Initial revision

1 files changed, 56 insertions, 0 deletions

diff --git a/zwgc/mux.h b/zwgc/mux.h
new file mode 100644
index 0000000..a0741c9
--- /dev/null
+++ b/zwgc/mux.h
@@ -0,0 +1,56 @@
+#ifndef mux_MODULE
+#define mux_MODULE
+
+/*
+ * MAX_SOURCES - the greatest file descriptor # that can be waited on minus one
+ *               This can not exceed FD_SETSIZE from <sys/types.h>.
+ */
+
+#define  MAX_SOURCES  32
+
+/*
+ * mux_end_loop_p - Setting this to true during a mux_loop causes the mux_loop
+ *                  to be exited.
+ */
+
+extern int mux_end_loop_p;
+
+/*
+ *    void mux_init()
+ *        Requires: mux_init has never been called before
+ *        Effects: Initializes the mux module.  Must be called before
+ *                 any other mux call.
+ */
+
+extern void mux_init();
+
+/*
+ *    void mux_add_input_source(int descriptior; void (*handler)(); void *arg)
+ *        Requires: 0<=descriptor<MAX_SOURCES, mux_init has been called
+ *        Modifies: Removes the previous input handler if any for descriptor
+ *        Effects: Registers handler as the input handler for file descriptor
+ *                 descriptor.  When mux_loop() is running and input is
+ *                 available on descriptor, handler will be called with
+ *                 argument arg.
+ */
+
+extern void mux_add_input_source();
+
+/*
+ *    void mux_loop()
+ *        Requires: mux_init has been called.
+ *        Effects: Loops until mux_end_loop_p becomes true.  (Sets
+ *                 mux_end_loop_p false to start).  Whenever input is
+ *                 available on an input source which has a registered
+ *                 handler (see mux_add_input_source), that handler is
+ *                 called with its argument.  It is guarenteed that if
+ *                 input is available on a source, its respective input
+ *                 handler, if any, will eventually be called.  No other
+ *                 ordering guarentees are made.  When some signal handler
+ *                 or input handler eventually sets mux_end_loop_p to
+ *                 true, we return.
+ */
+
+extern void mux_loop();
+
+#endif