Android adb自身调试log开关

本文介绍下如何打开adb源码中的debug log

1.adb源码log是可以动态打开和关闭的，控制逻辑代码如下

static NoDestructor<std::mutex> log_mutex;
static NoDestructor<CachedProperty> log_property GUARDED_BY(log_mutex)("debug.adbd.logging");
static std::optional<LogStatus> cached_log_status GUARDED_BY(log_mutex);

static NoDestructor<CachedProperty> persist_log_property
        GUARDED_BY(log_mutex)("persist.debug.adbd.logging");
static std::optional<LogStatus> cached_persist_log_status GUARDED_BY(log_mutex);

static LogStatus ParseLogStatus(std::string_view str) {
    LogStatus result = {};
    for (const auto& part : android::base::Split(std::string(str), ",")) {
        if (part == "cnxn") {
            result[adb::LogType::Connection] = true;
        } else if (part == "service") {
            result[adb::LogType::Service] = true;
        } else if (part == "shell") {
            result[adb::LogType::Shell] = true;
        } else if (part == "all") {
            result[adb::LogType::Connection] = true;
            result[adb::LogType::Service] = true;
            result[adb::LogType::Shell] = true;
        }
    }
    return result;
}

static LogStatus GetLogStatus(android::base::CachedProperty* property,
                              std::optional<LogStatus>* cached_status) REQUIRES(log_mutex) {
    bool changed;
    const char* value = property->Get(&changed);
    if (changed || !*cached_status) {
        **cached_status = ParseLogStatus(value);
    }
    return **cached_status;
}

namespace adb {
bool is_logging_enabled(LogType type) {
    std::lock_guard<std::mutex> lock(*log_mutex);
    return GetLogStatus(log_property.get(), &cached_log_status)[type] ||
           GetLogStatus(persist_log_property.get(), &cached_persist_log_status)[type];
}
}  // namespace adb

2.配置方法

adb shell  setprop persist.debug.adbd.logging  service   //打开LogType为service的log

例如：

daemon/services.cpp:262:    ADB_LOG(Service) << "transport " << transport->serial_name() << " opening service " << name;

打开后执行adb remount，可以抓到如下log

I adbd    : transport UsbFfs opening service shell,v2,TERM=xterm-256color,raw:remount

 adb shell  setprop persist.debug.adbd.logging all    //打开所有logtype

3.打开adb trace log方法

adb shell setprop persist.adb.trace_mask 1
adb shell pkill adbd   //需要重启adbd 生效

trace log会保存在/data/adb/文件夹下