+/* return value: 0 = subbuffer is finished, it won't produce data anymore
+ * 1 = got subbuffer successfully
+ * <0 = error
+ */
+
+#define GET_SUBBUF_OK 1
+#define GET_SUBBUF_DONE 0
+#define GET_SUBBUF_DIED 2
+
+#define PUT_SUBBUF_OK 1
+#define PUT_SUBBUF_DIED 0
+#define PUT_SUBBUF_PUSHED 2
+
+int test_sigpipe(void)
+{
+ sigset_t sigset;
+ int result;
+
+ result = sigemptyset(&sigset);
+ if(result == -1) {
+ perror("sigemptyset");
+ return -1;
+ }
+ result = sigaddset(&sigset, SIGPIPE);
+ if(result == -1) {
+ perror("sigaddset");
+ return -1;
+ }
+
+ result = sigtimedwait(&sigset, NULL, &(struct timespec){0,0});
+ if(result == -1 && errno == EAGAIN) {
+ /* no signal received */
+ return 0;
+ }
+ else if(result == -1) {
+ perror("sigtimedwait");
+ return -1;
+ }
+ else if(result == SIGPIPE) {
+ /* received sigpipe */
+ return 1;
+ }
+ else {
+ assert(0);
+ }
+}
+
+int get_subbuffer(struct buffer_info *buf)
+{
+ char *send_msg;
+ char *received_msg;
+ char *rep_code;
+ int retval;
+ int result;
+
+ asprintf(&send_msg, "get_subbuffer %s", buf->name);
+ result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
+ free(send_msg);
+ if(test_sigpipe()) {
+ WARN("process %d destroyed before we could connect to it", buf->pid);
+ return GET_SUBBUF_DONE;
+ }
+ else if(result < 0) {
+ ERR("get_subbuffer: ustcomm_send_request failed");
+ return -1;
+ }
+ else if(result == 0) {
+ DBG("app died while being traced");
+ return GET_SUBBUF_DIED;
+ }
+
+ result = sscanf(received_msg, "%as %ld", &rep_code, &buf->consumed_old);
+ if(result != 2 && result != 1) {
+ ERR("unable to parse response to get_subbuffer");
+ return -1;
+ }
+
+ DBG("received msg is %s", received_msg);
+
+ if(!strcmp(rep_code, "OK")) {
+ DBG("got subbuffer %s", buf->name);
+ retval = GET_SUBBUF_OK;
+ }
+ else if(nth_token_is(received_msg, "END", 0) == 1) {
+ return GET_SUBBUF_DONE;
+ }
+ else {
+ DBG("error getting subbuffer %s", buf->name);
+ retval = -1;
+ }
+
+ /* FIMXE: free correctly the stuff */
+ free(received_msg);
+ free(rep_code);
+ return retval;
+}
+
+int put_subbuffer(struct buffer_info *buf)
+{
+ char *send_msg;
+ char *received_msg;
+ char *rep_code;
+ int retval;
+ int result;
+
+ asprintf(&send_msg, "put_subbuffer %s %ld", buf->name, buf->consumed_old);
+ result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
+ if(result < 0) {
+ ERR("put_subbuffer: send_message failed");
+ return -1;
+ }
+ free(send_msg);
+
+ result = sscanf(received_msg, "%as", &rep_code);
+ if(result != 1) {
+ ERR("unable to parse response to put_subbuffer");
+ return -1;
+ }
+ free(received_msg);
+
+ if(!strcmp(rep_code, "OK")) {
+ DBG("subbuffer put %s", buf->name);
+ retval = PUT_SUBBUF_OK;
+ }
+ else {
+ DBG("put_subbuffer: received error, we were pushed");
+ return PUT_SUBBUF_PUSHED;
+ }
+
+ free(rep_code);
+ return retval;
+}
+
+/* This write is patient because it restarts if it was incomplete.
+ */
+
+ssize_t patient_write(int fd, const void *buf, size_t count)
+{
+ const char *bufc = (const char *) buf;
+ int result;
+
+ for(;;) {
+ result = write(fd, bufc, count);
+ if(result <= 0) {
+ return result;
+ }
+ count -= result;
+ bufc += result;
+
+ if(count == 0) {
+ break;
+ }
+ }
+
+ return bufc-(const char *)buf;
+}
+
+void *consumer_thread(void *arg)
+{
+ struct buffer_info *buf = (struct buffer_info *) arg;
+ int result;
+
+ for(;;) {
+ /* get the subbuffer */
+ result = get_subbuffer(buf);
+ if(result == -1) {
+ ERR("error getting subbuffer");
+ continue;
+ }
+ else if(result == GET_SUBBUF_DONE) {
+ /* this is done */
+ break;
+ }
+ else if(result == GET_SUBBUF_DIED) {
+ finish_consuming_dead_subbuffer(buf);
+ 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 */
+ }
+
+ /* put the subbuffer */
+ result = put_subbuffer(buf);
+ if(result == -1) {
+ ERR("unknown error putting subbuffer (channel=%s)", buf->name);
+ break;
+ }
+ else if(result == PUT_SUBBUF_PUSHED) {
+ ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
+ break;
+ }
+ else if(result == PUT_SUBBUF_DIED) {
+ WARN("application died while putting subbuffer");
+ /* FIXME: probably need to skip the first subbuffer in finish_consuming_dead_subbuffer */
+ finish_consuming_dead_subbuffer(buf);
+ }
+ else if(result == PUT_SUBBUF_OK) {
+ }
+ }
+
+ DBG("thread for buffer %s is stopping", buf->name);