diff --git a/array/array_allocate.c b/array/array_allocate.c
index 0c25e67..db86ad5 100644
--- a/array/array_allocate.c
+++ b/array/array_allocate.c
@@ -75,6 +75,6 @@ void* array_allocate(array* x,uint64 membersize,int64 pos) {
     x->allocated=wanted;
     byte_zero(x->p+x->initialized,x->allocated-x->initialized);
   }
-  x->initialized=pos*membersize;
+  x->initialized=(pos+1)*membersize;
   return x->p+pos*membersize;
 }
diff --git a/io.h b/io.h
index 0d96388..5edf66b 100644
--- a/io.h
+++ b/io.h
@@ -50,6 +50,9 @@ int64 io_canread();
 /* return next descriptor from io_wait that can be written to */
 int64 io_canwrite();
 
+/* return next descriptor with expired timeout */
+int64 io_timeouted();
+
 /* put d on internal data structure, return 1 on success, 0 on error */
 int io_fd(int64 d);
 
diff --git a/io/io_check.c b/io/io_check.c
new file mode 100644
index 0000000..2516b12
--- /dev/null
+++ b/io/io_check.c
@@ -0,0 +1,9 @@
+#include <unistd.h>
+#include <sys/time.h>
+#include <poll.h>
+#include <errno.h>
+#include "io_internal.h"
+
+void io_check() {
+  io_waituntil2(0);
+}
diff --git a/io/io_close.c b/io/io_close.c
index b00a211..190a55c 100644
--- a/io/io_close.c
+++ b/io/io_close.c
@@ -4,5 +4,9 @@
 void io_close(int64 d) {
   close(d);
   io_entry* e=array_get(&io_fds,sizeof(io_entry),d);
-  if (e) e->inuse=0;
+  if (e) {
+    e->inuse=0;
+    io_dontwantread(d);
+    io_dontwantwrite(d);
+  }
 }
diff --git a/io/io_fd.c b/io/io_fd.c
index cfc4e11..5969a35 100644
--- a/io/io_fd.c
+++ b/io/io_fd.c
@@ -12,5 +12,6 @@ int io_fd(int64 d) {
   if (!(e=array_allocate(&io_fds,sizeof(io_entry),d))) return 0;
   e->inuse=1;
   if (r&O_NDELAY) e->nonblock=1;
+  e->next_read=e->next_write=-1;
   return 1;
 }
diff --git a/io/io_tryread.c b/io/io_tryread.c
index 4cd922b..d69aa4a 100644
--- a/io/io_tryread.c
+++ b/io/io_tryread.c
@@ -16,7 +16,10 @@ int64 io_tryread(int64 d,char* buf,int64 len) {
     p.events=POLLIN;
     switch (poll(&p,1,0)) {
     case -1: return -3;
-    case 0: errno=EAGAIN; return -1;
+    case 0: errno=EAGAIN;
+	    e->canread=0;
+	    e->next_read=-1;
+	    return -1;
     }
     new.it_interval.tv_usec=0;
     new.it_interval.tv_sec=0;
@@ -37,5 +40,9 @@ int64 io_tryread(int64 d,char* buf,int64 len) {
     if (errno!=EAGAIN)
       r=-3;
   }
+  if (r==-1 || r==0) {
+    e->canread=0;
+    e->next_read=-1;
+  }
   return r;
 }
diff --git a/io/io_trywrite.c b/io/io_trywrite.c
index 21bd2d9..73586c6 100644
--- a/io/io_trywrite.c
+++ b/io/io_trywrite.c
@@ -16,7 +16,10 @@ int64 io_trywrite(int64 d,const char* buf,int64 len) {
     p.events=POLLOUT;
     switch (poll(&p,1,0)) {
     case -1: return -3;
-    case 0: errno=EAGAIN; return -1;
+    case 0: errno=EAGAIN;
+	    e->canwrite=0;
+	    e->next_write=-1;
+	    return -1;
     }
     new.it_interval.tv_usec=0;
     new.it_interval.tv_sec=0;
@@ -32,8 +35,14 @@ int64 io_trywrite(int64 d,const char* buf,int64 len) {
     new.it_value.tv_sec=0;
     setitimer(ITIMER_REAL,&new,&old);
   }
-  if (r==-1)
+  if (r==-1) {
+    if (errno==EINTR) errno=EAGAIN;
     if (errno!=EAGAIN)
       r=-3;
+  }
+  if (r==-1 || r==0) {
+    e->canwrite=0;
+    e->next_write=-1;
+  }
   return r;
 }
diff --git a/io/io_waituntil2.c b/io/io_waituntil2.c
index 006d286..5b78a71 100644
--- a/io/io_waituntil2.c
+++ b/io/io_waituntil2.c
@@ -29,10 +29,18 @@ again:
     if (errno==EINTR) goto again;
     return -1;
   }
-  for (i=0; i<r; ++i) {
+  for (i=r-1; i>=0; --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;
+    if (p->revents&POLLIN) {
+      e->canread=1;
+      e->next_read=first_readable;
+      first_readable=p->fd;
+    }
+    if (p->revents&POLLOUT) {
+      e->canwrite=1;
+      e->next_write=first_writeable;
+      first_writeable=p->fd;
+    }
     p++;
   }
   return i;
diff --git a/io_internal.h b/io_internal.h
index eb206aa..ba75b11 100644
--- a/io_internal.h
+++ b/io_internal.h
@@ -9,10 +9,15 @@ typedef struct {
   unsigned int nonblock:1;
   unsigned int inuse:1;
   tai6464 timeout;
+  long next_read;
+  long next_write;
 } io_entry;
 
 array io_fds;
 uint64 io_wanted_fds;
 array io_pollfds;
 
+unsigned long first_readable;
+unsigned long first_writeable;
+
 int64 io_waituntil2(int64 milliseconds);
diff --git a/test/io5.c b/test/io5.c
new file mode 100644
index 0000000..b632f3b
--- /dev/null
+++ b/test/io5.c
@@ -0,0 +1,95 @@
+#include "socket.h"
+#include "io.h"
+#include "buffer.h"
+#include "ip6.h"
+#include <errno.h>
+
+main() {
+  int s=socket_tcp6();
+  uint32 scope_id;
+  char ip[16];
+  uint16 port;
+  if (socket_bind6_reuse(s,V6any,1234,0)==-1) return 111;
+  if (socket_listen(s,16)==-1) return 111;
+  io_nonblock(s);
+  if (!io_fd(s)) return 111;
+  io_wantread(s);
+  buffer_puts(buffer_2,"listening on port 1234 (fd #");
+  buffer_putulong(buffer_2,s);
+  buffer_putsflush(buffer_2,")\n");
+  for (;;) {
+    int64 i;
+    io_wait();
+    buffer_putsflush(buffer_2,"io_wait() returned!\n");
+    while ((i=io_canread())!=-1) {
+      if (i==s) {
+	int n;
+	while ((n=socket_accept6(s,ip,&port,&scope_id))!=-1) {
+	  char buf[IP6_FMT];
+	  buffer_puts(buffer_2,"accepted new connection from ");
+	  buffer_put(buffer_2,buf,fmt_ip6(buf,ip));
+	  buffer_puts(buffer_2,":");
+	  buffer_putulong(buffer_2,port);
+	  buffer_puts(buffer_2," (fd ");
+	  buffer_putulong(buffer_2,n);
+	  buffer_puts(buffer_2,")");
+	  if (io_fd(n)) {
+	    io_wantread(n);
+	  } else {
+	    buffer_puts(buffer_2,", but io_fd failed.");
+	    io_close(n);
+	  }
+	  buffer_putnlflush(buffer_2);
+	}
+	if (errno!=EAGAIN) {
+	  buffer_puts(buffer_2,"socket_accept6: ");
+	  buffer_puterror(buffer_2);
+	  buffer_putnlflush(buffer_2);
+	}
+      } else {
+	char buf[1024];
+	int l=io_tryread(i,buf,sizeof buf);
+	if (l==-1) {
+	  buffer_puts(buffer_2,"io_tryread(");
+	  buffer_putulong(buffer_2,i);
+	  buffer_puts(buffer_2,"): ");
+	  buffer_puterror(buffer_2);
+	  buffer_putnlflush(buffer_2);
+	  io_close(i);
+	} else if (l==0) {
+	  buffer_puts(buffer_2,"eof on fd #");
+	  buffer_putulong(buffer_2,i);
+	  buffer_putnlflush(buffer_2);
+	  io_close(i);
+	} else {
+	  int r;
+	  switch (r=io_trywrite(i,buf,l)) {
+	  case -1:
+	    buffer_puts(buffer_2,"io_tryread(");
+	    buffer_putulong(buffer_2,i);
+	    buffer_puts(buffer_2,"): ");
+	    buffer_puterror(buffer_2);
+	    buffer_putnlflush(buffer_2);
+	    io_close(i);
+	    break;
+	  case 0:
+	    buffer_puts(buffer_2,"write eof on fd #");
+	    buffer_putulong(buffer_2,i);
+	    buffer_putnlflush(buffer_2);
+	    io_close(i);
+	  default:
+	    if (r!=l) {
+	      buffer_puts(buffer_2,"short write on fd #");
+	      buffer_putulong(buffer_2,i);
+	      buffer_puts(buffer_2,": wrote ");
+	      buffer_putulong(buffer_2,r);
+	      buffer_puts(buffer_2,", wanted to write ");
+	      buffer_putulong(buffer_2,l);
+	      buffer_putsflush(buffer_2,").\n");
+	    }
+	  }
+	}
+      }
+    }
+  }
+}