1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
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
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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.
15 */
16
17 #include <stdint.h>
18
19 #include <common_time/cc_helper.h>
20 #include <common_time/ICommonClock.h>
21 #include <utils/threads.h>
22
23 namespace android {
24
25 Mutex CCHelper::lock_;
26 sp<ICommonClock> CCHelper::common_clock_;
27 sp<ICommonClockListener> CCHelper::common_clock_listener_;
28 uint32_t CCHelper::ref_count_ = 0;
29
verifyClock_l()30 bool CCHelper::verifyClock_l() {
31 bool ret = false;
32
33 if (common_clock_ == NULL) {
34 common_clock_ = ICommonClock::getInstance();
35 if (common_clock_ == NULL)
36 goto bailout;
37 }
38
39 if (ref_count_ > 0) {
40 if (common_clock_listener_ == NULL) {
41 common_clock_listener_ = new CommonClockListener();
42 if (common_clock_listener_ == NULL)
43 goto bailout;
44
45 if (OK != common_clock_->registerListener(common_clock_listener_))
46 goto bailout;
47 }
48 }
49
50 ret = true;
51
52 bailout:
53 if (!ret) {
54 common_clock_listener_ = NULL;
55 common_clock_ = NULL;
56 }
57 return ret;
58 }
59
CCHelper()60 CCHelper::CCHelper() {
61 Mutex::Autolock lock(&lock_);
62 ref_count_++;
63 verifyClock_l();
64 }
65
~CCHelper()66 CCHelper::~CCHelper() {
67 Mutex::Autolock lock(&lock_);
68
69 assert(ref_count_ > 0);
70 ref_count_--;
71
72 // If we were the last CCHelper instance in the system, and we had
73 // previously register a listener, unregister it now so that the common time
74 // service has the chance to go into auto-disabled mode.
75 if (!ref_count_ &&
76 (common_clock_ != NULL) &&
77 (common_clock_listener_ != NULL)) {
78 common_clock_->unregisterListener(common_clock_listener_);
79 common_clock_listener_ = NULL;
80 }
81 }
82
onTimelineChanged(uint64_t)83 void CCHelper::CommonClockListener::onTimelineChanged(uint64_t /*timelineID*/) {
84 // do nothing; listener is only really used as a token so the server can
85 // find out when clients die.
86 }
87
88 // Helper methods which attempts to make calls to the common time binder
89 // service. If the first attempt fails with DEAD_OBJECT, the helpers will
90 // attempt to make a connection to the service again (assuming that the process
91 // hosting the service had crashed and the client proxy we are holding is dead)
92 // If the second attempt fails, or no connection can be made, the we let the
93 // error propagate up the stack and let the caller deal with the situation as
94 // best they can.
95 #define CCHELPER_METHOD(decl, call) \
96 status_t CCHelper::decl { \
97 Mutex::Autolock lock(&lock_); \
98 \
99 if (!verifyClock_l()) \
100 return DEAD_OBJECT; \
101 \
102 status_t status = common_clock_->call; \
103 if (DEAD_OBJECT == status) { \
104 if (!verifyClock_l()) \
105 return DEAD_OBJECT; \
106 status = common_clock_->call; \
107 } \
108 \
109 return status; \
110 }
111
112 #define VERIFY_CLOCK()
113
114 CCHELPER_METHOD(isCommonTimeValid(bool* valid, uint32_t* timelineID),
115 isCommonTimeValid(valid, timelineID))
116 CCHELPER_METHOD(commonTimeToLocalTime(int64_t commonTime, int64_t* localTime),
117 commonTimeToLocalTime(commonTime, localTime))
118 CCHELPER_METHOD(localTimeToCommonTime(int64_t localTime, int64_t* commonTime),
119 localTimeToCommonTime(localTime, commonTime))
120 CCHELPER_METHOD(getCommonTime(int64_t* commonTime),
121 getCommonTime(commonTime))
122 CCHELPER_METHOD(getCommonFreq(uint64_t* freq),
123 getCommonFreq(freq))
124 CCHELPER_METHOD(getLocalTime(int64_t* localTime),
125 getLocalTime(localTime))
126 CCHELPER_METHOD(getLocalFreq(uint64_t* freq),
127 getLocalFreq(freq))
128
129 } // namespace android
130