System.Net.AutoWebProxyScriptEngine.GetProxies C# (CSharp) Method

        internal StringCollection GetProxies(Uri destination, bool returnFirstOnly, out AutoWebProxyState autoWebProxyState, ref int syncStatus)
        {
            GlobalLog.Print("AutoWebProxyScriptEngine#" + ValidationHelper.HashString(this) + "::GetProxies() state:" + ValidationHelper.ToString(state));


            if (state==AutoWebProxyState.DiscoveryFailure) {
                // No engine will be available anyway, shortcut the call.
                autoWebProxyState = state;
                return null;
            }

            // This whole thing has to be locked, both to prevent simultaneous downloading / compilation, and
            // because the script isn't threadsafe.
            string scriptReturn = null;
            try
            {
                EnterLock(ref syncStatus);
                if (syncStatus != SyncStatus.LockOwner)
                {
                    // This is typically because a download got aborted.
                    autoWebProxyState = AutoWebProxyState.DownloadFailure;
                    return null;
                }

                autoWebProxyState = EnsureEngineAvailable(ref syncStatus);
                if (autoWebProxyState != AutoWebProxyState.CompilationSuccess)
                {
                    // the script can't run, say we're not ready and bypass
                    return null;
                }
                autoWebProxyState = AutoWebProxyState.ExecutionFailure;
                try {
                    scriptReturn = scriptInstance.FindProxyForURL(destination.ToString(), destination.Host);
                    autoWebProxyState = AutoWebProxyState.ExecutionSuccess;
                    GlobalLog.Print("AutoWebProxyScriptEngine#" + ValidationHelper.HashString(this) + "::GetProxies() calling ExecuteFindProxyForURL() for destination:" + ValidationHelper.ToString(destination) + " returned scriptReturn:" + ValidationHelper.ToString(scriptReturn));
                }
                catch (Exception exception) {
                    if (NclUtilities.IsFatal(exception)) throw;
                    if(Logging.On)Logging.PrintWarning(Logging.Web, SR.GetString(SR.net_log_proxy_script_execution_error, exception));
                    GlobalLog.Print("AutoWebProxyScriptEngine#" + ValidationHelper.HashString(this) + "::GetProxies() calling ExecuteFindProxyForURL() for destination:" + ValidationHelper.ToString(destination) + " threw:" + ValidationHelper.ToString(exception));
                }
            }
            finally
            {
                ExitLock(ref syncStatus);
            }

            if (autoWebProxyState==AutoWebProxyState.ExecutionFailure) {
                // the script failed at runtime, say we're not ready and bypass
                return null;
            }
            StringCollection proxies = ParseScriptReturn(scriptReturn, destination, returnFirstOnly);
            GlobalLog.Print("AutoWebProxyScriptEngine#" + ValidationHelper.HashString(this) + "::GetProxies() proxies:" + ValidationHelper.ToString(proxies));
            return proxies;
        }