SymbolNotFound::SymbolNotFound(const std::string& sym)
: SystemError(0, "symbol not found: " + sym),
_symbol(sym)
{
log_finer("symbol " << sym << " not found; " << what());
}
OpenLibraryFailed::OpenLibraryFailed(const std::string& msg)
: SystemError(msg)
{
log_finer("open library failed: " << what());
}
SystemError::SystemError(const char* fn, const std::string& what)
: std::runtime_error(fn && fn[0] ? (std::string("function ") + fn + " failed: " + what) : what),
m_errno(0)
{
log_finer("system error: " << std::exception::what());
}
SystemError::SystemError(const char* fn)
: std::runtime_error(getErrnoString(fn)),
m_errno(errno)
{
log_finer("system error: " << what());
}
SystemError::SystemError(const std::string& msg)
: std::runtime_error(msg),
m_errno(0)
{
log_finer("system error: " << what());
}
/**
* Decode a header version 1.
* Reads parts of the message from the medium using recv_int().
*/
int decode_header(int first) {
log_finer("decoding message header ...");
// set type as specified in protocol version 1
first = fmod(first, pow(2, 24));
int type = floor(first / pow(2, 20));
log_finest("message type: %d", type);
// set id as specified in protocol version 1
first = fmod(first, pow(2, 20));
int id = floor(first / pow(2, 16));
log_finest("target id : %d", id);
// the last two bytes mark the size of this frame
int size = fmod(first, pow(2, 16));
log_finest("payload size: %d", size);
// 8 bit protocol version
// 4 bit message type
// 4 bit component identifier
// 16 bit size or value, depending on type
// <size> bytes data, depending on type
// perform actions, depending on the message type
switch(type) {
case reset: // This is a soft reset.
// Clear all queues and propagate a hardware reset.
// Afterwards, answer with a reset type message to acknowledge successful reset.
break;
// 1-6 are not assigned
case debug: // This is an error message.
// By design, error messages should only be sent by the server.
// Consequently, receiving such a message is an error ;)
break;
case data: // This is a blocking data package.
if(size > 0) {
// the size is given in byte
int payload[size];
log_finer("reading payload ...");
// read <size> bytes
int i;
for(i = 0; i < size; i++) {
payload[i] = medium_recv_int();
log_finest("value %d: %d", i, payload[i]);
}
recv_message(id, payload, size);
}
break;
case poll: // This is a poll. Receiving a poll from the client means reading <size> values from out-going port <id>.
pollCount[id] += size;
break;
case gpio: // This marks a GPIO message. We need to switch over the target component.
#if gpi_count > 0 || gpo_count > 0
gpio_write(id, size);
#endif
case ack: // This is an acknowledgement.
// By design, acks should only be sent by the server.
// Consequently, receiving such a message is an error ;)
break;
default:
log_warn("WARNING: unknown type %d for protocol version 1. The frame will be ignored.", type);
return 1;
}
log_finer("finished message interpretation");
return 0;
}
