struct io_conn;
/**
- * union io_plan_arg - scratch space for struct io_plan read/write fns.
+ * union io_plan_union - type for struct io_plan read/write fns.
*/
-union io_plan_arg {
+union io_plan_union {
char *cp;
void *vp;
const void *const_vp;
char c[sizeof(size_t)];
};
-enum io_plan_status {
- /* As before calling next function. */
- IO_UNSET,
- /* Normal. */
- IO_POLLING,
- /* Waiting for io_wake */
- IO_WAITING,
- /* Always do this. */
- IO_ALWAYS,
- /* Closing (both plans will be the same). */
- IO_CLOSING
+/**
+ * struct io_plan_arg - scratch space for struct io_plan read/write fns.
+ */
+struct io_plan_arg {
+ union io_plan_union u1, u2;
};
enum io_direction {
};
/**
- * struct io_plan - one half of I/O to do
- * @status: the status of this plan.
- * @io: function to call when fd becomes read/writable, returns 0 to be
- * called again, 1 if it's finished, and -1 on error (fd will be closed)
- * @next: the next function which is called if io returns 1.
- * @next_arg: the argument to @next
- * @u1, @u2: scratch space for @io.
+ * io_plan_arg - get a conn's io_plan_arg for a given direction.
+ * @conn: the connection.
+ * @dir: IO_IN or IO_OUT.
+ *
+ * This is how an io helper gets scratch space to store into; you must call
+ * io_set_plan() when you've initialized it.
+ *
+ * Example:
+ * #include <ccan/io/io_plan.h>
+ *
+ * // Simple helper to read a single char.
+ * static int do_readchar(int fd, struct io_plan_arg *arg)
+ * {
+ * return read(fd, arg->u1.cp, 1) <= 0 ? -1 : 1;
+ * }
+ *
+ * static struct io_plan *io_read_char_(struct io_conn *conn, char *in,
+ * struct io_plan *(*next)(struct io_conn*,void*),
+ * void *next_arg)
+ * {
+ * struct io_plan_arg *arg = io_plan_arg(conn, IO_IN);
+ *
+ * // Store information we need in the plan unions u1 and u2.
+ * arg->u1.cp = in;
+ *
+ * return io_set_plan(conn, IO_IN, do_readchar, next, next_arg);
+ * }
*/
-struct io_plan {
- enum io_plan_status status;
-
- int (*io)(int fd, struct io_plan *plan);
-
- struct io_plan *(*next)(struct io_conn *, void *arg);
- void *next_arg;
-
- union io_plan_arg u1, u2;
-};
-
-/* Helper to get a conn's io_plan. */
-struct io_plan *io_get_plan(struct io_conn *conn, enum io_direction dir);
+struct io_plan_arg *io_plan_arg(struct io_conn *conn, enum io_direction dir);
+/**
+ * io_set_plan - set a conn's io_plan.
+ * @conn: the connection.
+ * @dir: IO_IN or IO_OUT.
+ * @io: the IO function to call when the fd is ready.
+ * @next: the next callback when @io returns 1.
+ * @next_arg: the argument to @next.
+ *
+ * If @conn has debug set, the io function will be called immediately,
+ * so it's important that this be the last thing in your function!
+ *
+ * See also:
+ * io_get_plan_arg()
+ */
+struct io_plan *io_set_plan(struct io_conn *conn, enum io_direction dir,
+ int (*io)(int fd, struct io_plan_arg *arg),
+ struct io_plan *(*next)(struct io_conn *, void *),
+ void *next_arg);
#endif /* CCAN_IO_PLAN_H */