+void *consumer_thread(void *arg)
+{
+ struct buffer_info *buf = (struct buffer_info *) arg;
+ int result;
+
+ for(;;) {
+ result = get_subbuffer(buf);
+ if(result == -1) {
+ ERR("error getting subbuffer");
+ continue;
+ }
+ if(result == 0) {
+ /* this is done */
+ break;
+ }
+
+ /* write data to file */
+ result = patient_write(buf->file_fd, buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1)), buf->subbuf_size);
+ if(result == -1) {
+ PERROR("write");
+ /* FIXME: maybe drop this trace */
+ }
+
+ result = put_subbuffer(buf);
+ if(result == -1) {
+ ERR("error putting subbuffer");
+ break;
+ }
+ }
+
+ DBG("thread for buffer %s is stopping", buf->name);
+
+ return NULL;
+}
+
+int add_buffer(pid_t pid, char *bufname)
+{
+ struct buffer_info *buf;
+ char *send_msg;
+ char *received_msg;
+ int result;
+ char *tmp;
+ int fd;
+ pthread_t thr;
+
+ buf = (struct buffer_info *) malloc(sizeof(struct buffer_info));
+ if(buf == NULL) {
+ ERR("add_buffer: insufficient memory");
+ return -1;
+ }
+
+ buf->name = bufname;
+ buf->pid = pid;
+
+ /* get shmid */
+ asprintf(&send_msg, "get_shmid %s", buf->name);
+ send_message(pid, send_msg, &received_msg);
+ free(send_msg);
+ DBG("got buffer name %s", buf->name);
+
+ result = sscanf(received_msg, "%d", &buf->shmid);
+ if(result != 1) {
+ ERR("unable to parse response to get_shmid");
+ return -1;
+ }
+ free(received_msg);
+ DBG("got shmid %d", buf->shmid);
+
+ /* get n_subbufs */
+ asprintf(&send_msg, "get_n_subbufs %s", buf->name);
+ send_message(pid, send_msg, &received_msg);
+ free(send_msg);
+
+ result = sscanf(received_msg, "%d", &buf->n_subbufs);
+ if(result != 1) {
+ ERR("unable to parse response to get_n_subbufs");
+ return -1;
+ }
+ free(received_msg);
+ DBG("got n_subbufs %d", buf->n_subbufs);
+
+ /* get subbuf size */
+ asprintf(&send_msg, "get_subbuf_size %s", buf->name);
+ send_message(pid, send_msg, &received_msg);
+ free(send_msg);
+
+ result = sscanf(received_msg, "%d", &buf->subbuf_size);
+ if(result != 1) {
+ ERR("unable to parse response to get_subbuf_size");
+ return -1;
+ }
+ free(received_msg);
+ DBG("got subbuf_size %d", buf->subbuf_size);
+
+ /* attach memory */
+ buf->mem = shmat(buf->shmid, NULL, 0);
+ if(buf->mem == (void *) 0) {
+ perror("shmat");
+ return -1;
+ }
+ DBG("successfully attached memory");
+
+ /* open file for output */
+ asprintf(&tmp, "/tmp/trace/%s_0", buf->name);
+ result = fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC, 00600);
+ if(result == -1) {
+ PERROR("open");
+ return -1;
+ }
+ buf->file_fd = fd;
+ free(tmp);
+
+ //list_add(&buf->list, &buffers);
+
+ pthread_create(&thr, NULL, consumer_thread, buf);
+
+ return 0;
+}
+