1 //===-- Communication.cpp ---------------------------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 // Project includes
14 #include "lldb/lldb-private-log.h"
15 #include "lldb/Core/Communication.h"
16 #include "lldb/Core/Connection.h"
17 #include "lldb/Core/Log.h"
18 #include "lldb/Core/Timer.h"
19 #include "lldb/Core/Event.h"
20 #include "lldb/Host/Host.h"
21 #include <string.h>
22
23 using namespace lldb;
24 using namespace lldb_private;
25
26 ConstString &
GetStaticBroadcasterClass()27 Communication::GetStaticBroadcasterClass ()
28 {
29 static ConstString class_name ("lldb.communication");
30 return class_name;
31 }
32
33 //----------------------------------------------------------------------
34 // Constructor
35 //----------------------------------------------------------------------
Communication(const char * name)36 Communication::Communication(const char *name) :
37 Broadcaster (NULL, name),
38 m_connection_sp (),
39 m_read_thread (LLDB_INVALID_HOST_THREAD),
40 m_read_thread_enabled (false),
41 m_bytes(),
42 m_bytes_mutex (Mutex::eMutexTypeRecursive),
43 m_write_mutex (Mutex::eMutexTypeNormal),
44 m_callback (NULL),
45 m_callback_baton (NULL),
46 m_close_on_eof (true)
47
48 {
49 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_OBJECT | LIBLLDB_LOG_COMMUNICATION,
50 "%p Communication::Communication (name = %s)",
51 this, name);
52
53 SetEventName (eBroadcastBitDisconnected, "disconnected");
54 SetEventName (eBroadcastBitReadThreadGotBytes, "got bytes");
55 SetEventName (eBroadcastBitReadThreadDidExit, "read thread did exit");
56 SetEventName (eBroadcastBitReadThreadShouldExit, "read thread should exit");
57 SetEventName (eBroadcastBitPacketAvailable, "packet available");
58
59 CheckInWithManager();
60 }
61
62 //----------------------------------------------------------------------
63 // Destructor
64 //----------------------------------------------------------------------
~Communication()65 Communication::~Communication()
66 {
67 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_OBJECT | LIBLLDB_LOG_COMMUNICATION,
68 "%p Communication::~Communication (name = %s)",
69 this, m_broadcaster_name.AsCString(""));
70 Clear();
71 }
72
73 void
Clear()74 Communication::Clear()
75 {
76 SetReadThreadBytesReceivedCallback (NULL, NULL);
77 Disconnect (NULL);
78 StopReadThread (NULL);
79 }
80
81 ConnectionStatus
Connect(const char * url,Error * error_ptr)82 Communication::Connect (const char *url, Error *error_ptr)
83 {
84 Clear();
85
86 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_COMMUNICATION, "%p Communication::Connect (url = %s)", this, url);
87
88 lldb::ConnectionSP connection_sp (m_connection_sp);
89 if (connection_sp.get())
90 return connection_sp->Connect (url, error_ptr);
91 if (error_ptr)
92 error_ptr->SetErrorString("Invalid connection.");
93 return eConnectionStatusNoConnection;
94 }
95
96 ConnectionStatus
Disconnect(Error * error_ptr)97 Communication::Disconnect (Error *error_ptr)
98 {
99 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_COMMUNICATION, "%p Communication::Disconnect ()", this);
100
101 lldb::ConnectionSP connection_sp (m_connection_sp);
102 if (connection_sp.get())
103 {
104 ConnectionStatus status = connection_sp->Disconnect (error_ptr);
105 // We currently don't protect connection_sp with any mutex for
106 // multi-threaded environments. So lets not nuke our connection class
107 // without putting some multi-threaded protections in. We also probably
108 // don't want to pay for the overhead it might cause if every time we
109 // access the connection we have to take a lock.
110 //
111 // This unique pointer will cleanup after itself when this object goes away,
112 // so there is no need to currently have it destroy itself immediately
113 // upon disconnnect.
114 //connection_sp.reset();
115 return status;
116 }
117 return eConnectionStatusNoConnection;
118 }
119
120 bool
IsConnected() const121 Communication::IsConnected () const
122 {
123 lldb::ConnectionSP connection_sp (m_connection_sp);
124 if (connection_sp.get())
125 return connection_sp->IsConnected ();
126 return false;
127 }
128
129 bool
HasConnection() const130 Communication::HasConnection () const
131 {
132 return m_connection_sp.get() != NULL;
133 }
134
135 size_t
Read(void * dst,size_t dst_len,uint32_t timeout_usec,ConnectionStatus & status,Error * error_ptr)136 Communication::Read (void *dst, size_t dst_len, uint32_t timeout_usec, ConnectionStatus &status, Error *error_ptr)
137 {
138 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_COMMUNICATION,
139 "%p Communication::Read (dst = %p, dst_len = %" PRIu64 ", timeout = %u usec) connection = %p",
140 this,
141 dst,
142 (uint64_t)dst_len,
143 timeout_usec,
144 m_connection_sp.get());
145
146 if (m_read_thread_enabled)
147 {
148 // We have a dedicated read thread that is getting data for us
149 size_t cached_bytes = GetCachedBytes (dst, dst_len);
150 if (cached_bytes > 0 || timeout_usec == 0)
151 {
152 status = eConnectionStatusSuccess;
153 return cached_bytes;
154 }
155
156 if (m_connection_sp.get() == NULL)
157 {
158 if (error_ptr)
159 error_ptr->SetErrorString("Invalid connection.");
160 status = eConnectionStatusNoConnection;
161 return 0;
162 }
163 // Set the timeout appropriately
164 TimeValue timeout_time;
165 if (timeout_usec != UINT32_MAX)
166 {
167 timeout_time = TimeValue::Now();
168 timeout_time.OffsetWithMicroSeconds (timeout_usec);
169 }
170
171 Listener listener ("Communication::Read");
172 listener.StartListeningForEvents (this, eBroadcastBitReadThreadGotBytes | eBroadcastBitReadThreadDidExit);
173 EventSP event_sp;
174 while (listener.WaitForEvent (timeout_time.IsValid() ? &timeout_time : NULL, event_sp))
175 {
176 const uint32_t event_type = event_sp->GetType();
177 if (event_type & eBroadcastBitReadThreadGotBytes)
178 {
179 return GetCachedBytes (dst, dst_len);
180 }
181
182 if (event_type & eBroadcastBitReadThreadDidExit)
183 {
184 Disconnect (NULL);
185 break;
186 }
187 }
188 return 0;
189 }
190
191 // We aren't using a read thread, just read the data synchronously in this
192 // thread.
193 lldb::ConnectionSP connection_sp (m_connection_sp);
194 if (connection_sp.get())
195 {
196 return connection_sp->Read (dst, dst_len, timeout_usec, status, error_ptr);
197 }
198
199 if (error_ptr)
200 error_ptr->SetErrorString("Invalid connection.");
201 status = eConnectionStatusNoConnection;
202 return 0;
203 }
204
205
206 size_t
Write(const void * src,size_t src_len,ConnectionStatus & status,Error * error_ptr)207 Communication::Write (const void *src, size_t src_len, ConnectionStatus &status, Error *error_ptr)
208 {
209 lldb::ConnectionSP connection_sp (m_connection_sp);
210
211 Mutex::Locker locker(m_write_mutex);
212 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_COMMUNICATION,
213 "%p Communication::Write (src = %p, src_len = %" PRIu64 ") connection = %p",
214 this,
215 src,
216 (uint64_t)src_len,
217 connection_sp.get());
218
219 if (connection_sp.get())
220 return connection_sp->Write (src, src_len, status, error_ptr);
221
222 if (error_ptr)
223 error_ptr->SetErrorString("Invalid connection.");
224 status = eConnectionStatusNoConnection;
225 return 0;
226 }
227
228
229 bool
StartReadThread(Error * error_ptr)230 Communication::StartReadThread (Error *error_ptr)
231 {
232 if (error_ptr)
233 error_ptr->Clear();
234
235 if (IS_VALID_LLDB_HOST_THREAD(m_read_thread))
236 return true;
237
238 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_COMMUNICATION,
239 "%p Communication::StartReadThread ()", this);
240
241
242 char thread_name[1024];
243 snprintf(thread_name, sizeof(thread_name), "<lldb.comm.%s>", m_broadcaster_name.AsCString());
244
245 m_read_thread_enabled = true;
246 m_read_thread = Host::ThreadCreate (thread_name, Communication::ReadThread, this, error_ptr);
247 if (!IS_VALID_LLDB_HOST_THREAD(m_read_thread))
248 m_read_thread_enabled = false;
249 return m_read_thread_enabled;
250 }
251
252 bool
StopReadThread(Error * error_ptr)253 Communication::StopReadThread (Error *error_ptr)
254 {
255 if (!IS_VALID_LLDB_HOST_THREAD(m_read_thread))
256 return true;
257
258 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_COMMUNICATION,
259 "%p Communication::StopReadThread ()", this);
260
261 m_read_thread_enabled = false;
262
263 BroadcastEvent (eBroadcastBitReadThreadShouldExit, NULL);
264
265 //Host::ThreadCancel (m_read_thread, error_ptr);
266
267 bool status = Host::ThreadJoin (m_read_thread, NULL, error_ptr);
268 m_read_thread = LLDB_INVALID_HOST_THREAD;
269 return status;
270 }
271
272
273 size_t
GetCachedBytes(void * dst,size_t dst_len)274 Communication::GetCachedBytes (void *dst, size_t dst_len)
275 {
276 Mutex::Locker locker(m_bytes_mutex);
277 if (m_bytes.size() > 0)
278 {
279 // If DST is NULL and we have a thread, then return the number
280 // of bytes that are available so the caller can call again
281 if (dst == NULL)
282 return m_bytes.size();
283
284 const size_t len = std::min<size_t>(dst_len, m_bytes.size());
285
286 ::memcpy (dst, m_bytes.c_str(), len);
287 m_bytes.erase(m_bytes.begin(), m_bytes.begin() + len);
288
289 return len;
290 }
291 return 0;
292 }
293
294 void
AppendBytesToCache(const uint8_t * bytes,size_t len,bool broadcast,ConnectionStatus status)295 Communication::AppendBytesToCache (const uint8_t * bytes, size_t len, bool broadcast, ConnectionStatus status)
296 {
297 lldb_private::LogIfAnyCategoriesSet (LIBLLDB_LOG_COMMUNICATION,
298 "%p Communication::AppendBytesToCache (src = %p, src_len = %" PRIu64 ", broadcast = %i)",
299 this, bytes, (uint64_t)len, broadcast);
300 if ((bytes == NULL || len == 0)
301 && (status != lldb::eConnectionStatusEndOfFile))
302 return;
303 if (m_callback)
304 {
305 // If the user registered a callback, then call it and do not broadcast
306 m_callback (m_callback_baton, bytes, len);
307 }
308 else if (bytes != NULL && len > 0)
309 {
310 Mutex::Locker locker(m_bytes_mutex);
311 m_bytes.append ((const char *)bytes, len);
312 if (broadcast)
313 BroadcastEventIfUnique (eBroadcastBitReadThreadGotBytes);
314 }
315 }
316
317 size_t
ReadFromConnection(void * dst,size_t dst_len,uint32_t timeout_usec,ConnectionStatus & status,Error * error_ptr)318 Communication::ReadFromConnection (void *dst,
319 size_t dst_len,
320 uint32_t timeout_usec,
321 ConnectionStatus &status,
322 Error *error_ptr)
323 {
324 lldb::ConnectionSP connection_sp (m_connection_sp);
325 if (connection_sp.get())
326 return connection_sp->Read (dst, dst_len, timeout_usec, status, error_ptr);
327 return 0;
328 }
329
330 bool
ReadThreadIsRunning()331 Communication::ReadThreadIsRunning ()
332 {
333 return m_read_thread_enabled;
334 }
335
336 void *
ReadThread(void * p)337 Communication::ReadThread (void *p)
338 {
339 Communication *comm = (Communication *)p;
340
341 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_COMMUNICATION));
342
343 if (log)
344 log->Printf ("%p Communication::ReadThread () thread starting...", p);
345
346 uint8_t buf[1024];
347
348 Error error;
349 ConnectionStatus status = eConnectionStatusSuccess;
350 bool done = false;
351 while (!done && comm->m_read_thread_enabled)
352 {
353 size_t bytes_read = comm->ReadFromConnection (buf, sizeof(buf), 5 * TimeValue::MicroSecPerSec, status, &error);
354 if (bytes_read > 0)
355 comm->AppendBytesToCache (buf, bytes_read, true, status);
356 else if ((bytes_read == 0)
357 && status == eConnectionStatusEndOfFile)
358 {
359 if (comm->GetCloseOnEOF ())
360 comm->Disconnect ();
361 comm->AppendBytesToCache (buf, bytes_read, true, status);
362 }
363
364 switch (status)
365 {
366 case eConnectionStatusSuccess:
367 break;
368
369 case eConnectionStatusEndOfFile:
370 if (comm->GetCloseOnEOF())
371 done = true;
372 break;
373 case eConnectionStatusNoConnection: // No connection
374 case eConnectionStatusLostConnection: // Lost connection while connected to a valid connection
375 done = true;
376 // Fall through...
377 case eConnectionStatusError: // Check GetError() for details
378 case eConnectionStatusTimedOut: // Request timed out
379 if (log)
380 error.LogIfError (log,
381 "%p Communication::ReadFromConnection () => status = %s",
382 p,
383 Communication::ConnectionStatusAsCString (status));
384 break;
385 }
386 }
387 log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_COMMUNICATION);
388 if (log)
389 log->Printf ("%p Communication::ReadThread () thread exiting...", p);
390
391 // Let clients know that this thread is exiting
392 comm->BroadcastEvent (eBroadcastBitReadThreadDidExit);
393 return NULL;
394 }
395
396 void
SetReadThreadBytesReceivedCallback(ReadThreadBytesReceived callback,void * callback_baton)397 Communication::SetReadThreadBytesReceivedCallback
398 (
399 ReadThreadBytesReceived callback,
400 void *callback_baton
401 )
402 {
403 m_callback = callback;
404 m_callback_baton = callback_baton;
405 }
406
407 void
SetConnection(Connection * connection)408 Communication::SetConnection (Connection *connection)
409 {
410 Disconnect (NULL);
411 StopReadThread(NULL);
412 m_connection_sp.reset(connection);
413 }
414
415 const char *
ConnectionStatusAsCString(lldb::ConnectionStatus status)416 Communication::ConnectionStatusAsCString (lldb::ConnectionStatus status)
417 {
418 switch (status)
419 {
420 case eConnectionStatusSuccess: return "success";
421 case eConnectionStatusError: return "error";
422 case eConnectionStatusTimedOut: return "timed out";
423 case eConnectionStatusNoConnection: return "no connection";
424 case eConnectionStatusLostConnection: return "lost connection";
425 case eConnectionStatusEndOfFile: return "end of file";
426 }
427
428 static char unknown_state_string[64];
429 snprintf(unknown_state_string, sizeof (unknown_state_string), "ConnectionStatus = %i", status);
430 return unknown_state_string;
431 }
432