1/*
2 * Copyright 2015 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 <binder/ProcessInfoService.h>
18#include <binder/IServiceManager.h>
19
20#include <utils/Log.h>
21#include <utils/String16.h>
22
23namespace android {
24
25ProcessInfoService::ProcessInfoService() {
26    updateBinderLocked();
27}
28
29status_t ProcessInfoService::getProcessStatesImpl(size_t length, /*in*/ int32_t* pids,
30        /*out*/ int32_t* states) {
31    status_t err = NO_ERROR;
32    sp<IProcessInfoService> pis;
33    mProcessInfoLock.lock();
34    pis = mProcessInfoService;
35    mProcessInfoLock.unlock();
36
37    for (int i = 0; i < BINDER_ATTEMPT_LIMIT; i++) {
38
39        if (pis != NULL) {
40            err = pis->getProcessStatesFromPids(length, /*in*/ pids, /*out*/ states);
41            if (err == NO_ERROR) return NO_ERROR; // success
42            if (IInterface::asBinder(pis)->isBinderAlive()) return err;
43        }
44        sleep(1);
45
46        mProcessInfoLock.lock();
47        if (pis == mProcessInfoService) {
48            updateBinderLocked();
49        }
50        pis = mProcessInfoService;
51        mProcessInfoLock.unlock();
52    }
53
54    ALOGW("%s: Could not retrieve process states from ProcessInfoService after %d retries.",
55            __FUNCTION__, BINDER_ATTEMPT_LIMIT);
56
57    return TIMED_OUT;
58}
59
60void ProcessInfoService::updateBinderLocked() {
61    const sp<IServiceManager> sm(defaultServiceManager());
62    if (sm != NULL) {
63        const String16 name("processinfo");
64        mProcessInfoService = interface_cast<IProcessInfoService>(sm->checkService(name));
65    }
66}
67
68ANDROID_SINGLETON_STATIC_INSTANCE(ProcessInfoService);
69
70}; // namespace android
71