chan flags close/closed installed

runtime not finished.

R=r
OCL=26217
CL=26217

src/cmd/gc/Makefile

@@ -41,7 +41,7 @@ y.tab.c: y.tab.h
 	test -f y.tab.c && touch y.tab.c
 
 builtin.c:	sys.go unsafe.go mkbuiltin1.c mkbuiltin
-	mkbuiltin >builtin.c || \
+	./mkbuiltin >builtin.c || \
 	(echo 'mkbuiltin failed; using bootstrap copy of builtin.c'; cp builtin.c.boot builtin.c)
 
 clean:

src/cmd/gc/builtin.c.boot

@@ -41,6 +41,8 @@ char *sysimport =
 	"func sys.chanrecv3 (hchan chan any, elem *any) (pres bool)\n"
 	"func sys.chansend1 (hchan chan any, elem any)\n"
 	"func sys.chansend2 (hchan chan any, elem any) (pres bool)\n"
+	"func sys.closechan (hchan chan any)\n"
+	"func sys.closedchan (hchan chan any) (? bool)\n"
 	"func sys.newselect (size int) (sel *uint8)\n"
 	"func sys.selectsend (sel *uint8, hchan chan any, elem any) (selected bool)\n"
 	"func sys.selectrecv (sel *uint8, hchan chan any, elem *any) (selected bool)\n"

src/cmd/gc/go.h

@@ -309,6 +309,7 @@ enum
 	OAS, OASOP, OCASE, OXCASE, OFALL, OXFALL,
 	OGOTO, OPROC, OMAKE, ONEW, OEMPTY, OSELECT,
 	OLEN, OCAP, OPANIC, OPANICN, OPRINT, OPRINTN, OTYPEOF,
+	OCLOSE, OCLOSED,
 
 	OOROR,
 	OANDAND,

src/cmd/gc/go.y

@@ -15,7 +15,7 @@
 %token	<val>		LLITERAL
 %token	<lint>		LASOP
 %token	<sym>		LNAME LBASETYPE LATYPE LPACK LACONST
-%token	<sym>		LPACKAGE LIMPORT LDEFER
+%token	<sym>		LPACKAGE LIMPORT LDEFER LCLOSE LCLOSED
 %token	<sym>		LMAP LCHAN LINTERFACE LFUNC LSTRUCT
 %token	<sym>		LCOLAS LFALL LRETURN LDDD
 %token	<sym>		LLEN LCAP LPANIC LPANICN LPRINT LPRINTN
@@ -888,6 +888,14 @@ pexpr:
 	{
 		$$ = nod(OLEN, $3, N);
 	}
+|	LCLOSE '(' expr ')'
+	{
+		$$ = nod(OCLOSE, $3, N);
+	}
+|	LCLOSED '(' expr ')'
+	{
+		$$ = nod(OCLOSED, $3, N);
+	}
 |	LCAP '(' expr ')'
 	{
 		$$ = nod(OCAP, $3, N);
@@ -1023,6 +1031,8 @@ sym2:
 sym3:
 	LLEN
 |	LCAP
+|	LCLOSE
+|	LCLOSED
 |	LPANIC
 |	LPANICN
 |	LPRINT

src/cmd/gc/lex.c

@@ -1112,7 +1112,6 @@ static	struct
 	"any",		LBASETYPE,	TANY,
 	"sys",		LPACK,		Txxx,
 
-/* keywords */
 	"break",	LBREAK,		Txxx,
 	"case",		LCASE,		Txxx,
 	"chan",		LCHAN,		Txxx,
@@ -1151,6 +1150,9 @@ static	struct
 	"type",		LTYPE,		Txxx,
 	"var",		LVAR,		Txxx,
 
+	"close",	LCLOSE,		Txxx,
+	"closed",	LCLOSED,	Txxx,
+
 	"notwithstanding",		LIGNORE,	Txxx,
 	"thetruthofthematter",		LIGNORE,	Txxx,
 	"despiteallobjections",		LIGNORE,	Txxx,

src/cmd/gc/mkbuiltin

@@ -21,7 +21,8 @@ case "$USER" in
 ken | r | rsc)
 	if ! cmp _builtin.c builtin.c.boot
 	then
-		p4 open builtin.c.boot
+		PATH=$PATH:/usr/local/bin
+		p4 open builtin.c.boot >/dev/null
 		cp _builtin.c builtin.c.boot
 	fi
 esac

src/cmd/gc/subr.c

@@ -688,6 +688,8 @@ opnames[] =
 	[OLABEL]	= "LABEL",
 	[OLE]		= "LE",
 	[OLEN]		= "LEN",
+	[OCLOSE]	= "CLOSE",
+	[OCLOSED]	= "CLOSED",
 	[OCAP]		= "CAP",
 	[OLIST]		= "LIST",
 	[OLITERAL]	= "LITERAL",

src/cmd/gc/sys.go

@@ -55,6 +55,8 @@ func	chanrecv2(hchan chan any) (elem any, pres bool);
 func	chanrecv3(hchan chan any, elem *any) (pres bool);
 func	chansend1(hchan chan any, elem any);
 func	chansend2(hchan chan any, elem any) (pres bool);
+func	closechan(hchan chan any);
+func	closedchan(hchan chan any) bool;
 
 func	newselect(size int) (sel *byte);
 func	selectsend(sel *byte, hchan chan any, elem any) (selected bool);

src/cmd/gc/walk.c

@@ -126,6 +126,8 @@ loop:
 
 	case OASOP:
 	case OAS:
+	case OCLOSE:
+	case OCLOSED:
 	case OCALLMETH:
 	case OCALLINTER:
 	case OCALL:
@@ -852,6 +854,20 @@ loop:
 		}
 		goto ret;
 
+	case OCLOSE:
+		if(top != Etop)
+			goto nottop;
+		walktype(n->left, Erv);		// chan
+		indir(n, chanop(n, top));
+		goto ret;
+
+	case OCLOSED:
+		if(top == Elv)
+			goto nottop;
+		walktype(n->left, Erv);		// chan
+		indir(n, chanop(n, top));
+		goto ret;
+
 	case OSEND:
 		if(top == Elv)
 			goto nottop;
@@ -2447,6 +2463,40 @@ chanop(Node *n, int top)
 	default:
 		fatal("chanop: unknown op %O", n->op);
 
+	case OCLOSE:
+		// closechan(hchan *chan any);
+		t = fixchan(n->left->type);
+		if(t == T)
+			break;
+
+		a = n->left;			// chan
+		r = a;
+
+		on = syslook("closechan", 1);
+		argtype(on, t->type);	// any-1
+
+		r = nod(OCALL, on, r);
+		walktype(r, top);
+		r->type = n->type;
+		break;
+
+	case OCLOSED:
+		// closedchan(hchan *chan any) bool;
+		t = fixchan(n->left->type);
+		if(t == T)
+			break;
+
+		a = n->left;			// chan
+		r = a;
+
+		on = syslook("closedchan", 1);
+		argtype(on, t->type);	// any-1
+
+		r = nod(OCALL, on, r);
+		walktype(r, top);
+		n->type = r->type;
+		break;
+
 	case OMAKE:
 		cl = listcount(n->left);
 		if(cl > 1)

src/runtime/chan.c

@@ -7,6 +7,14 @@
 static	int32	debug	= 0;
 static	Lock		chanlock;
 
+enum
+{
+	Wclosed		= 0x0001,
+	Rclosed		= 0xfffe,
+	Rincr		= 0x0002,
+	Rmax		= 0x8000,
+};
+
 typedef	struct	Hchan	Hchan;
 typedef	struct	Link	Link;
 typedef	struct	WaitQ	WaitQ;
@@ -32,7 +40,9 @@ struct	WaitQ
 
 struct	Hchan
 {
-	uint32	elemsize;
+	uint16	elemsize;
+	uint16	closed;			// Wclosed closed() hash been called
+					// Rclosed read-count after closed()
 	uint32	dataqsiz;		// size of the circular q
 	uint32	qcount;			// total data in the q
 	Alg*	elemalg;		// interface for element type
@@ -535,7 +545,6 @@ sys·selectdefault(Select *sel, ...)
 	}
 }
 
-
 // selectgo(sel *byte);
 void
 sys·selectgo(Select *sel)
@@ -790,6 +799,42 @@ retc:
 	*as = true;
 }
 
+// closechan(sel *byte);
+void
+sys·closechan(Hchan *c)
+{
+	if(c == nil)
+		throw("closechan: channel not allocated");
+
+	// if wclosed already set
+	// work has been done - just return
+	if(c->closed & Wclosed)
+		return;
+
+	// set wclosed
+	c->closed |= Wclosed;
+}
+
+// closedchan(sel *byte) bool;
+void
+sys·closedchan(Hchan *c, bool closed)
+{
+	if(c == nil)
+		throw("closedchan: channel not allocated");
+
+	closed = 0;
+
+	// test rclosed
+	if(c->closed & Rclosed) {
+		// see if rclosed has been set a lot
+		if(c->closed & Rmax)
+			throw("closedchan: ignored");
+		c->closed += Rincr;
+		closed = 1;
+	}
+	FLUSH(&closed);
+}
+
 static SudoG*
 dequeue(WaitQ *q, Hchan *c)
 {