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      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
     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
     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
     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
    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
    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