1 /******************************************************************************
2  *
3  *  Copyright (C) 2012 Broadcom Corporation
4  *
5  *  Licensed under the Apache License, Version 2.0 (the "License");
6  *  you may not use this file except in compliance with the License.
7  *  You may obtain a copy of the License at:
8  *
9  *  http://www.apache.org/licenses/LICENSE-2.0
10  *
11  *  Unless required by applicable law or agreed to in writing, software
12  *  distributed under the License is distributed on an "AS IS" BASIS,
13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  *  See the License for the specific language governing permissions and
15  *  limitations under the License.
16  *
17  ******************************************************************************/
18 
19 /************************************************************************************
20  *
21  *  Filename:      bt_utils.c
22  *
23  *  Description:   Miscellaneous helper functions
24  *
25  *
26  ***********************************************************************************/
27 
28 #define LOG_TAG "bt_utils"
29 
30 #include <cutils/properties.h>
31 #include <cutils/sched_policy.h>
32 #include <errno.h>
33 #include <pthread.h>
34 #include <sys/resource.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <unistd.h>
38 #include <utils/ThreadDefs.h>
39 
40 #include "bt_types.h"
41 #include "bt_utils.h"
42 #include "btcore/include/module.h"
43 #include "osi/include/compat.h"
44 #include "osi/include/log.h"
45 
46 /*******************************************************************************
47 **  Type definitions for callback functions
48 ********************************************************************************/
49 static pthread_once_t g_DoSchedulingGroupOnce[TASK_HIGH_MAX];
50 static BOOLEAN g_DoSchedulingGroup[TASK_HIGH_MAX];
51 static pthread_mutex_t         gIdxLock;
52 static int g_TaskIdx;
53 static int g_TaskIDs[TASK_HIGH_MAX];
54 #define INVALID_TASK_ID  (-1)
55 
init(void)56 static future_t *init(void) {
57   int i;
58   pthread_mutexattr_t lock_attr;
59 
60   for(i = 0; i < TASK_HIGH_MAX; i++) {
61     g_DoSchedulingGroupOnce[i] = PTHREAD_ONCE_INIT;
62     g_DoSchedulingGroup[i] = TRUE;
63     g_TaskIDs[i] = INVALID_TASK_ID;
64   }
65 
66   pthread_mutexattr_init(&lock_attr);
67   pthread_mutex_init(&gIdxLock, &lock_attr);
68   return NULL;
69 }
70 
clean_up(void)71 static future_t *clean_up(void) {
72   pthread_mutex_destroy(&gIdxLock);
73   return NULL;
74 }
75 
76 const module_t bt_utils_module = {
77   .name = BT_UTILS_MODULE,
78   .init = init,
79   .start_up = NULL,
80   .shut_down = NULL,
81   .clean_up = clean_up,
82   .dependencies = {
83     NULL
84   }
85 };
86 
87 
88 /*****************************************************************************
89 **
90 ** Function        check_do_scheduling_group
91 **
92 ** Description     check if it is ok to change schedule group
93 **
94 ** Returns         void
95 **
96 *******************************************************************************/
check_do_scheduling_group(void)97 static void check_do_scheduling_group(void) {
98     char buf[PROPERTY_VALUE_MAX];
99     int len = property_get("debug.sys.noschedgroups", buf, "");
100     if (len > 0) {
101         int temp;
102         if (sscanf(buf, "%d", &temp) == 1) {
103             g_DoSchedulingGroup[g_TaskIdx] = temp == 0;
104         }
105     }
106 }
107 
108 /*****************************************************************************
109 **
110 ** Function        raise_priority_a2dp
111 **
112 ** Description     Raise task priority for A2DP streaming
113 **
114 ** Returns         void
115 **
116 *******************************************************************************/
raise_priority_a2dp(tHIGH_PRIORITY_TASK high_task)117 void raise_priority_a2dp(tHIGH_PRIORITY_TASK high_task) {
118     int rc = 0;
119     int tid = gettid();
120     int priority = ANDROID_PRIORITY_AUDIO;
121 
122     pthread_mutex_lock(&gIdxLock);
123     g_TaskIdx = high_task;
124 
125     pthread_once(&g_DoSchedulingGroupOnce[g_TaskIdx], check_do_scheduling_group);
126     if (g_DoSchedulingGroup[g_TaskIdx]) {
127         // set_sched_policy does not support tid == 0
128         rc = set_sched_policy(tid, SP_AUDIO_SYS);
129     }
130     g_TaskIDs[high_task] = tid;
131     pthread_mutex_unlock(&gIdxLock);
132 
133     if (rc) {
134         LOG_WARN("failed to change sched policy, tid %d, err: %d", tid, errno);
135     }
136 
137     // always use urgent priority for HCI worker thread until we can adjust
138     // its prio individually. All other threads can be dynamically adjusted voa
139     // adjust_priority_a2dp()
140 
141     if (high_task == TASK_HIGH_HCI_WORKER)
142        priority = ANDROID_PRIORITY_URGENT_AUDIO;
143 
144     if (setpriority(PRIO_PROCESS, tid, priority) < 0) {
145         LOG_WARN("failed to change priority tid: %d to %d", tid, priority);
146     }
147 }
148 
149 /*****************************************************************************
150 **
151 ** Function        adjust_priority_a2dp
152 **
153 ** Description     increase the a2dp consumer task priority temporarily when start
154 **                 audio playing, to avoid overflow the audio packet queue, restore
155 **                 the a2dp consumer task priority when stop audio playing.
156 **
157 ** Returns         void
158 **
159 *******************************************************************************/
adjust_priority_a2dp(int start)160 void adjust_priority_a2dp(int start) {
161     int priority = start ? ANDROID_PRIORITY_URGENT_AUDIO : ANDROID_PRIORITY_AUDIO;
162     int tid;
163     int i;
164 
165     for (i = 0; i < TASK_HIGH_MAX; i++)
166     {
167         tid = g_TaskIDs[i];
168         if (tid != INVALID_TASK_ID)
169         {
170             if (setpriority(PRIO_PROCESS, tid, priority) < 0)
171             {
172                 LOG_WARN("failed to change priority tid: %d to %d", tid, priority);
173             }
174         }
175     }
176 }
177