From db93f44502b69fdf0682f5eb77e0da899d7d4897 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 30 May 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-05-30

---
 port/devpipe.c | 10 +++-----
 port/netif.c   |  4 +--
 port/portdat.h | 50 --------------------------------------
 port/portfns.h |  3 ++-
 port/qio.c     | 66 ++++++++++++++++++++++++++++++++++++++++++++++++--
 5 files changed, 72 insertions(+), 61 deletions(-)

diff --git a/port/devpipe.c b/port/devpipe.c
index 38a4d0a46646f039f414f984d35d7b1112c0cfb7..c1f1521c48b3a5a9227676643484ac8d16ed6161 100644
--- a/port/devpipe.c
+++ b/port/devpipe.c
@@ -65,19 +65,17 @@ pipeattach(char *spec)
 		exhausted("memory");
 	p->ref = 1;
 
-	p->q[0] = qopen(64*1024, 0, 0);
+	p->q[0] = qopen(64*1024, 0, 0, 0);
 	if(p->q[0] == 0){
 		free(p);
 		exhausted("memory");
 	}
-	p->q[0]->state &= ~Qmsg;
-	p->q[1] = qopen(32*1024, 0, 0);
+	p->q[1] = qopen(32*1024, 0, 0, 0);
 	if(p->q[1] == 0){
 		free(p->q[0]);
 		free(p);
 		exhausted("memory");
 	}
-	p->q[1]->state &= ~Qmsg;
 
 	lock(&pipealloc);
 	p->path = ++pipealloc.path;
@@ -139,10 +137,10 @@ pipestat(Chan *c, char *db)
 		devdir(c, c->qid, ".", 2*DIRLEN, eve, CHDIR|0555, &dir);
 		break;
 	case Qdata0:
-		devdir(c, c->qid, "data", p->q[0]->len, eve, 0660, &dir);
+		devdir(c, c->qid, "data", qlen(p->q[0]), eve, 0660, &dir);
 		break;
 	case Qdata1:
-		devdir(c, c->qid, "data1", p->q[1]->len, eve, 0660, &dir);
+		devdir(c, c->qid, "data1", qlen(p->q[1]), eve, 0660, &dir);
 		break;
 	default:
 		panic("pipestat");
diff --git a/port/netif.c b/port/netif.c
index 704ba7a771cc39a02f6fb14871f7bc525e8ab04e..d6afccfa2d26836a3f317cefe6a0e7ca8dc4aae1 100644
--- a/port/netif.c
+++ b/port/netif.c
@@ -24,7 +24,7 @@ netifinit(Netif *nif, char *name, int nfile, ulong limit)
 	nif->f = xalloc(nfile*sizeof(Netfile*));
 	memset(nif->f, 0, nfile*sizeof(Netfile*));
 	nif->limit = limit;
-	nif->out = qopen(limit, 0, 0);
+	nif->out = qopen(limit, 1, 0, 0);
 }
 
 /*
@@ -339,7 +339,7 @@ openfile(Netif *nif, int id)
 				error(Enodev);
 			}
 			*fp = f;
-			f->in = qopen(nif->limit, 0, 0);
+			f->in = qopen(nif->limit, 1, 0, 0);
 			qlock(f);
 		} else {
 			qlock(f);
diff --git a/port/portdat.h b/port/portdat.h
index 28ffc0742266964f34975ce5e09569bf092664f6..51085e68c9c061d4940496f9580b7f2ccaf0dcef 100644
--- a/port/portdat.h
+++ b/port/portdat.h
@@ -636,56 +636,6 @@ struct Proc
 	PMMU;
 };
 
-/*
- *  IO queues
- */
-struct Block
-{
-	Block	*next;
-
-	uchar	*rp;			/* first unconsumed byte */
-	uchar	*wp;			/* first empty byte */
-	uchar	*lim;			/* 1 past the end of the buffer */
-	uchar	*base;			/* start of the buffer */
-	uchar	flag;
-
-	Rendez	r;			/* waiting reader */
-};
-#define BLEN(b)		((b)->wp - (b)->rp)
-
-struct Queue
-{
-	Lock;
-
-	Block	*bfirst;	/* buffer */
-	Block	*blast;
-
-	int	len;		/* bytes in queue */
-	int	limit;		/* max bytes in queue */
-	int	state;
-
-	void	(*kick)(void*);	/* restart output */
-	void	*arg;		/* argument to kick */
-
-	QLock	rlock;		/* mutex for reading processes */
-	Rendez	rr;		/* process waiting to read */
-	QLock	wlock;		/* mutex for writing processes */
-	Rendez	wr;		/* process waiting to write */
-};
-
-enum
-{
-	/* Block.flag */
-	Bfilled=1,		/* block filled */
-
-	/* Queue.state */	
-	Qstarve=	(1<<0),		/* consumer starved */
-	Qmsg=		(1<<1),		/* message stream */
-	Qclosed=	(1<<2),
-	Qflow=		(1<<3),
-};
-
-
 enum
 {
 	PRINTSIZE =	256,
diff --git a/port/portfns.h b/port/portfns.h
index 8a3fc9f314db3bd8d562acfb804d33dfa4d2e9c2..7fd1bb151262286a7dd0d5462c1b61d5fae712ff 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -173,8 +173,9 @@ ulong		pwait(Waitmsg*);
 void		qclose(Queue*);
 int		qconsume(Queue*, uchar*, int);
 void		qhangup(Queue*);
+int		qlen(Queue*);
 void		qlock(QLock*);
-Queue*		qopen(int, void (*)(void*), void*);
+Queue*		qopen(int, int, void (*)(void*), void*);
 int		qproduce(Queue*, uchar*, int);
 long		qread(Queue*, char*, int);
 void		qreopen(Queue*);
diff --git a/port/qio.c b/port/qio.c
index 37318161de1fbde3f3714b1ee159727e8ae43279..119a7528a2d5c0da4deb801304302918185c0391 100644
--- a/port/qio.c
+++ b/port/qio.c
@@ -5,6 +5,9 @@
 #include	"fns.h"
 #include	"../port/error.h"
 
+/*
+ *  interrupt level memory allocation
+ */
 typedef struct Chunk	Chunk;
 typedef	struct Chunkl	Chunkl;
 typedef	struct Arena	Arena;
@@ -38,6 +41,56 @@ struct Arena
 
 static Arena arena;
 
+/*
+ *  IO queues
+ */
+typedef struct Block	Block;
+typedef struct Queue	Queue;
+
+struct Block
+{
+	Block	*next;
+
+	uchar	*rp;			/* first unconsumed byte */
+	uchar	*wp;			/* first empty byte */
+	uchar	*lim;			/* 1 past the end of the buffer */
+	uchar	*base;			/* start of the buffer */
+	uchar	flag;
+};
+#define BLEN(b)		((b)->wp - (b)->rp)
+
+struct Queue
+{
+	Lock;
+
+	Block	*bfirst;	/* buffer */
+	Block	*blast;
+
+	int	len;		/* bytes in queue */
+	int	limit;		/* max bytes in queue */
+	int	state;
+
+	void	(*kick)(void*);	/* restart output */
+	void	*arg;		/* argument to kick */
+
+	QLock	rlock;		/* mutex for reading processes */
+	Rendez	rr;		/* process waiting to read */
+	QLock	wlock;		/* mutex for writing processes */
+	Rendez	wr;		/* process waiting to write */
+};
+
+enum
+{
+	/* Block.flag */
+	Bfilled=1,		/* block filled */
+
+	/* Queue.state */	
+	Qstarve=	(1<<0),		/* consumer starved */
+	Qmsg=		(1<<1),		/* message stream */
+	Qclosed=	(1<<2),
+	Qflow=		(1<<3),
+};
+
 /*
  *  Manage interrupt level memory allocation.
  */
@@ -297,7 +350,7 @@ qproduce(Queue *q, uchar *p, int len)
  *  called by non-interrupt code
  */
 Queue*
-qopen(int limit, void (*kick)(void*), void *arg)
+qopen(int limit, int msg, void (*kick)(void*), void *arg)
 {
 	Queue *q;
 
@@ -309,7 +362,7 @@ qopen(int limit, void (*kick)(void*), void *arg)
 	q->limit = limit;
 	q->kick = kick;
 	q->arg = arg;
-	q->state = Qmsg;
+	q->state = msg ? Qmsg : 0;
 
 	return q;
 }
@@ -518,3 +571,12 @@ qreopen(Queue *q)
 {
 	q->state &= ~Qclosed;
 }
+
+/*
+ *  return bytes queued
+ */
+int
+qlen(Queue *q)
+{
+	return q->len;
+}