harmonize semantics of io_sendfile and iob_send

CHANGES

@@ -2,6 +2,9 @@
   add Linux SIGIO support to IO
   expand IO api to be able to cope with edge triggered event
     notification: introduce io_eagain
+  the integer scan routines should only write *dest if they actually
+    scanned something
+  io_sendfile and iob_send should return -1 to -3 just like io_trywrite
 
 0.16:
   add buffer_fromsa (make buffer from stralloc)

io/io_sendfile.c

@@ -11,7 +11,7 @@ int64 io_sendfile(int64 s,int64 fd,uint64 off,uint64 n) {
   int r=sendfile(fd,s,off,n,0,&sbytes,0);
   if (r==0) return n;
   if (r==-1)
-    return (errno==EAGAIN?sbytes:-1);
+    return (errno==EAGAIN?(sbytes?sbytes:-1):-3);
 }
 #elif defined(__linux__)
 
@@ -26,7 +26,16 @@ _syscall4(int,sendfile,int,out,int,in,long *,offset,unsigned long,count)
 
 int64 io_sendfile(int64 s,int64 fd,uint64 off,uint64 n) {
   off_t o=off;
-  return sendfile(s,fd,&o,n);
+  io_entry* e=array_get(&io_fds,sizeof(io_entry),s);
+  off_t i=sendfile(s,fd,&o,n);
+  if (i==-1) {
+    if (e) {
+      e->canwrite=0;
+      e->next_write=-1;
+    }
+    if (errno!=EAGAIN) i=-3;
+  }
+  return i;
 }
 
 #else
@@ -37,6 +46,7 @@ int64 io_sendfile(int64 out,int64 in,uint64 off,uint64 bytes) {
   char buf[BUFSIZE];
   int n,m;
   uint64 sent=0;
+  io_entry* e=array_get(&io_fds,sizeof(io_entry),out);
   if (lseek(in,off,SEEK_SET) != off)
     return -1;
   while (bytes>0) {
@@ -44,8 +54,16 @@ int64 io_sendfile(int64 out,int64 in,uint64 off,uint64 bytes) {
     if ((n=read(in,tmp,(bytes<BUFSIZE)?bytes:BUFSIZE))<=0)
       return (sent?sent:-1);
     while (n>0) {
-      if ((m=write(out,tmp,n))<0)
+      if ((m=write(out,tmp,n))<0) {
+	if (m==-1) {
+	  if (e) {
+	    e->canwrite=0;
+	    e->next_write=-1;
+	  }
+	  return errno==EAGAIN?(sent?sent:-1):-3;
+	}
 	goto abort;
+      }
       sent+=m;
       n-=m;
       tmp+=m;

io/iob_send.c

@@ -59,11 +59,13 @@ int64 iob_send(int64 s,io_batch* b) {
       if (r==0)
 	sent=b->bytesleft;
       else if (r==-1 && errno==EAGAIN)
-	sent=sbytes;
+	if ((sent=sbytes)) sent=-1;
       else
-	sent=-1;
-    } else
+	sent=-3;
+    } else {
       sent=writev(s,v,headers);
+      if (sent==-1 && errno!=EAGAIN) sent=-3;
+    }
 #else
 #ifdef TCP_CORK
     if (b->bufs && b->files && !b->next) {
@@ -71,18 +73,16 @@ int64 iob_send(int64 s,io_batch* b) {
       setsockopt(s,IPPROTO_TCP,TCP_CORK,&one,sizeof(one));
     }
 #endif
-    if (headers)
+    if (headers) {
       sent=writev(s,v,headers);
-    else
+      if (sent==-1 && errno==EAGAIN) sent=-3;
+    } else
       sent=io_sendfile(s,e->fd,e->offset,e->n);
 #endif
     if (sent>0)
       total+=sent;
     else
-      if (!total) {
-	if (errno!=EAGAIN) return -3;
-	return -1;
-      }
+      return total?total:sent;
     if (sent==b->bytesleft) {
       b->bytesleft=0;
 #ifdef TCP_CORK

test/httpd.c

@@ -275,7 +275,7 @@ emerge:
       struct http_data* h=io_getcookie(i);
       int64 r=iob_send(i,&h->iob);
 /*      printf("iob_send returned %lld\n",r); */
-      if (r==-1) io_eagain(i);
+      if (r==-1) io_eagain(i); else
       if (r<=0) {
 	array_trunc(&h->r);
 	iob_reset(&h->iob);