new read function

mread.c

@@ -0,0 +1,123 @@
+#include "marignotti.h"
+#include <gno/kerntool.h>
+#include <errno.h>
+
+#include <misctool.h>
+
+#pragma noroot
+#pragma optimize 79
+
+// called through GSOS.
+int mread(int ipid, void *p1, void *p2, void *p3, void *p4, void *p5)
+{
+    rrBuff rr;
+
+    Entry *e;
+    int xerrno = 0;
+    LongWord count;
+    LongWord timeout;
+    Word terr;
+    Word t;
+    
+    char *buffer = (char *)p1;
+    LongWord nbytes = *(LongWord *)p2;
+    *(LongWord *)p2 = 0;
+
+    
+    e = find_entry(ipid);
+    
+    if (!e)
+    {
+        return EBADF;
+    }
+
+    count = e->_RCVLOWAT;
+    if (count > nbytes) count = nbytes;
+
+    // call immediately if possible, otherwise queue it up.
+    IncBusy();
+    terr = TCPIPStatusTCP(ipid, &e->sr);
+    t = _toolErr;
+    DecBusy();
+    if (t) terr = t;
+    
+    if (t || terr == tcperrBadConnection || terr == tcperrNoResources)
+    {
+        return ENOTCONN;
+    }
+    
+    // eof or data available?
+    
+    if (e->sr.srRcvQueued >= count || terr == tcperrConClosing)
+    {        
+        count = e->sr.srRcvQueued;
+        if (count > nbytes) count = nbytes;
+        
+        if (count)
+        {
+            IncBusy();
+            terr = TCPIPReadTCP(ipid, 0, (Ref)buffer, count, &rr);
+            t = _toolErr;
+            DecBusy();
+            if (t) terr = t;
+
+            *(LongWord *)p2 = rr.rrBuffCount;    
+        }
+        return 0;
+    }
+        
+    if (e->_NONBLOCK) return EAGAIN;
+
+
+    if (e->_RCVTIMEO) 
+        timeout = GetTick() + e->_RCVTIMEO;   
+    else
+        timeout = 0;
+        
+    for(;;)
+    {
+        xerrno = queue_command(e, kCommandRead, count, timeout);
+        if (xerrno == EINTR) return EINTR;
+        if (xerrno) return EIO;
+        
+        if (e->command) continue;  // reset to 0 if processed.
+         
+        terr = e->terr;
+        
+        if (terr  && terr != tcperrConClosing)
+        {
+            return EIO;
+        }
+        
+        // 3 things may have happened.
+        // 1. sufficient data available.
+        // 2. connection closed.
+        // 3. timeout.
+
+        
+        if (e->sr.srRcvQueued >= count || terr == tcperrConClosing)
+        {
+            count = e->sr.srRcvQueued;
+            if (count > nbytes) count = nbytes;
+        
+            if (count)
+            {
+                IncBusy();
+                terr = TCPIPReadTCP(ipid, 0, (Ref)buffer, count, &rr);
+                t = _toolErr;
+                DecBusy();
+                                
+                *(LongWord *)p2 = rr.rrBuffCount;
+            }
+            return 0;
+        }
+                
+        if (timeout && timeout > GetTick())
+            return EAGAIN;
+            
+    }
+
+    // should not hit...
+    return 0;
+}
+