runtime: convert parfor to Go

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews, khr
https://golang.org/cl/132100043

src/pkg/runtime/export_test.go

@@ -66,18 +66,54 @@ type ParFor struct {
 	wait    bool
 }
 
-func newParFor(nthrmax uint32) *ParFor
-func parForSetup(desc *ParFor, nthr, n uint32, ctx *byte, wait bool, body func(*ParFor, uint32))
-func parForDo(desc *ParFor)
-func parForIters(desc *ParFor, tid uintptr) (uintptr, uintptr)
+var (
+	newparfor_m,
+	parforsetup_m,
+	parfordo_m,
+	parforiters_m mFunction
+)
+
+func NewParFor(nthrmax uint32) *ParFor {
+	mp := acquirem()
+	mp.scalararg[0] = uint(nthrmax)
+	onM(&newparfor_m)
+	desc := (*ParFor)(mp.ptrarg[0])
+	mp.ptrarg[0] = nil
+	releasem(mp)
+	return desc
+}
+
+func ParForSetup(desc *ParFor, nthr, n uint32, ctx *byte, wait bool, body func(*ParFor, uint32)) {
+	mp := acquirem()
+	mp.ptrarg[0] = unsafe.Pointer(desc)
+	mp.ptrarg[1] = unsafe.Pointer(ctx)
+	mp.ptrarg[2] = **(**unsafe.Pointer)(unsafe.Pointer(&body))
+	mp.scalararg[0] = uint(nthr)
+	mp.scalararg[1] = uint(n)
+	mp.scalararg[2] = 0
+	if wait {
+		mp.scalararg[2] = 1
+	}
+	onM(&parforsetup_m)
+	releasem(mp)
+}
 
-var NewParFor = newParFor
-var ParForSetup = parForSetup
-var ParForDo = parForDo
+func ParForDo(desc *ParFor) {
+	mp := acquirem()
+	mp.ptrarg[0] = unsafe.Pointer(desc)
+	onM(&parfordo_m)
+	releasem(mp)
+}
 
 func ParForIters(desc *ParFor, tid uint32) (uint32, uint32) {
-	begin, end := parForIters(desc, uintptr(tid))
-	return uint32(begin), uint32(end)
+	mp := acquirem()
+	mp.ptrarg[0] = unsafe.Pointer(desc)
+	mp.scalararg[0] = uint(tid)
+	onM(&parforiters_m)
+	begin := uint32(mp.scalararg[0])
+	end := uint32(mp.scalararg[1])
+	releasem(mp)
+	return begin, end
 }
 
 //go:noescape

src/pkg/runtime/parfor.c

@@ -192,8 +192,47 @@ exit:
 
 // For testing from Go.
 void
-runtime·parforiters(ParFor *desc, uintptr tid, uintptr *start, uintptr *end)
+runtime·newparfor_m(void)
 {
-	*start = (uint32)desc->thr[tid].pos;
-	*end = (uint32)(desc->thr[tid].pos>>32);
+	g->m->ptrarg[0] = runtime·parforalloc(g->m->scalararg[0]);
+}
+
+void
+runtime·parforsetup_m(void)
+{
+	ParFor *desc;
+	void *ctx;
+	void (*body)(ParFor*, uint32);
+
+	desc = g->m->ptrarg[0];
+	g->m->ptrarg[0] = nil;
+	ctx = g->m->ptrarg[1];
+	g->m->ptrarg[1] = nil;
+	body = g->m->ptrarg[2];
+	g->m->ptrarg[2] = nil;
+
+	runtime·parforsetup(desc, g->m->scalararg[0], g->m->scalararg[1], ctx, g->m->scalararg[2], body);
+}
+
+void
+runtime·parfordo_m(void)
+{
+	ParFor *desc;
+
+	desc = g->m->ptrarg[0];
+	g->m->ptrarg[0] = nil;
+	runtime·parfordo(desc);
+}
+
+void
+runtime·parforiters_m(void)
+{
+	ParFor *desc;
+	uintptr tid;
+
+	desc = g->m->ptrarg[0];
+	g->m->ptrarg[0] = nil;
+	tid = g->m->scalararg[0];
+	g->m->scalararg[0] = desc->thr[tid].pos;
+	g->m->scalararg[1] = desc->thr[tid].pos>>32;
 }