From ac34066f309b45ab0e9add8833bbe683ebfb0f9f Mon Sep 17 00:00:00 2001
From: Charl Wentzel <charl.wentzel@vodamail.co.za>
Date: Thu, 2 Jun 2016 12:38:47 +0200
Subject: [PATCH] Important Update: (Massive CPU usage improvement) - Bug fix:
 Select timeout not constant, reduces to zero - Only scan FDs if Select event
 occured

---
 SelectCore.cpp | 75 ++++++++++++++++++++++++++------------------------
 1 file changed, 39 insertions(+), 36 deletions(-)

diff --git a/SelectCore.cpp b/SelectCore.cpp
index f877e2d..56ba023 100644
--- a/SelectCore.cpp
+++ b/SelectCore.cpp
@@ -160,13 +160,14 @@ bool CSelect::Test()
     TSelectHandle   ** HandlePtr    = NULL;
     int             TestFD          = 0;
     int             Events          = 0;
+    timeval         STimeout        = Timeout;
 
     // Set Test sets
     ReadFDS     = ReadTestFDS;
     WriteFDS    = WriteTestFDS;
 
     // Perform select
-    Events = select( MaxFD, &ReadFDS, &WriteFDS, (fd_set*)NULL, &Timeout );
+    Events = select( MaxFD, &ReadFDS, &WriteFDS, (fd_set*)NULL, &STimeout );
     if (Events < 0)
     {
         LogMessage( dlHigh, "Select: Select operation failed" );
@@ -174,47 +175,49 @@ bool CSelect::Test()
     }
 
     // Check all descriptors for events
-    Handle = FirstHandle;
-    while (Handle)
-    {
-        // Check if to remove from list
-        if (!Handle->Read && !Handle->Write)
+    if (Events) {
+        Handle = FirstHandle;
+        while (Handle)
         {
-            // Update Maximum Test FD
-            if (Handle->FD == MaxFD-1) {
-                for (TestFD = MaxFD-1; TestFD >= 0; TestFD--) {
-                    if (FD_ISSET( TestFD, &ReadTestFDS ) || FD_ISSET( TestFD, &WriteTestFDS )) {
-                        break;
+            // Check if to remove from list
+            if (!Handle->Read && !Handle->Write)
+            {
+                // Update Maximum Test FD
+                if (Handle->FD == MaxFD-1) {
+                    for (TestFD = MaxFD-1; TestFD >= 0; TestFD--) {
+                        if (FD_ISSET( TestFD, &ReadTestFDS ) || FD_ISSET( TestFD, &WriteTestFDS )) {
+                            break;
+                        }
                     }
+                    MaxFD = TestFD+1;
                 }
-                MaxFD = TestFD+1;
+
+                // Remove from list
+                HandlePtr = &FirstHandle;
+                while (*HandlePtr && (*HandlePtr != Handle))
+                    HandlePtr = &((*HandlePtr)->Next);
+                *HandlePtr = (*HandlePtr)->Next;
+
+                // Destroy and go to next
+                free( Handle );
+                Handle = *HandlePtr;
+                continue;
             }
+            else
+            {
+                // Check read Event
+                if (FD_ISSET( Handle->FD, &ReadFDS ) && Handle->Function) {
+                    Handle->Function->Read( Handle->FD );
+                }
 
-            // Remove from list
-            HandlePtr = &FirstHandle;
-            while (*HandlePtr && (*HandlePtr != Handle))
-                HandlePtr = &((*HandlePtr)->Next);
-            *HandlePtr = (*HandlePtr)->Next;
-
-            // Destroy and go to next
-            free( Handle );
-            Handle = *HandlePtr;
-            continue;
+                // Check Write Event
+                if (FD_ISSET( Handle->FD, &WriteFDS ) && Handle->Function) {
+                    Handle->Function->Write( Handle->FD );
+                }
+            }
+            // Next
+            Handle = Handle->Next;
         }
-        else
-        {
-            // Check read Event
-            if (FD_ISSET( Handle->FD, &ReadFDS ) && Handle->Function) {
-                Handle->Function->Read( Handle->FD );
-            }
-
-            // Check Write Event
-            if (FD_ISSET( Handle->FD, &WriteFDS ) && Handle->Function) {
-                Handle->Function->Write( Handle->FD );
-            }
-        }
-        // Next
-        Handle = Handle->Next;
     }
 
     // return success