size_t
GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock (StringExtractorGDBRemote &packet, uint32_t timeout_usec)
{
uint8_t buffer[8192];
Error error;
Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS | GDBR_LOG_VERBOSE));
// Check for a packet from our cache first without trying any reading...
if (CheckForPacket (NULL, 0, packet))
return packet.GetStringRef().size();
bool timed_out = false;
while (IsConnected() && !timed_out)
{
lldb::ConnectionStatus status = eConnectionStatusNoConnection;
size_t bytes_read = Read (buffer, sizeof(buffer), timeout_usec, status, &error);
if (log)
log->Printf ("%s: Read (buffer, (sizeof(buffer), timeout_usec = 0x%x, status = %s, error = %s) => bytes_read = %" PRIu64,
__PRETTY_FUNCTION__,
timeout_usec,
Communication::ConnectionStatusAsCString (status),
error.AsCString(),
(uint64_t)bytes_read);
if (bytes_read > 0)
{
if (CheckForPacket (buffer, bytes_read, packet))
return packet.GetStringRef().size();
}
else
{
switch (status)
{
case eConnectionStatusTimedOut:
timed_out = true;
break;
case eConnectionStatusSuccess:
//printf ("status = success but error = %s\n", error.AsCString("<invalid>"));
break;
case eConnectionStatusEndOfFile:
case eConnectionStatusNoConnection:
case eConnectionStatusLostConnection:
case eConnectionStatusError:
Disconnect();
break;
}
}
}
packet.Clear ();
return 0;
}
bool
GDBRemoteCommunication::CheckForPacket (const uint8_t *src, size_t src_len, StringExtractorGDBRemote &packet)
{
// Put the packet data into the buffer in a thread safe fashion
Mutex::Locker locker(m_bytes_mutex);
Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
if (src && src_len > 0)
{
if (log && log->GetVerbose())
{
StreamString s;
log->Printf ("GDBRemoteCommunication::%s adding %u bytes: %.*s",
__FUNCTION__,
(uint32_t)src_len,
(uint32_t)src_len,
src);
}
m_bytes.append ((const char *)src, src_len);
}
// Parse up the packets into gdb remote packets
if (!m_bytes.empty())
{
// end_idx must be one past the last valid packet byte. Start
// it off with an invalid value that is the same as the current
// index.
size_t content_start = 0;
size_t content_length = 0;
size_t total_length = 0;
size_t checksum_idx = std::string::npos;
switch (m_bytes[0])
{
case '+': // Look for ack
case '-': // Look for cancel
case '\x03': // ^C to halt target
content_length = total_length = 1; // The command is one byte long...
break;
case '$':
// Look for a standard gdb packet?
{
size_t hash_pos = m_bytes.find('#');
if (hash_pos != std::string::npos)
{
if (hash_pos + 2 < m_bytes.size())
{
checksum_idx = hash_pos + 1;
// Skip the dollar sign
content_start = 1;
// Don't include the # in the content or the $ in the content length
content_length = hash_pos - 1;
total_length = hash_pos + 3; // Skip the # and the two hex checksum bytes
}
else
{
// Checksum bytes aren't all here yet
content_length = std::string::npos;
}
}
}
break;
default:
{
// We have an unexpected byte and we need to flush all bad
// data that is in m_bytes, so we need to find the first
// byte that is a '+' (ACK), '-' (NACK), \x03 (CTRL+C interrupt),
// or '$' character (start of packet header) or of course,
// the end of the data in m_bytes...
const size_t bytes_len = m_bytes.size();
bool done = false;
uint32_t idx;
for (idx = 1; !done && idx < bytes_len; ++idx)
{
switch (m_bytes[idx])
{
case '+':
case '-':
case '\x03':
case '$':
done = true;
break;
default:
break;
}
}
if (log)
log->Printf ("GDBRemoteCommunication::%s tossing %u junk bytes: '%.*s'",
__FUNCTION__, idx, idx, m_bytes.c_str());
m_bytes.erase(0, idx);
}
break;
}
if (content_length == std::string::npos)
{
packet.Clear();
return false;
}
else if (total_length > 0)
{
// We have a valid packet...
assert (content_length <= m_bytes.size());
assert (total_length <= m_bytes.size());
assert (content_length <= total_length);
bool success = true;
std::string &packet_str = packet.GetStringRef();
if (log)
{
// If logging was just enabled and we have history, then dump out what
// we have to the log so we get the historical context. The Dump() call that
// logs all of the packet will set a boolean so that we don't dump this more
// than once
if (!m_history.DidDumpToLog ())
m_history.Dump (log);
log->Printf("<%4" PRIu64 "> read packet: %.*s", (uint64_t)total_length, (int)(total_length), m_bytes.c_str());
}
m_history.AddPacket (m_bytes.c_str(), total_length, History::ePacketTypeRecv, total_length);
// Clear packet_str in case there is some existing data in it.
packet_str.clear();
// Copy the packet from m_bytes to packet_str expanding the
// run-length encoding in the process.
// Reserve enough byte for the most common case (no RLE used)
packet_str.reserve(m_bytes.length());
for (std::string::const_iterator c = m_bytes.begin() + content_start; c != m_bytes.begin() + content_start + content_length; ++c)
{
if (*c == '*')
{
// '*' indicates RLE. Next character will give us the
// repeat count and previous character is what is to be
// repeated.
char char_to_repeat = packet_str.back();
// Number of time the previous character is repeated
int repeat_count = *++c + 3 - ' ';
// We have the char_to_repeat and repeat_count. Now push
// it in the packet.
for (int i = 0; i < repeat_count; ++i)
packet_str.push_back(char_to_repeat);
}
else
{
packet_str.push_back(*c);
}
}
if (m_bytes[0] == '$')
{
assert (checksum_idx < m_bytes.size());
if (::isxdigit (m_bytes[checksum_idx+0]) ||
::isxdigit (m_bytes[checksum_idx+1]))
{
if (GetSendAcks ())
{
const char *packet_checksum_cstr = &m_bytes[checksum_idx];
char packet_checksum = strtol (packet_checksum_cstr, NULL, 16);
char actual_checksum = CalculcateChecksum (packet_str.c_str(), packet_str.size());
success = packet_checksum == actual_checksum;
if (!success)
{
if (log)
log->Printf ("error: checksum mismatch: %.*s expected 0x%2.2x, got 0x%2.2x",
(int)(total_length),
m_bytes.c_str(),
(uint8_t)packet_checksum,
(uint8_t)actual_checksum);
}
// Send the ack or nack if needed
if (!success)
SendNack();
else
SendAck();
}
}
else
{
success = false;
if (log)
log->Printf ("error: invalid checksum in packet: '%s'\n", m_bytes.c_str());
}
}
m_bytes.erase(0, total_length);
packet.SetFilePos(0);
return success;
}
}
packet.Clear();
return false;
}
StateType GDBRemoteClientBase::SendContinuePacketAndWaitForResponse(
ContinueDelegate &delegate, const UnixSignals &signals,
llvm::StringRef payload, StringExtractorGDBRemote &response) {
Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PROCESS));
response.Clear();
{
std::lock_guard<std::mutex> lock(m_mutex);
m_continue_packet = payload;
m_should_stop = false;
}
ContinueLock cont_lock(*this);
if (!cont_lock)
return eStateInvalid;
OnRunPacketSent(true);
for (;;) {
PacketResult read_result = ReadPacket(response, kInterruptTimeout, false);
switch (read_result) {
case PacketResult::ErrorReplyTimeout: {
std::lock_guard<std::mutex> lock(m_mutex);
if (m_async_count == 0)
continue;
if (steady_clock::now() >= m_interrupt_time + kInterruptTimeout)
return eStateInvalid;
}
case PacketResult::Success:
break;
default:
if (log)
log->Printf("GDBRemoteClientBase::%s () ReadPacket(...) => false",
__FUNCTION__);
return eStateInvalid;
}
if (response.Empty())
return eStateInvalid;
const char stop_type = response.GetChar();
if (log)
log->Printf("GDBRemoteClientBase::%s () got packet: %s", __FUNCTION__,
response.GetStringRef().c_str());
switch (stop_type) {
case 'W':
case 'X':
return eStateExited;
case 'E':
// ERROR
return eStateInvalid;
default:
if (log)
log->Printf("GDBRemoteClientBase::%s () unrecognized async packet",
__FUNCTION__);
return eStateInvalid;
case 'O': {
std::string inferior_stdout;
response.GetHexByteString(inferior_stdout);
delegate.HandleAsyncStdout(inferior_stdout);
break;
}
case 'A':
delegate.HandleAsyncMisc(
llvm::StringRef(response.GetStringRef()).substr(1));
break;
case 'J':
delegate.HandleAsyncStructuredDataPacket(response.GetStringRef());
break;
case 'T':
case 'S':
// Do this with the continue lock held.
const bool should_stop = ShouldStop(signals, response);
response.SetFilePos(0);
// The packet we should resume with. In the future
// we should check our thread list and "do the right thing"
// for new threads that show up while we stop and run async
// packets. Setting the packet to 'c' to continue all threads
// is the right thing to do 99.99% of the time because if a
// thread was single stepping, and we sent an interrupt, we
// will notice above that we didn't stop due to an interrupt
// but stopped due to stepping and we would _not_ continue.
// This packet may get modified by the async actions (e.g. to send a
// signal).
m_continue_packet = 'c';
cont_lock.unlock();
delegate.HandleStopReply();
if (should_stop)
return eStateStopped;
switch (cont_lock.lock()) {
case ContinueLock::LockResult::Success:
break;
case ContinueLock::LockResult::Failed:
return eStateInvalid;
case ContinueLock::LockResult::Cancelled:
return eStateStopped;
}
OnRunPacketSent(false);
break;
}
}
}