 5307b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten try { 5407b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten // make good use of our CAP_SYS_NICE capability 5507b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten Process.setThreadGroup(tid, Binder.getCallingPid() == pid ? 5607b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten Process.THREAD_GROUP_AUDIO_SYS : Process.THREAD_GROUP_AUDIO_APP); 5707b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten // must be in this order or it fails the schedulability constraint 5807b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten Process.setThreadScheduler(tid, Process.SCHED_FIFO, prio); 5907b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten } catch (RuntimeException e) { 6007b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten return PackageManager.PERMISSION_DENIED; 6107b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten } 6207b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten return PackageManager.PERMISSION_GRANTED; 6307b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten } 6407b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten 6507b0465095bd9ab3412caefa4fcacbdc3825c64bGlenn Kasten} 66