2 * Copyright (C) 2011 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef ANDROID_COMMON_CLOCK_SERVICE_H
18 #define ANDROID_COMMON_CLOCK_SERVICE_H
20 #include <sys/socket.h>
21 #include <common_time/ICommonClock.h>
25 class CommonTimeServer;
27 class CommonClockService : public BnCommonClock,
28 public android::IBinder::DeathRecipient {
30 static sp<CommonClockService> instantiate(CommonTimeServer& timeServer);
32 virtual status_t dump(int fd, const Vector<String16>& args);
34 virtual status_t isCommonTimeValid(bool* valid, uint32_t *timelineID);
35 virtual status_t commonTimeToLocalTime(int64_t common_time,
37 virtual status_t localTimeToCommonTime(int64_t local_time,
38 int64_t* common_time);
39 virtual status_t getCommonTime(int64_t* common_time);
40 virtual status_t getCommonFreq(uint64_t* freq);
41 virtual status_t getLocalTime(int64_t* local_time);
42 virtual status_t getLocalFreq(uint64_t* freq);
43 virtual status_t getEstimatedError(int32_t* estimate);
44 virtual status_t getTimelineID(uint64_t* id);
45 virtual status_t getState(ICommonClock::State* state);
46 virtual status_t getMasterAddr(struct sockaddr_storage* addr);
48 virtual status_t registerListener(
49 const sp<ICommonClockListener>& listener);
50 virtual status_t unregisterListener(
51 const sp<ICommonClockListener>& listener);
53 void notifyOnTimelineChanged(uint64_t timelineID);
56 CommonClockService(CommonTimeServer& timeServer)
57 : mTimeServer(timeServer) { };
59 virtual void binderDied(const wp<IBinder>& who);
61 CommonTimeServer& mTimeServer;
63 // locks used to synchronize access to the list of registered listeners.
64 // The callback lock is held whenever the list is used to perform callbacks
65 // or while the list is being modified. The registration lock used to
66 // serialize access across registerListener, unregisterListener, and
69 // The reason for two locks is that registerListener, unregisterListener,
70 // and binderDied each call into the core service and obtain the core
71 // service thread lock when they call reevaluateAutoDisableState. The core
72 // service thread obtains the main thread lock whenever its thread is
73 // running, and sometimes needs to call notifyOnTimelineChanged which then
74 // obtains the callback lock. If callers of registration functions were
75 // holding the callback lock when they called into the core service, we
76 // would have a classic A/B, B/A ordering deadlock. To avoid this, the
77 // registration functions hold the registration lock for the duration of
78 // their call, but hold the callback lock only while they mutate the list.
79 // This way, the list's size cannot change (because of the registration
80 // lock) during the call into reevaluateAutoDisableState, but the core work
81 // thread can still safely call notifyOnTimelineChanged while holding the
84 Mutex mRegistrationLock;
86 Vector<sp<ICommonClockListener> > mListeners;
89 }; // namespace android
91 #endif // ANDROID_COMMON_CLOCK_SERVICE_H