X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=sys%2Fsrc%2Flibregexp%2Frregexec.c;h=c928cccb7b84087d02c9a271dd96985a707e7bcd;hb=930be3d3173ce989d71675acedfca1fdf5466751;hp=5727187331e7f686d49206e0e6f0fa8e2f69a8c2;hpb=0a460e1722c50e31653359f8a86fe0b606d2b513;p=plan9front.git

diff --git a/sys/src/libregexp/rregexec.c b/sys/src/libregexp/rregexec.c
index 572718733..c928cccb7 100644
--- a/sys/src/libregexp/rregexec.c
+++ b/sys/src/libregexp/rregexec.c
@@ -4,27 +4,26 @@
 #include "regimpl.h"
 
 typedef struct RethreadQ RethreadQ;
-struct RethreadQ
-{
+struct RethreadQ {
 	Rethread *head;
 	Rethread **tail;
 };
 
 int
-rregexec(Reprog *prog, Rune *str, Resub *sem, int msize)
+rregexec(Reprog *p, Rune *str, Resub *sem, int msize)
 {
 	RethreadQ lists[2], *clist, *nlist, *tmp;
-	Rethread *t, *nextthr, **availthr;
-	Reinst *curinst;
-	Rune *rsp, *rep, endr, last;
-	int i, match, first, gen, pri, matchpri;
+	Rethread *t, *next, *pool, *avail;
+	Reinst *ci;
+	Rune *rsp, *rep, endr, r;
+	int matchgen, gen;
 
+	memset(p->threads, 0, sizeof(Rethread)*p->nthr);
 	if(msize > NSUBEXPM)
 		msize = NSUBEXPM;
-
-	if(prog->startinst->gen != 0) {
-		for(curinst = prog->startinst; curinst < prog->startinst + prog->len; curinst++)
-			curinst->gen = 0;
+	if(p->startinst->gen != 0) {
+		for(ci = p->startinst; ci < p->startinst + p->len; ci++)
+			ci->gen = 0;
 	}
 
 	clist = lists;
@@ -34,11 +33,10 @@ rregexec(Reprog *prog, Rune *str, Resub *sem, int msize)
 	nlist->head = nil;
 	nlist->tail = &nlist->head;
 
-	for(i = 0; i < prog->nthr; i++)
-		prog->thrpool[i] = prog->threads + i;
-	availthr = prog->thrpool + prog->nthr;
+	pool = p->threads;
+	avail = nil;
+	gen = matchgen = 0;
 
-	pri = matchpri = gen = match = 0;
 	rsp = str;
 	rep = nil;
 	endr = L'\0';
@@ -51,132 +49,130 @@ rregexec(Reprog *prog, Rune *str, Resub *sem, int msize)
 			*sem->rep = '\0';
 		}
 	}
-	last = 1;
-	for(; last != L'\0'; rsp++) {
+
+	for(r = L'☺'; r != L'\0'; rsp++) {
+		r = *rsp;
 		gen++;
-		last = *rsp;
-		first = 1;
+		if(matchgen == 0) {
+			if(avail == nil) {
+				assert(pool < p->threads + p->nthr);
+				t = pool++;
+			} else {
+				t = avail;
+				avail = avail->next;
+			}
+			t->i = p->startinst;
+			if(msize > 0)
+				memset(t->sem, 0, sizeof(Resub)*msize);
+			t->next = nil;
+			t->gen = gen;
+			*clist->tail = t;
+			clist->tail = &t->next;
+		}
 		t = clist->head;
 		if(t == nil)
-			goto Start;
-		curinst = t->pc;
+			break;
+		ci = t->i;
 Again:
-		if(curinst->gen == gen)
+		if(ci->gen == gen)
 			goto Done;
-		curinst->gen = gen;
-		switch(curinst->op) {
+		ci->gen = gen;
+		switch(ci->op) {
 		case ORUNE:
-			if(*rsp != curinst->r)
+			if(r != ci->r)
 				goto Done;
 		case OANY: /* fallthrough */
-		Any:
-			nextthr = t->next;
-			t->pc = curinst + 1;
+			next = t->next;
+			t->i = ci + 1;
 			t->next = nil;
 			*nlist->tail = t;
 			nlist->tail = &t->next;
-			if(nextthr == nil)
-				break;
-			t = nextthr;
-			curinst = t->pc;
-			goto Again;
+			goto Next;
 		case OCLASS:
 		Class:
-			if(*rsp < curinst->r)
+			if(r < ci->r)
 				goto Done;
-			if(*rsp > curinst->r1) {
-				curinst++;
+			if(r > ci->r1) {
+				ci++;
 				goto Class;
 			}
-			nextthr = t->next;
-			t->pc = curinst->a;
+			next = t->next;
+			t->i = ci->a;
 			t->next = nil;
 			*nlist->tail = t;
 			nlist->tail = &t->next;
-			if(nextthr == nil)
-				break;
-			t = nextthr;
-			curinst = t->pc;
-			goto Again;
+			goto Next;
 		case ONOTNL:
-			if(*rsp != L'\n') {
-				curinst++;
+			if(r != L'\n') {
+				ci++;
 				goto Again;
 			}
 			goto Done;
 		case OBOL:
 			if(rsp == str || rsp[-1] == L'\n') {
-				curinst++;
+				ci++;
 				goto Again;
 			}
 			goto Done;
 		case OEOL:
-			if(*rsp == L'\0' && rep == nil) {
-				curinst++;
+			if(r == L'\n' || r == L'\0' && rep == nil) {
+				ci++;
 				goto Again;
 			}
-			if(*rsp == '\n')
-				goto Any;
 			goto Done;
 		case OJMP:
-			curinst = curinst->a;
+			ci = ci->a;
 			goto Again;
 		case OSPLIT:
-			nextthr = *--availthr;
-			nextthr->pc = curinst->b;
+			if(avail == nil) {
+				assert(pool < p->threads + p->nthr);
+				next = pool++;
+			} else {
+				next = avail;
+				avail = avail->next;
+			}
+			next->i = ci->b;
 			if(msize > 0)
-				memcpy(nextthr->sem, t->sem, sizeof(Resub)*msize);
-			nextthr->pri = t->pri;
-			nextthr->next = t->next;
-			t->next = nextthr;
-			curinst = curinst->a;
+				memcpy(next->sem, t->sem, sizeof(Resub)*msize);
+			next->next = t->next;
+			next->gen = t->gen;
+			t->next = next;
+			ci = ci->a;
 			goto Again;
 		case OSAVE:
-			if(curinst->sub < msize)
-				t->sem[curinst->sub].rsp = rsp;
-			curinst++;
+			if(ci->sub < msize)
+				t->sem[ci->sub].rsp = rsp;
+			ci++;
 			goto Again;
 		case OUNSAVE:
-			if(curinst->sub == 0) {
-				/* "Highest" priority is the left-most longest. */
-				if (t->pri > matchpri)
-					goto Done;
-				match = 1;
-				matchpri = t->pri;
+			if(ci->sub == 0) {
+				matchgen = t->gen;
 				if(sem != nil && msize > 0) {
 					memcpy(sem, t->sem, sizeof(Resub)*msize);
 					sem->rep = rsp;
 				}
 				goto Done;
 			}
-			if(curinst->sub < msize)
-				t->sem[curinst->sub].rep = rsp;
-			curinst++;
+			if(ci->sub < msize)
+				t->sem[ci->sub].rep = rsp;
+			ci++;
 			goto Again;
 		Done:
-			*availthr++ = t;
-			t = t->next;
-			if(t == nil)
+			next = t->next;
+			t->next = avail;
+			avail = t;
+		Next:
+			if(next == nil)
 				break;
-			curinst = t->pc;
-			goto Again;
-		}
-Start:
-		/* Start again once if we haven't found anything. */
-		if(first == 1 && match == 0) {
-			first = 0;
-			t = *--availthr;
-			if(msize > 0)
-				memset(t->sem, 0, sizeof(Resub)*msize);
-			/* "Lower" priority thread */
-			t->pri = matchpri = pri++;
-			t->next = nil;
-			curinst = prog->startinst;
+			if(matchgen && next->gen > matchgen) {
+				*clist->tail = avail;
+				avail = next;
+				break;
+			}
+			t = next;
+			ci = t->i;
 			goto Again;
 		}
-		/* If we have a match and no extant threads, we are done. */
-		if(match == 1 && nlist->head == nil)
-			break;
 		tmp = clist;
 		clist = nlist;
 		nlist = tmp;
@@ -185,5 +181,5 @@ Start:
 	}
 	if(rep != nil)
 		*rep = endr;
-	return match;
+	return matchgen > 0 ? 1 : 0;
 }