select

mselect.c

@@ -0,0 +1,122 @@
+#include "marignotti.h"
+#include <gno/kerntool.h>
+#include <errno.h>
+
+#pragma noroot
+#pragma optimize 79
+
+/*
+ * return value is ignored.
+ * 
+ */
+
+static boolean readable(Entry *e)
+{
+    if (e->_SHUT_RD)
+        return false;
+        
+    if (e->sr.srState > TCPSESTABLISHED && e->sr.srRcvQueued)
+        return true;
+
+    if (e->sr.srRcvQueued >= e->_RCVLOWAT)
+        return true;
+        
+    return false;
+}
+
+static boolean writable(Entry *e)
+{
+    if (e->_SHUT_WR)
+        return false;
+    
+    if (e->sr.srState != TCPSESTABLISHED)
+        return false;
+    
+    if (e->sr.srRcvQueued <= e->_SNDLOWAT)
+        return true;
+        
+    return false;
+}
+
+static boolean exceptable(Entry *e)
+{
+
+    switch (e->terr)
+    {
+    case tcperrOK:
+        break;
+    case tcperrConClosing:
+    case tcperrClosing:
+    case tcperrConReset:
+        if (!e->sr.srRcvQueued)
+            return true;
+        break;
+    }
+
+    if (e->sr.srRcvQueued)
+        return false;
+        
+    if (e->sr.srNetworkError)
+        return true;
+
+    if (e->sr.srState > TCPSESTABLISHED)
+        return true;
+    
+    return false;
+}
+
+int mselect(Entry *e, void *p1, void *p2, void *p3, void *p4, void *p5)
+{
+    Word t;
+    Word terr;
+    
+    int pid = *(int *)p2;
+    int flag = *(int *)p3;
+
+    *(int *)p3 = 0;
+
+    IncBusy();
+    terr = TCPIPStatusTCP(e->ipid, &e->sr);
+    t = _toolErr;
+    if (t) terr = t;
+    e->terr = terr;
+    DecBusy();
+        
+    if (e->sr.srState == TCPSLISTEN)
+    {
+        // for a listen socket, "read" means "accept".
+        switch (flag)
+        {
+        case 0:
+            if (e->sr.srAcceptCount)
+                *(int *)p3 = 1;
+            break;
+        }
+    
+    }
+    else
+    {
+        switch (flag)
+        {
+        case 0:
+            // readable.
+            *(int *)p3 = readable(e);
+            break;
+            
+        case 1:
+            // writable.
+            *(int *)p3 = writable(e);
+            break;
+            
+        case 2:
+            // exception.
+            *(int *)p3 = exceptable(e);
+            break;                
+
+        }
+    
+    }
+    
+    
+    return 0;
+}