task_register() conversion: stdin task

[paraslash.git] / stdin.c

diff --git a/stdin.c b/stdin.c
index ccd4487ae206ef11b2e0e96e424370c9129770b2..ed66316964c15a2cac030ae713c25e30c69951c6 100644 (file)
--- a/stdin.c
+++ b/stdin.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2013 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2014 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -30,7 +30,7 @@
  */
 static void stdin_pre_select(struct sched *s, struct task *t)
 {
-       struct stdin_task *sit = container_of(t, struct stdin_task, task);
+       struct stdin_task *sit = task_context(t);
        int ret;
 
        ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT);
@@ -56,7 +56,7 @@ static void stdin_pre_select(struct sched *s, struct task *t)
  */
 static int stdin_post_select(struct sched *s, struct task *t)
 {
-       struct stdin_task *sit = container_of(t, struct stdin_task, task);
+       struct stdin_task *sit = task_context(t);
        ssize_t ret;
        size_t sz, n;
        char *buf = NULL;
@@ -69,6 +69,12 @@ static int stdin_post_select(struct sched *s, struct task *t)
        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
@@ -82,30 +88,45 @@ static int stdin_post_select(struct sched *s, struct task *t)
                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;
 }
 
 /**
- * Initialize a stdin task structure with default values.
+ * Register a stdin task structure.
  *
- * \param sit The stdin task structure.
+ * \param sit The stdin task structure to register.
+ * \param s The task will be added to this scheduler's task list.
  *
- * 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.
+ * This allocates a buffer tree pool for I/O, sets up \a sit and registers a
+ * task with \a sit as context pointer.
  */
-void stdin_set_defaults(struct stdin_task *sit)
+void stdin_task_register(struct stdin_task *sit, struct sched *s)
 {
        int ret;
+       struct task_info ti = {
+               .name = "stdin",
+               .pre_select = stdin_pre_select,
+               .post_select = stdin_post_select,
+               .context = sit,
+       };
 
-       sit->task.pre_select = stdin_pre_select;
-       sit->task.new_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;
+       sit->task = task_register(&ti, s);
 }