diff --git a/GNUmakefile b/GNUmakefile
index 6225b6d..8ab8a06 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -60,7 +60,7 @@ $(DNS_OBJS): dns.h stralloc.h taia.h tai.h uint64.h iopause.h
 $(CASE_OBJS): case.h
 $(ARRAY_OBJS): uint64.h array.h
 $(MULT_OBJS): uint64.h uint32.h uint16.h safemult.h
-$(IO_OBJS): uint64.h array.h io.h
+$(IO_OBJS): uint64.h array.h io.h io_internal.h taia.h tai.h
 
 iopause.o: select.h
 openreadclose.o readclose.o: readclose.h
diff --git a/array/array_allocate.c b/array/array_allocate.c
index 21c4d88..0c25e67 100644
--- a/array/array_allocate.c
+++ b/array/array_allocate.c
@@ -54,7 +54,7 @@ void* array_allocate(array* x,uint64 membersize,int64 pos) {
   if (__unlikely(x->allocated<0)) return 0; /* array is failed */
   if (__unlikely(pos+1<1)) return 0;
   /* second case of overflow: pos*membersize too large */
-  if (__unlikely(umult64(membersize,pos+1,&wanted))) return 0;
+  if (__unlikely(!umult64(membersize,pos+1,&wanted))) return 0;
 
   if (__unlikely(wanted > x->allocated)) {
     /* round up a little */
diff --git a/array/array_get.c b/array/array_get.c
index 2fe14e8..e10195b 100644
--- a/array/array_get.c
+++ b/array/array_get.c
@@ -23,7 +23,7 @@
 void* array_get(array* x,uint64 membersize,int64 pos) {
   uint64 wanted;
   if (__unlikely(pos+1<1)) return 0;
-  if (__unlikely(umult64(membersize,pos,&wanted))) return 0;
+  if (__unlikely(!umult64(membersize,pos,&wanted))) return 0;
 
   if (__unlikely(wanted > x->allocated)) return 0;
   return x->p+pos*membersize;
diff --git a/array/array_truncate.c b/array/array_truncate.c
index 71624da..512a5cf 100644
--- a/array/array_truncate.c
+++ b/array/array_truncate.c
@@ -11,7 +11,7 @@
 void array_truncate(array* x,uint64 membersize,int64 len) {
   uint64 wanted;
   if (__unlikely(len<0)) return;
-  if (__unlikely(umult64(membersize,len,&wanted))) return;
+  if (__unlikely(!umult64(membersize,len,&wanted))) return;
   if (__unlikely(wanted > x->initialized)) return;
   x->initialized=wanted;
 }
diff --git a/io/io_wait.c b/io/io_wait.c
index 7ea4d8c..9c0ff29 100644
--- a/io/io_wait.c
+++ b/io/io_wait.c
@@ -5,30 +5,5 @@
 #include "io_internal.h"
 
 void io_wait() {
-  struct pollfd* p;
-  long i,r;
-  if (!io_wanted_fds) return;
-  for (i=r=0; i<array_length(&io_fds,sizeof(io_entry)); ++i) {
-    io_entry* e=array_get(&io_fds,sizeof(io_entry),i);
-    if (!e) return;
-    e->canread=e->canwrite=0;
-    if (e->wantread || e->wantwrite) {
-      struct pollfd* p;
-      if ((p=array_allocate(&io_pollfds,sizeof(struct pollfd),r))) {
-	p->fd=i;
-	p->events=(e->wantread?POLLIN:0) + (e->wantwrite?POLLOUT:0);
-	++r;
-      } else
-	return;
-    }
-  }
-  p=array_start(&io_pollfds);
-  while ((i=poll(array_start(&io_pollfds),r,99999999))==0);
-  if (i==-1) return;
-  for (i=0; i<r; ++i) {
-    io_entry* e=array_get(&io_fds,sizeof(io_entry),p->fd);
-    if (p->revents&POLLIN) e->canread=1;
-    if (p->revents&POLLOUT) e->canwrite=1;
-    p++;
-  }
+  io_waituntil2(-1);
 }
diff --git a/io_internal.h b/io_internal.h
index 89babfc..eb206aa 100644
--- a/io_internal.h
+++ b/io_internal.h
@@ -14,3 +14,5 @@ typedef struct {
 array io_fds;
 uint64 io_wanted_fds;
 array io_pollfds;
+
+int64 io_waituntil2(int64 milliseconds);
diff --git a/mult/imult16.c b/mult/imult16.c
index 45bc8b9..3cff0c0 100644
--- a/mult/imult16.c
+++ b/mult/imult16.c
@@ -4,7 +4,7 @@ int imult16(int16 a,int16 b,int16* c) {
   int neg=(a<0);
   if (neg) a=-a;
   if (b<0) { neg^=1; b=-b; }
-  if (umult16(a,b,c)) return 1;
+  if (umult16(a,b,c)) return 0;
   if (neg) *c=-*c;
-  return 0;
+  return 1;
 }
diff --git a/mult/imult32.c b/mult/imult32.c
index 044fabb..27393dc 100644
--- a/mult/imult32.c
+++ b/mult/imult32.c
@@ -4,7 +4,7 @@ int imult32(int32 a,int32 b,int32* c) {
   int neg=(a<0);
   if (neg) a=-a;
   if (b<0) { neg^=1; b=-b; }
-  if (umult32(a,b,c)) return 1;
+  if (umult32(a,b,c)) return 0;
   if (neg) *c=-*c;
-  return 0;
+  return 1;
 }
diff --git a/mult/imult64.c b/mult/imult64.c
index c227aad..f51bbeb 100644
--- a/mult/imult64.c
+++ b/mult/imult64.c
@@ -4,8 +4,8 @@ int imult64(int64 a,int64 b,int64* c) {
   int neg=(a<0);
   if (neg) a=-a;
   if (b<0) { neg^=1; b=-b; }
-  if (umult64(a,b,c)) return 1;
+  if (umult64(a,b,c)) return 0;
   if (neg) *c=-*c;
-  return 0;
+  return 1;
 }
 
diff --git a/mult/umult16.c b/mult/umult16.c
index 879ffe5..8007f6e 100644
--- a/mult/umult16.c
+++ b/mult/umult16.c
@@ -2,7 +2,7 @@
 
 int umult16(uint16 a,uint16 b,uint16* c) {
   unsigned long x=(unsigned long)a*b;
-  if (x>0xffff) return 1;
+  if (x>0xffff) return 0;
   *c=x&0xffff;
-  return 0;
+  return 1;
 }
diff --git a/mult/umult32.c b/mult/umult32.c
index ba04ed7..89ee9a6 100644
--- a/mult/umult32.c
+++ b/mult/umult32.c
@@ -2,7 +2,7 @@
 
 int umult32(uint32 a,uint32 b,uint32* c) {
   unsigned long long x=(unsigned long long)a*b;
-  if (x>0xffffffff) return 1;
+  if (x>0xffffffff) return 0;
   *c=x&0xffffffff;
-  return 0;
+  return 1;
 }
diff --git a/mult/umult64.c b/mult/umult64.c
index a72d1ca..6d5e37a 100644
--- a/mult/umult64.c
+++ b/mult/umult64.c
@@ -12,11 +12,11 @@ int umult64(uint64 a,uint64 b,uint64* c) {
   //     = ahi*x*bhi*x + ahi*x*blo + alo*bhi*x + alo*blo
 
   // -> overflow if ahi*bhi != zero */
-  if (ahi && bhi) return 1;
+  if (ahi && bhi) return 0;
 
   a=(uint64)(ahi)*blo+(uint64)(alo)*bhi;
-  if (a>0xffffffff) return 1;
+  if (a>0xffffffff) return 0;
   *c=(a<<32)+(uint64)(alo)*blo;
-  return 0;
+  return 1;
 }
 
diff --git a/safemult.h b/safemult.h
index a1194a4..9ef14ec 100644
--- a/safemult.h
+++ b/safemult.h
@@ -5,7 +5,7 @@
 #include "uint32.h"
 #include "uint64.h"
 
-/* return 1 for overflow, 0 for ok */
+/* return 0 for overflow, 1 for ok */
 int umult16(uint16 a,uint16 b,uint16* c);
 int imult16( int16 a, int16 b, int16* c);
 
diff --git a/test/array.c b/test/array.c
index c3217c3..1797f25 100644
--- a/test/array.c
+++ b/test/array.c
@@ -15,4 +15,5 @@ main() {
   assert(byte_equal(x.p,11,"fnordfoobar"));
   array_cate(&x,&y,1,4);
   assert(x.initialized=14 && byte_equal(x.p,14,"fnordfoobarnor"));
+  return 0;
 }