1 /*
2 * Copyright 2014 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 <errno.h>
18 #include <stdlib.h>
19 #include <ctype.h>
20
21 #define LOG_TAG "ADebug"
22 #include <cutils/atomic.h>
23 #include <utils/Log.h>
24 #include <utils/misc.h>
25
26 #include <cutils/properties.h>
27
28 #include <ADebug.h>
29 #include <AStringUtils.h>
30 #include <AUtils.h>
31
32 #define UNUSED(x) ((void)(x))
33
34 namespace android {
35
36 //static
GetLevelFromSettingsString(const char * name,const char * value,long def)37 long ADebug::GetLevelFromSettingsString(
38 const char *name, const char *value, long def) {
39 // split on ,
40 const char *next = value, *current;
41 while (next != NULL) {
42 current = next;
43 next = strchr(current, ',');
44 if (next != NULL) {
45 ++next; // pass ,
46 }
47
48 while (isspace(*current)) {
49 ++current;
50 }
51 // check for :
52 char *colon = strchr(current, ':');
53
54 // get level
55 char *end;
56 errno = 0; // strtol does not clear errno, but it can be set for any return value
57 long level = strtol(current, &end, 10);
58 while (isspace(*end)) {
59 ++end;
60 }
61 if (errno != 0 || end == current || (end != colon && *end != '\0' && end != next)) {
62 // invalid level - skip
63 continue;
64 }
65 if (colon != NULL) {
66 // check if pattern matches
67 do { // skip colon and spaces
68 ++colon;
69 } while (isspace(*colon));
70 size_t globLen = (next == NULL ? strlen(colon) : (next - 1 - colon));
71 while (globLen > 0 && isspace(colon[globLen - 1])) {
72 --globLen; // trim glob
73 }
74
75 if (!AStringUtils::MatchesGlob(
76 colon, globLen, name, strlen(name), true /* ignoreCase */)) {
77 continue;
78 }
79 }
80
81 // update value
82 def = level;
83 }
84 return def;
85 }
86
87 //static
GetLevelFromProperty(const char * name,const char * propertyName,long def)88 long ADebug::GetLevelFromProperty(
89 const char *name, const char *propertyName, long def) {
90 char value[PROPERTY_VALUE_MAX];
91 if (property_get(propertyName, value, NULL)) {
92 def = GetLevelFromSettingsString(name, value, def);
93 }
94 return def;
95 }
96
97 //static
GetDebugLevelFromProperty(const char * name,const char * propertyName,ADebug::Level def)98 ADebug::Level ADebug::GetDebugLevelFromProperty(
99 const char *name, const char *propertyName, ADebug::Level def) {
100 long level = GetLevelFromProperty(name, propertyName, (long)def);
101 return (Level)min(max(level, (long)kDebugNone), (long)kDebugMax);
102 }
103
104 //static
GetDebugName(const char * name)105 char *ADebug::GetDebugName(const char *name) {
106 char *debugName = strdup(name);
107 const char *terms[] = { "omx", "video", "audio" };
108 for (size_t i = 0; i < NELEM(terms) && debugName != NULL; i++) {
109 const char *term = terms[i];
110 const size_t len = strlen(term);
111 char *match = strcasestr(debugName, term);
112 if (match != NULL && (match == debugName || match[-1] == '.'
113 || match[len] == '.' || match[len] == '\0')) {
114 char *src = match + len;
115 if (match == debugName || match[-1] == '.') {
116 src += (*src == '.'); // remove trailing or double .
117 }
118 memmove(match, src, debugName + strlen(debugName) - src + 1);
119 }
120 }
121
122 return debugName;
123 }
124
125 //static
getExperimentFlag(bool allow,const char * name,uint64_t modulo,uint64_t limit,uint64_t plus,uint64_t timeDivisor)126 bool ADebug::getExperimentFlag(
127 bool allow, const char *name, uint64_t modulo,
128 uint64_t limit, uint64_t plus, uint64_t timeDivisor) {
129 // see if this experiment should be disabled/enabled based on properties.
130 // default to 2 to allow 0/1 specification
131 const int undefined = 2;
132 long level = GetLevelFromProperty(name, "debug.stagefright.experiments", undefined);
133 if (level != undefined) {
134 ALOGI("experiment '%s': %s from property", name, level ? "ENABLED" : "disabled");
135 return allow && (level != 0);
136 }
137
138 #ifndef ENABLE_STAGEFRIGHT_AUTO_EXPERIMENTS
139 UNUSED(modulo);
140 UNUSED(limit);
141 UNUSED(plus);
142 UNUSED(timeDivisor);
143 return false;
144 #else
145 // Disable automatic experiments in "non-experimental" builds (that is, _all_ builds
146 // as there is no "experimental" build).
147 // TODO: change build type to enable automatic experiments in the future for some builds
148 char value[PROPERTY_VALUE_MAX];
149 if (property_get("ro.build.type", value, NULL)) {
150 if (strcmp(value, "experimental")) {
151 return false;
152 }
153 }
154
155 static volatile int32_t haveSerial = 0;
156 static uint64_t serialNum;
157 if (!android_atomic_acquire_load(&haveSerial)) {
158 // calculate initial counter value based on serial number
159 static char serial[PROPERTY_VALUE_MAX];
160 property_get("ro.serialno", serial, "0");
161 uint64_t num = 0; // it is okay for this number to overflow
162 for (size_t i = 0; i < NELEM(serial) && serial[i] != '\0'; ++i) {
163 const char &c = serial[i];
164 // try to use most letters of serialno
165 if (isdigit(c)) {
166 num = num * 10 + (c - '0');
167 } else if (islower(c)) {
168 num = num * 26 + (c - 'a');
169 } else if (isupper(c)) {
170 num = num * 26 + (c - 'A');
171 } else {
172 num = num * 256 + c;
173 }
174 }
175 serialNum = num;
176 android_atomic_release_store(1, &haveSerial);
177 }
178 ALOGD("serial: %llu, time: %lld", (long long unsigned)serialNum, (long long)time(NULL));
179 // MINOR: use modulo for counter and time, so that their sum does not
180 // roll over, and mess up the correlation between related experiments.
181 // e.g. keep (a mod 2N) = 0 impl (a mod N) = 0
182 time_t counter = (time(NULL) / timeDivisor) % modulo + plus + serialNum % modulo;
183 bool enable = allow && (counter % modulo < limit);
184 ALOGI("experiment '%s': %s", name, enable ? "ENABLED" : "disabled");
185 return enable;
186 #endif
187 }
188
189 } // namespace android
190
191