struct io_conn;
/**
- * struct io_plan - a plan of what I/O to do.
- * @pollflag: POLLIN or POLLOUT.
- * @io: function to call when fd is available for @pollflag.
- * @next: function to call after @io returns true.
- * @next_arg: argument to @next.
- * @u: scratch area for I/O.
- *
- * When the fd is POLLIN or POLLOUT (according to @pollflag), @io is
- * called. If it returns -1, io_close() becomed the new plan (and errno
- * is saved). If it returns 1, @next is called, otherwise @io is
- * called again when @pollflag is available.
- *
- * You can use this to write your own io_plan functions.
+ * union io_plan_arg - scratch space for struct io_plan read/write fns.
*/
-struct io_plan {
- int pollflag;
- /* Only NULL if idle. */
- int (*io)(int fd, struct io_plan *plan);
- /* Only NULL if closing. */
- struct io_plan (*next)(struct io_conn *, void *arg);
- void *next_arg;
+union io_plan_arg {
+ char *cp;
+ void *vp;
+ const void *const_vp;
+ size_t s;
+ char c[sizeof(size_t)];
+};
- union {
- struct {
- char *buf;
- size_t len;
- } read;
- struct {
- const char *buf;
- size_t len;
- } write;
- struct {
- char *buf;
- size_t *lenp;
- } readpart;
- struct {
- const char *buf;
- size_t *lenp;
- } writepart;
- struct {
- int saved_errno;
- } close;
- struct {
- void *p;
- size_t len;
- } ptr_len;
- struct {
- void *p1;
- void *p2;
- } ptr_ptr;
- struct {
- size_t len1;
- size_t len2;
- } len_len;
- } u;
+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
};
-#ifdef DEBUG
-/**
- * io_debug - routine to select connection(s) to debug.
- *
- * If this is set, the routine should return true if the connection is a
- * debugging candidate. If so, the callchain for I/O operations on this
- * connection will be linear, for easier use of a debugger.
- */
-extern bool (*io_debug)(struct io_conn *conn);
+enum io_direction {
+ IO_IN,
+ IO_OUT
+};
/**
- * io_plan_other - mark the next plan not being for the current connection
- *
- * Most routines which take a plan are about to apply it to the current
- * connection. We (ab)use this pattern for debugging: as soon as such a
- * plan is created, it is called, to create a linear call chain.
- *
- * Some routines, like io_break() and io_wake() take an io_plan, but they
- * must not be applied immediately to the current connection, so we call this
- * first.
+ * 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.
*/
-#define io_plan_other() ((io_plan_for_other = true))
+struct io_plan {
+ enum io_plan_status status;
-/**
- * io_plan_debug - hook for debugging a plan.
- *
- * After constructing a plan, call this. If the current connection is being
- * debugged, then it will be immediately serviced with this plan.
- */
-void io_plan_debug(struct io_plan *plan);
-extern bool io_plan_for_other;
-#else
-#define io_plan_other() (void)0
-static inline void io_plan_debug(struct io_plan *plan) { }
-#endif
+ 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);
#endif /* CCAN_IO_PLAN_H */
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