Android 模拟器的上使用GPS的bug
由于最近研究Android 模拟器的GPS模块的实现，发现了模拟器GPS的bug。
启动模拟器，通过DDMS发送经纬度，通过应用可以抓到数据，进入设置，安全与位置，关闭GPS，再打开，再次打开GPS测试软件，再次发送经纬度，怎么也收不到。
查看了代码发现Android模拟器中完成GPS模块的功能主要是一个HAL层代码，通过socket接收发送过来的经纬度信息，其中代码是有问题的，GPS模块的工作主要是一个线程，当关闭GPS模块的时候这个线程结束了，再次打开的时候不会去启动这个线程，所以GPS模块就不工作了，具体看如下代码：
static voidgps_state_thread( void* arg ){ GpsState* state = (GpsState*) arg; NmeaReader reader[1]; int epoll_fd = epoll_create(2); int started = 0; int gps_fd = state->fd; int control_fd = state->control[1]; nmea_reader_init( reader ); // register control file descriptors for polling epoll_register( epoll_fd, control_fd ); epoll_register( epoll_fd, gps_fd ); D("gps thread running"); // now loop for (;;) { struct epoll_event events[2]; int ne, nevents; nevents = epoll_wait( epoll_fd, events, 2, -1 ); if (nevents < 0) { if (errno != EINTR) LOGE("epoll_wait() unexpected error: %s", strerror(errno)); continue; } D("gps thread received %d events", nevents); for (ne = 0; ne < nevents; ne++) { if ((events[ne].events & (EPOLLERR|EPOLLHUP)) != 0) { LOGE("EPOLLERR or EPOLLHUP after epoll_wait() !?"); return; } if ((events[ne].events & EPOLLIN) != 0) { int fd = events[ne].data.fd; if (fd == control_fd) { char cmd = 255; int ret; D("gps control fd event"); do { ret = read( fd, &cmd, 1 ); } while (ret < 0 && errno == EINTR); if (cmd == CMD_QUIT) { D("gps thread quitting on demand"); return; } else if (cmd == CMD_START) { if (!started) { D("gps thread starting location_cb=%p", state->callbacks.location_cb); started = 1; nmea_reader_set_callback( reader, state->callbacks.location_cb ); } } else if (cmd == CMD_STOP) { if (started) { D("gps thread stopping"); started = 0; nmea_reader_set_callback( reader, NULL ); } } } else if (fd == gps_fd) { char buff[32]; D("gps fd event"); for (;;) { int nn, ret; ret = read( fd, buff, sizeof(buff) ); if (ret < 0) { if (errno == EINTR) continue; if (errno != EWOULDBLOCK) LOGE("error while reading from gps daemon socket: %s:", strerror(errno)); break; } D("received %d bytes: %.*s", ret, ret, buff); for (nn = 0; nn < ret; nn++) nmea_reader_addc( reader, buff[nn] ); } D("gps fd event end"); } else { LOGE("epoll_wait() returned unkown fd %d ?", fd); } } } }}以上只是我的拙见。