Method IncreaseSendBuff

library/cpp/netliba/socket/socket.cpp:404–440

    }

    bool TAbstractSocket::IncreaseSendBuff() {
        int buffSize;
        socklen_t sz = sizeof(buffSize);
        if (GetSockOpt(SOL_SOCKET, SO_SNDBUF, &buffSize, &sz)) {
            return false;
        }
        // worst case: 200000 pps * 8k * 0.01sec = 16Mb so 32Mb hard limit is reasonable value
        if (buffSize < 0 || buffSize > (1 << 25)) {
            fprintf(stderr, "GetSockOpt returns wrong or too big value for SO_SNDBUF: %d\n", buffSize);
            return false;
        }
            //linux returns the doubled value. man 7 socket:
            //
            // SO_SNDBUF
            //         Sets or gets the maximum socket send buffer in bytes.  The  ker-
            //         nel doubles this value (to allow space for bookkeeping overhead)
            //         when it is set using setsockopt(), and  this  doubled  value  is
            //         returned  by  getsockopt().   The  default  value  is set by the
            //         wmem_default sysctl and the maximum allowed value is set by  the
            //         wmem_max sysctl.  The minimum (doubled) value for this option is
            //         2048.
            //
#ifndef _linux_
        buffSize += buffSize;
#endif

        // false if previous value was less than current value.
        // It means setsockopt was not successful. (for example: system limits)
        // we will try to set it again but return false
        const bool rv = !(buffSize <= SendSysSocketSizePrev);
        if (SetSockOpt(SOL_SOCKET, SO_SNDBUF, &buffSize, sz) == 0) {
            SendSysSocketSize = buffSize;
            SendSysSocketSizePrev = buffSize;
            return rv;
        }
        return false;
    }

    int TAbstractSocket::GetSendSysSocketSize() {
        return SendSysSocketSize;