X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fio%2Fio_plan.h;h=61d762454463b0f12868ff5a74fcdccbaa265f32;hb=710d42d071a10093077d30d6e521f9599a9bc997;hp=e87011e7d6a193e7591f2cdc44b400cb11b5ef0d;hpb=d4af94ec86618e89b449a27590a7b4f8e4365943;p=ccan

diff --git a/ccan/io/io_plan.h b/ccan/io/io_plan.h
index e87011e7..61d76245 100644
--- a/ccan/io/io_plan.h
+++ b/ccan/io/io_plan.h
@@ -9,7 +9,8 @@ struct io_conn;
  * @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.
+ * @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
@@ -27,74 +28,105 @@ struct io_plan {
 	void *next_arg;
 
 	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;
+		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;
 };
 
 #ifdef DEBUG
 /**
- * io_debug - routine to select connection(s) to 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;
  */
-extern bool (*io_debug)(struct io_conn *conn);
+extern bool (*io_debug_conn)(struct io_conn *conn);
 
 /**
- * io_plan_other - mark the next plan not being for the current connection
+ * io_debug - if we're debugging the current connection, call 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.
+ * 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.
  *
- * 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.
+ * Example:
+ *	#define io_idle() io_debug(io_idle_())
+ *	struct io_plan io_idle_(void);
  */
-#define io_plan_other() ((io_plan_for_other = true))
+struct io_plan io_debug(struct io_plan plan);
 
 /**
- * io_plan_debug - hook for debugging a plan.
+ * io_debug_io - return from function which actually does I/O.
  *
- * After constructing a plan, call this.  If the current connection is being
- * debugged, then it will be immediately serviced with this plan.
+ * 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);
+ * }
  */
-void io_plan_debug(struct io_plan *plan);
-extern bool io_plan_for_other;
+int io_debug_io(int ret);
+
+/**
+ * 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))
+
+extern bool io_plan_nodebug;
 #else
-#define io_plan_other() (void)0
-static inline void io_plan_debug(struct io_plan *plan) { }
+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
 
 #endif /* CCAN_IO_PLAN_H */