diff --git a/C/src/xplaneConnect.c b/C/src/xplaneConnect.c index d48ac02..11cc6a8 100755 --- a/C/src/xplaneConnect.c +++ b/C/src/xplaneConnect.c @@ -117,13 +117,16 @@ XPCSocket aopenUDP(const char *xpIP, unsigned short xpPort, unsigned short port) exit(EXIT_FAILURE); } - // Set timeout to 100ms + // Set socket timeout period for sendUDP to 1 millisecond + // Without this, playback may become choppy due to process blocking #ifdef _WIN32 - DWORD timeout = 100; + // Minimum socket timeout in Windows is 1 millisecond (0 makes it blocking) + DWORD timeout = 1; #else + // Set socket timeout to 1 millisecond = 1,000 microseconds to make it the same as Windows (0 makes it blocking) struct timeval timeout; timeout.tv_sec = 0; - timeout.tv_usec = 250000; + timeout.tv_usec = 1000; #endif if (setsockopt(sock.sock, SOL_SOCKET, SO_RCVTIMEO, (char*)&timeout, sizeof(timeout)) < 0) { @@ -188,13 +191,13 @@ int sendUDP(XPCSocket sock, char buffer[], int len) /// \returns If an error occurs, a negative number. Otherwise, the number of bytes read. int readUDP(XPCSocket sock, char buffer[], int len) { -#ifdef _WIN32 - // Windows readUDP needs the select command- minimum timeout is 1ms. - // Without this playback becomes choppy + // For readUDP, use the select command - minimum timeout of 0 makes it polling. + // Without this, playback may become choppy due to process blocking // Definitions FD_SET stReadFDS; FD_SET stExceptFDS; + struct timeval tv; // Setup for Select FD_ZERO(&stReadFDS); @@ -202,9 +205,10 @@ int readUDP(XPCSocket sock, char buffer[], int len) FD_ZERO(&stExceptFDS); FD_SET(sock.sock, &stExceptFDS); - struct timeval tv; + // Set timeout period for select to 0.05 sec = 50 milliseconds = 50,000 microseconds (0 makes it polling) + // TO DO - This could be set to 0 if a message handling system were implemented, like in the plugin. tv.tv_sec = 0; - tv.tv_usec = 100000; + tv.tv_usec = 50000; // Select Command int status = select(-1, &stReadFDS, (FD_SET*)0, &stExceptFDS, &tv); @@ -218,11 +222,9 @@ int readUDP(XPCSocket sock, char buffer[], int len) // No data return 0; } + + // If no error: Read Data status = recv(sock.sock, buffer, len, 0); -#else - // For apple or linux-just read - will timeout in 0.5 ms - int status = (int)recv(sock.sock, buffer, len, 0); -#endif if (status < 0) { printError("readUDP", "Error reading socket");