pty select() support

drivers/tty/pty.c

@@ -22,6 +22,7 @@
 #include <signal.h>
 #include <minix/com.h>
 #include <minix/callnr.h>
+#include <sys/select.h>
 #include "tty.h"
 
 #if NR_PTYS > 0
@@ -51,6 +52,11 @@ typedef struct pty {
   int		ocount;		/* # characters in the buffer */
   char		*ohead, *otail;	/* head and tail of the circular buffer */
   char		obuf[128];	/* buffer for bytes going to the pty reader */
+
+  /* select() data. */
+  int		select_ops,	/* Which operations do we want to know about? */
+  		select_proc,	/* Who wants to know about it? */
+  		select_ready_ops;	/* For callback. */
 } pty_t;
 
 #define PTY_ACTIVE	0x01	/* pty is open/active */
@@ -68,6 +74,7 @@ FORWARD _PROTOTYPE( int pty_read, (tty_t *tp, int try)				);
 FORWARD _PROTOTYPE( int pty_close, (tty_t *tp, int try)			);
 FORWARD _PROTOTYPE( int pty_icancel, (tty_t *tp, int try)		);
 FORWARD _PROTOTYPE( int pty_ocancel, (tty_t *tp, int try)		);
+FORWARD _PROTOTYPE( int pty_select, (tty_t *tp, message *m)		);
 
 
 /*==========================================================================*
@@ -182,6 +189,10 @@ message *m_ptr;
 	}
 	break;
 
+    case DEV_SELECT:
+    	r = pty_select(tp, m_ptr);
+    	break;
+
     case CANCEL:
 	if (m_ptr->PROC_NR == pp->rdproc) {
 		/* Cancel a read from a PTY. */
@@ -215,6 +226,7 @@ int try;
   int count, ocount, s;
   phys_bytes user_phys;
 
+
   /* PTY closed down? */
   if (pp->state & PTY_CLOSED) {
   	if(try) return 1;
@@ -229,14 +241,12 @@ int try;
   /* While there is something to do. */
   for (;;) {
 	ocount = buflen(pp->obuf) - pp->ocount;
+	if(try) return (ocount > 0);
 	count = bufend(pp->obuf) - pp->ohead;
 	if (count > ocount) count = ocount;
 	if (count > tp->tty_outleft) count = tp->tty_outleft;
-	if (count == 0 || tp->tty_inhibited) {
+	if (count == 0 || tp->tty_inhibited)
-		if(try) return 0;
 		break;
-	}
-	if(try) return 1;
 
 	/* Copy from user space to the PTY output buffer. */
 	if((s = sys_vircopy(tp->tty_outproc, D, (vir_bytes) tp->tty_out_vir,
@@ -339,7 +349,6 @@ pty_t *pp;
 /* Finish the read request of a PTY reader if there is at least one byte
  * transferred.
  */
-
   if (pp->rdcum > 0) {
         if (pp->rdsendreply) {
 		tty_reply(TASK_REPLY, pp->rdcaller, pp->rdproc, pp->rdcum);
@@ -348,6 +357,7 @@ pty_t *pp;
 	else
 		notify(pp->rdcaller);
   }
+
 }
 
 
@@ -364,6 +374,7 @@ int try;
   pty_t *pp = tp->tty_priv;
   char c;
 
+
   if (pp->state & PTY_CLOSED) {
 	if(try) return 1;
 	if (tp->tty_inleft > 0) {
@@ -482,6 +493,7 @@ tty_t *tp;
   line = tp - &tty_table[NR_CONS + NR_RS_LINES];
   pp = tp->tty_priv = &pty_table[line];
   pp->tty = tp;
+  pp->select_ops = 0;
 
   /* Set up output queue. */
   pp->ohead = pp->otail = pp->obuf;
@@ -493,6 +505,7 @@ tty_t *tp;
   tp->tty_icancel = pty_icancel;
   tp->tty_ocancel = pty_ocancel;
   tp->tty_close = pty_close;
+  tp->tty_select_ops = 0;
 }
 
 
@@ -506,7 +519,7 @@ PUBLIC int pty_status(message *m_ptr)
 
 	event_found = 0;
 	for (i= 0, pp = pty_table; i<NR_PTYS; i++, pp++) {
-		if (((pp->state & TTY_CLOSED && pp->rdleft > 0) ||
+		if ((((pp->state & TTY_CLOSED) && pp->rdleft > 0) ||
 			pp->rdcum > 0) &&
 			pp->rdcaller == m_ptr->m_source)
 		{
@@ -519,7 +532,7 @@ PUBLIC int pty_status(message *m_ptr)
 			break;
 		}
 
-		if (((pp->state & TTY_CLOSED && pp->wrleft > 0) ||
+		if ((((pp->state & TTY_CLOSED) && pp->wrleft > 0) ||
 			pp->wrcum > 0) &&
 			pp->wrcaller == m_ptr->m_source)
 		{
@@ -534,8 +547,79 @@ PUBLIC int pty_status(message *m_ptr)
 			event_found = 1;
 			break;
 		}
+
+		if(pp->select_ready_ops && pp->select_proc == m_ptr->m_source) {
+			m_ptr->m_type = DEV_IO_READY;
+			m_ptr->DEV_MINOR = PTYPX_MINOR + i;
+			m_ptr->DEV_SEL_OPS = pp->select_ready_ops;
+			pp->select_ready_ops = 0;
+			event_found = 1;
+			break;
+		}
 	}
 	return event_found;
 }
 
+/*==========================================================================*
+ *				select_try_pty				    *
+ *==========================================================================*/
+PRIVATE int select_try_pty(tty_t *tp, int ops)
+{
+  	pty_t *pp = tp->tty_priv;
+	int r = 0;
+
+	if(ops & SEL_WR)  {
+		/* Write won't block on error. */
+		if (pp->state & TTY_CLOSED) r |= SEL_WR;
+		else if (pp->wrleft != 0 || pp->wrcum != 0) r |= SEL_WR;
+		else r |= SEL_WR;
+	}
+
+	if(ops & SEL_RD) {
+		/* Read won't block on error. */
+		if (pp->state & TTY_CLOSED) r |= SEL_RD;
+		else if(pp->rdleft != 0 || pp->rdcum != 0) r |= SEL_RD;
+		else if(pp->ocount > 0) r |= SEL_RD;	/* Actual data. */
+	}
+
+	return r;
+}
+
+/*==========================================================================*
+ *				select_retry_pty				    *
+ *==========================================================================*/
+PUBLIC void select_retry_pty(tty_t *tp)
+{
+  	pty_t *pp = tp->tty_priv;
+  	int r;
+
+	/* See if the pty side of a pty is ready to return a select. */
+	if(pp->select_ops && (r=select_try_pty(tp, pp->select_ops))) {
+		pp->select_ops &= ~r;
+		pp->select_ready_ops |= r;
+		notify(pp->select_proc);
+	}
+}
+
+/*==========================================================================*
+ *				pty_select				    *
+ *==========================================================================*/
+PRIVATE int pty_select(tty_t *tp, message *m)
+{
+  	pty_t *pp = tp->tty_priv;
+	int ops, ready_ops = 0, watch;
+
+	ops = m->PROC_NR & (SEL_RD|SEL_WR|SEL_ERR);
+	watch = (m->PROC_NR & SEL_NOTIFY) ? 1 : 0;
+
+	ready_ops = select_try_pty(tp, ops);
+
+	if(!ready_ops && ops && watch) {
+		pp->select_ops |= ops;
+		pp->select_proc = m->m_source;
+	}
+
+	return ready_ops;
+}
+
 #endif /* NR_PTYS > 0 */

drivers/tty/tty.c

@@ -82,15 +82,9 @@ unsigned long rs_irq_set = 0;
 /* Address of a tty structure. */
 #define tty_addr(line)	(&tty_table[line])
 
-/* First minor numbers for the various classes of TTY devices. */
-#define CONS_MINOR	  0
-#define LOG_MINOR	 15
-#define RS232_MINOR	 16
-#define TTYPX_MINOR	128
-#define PTYPX_MINOR	192
-
 /* Macros for magic tty types. */
 #define isconsole(tp)	((tp) < tty_addr(NR_CONS))
+#define ispty(tp)	((tp) >= tty_addr(NR_CONS+NR_RS_LINES))
 
 /* Macros for magic tty structure pointers. */
 #define FIRST_TTY	tty_addr(0)
@@ -181,7 +175,6 @@ PUBLIC void main(void)
     panic("TTY","Couldn't obtain kernel environment.", s);
   }
 
-printf("\n");
   while (TRUE) {
 
 	/* Check for and handle any events on any of the ttys. */
@@ -476,11 +469,8 @@ register message *m_ptr;	/* pointer to message sent to the task */
 
 	/* Try to write. */
 	handle_events(tp);
-	if (tp->tty_outleft == 0) {
+	if (tp->tty_outleft == 0) 
-  		if(tp->tty_select_ops)
-		  	select_retry(tp);
 		return;	/* already done */
-	}
 
 	/* None or not all the bytes could be written, so either suspend the
 	 * caller or break off the write if nonblocking.
@@ -494,8 +484,6 @@ register message *m_ptr;	/* pointer to message sent to the task */
 	}
   }
   tty_reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, r);
-  if(tp->tty_select_ops)
-  	select_retry(tp);
 }
 
 
@@ -807,7 +795,6 @@ PUBLIC int select_try(struct tty *tp, int ops)
 	 * (and it can be seen as an exceptional condition.)
 	 */
 	if (tp->tty_termios.c_ospeed == B0) {
-		printf("tty: hangup always ok\n");
 		ready_ops |= ops;
 	}
 
@@ -816,8 +803,8 @@ PUBLIC int select_try(struct tty *tp, int ops)
 		if (tp->tty_inleft > 0) {
 			ready_ops |= SEL_RD;	/* EIO - no blocking */
 		} else if(tp->tty_incount > 0) {
-			/* is a regular read possible? tty_incount
+			/* Is a regular read possible? tty_incount
-			 * says there is data. but a read will only succeed
+			 * says there is data. But a read will only succeed
 			 * in canonical mode if a newline has been seen.
 			 */
 			if(!(tp->tty_termios.c_lflag & ICANON) ||
@@ -828,12 +815,8 @@ PUBLIC int select_try(struct tty *tp, int ops)
 	}
 
 	if(ops & SEL_WR)  {
-  		if (tp->tty_outleft > 0) {
+  		if (tp->tty_outleft > 0)  ready_ops |= SEL_WR;
-			ready_ops |= SEL_WR;	/* EIO - no blocking */
+		else if((*tp->tty_devwrite)(tp, 1)) ready_ops |= SEL_WR;
-  		}
-		if((*tp->tty_devwrite)(tp, 1)) {
-			ready_ops |= SEL_WR;	/* real write possible */
-  		}
 	}
 
 	return ready_ops;
@@ -841,21 +824,8 @@ PUBLIC int select_try(struct tty *tp, int ops)
 
 PUBLIC int select_retry(struct tty *tp)
 {
-#if DEAD_CODE
-	int ops;
-	if((ops = select_try(tp, tp->tty_select_ops))) {
-		message m;
-		m.NOTIFY_TYPE = DEV_SELECTED;
-		m.NOTIFY_ARG = tp->tty_index;
-		m.NOTIFY_FLAGS = ops;
-		notify(tp->tty_select_proc, &m);
-		tp->tty_select_ops &= ~ops;
-	}
-#else
 	if (select_try(tp, tp->tty_select_ops))
 		notify(tp->tty_select_proc);
-#endif
-
 	return OK;
 }
 
@@ -915,6 +885,10 @@ tty_t *tp;			/* TTY to check for events. */
 	tp->tty_inleft = tp->tty_incum = 0;
 #endif
   }
+  if(tp->tty_select_ops)
+  	select_retry(tp);
+  if(ispty(tp))
+  	select_retry_pty(tp);
 }
 
 
@@ -1559,11 +1533,14 @@ PRIVATE void tty_init()
 								tty_devnop;
   	if (tp < tty_addr(NR_CONS)) {
 		scr_init(tp);
+  		tp->tty_minor = CONS_MINOR + s;
   	} else
   	if (tp < tty_addr(NR_CONS+NR_RS_LINES)) {
 		rs_init(tp);
+  		tp->tty_minor = RS232_MINOR + s-NR_CONS;
   	} else {
 		pty_init(tp);
+  		tp->tty_minor = s + TTYPX_MINOR + s-(NR_CONS+RS232_MINOR);
   	}
   }
 
@@ -1671,7 +1648,6 @@ register tty_t *tp;		/* pointer to tty struct */
 register message *m_ptr;	/* pointer to message sent to the task */
 {
 	int ops, ready_ops = 0, watch;
-	printf("doing select..\n");
 
 	ops = m_ptr->PROC_NR & (SEL_RD|SEL_WR|SEL_ERR);
 	watch = (m_ptr->PROC_NR & SEL_NOTIFY) ? 1 : 0;
@@ -1679,11 +1655,9 @@ register message *m_ptr;	/* pointer to message sent to the task */
 	ready_ops = select_try(tp, ops);
 
 	if(!ready_ops && ops && watch) {
-		printf("doing select.. ops %d\n", ops);
 		tp->tty_select_ops |= ops;
 		tp->tty_select_proc = m_ptr->m_source;
-	} else printf("not doing select.. ready_ops %d ops %d watch %d\n",
+	}
-		ready_ops, ops, watch);
 
         tty_reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, ready_ops);
 

drivers/tty/tty.h

@@ -2,6 +2,13 @@
 
 #include <timers.h>
 
+/* First minor numbers for the various classes of TTY devices. */
+#define CONS_MINOR	  0
+#define LOG_MINOR	 15
+#define RS232_MINOR	 16
+#define TTYPX_MINOR	128
+#define PTYPX_MINOR	192
+
 #define LINEWRAP	   1	/* console.c - wrap lines at column 80 */
 
 #define TTY_IN_BYTES     256	/* tty input queue size */
@@ -20,6 +27,7 @@ typedef _PROTOTYPE( void (*devfunarg_t), (struct tty *tp, int c) );
 typedef struct tty {
   int tty_events;		/* set when TTY should inspect this line */
   int tty_index;		/* index into TTY table */
+  int tty_minor;		/* device minor number */
 
   /* Input queue.  Typed characters are stored here until read by a program. */
   u16_t *tty_inhead;		/* pointer to place where next char goes */
@@ -156,6 +164,7 @@ _PROTOTYPE( void kbd_interrupt, (message *m)				);
 /* pty.c */
 _PROTOTYPE( void do_pty, (struct tty *tp, message *m_ptr)		);
 _PROTOTYPE( void pty_init, (struct tty *tp)				);
+_PROTOTYPE( void select_retry_pty, (struct tty *tp)				);
 _PROTOTYPE( int pty_status, (message *m_ptr)				);
 
 /* vidcopy.s */