sz = btr_pool_get_buffer(sit->btrp, &buf);
if (sz == 0)
return 0;
+ if (sit->must_set_nonblock_flag) {
+ ret = mark_fd_nonblocking(STDIN_FILENO);
+ if (ret < 0)
+ goto err;
+ sit->must_set_nonblock_flag = false;
+ }
/*
* Do not use the maximal size to avoid having only a single buffer
* reference for the whole pool. This is bad because if that single
return 0;
err:
btr_remove_node(&sit->btrn);
+ /* Revert to blocking mode if necessary. */
+ fcntl(STDIN_FILENO, F_SETFL, sit->fd_flags);
//btr_pool_free(sit->btrp);
return ret;
}
* \param sit The stdin task structure.
*
* This fills in the pre/post select function pointers of the task structure
- * given by \a sit. Moreover, the stdin file desctiptor is set to nonblocking
- * mode, and a buffer tree is created.
+ * given by \a sit and creates a buffer tree for I/O.
*/
void stdin_set_defaults(struct stdin_task *sit)
{
sit->task.post_select = stdin_post_select;
sit->btrp = btr_pool_new("stdin", 128 * 1024);
sprintf(sit->task.status, "stdin reader");
- ret = mark_fd_nonblocking(STDIN_FILENO);
- if (ret >= 0)
- return;
- PARA_EMERG_LOG("%s\n", para_strerror(-ret));
- exit(EXIT_FAILURE);
+ /*
+ * Both STDIN_FILENO and STDOUT_FILENO may refer to the same open file
+ * description (the terminal), and thus share the same file status
+ * flags. In order to not interfere with the stdout task, we only get
+ * the file status flags for STDIN here and save a copy. The nonblock
+ * flag is set later on the first read.
+ */
+ ret = fcntl(STDIN_FILENO, F_GETFL);
+ if (ret < 0) {
+ PARA_EMERG_LOG("F_GETFL: %s\n", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+ sit->fd_flags = ret;
+ sit->must_set_nonblock_flag = (sit->fd_flags & O_NONBLOCK) == 0;
}