* Licensed under the GPL v2. For licencing details see COPYING.
*/
-/** \file sched.c paraslash's scheduling functions */
+/** \file sched.c Paraslash's scheduling functions. */
#include <dirent.h> /* readdir() */
#include <assert.h>
/**
* Remove a task from the scheduler.
*
- * \param t the task to remove
+ * \param t The task to remove.
*
* If the pre_select pointer of \a t is not \p NULL, it is removed from
* the pre_select list of the scheduler. Same goes for \a post_select.
{
struct task *t, *tmp;
list_for_each_entry_safe(t, tmp, &pre_select_list, pre_select_node) {
- t->pre_select(s, t);
+ if (t->error >= 0)
+ t->pre_select(s, t);
// PARA_INFO_LOG("%s \n", t->status);
if (t->error >= 0)
continue;
+ /*
+ * We have to check whether the list is empty because the call
+ * to ->pre_select() might have called sched_shutdown(). In
+ * this case t has been unregistered already, so we must not
+ * unregister it again.
+ */
+ if (list_empty(&pre_select_list))
+ return;
unregister_task(t);
}
}
struct task *t, *tmp;
list_for_each_entry_safe(t, tmp, &post_select_list, post_select_node) {
- t->post_select(s, t);
+ if (t->error >= 0)
+ t->post_select(s, t);
// PARA_INFO_LOG("%s: %d\n", t->status, t->ret);
if (t->error >= 0)
continue;
+ /* nec., see sched_preselect() */
+ if (list_empty(&post_select_list))
+ return;
unregister_task(t);
}
}
/**
- * the core function for all paraslash programs
+ * The core function for all paraslash programs.
*
- * \param s pointer to the scheduler struct
+ * \param s Pointer to the scheduler struct.
*
* This function updates the global \a now pointer, calls all registered
* pre_select hooks which may set the timeout and add any file descriptors to
s->timeout = s->default_timeout;
s->max_fileno = -1;
sched_preselect(s);
+ if (list_empty(&pre_select_list) && list_empty(&post_select_list))
+ return 0;
ret = para_select(s->max_fileno + 1, &s->rfds, &s->wfds, &s->timeout);
if (ret < 0)
return ret;
}
/**
- * initialize the paraslash scheduler
+ * Initialize the paraslash scheduler.
*/
static void init_sched(void)
{
};
/**
- * add a task to the scheduler
+ * Add a task to the scheduler.
*
* \param t the task to add
*
}
/**
- * unregister all tasks
+ * Unregister all tasks.
*
* This will cause \a schedule() to return immediately because both the
* \a pre_select_list and the \a post_select_list are empty.
return;
list_for_each_entry_safe(t, tmp, &pre_select_list, pre_select_node)
unregister_task(t);
- /* remove tasks which do not have a pre_select hook */
list_for_each_entry_safe(t, tmp, &post_select_list, post_select_node)
unregister_task(t);
initialized = 0;
};
/**
- * get the list of all registered tasks.
+ * Get the list of all registered tasks.
*
- * \return the task list
+ * \return The task list.
*
* Each entry of the list contains an identifier which is simply a hex number
* that may be used in \a kill_task() to terminate the task.
}
/**
- * simulate an error for the given task
+ * Simulate an error for the given task.
*
- * \param id the task identifier
+ * \param id The task identifier.
*
* Find the task identified by \a id, set the tasks' error value to
* \p -E_TASK_KILLED and unregister the task.