1 /*
2  * Copyright (c) 2021 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include <stdio.h>
17 #include <stdint.h>
18 #include <unistd.h>
19 #include <pthread.h>
20 #include "hilog_wrapper.h"
21 #include "power/suspend_ops.h"
22 
23 #define SUSPEND_CHECK_INTERVAL_US       500000
24 
25 static pthread_mutex_t g_mutex = PTHREAD_MUTEX_INITIALIZER;
26 static pthread_cond_t g_cond = PTHREAD_COND_INITIALIZER;
27 static pthread_t g_suspendThread;
28 static AutoSuspendLoop g_suspendLoop = NULL;
29 static uint32_t g_suspendBlockCounter = 0;
30 
31 int usleep(useconds_t usec);
SuspendConditionSatisfied()32 static BOOL SuspendConditionSatisfied()
33 {
34     return (g_suspendBlockCounter == 0) ? TRUE : FALSE;
35 }
36 
WaitingSuspendCondition()37 static void WaitingSuspendCondition()
38 {
39     pthread_mutex_lock(&g_mutex);
40     while (SuspendConditionSatisfied() == FALSE) {
41         pthread_cond_wait(&g_cond, &g_mutex);
42     }
43     pthread_mutex_unlock(&g_mutex);
44 }
45 
SuspendThreadLoop(void * arg)46 static void *SuspendThreadLoop(void *arg)
47 {
48     if (!g_suspendLoop) {
49         return NULL;
50     }
51 
52     POWER_HILOGI("Suspend thread enter loop");
53     while (1) {
54         usleep(SUSPEND_CHECK_INTERVAL_US);
55         if (g_suspendLoop(WaitingSuspendCondition) == FALSE) {
56             break;
57         }
58     }
59     return NULL;
60 }
61 
Enable()62 static void Enable()
63 {
64     static BOOL started = FALSE;
65     if (started == TRUE) {
66         return;
67     }
68 
69     int32_t ret = pthread_create(&g_suspendThread, NULL, SuspendThreadLoop, NULL);
70     if (ret != 0) {
71         POWER_HILOGE("Failed to create suspend thread");
72         return;
73     }
74     pthread_detach(g_suspendThread);
75     started = TRUE;
76 }
77 
IncSuspendBlockCounter()78 static void IncSuspendBlockCounter()
79 {
80     pthread_mutex_lock(&g_mutex);
81     g_suspendBlockCounter++;
82     POWER_HILOGD("Suspend block counter: %{public}d", g_suspendBlockCounter);
83     pthread_mutex_unlock(&g_mutex);
84 }
85 
DecSuspendBlockCounter()86 static void DecSuspendBlockCounter()
87 {
88     pthread_mutex_lock(&g_mutex);
89     g_suspendBlockCounter--;
90     POWER_HILOGD("Suspend block counter: %{public}d", g_suspendBlockCounter);
91     if (SuspendConditionSatisfied() == TRUE) {
92         pthread_cond_signal(&g_cond);
93     }
94     pthread_mutex_unlock(&g_mutex);
95 }
96 
97 static struct AutoSuspendOps g_ops = {
98     .Enable = Enable,
99     .IncSuspendBlockCounter = IncSuspendBlockCounter,
100     .DecSuspendBlockCounter = DecSuspendBlockCounter,
101 };
102 
AutoSuspendOpsInit()103 struct AutoSuspendOps* AutoSuspendOpsInit()
104 {
105     g_suspendLoop = AutoSuspendLoopInit();
106     if (!g_suspendLoop) {
107         POWER_HILOGE("Failed to init auto suspend loop");
108         return NULL;
109     }
110     return &g_ops;
111 }
112