xemacs-beta: src/events.h comparison

comparison src/events.h @ 263:727739f917cb r20-5b30

Import from CVS: tag r20-5b30

author	cvs
date	Mon, 13 Aug 2007 10:24:41 +0200
parents	83b3d10dcba9
children	c5d627a313b1

comparison

equal deleted inserted replaced

-:9d8607af9e13
+:727739f917cb
 which are polled for user-input.
 select_device_cb	These callbacks are used by Unixoid event loops
 unselect_device_cb	(those that use select() and file descriptors and
 			have a separate input fd per device).
+create_stream_pair_cb  These callbacks are called by process code to
+delete_stream_pair_cb  create and delete a pait of input and output lstreams
+			which are used for subprocess I/O.
 quitp_cb		A handler function called from the `QUIT' macro which
 			should check whether the quit character has been
 			typed.  On systems with SIGIO, this will not be called
 			unless the `sigio_happened' flag is true (it is set
 			Currently only the OffiX Dnd Protocol is supported.
 #endif
 */
+/*
+Stream pairs description
+------------------------
+Since there are many possible processes/event loop combinations, the event code
+is responsible for creating an appropriare lstream type. The process
+implementation does not care about that implementation.
+The Create stream pair function is passed two void* values, which identify
+process-dependant 'handles'. The process implementation uses these handles
+to communicate with child processes. The function must be prepared to receive
+handle types of any process implementation. Since there only one process
+implementation exists in a particular XEmacs configuration, preprocessing
+is a mean of compiling in the support for the code which deals with particular
+handle types.
+For example, a unixoid type loop, which relies on file descriptors, may be
+asked to create a pair of streams by a unix-style process implementation.
+In this case, the handles passed are unix file descriptors, and the code
+may deal with these directly. Although, the same code may be used on Win32
+system with X-Windows. In this case, Win32 process implementation passes
+handles of type HANDLE, and the create_stream_pair function must call
+appropriate function to get file descriptors given HANDLEs, so that these
+descriptors may be passed to XtAddInput.
+The handle given may have special denying value, in which case the
+corresponding lstream should not be created.
+The return value of the function is a unique stream identifier. It is used
+by processes implementation, in its  platform-independant part. There is
+the get_process_from_usid function, which returns process object given its
+USID. The event stream is responsible for converting its internal handle
+type into USID.
+Example is the TTY event stream. When a file descriptor signals input, the
+event loop must determine process to which the input is destined. Thus,
+the imlementation uses process input stream file descriptor as USID, by
+simply casting the fd value to USID type.
+There are two special USID values. One, USID_ERROR, indicates that the stream
+pair cannot be created. The second, USID_DONTHASH, indicates that streams are
+created, but the event stream does not wish to be able to find the process
+by its USID. Specifically, if an event stream implementation never calss
+get_process_from_usid, this value should always be returned, to prevent
+accumulating useless information on USID to process relationship.
+*/
+/* typedef unsigned int USID; in lisp.h */
+#define USID_ERROR ((USID)-1)
+#define USID_DONTHASH ((USID)0)
 struct Lisp_Event;
 struct Lisp_Process;
 struct event_stream
 void (*select_console_cb)	(struct console *);
 void (*unselect_console_cb)	(struct console *);
 void (*select_process_cb)	(struct Lisp_Process *);
 void (*unselect_process_cb)	(struct Lisp_Process *);
 void (*quit_p_cb)		(void);
-};
+USID (*create_stream_pair_cb) (void* /* inhandle*/, void* /*outhandle*/ ,
+				 Lisp_Object* /* instream */,
+				 Lisp_Object* /* outstream */,
+				 int /* pty_flag */);
+USID (*delete_stream_pair_cb) (Lisp_Object /* instream */,
+				 Lisp_Object /* outstream */);
+};
 extern struct event_stream *event_stream;
 typedef enum emacs_event_type
 {
 Lisp_Object allocate_command_builder (Lisp_Object console);
 void format_event_object (char *buf, struct Lisp_Event *e, int brief);
 void character_to_event (Emchar c, struct Lisp_Event *event,
 			 struct console *con,
-			 int use_console_meta_flag);
+			 int use_console_meta_flag,
+			 int do_backspace_mapping);
 void enqueue_magic_eval_event (void (*fun) (Lisp_Object), Lisp_Object object);
 void zero_event (struct Lisp_Event *e);
 void deallocate_event_chain (Lisp_Object event);
 Lisp_Object event_chain_tail (Lisp_Object event);
 void event_stream_handle_magic_event (struct Lisp_Event *event);
 void event_stream_select_console   (struct console *c);
 void event_stream_unselect_console (struct console *c);
 void event_stream_select_process   (struct Lisp_Process *proc);
 void event_stream_unselect_process (struct Lisp_Process *proc);
+USID event_stream_create_stream_pair (void* inhandle, void* outhandle,
+		Lisp_Object* instream, Lisp_Object* outstream, int flags);
+USID event_stream_delete_stream_pair (Lisp_Object instream, Lisp_Object outstream);
 void event_stream_quit_p (void);
 struct low_level_timeout
 {
 int id;
 int event_stream_unixoid_unselect_console (struct console *con);
 int event_stream_unixoid_select_process   (struct Lisp_Process *proc);
 int event_stream_unixoid_unselect_process (struct Lisp_Process *proc);
 int read_event_from_tty_or_stream_desc (struct Lisp_Event *event,
 					struct console *c, int fd);
+USID event_stream_unixoid_create_stream_pair (void* inhandle, void* outhandle,
+					     Lisp_Object* instream,
+					     Lisp_Object* outstream,
+					     int flags);
+USID event_stream_unixoid_delete_stream_pair (Lisp_Object instream,
+					      Lisp_Object outstream);
+/* Beware: this evil macro evaluates its arg many times */
+#define FD_TO_USID(fd) ((fd)==0 ? (USID)999999 : ((fd)<0 ? USID_DONTHASH : (USID)(fd)))
 #endif /* HAVE_UNIXOID_EVENT_LOOP */
 extern int emacs_is_blocking;
 extern Lisp_Object Vcontrolling_terminal;

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comparison src/events.h @ 263:727739f917cb r20-5b30