Android之installd的进化

代码路径

frameworks/native/cmds/installd

7.1的installd

installd.rc --- socket服务端
service installd /system/bin/installd
    class main
    socket installd stream 600 system system


installd.cpp
main --> installd_main
static int installd_main(const int argc ATTRIBUTE_UNUSED, char *argv[]) {
    ···
    lsocket = android_get_control_socket(SOCKET_PATH);//创建socket服务端
    if (lsocket < 0) {
        ALOGE("Failed to get socket from environment: %s\n", strerror(errno));
        exit(1);
    }
    if (listen(lsocket, 5)) {//执行监听
        ALOGE("Listen on socket failed: %s\n", strerror(errno));
        exit(1);
    }
    fcntl(lsocket, F_SETFD, FD_CLOEXEC);

    for (;;) {
        alen = sizeof(addr);
        s = accept(lsocket, &addr, &alen);//接收数据
        if (s < 0) {
            ALOGE("Accept failed: %s\n", strerror(errno));
            continue;
        }
        fcntl(s, F_SETFD, FD_CLOEXEC);

        ALOGI("new connection\n");
        for (;;) {
            unsigned short count;
            if (readx(s, &count, sizeof(count))) {//读取数据
                ALOGE("failed to read size\n");
                break;
            }
            if ((count < 1) || (count >= BUFFER_MAX)) {
                ALOGE("invalid size %d\n", count);
                break;
            }
            if (readx(s, buf, count)) {
                ALOGE("failed to read command\n");
                break;
            }
            buf[count] = 0;
            if (selinux_enabled && selinux_status_updated() > 0) {
                selinux_android_seapp_context_reload();
            }
            if (execute(s, buf)) break;//分发数据
        }
        ALOGI("closing connection\n");
        close(s);
    }

    return 0;
}

10.0的installd

installd.rc
service installd /system/bin/installd
    class main

installd.cpp
main --> installd_main

static int installd_main(const int argc ATTRIBUTE_UNUSED, char *argv[]) {
    ···
    if ((ret = InstalldNativeService::start()) != android::OK) {//binder服务端
        SLOGE("Unable to start InstalldNativeService: %d", ret);
        exit(1);
    }

    IPCThreadState::self()->joinThreadPool();

    ····

    return 0;
}

详细解析
InstalldNativeService.cpp
status_t InstalldNativeService::start() {
    IPCThreadState::self()->disableBackgroundScheduling(true);
    status_t ret = BinderService<InstalldNativeService>::publish();//addService到ServiceManager中。
    if (ret != android::OK) {
        return ret;
    }
    sp<ProcessState> ps(ProcessState::self());
    ps->startThreadPool();
    ps->giveThreadPoolName();
    return android::OK;
}

InstalldNativeService.h
 static char const* getServiceName() { return "installd"; }