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.
- * @u1: scratch area for I/O.
- * @u2: 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 {
- char *cp;
- void *vp;
- const void *const_vp;
- size_t s;
- char c[sizeof(size_t)];
- } u1;
- union {
- char *p;
- void *vp;
- const void *const_vp;
- size_t s;
- char c[sizeof(size_t)];
- } u2;
+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_conn - 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.
- *
- * You will also see calls to any callbacks which wake the connection
- * which is being debugged.
- *
- * Example:
- * static bool debug_all(struct io_conn *conn)
- * {
- * return true();
- * }
- * ...
- * io_debug_conn = debug_all;
+ * 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.
*/
-extern bool (*io_debug_conn)(struct io_conn *conn);
+struct io_plan {
+ enum io_plan_status status;
-/**
- * io_debug - if we're debugging the current connection, call immediately.
- *
- * This determines if we are debugging the current connection: if so,
- * it immediately applies the plan and calls back into io_loop() to
- * create a linear call chain.
- *
- * Example:
- * #define io_idle() io_debug(io_idle_())
- * struct io_plan io_idle_(void);
- */
-struct io_plan io_debug(struct io_plan plan);
+ int (*io)(int fd, struct io_plan *plan);
-/**
- * io_debug_io - return from function which actually does I/O.
- *
- * This determines if we are debugging the current connection: if so,
- * it immediately sets the next function and calls into io_loop() to
- * create a linear call chain.
- *
- * Example:
- *
- * static int do_write(int fd, struct io_plan *plan)
- * {
- * ssize_t ret = write(fd, plan->u.write.buf, plan->u.write.len);
- * if (ret < 0)
- * return io_debug_io(-1);
- *
- * plan->u.write.buf += ret;
- * plan->u.write.len -= ret;
- * return io_debug_io(plan->u.write.len == 0);
- * }
- */
-int io_debug_io(int ret);
+ struct io_plan *(*next)(struct io_conn *, void *arg);
+ void *next_arg;
-/**
- * io_plan_no_debug - mark the next plan not to be called immediately.
- *
- * 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(), io_duplex() and io_wake() take an
- * io_plan, but they must not be applied immediately to the current
- * connection, so we call this first.
- *
- * Example:
- * #define io_break(ret, plan) (io_plan_no_debug(), io_break_((ret), (plan)))
- * struct io_plan io_break_(void *ret, struct io_plan plan);
- */
-#define io_plan_no_debug() ((io_plan_nodebug = true))
+ union io_plan_arg u1, u2;
+};
-extern bool io_plan_nodebug;
-#else
-static inline struct io_plan io_debug(struct io_plan plan)
-{
- return plan;
-}
-static inline int io_debug_io(int ret)
-{
- return ret;
-}
-#define io_plan_no_debug() (void)0
-#endif
+/* 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 */
projects / ccan / blobdiff