Source/NetworkConnection.mm

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2007 - 2011, Blue Static <http://www.bluestatic.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under the terms of the GNU
   6  * General Public License as published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
  10  * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with this program; if not,
  14  * write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  15  */
  16
  17 #import "NetworkConnection.h"
  18 #import "NetworkConnectionPrivate.h"
  19
  20 #import "AppDelegate.h"
  21 #import "LoggingController.h"
  22 #include "NetworkCallbackController.h"
  23
  24 // Other Run Loop Callbacks ////////////////////////////////////////////////////
  25
  26 void PerformQuitSignal(void* info)
  27 {
  28   NetworkConnection* obj = (NetworkConnection*)info;
  29   [obj performQuitSignal];
  30 }
  31
  32 ////////////////////////////////////////////////////////////////////////////////
  33
  34 @implementation NetworkConnection
  35
  36 @synthesize port = port_;
  37 @synthesize connected = connected_;
  38 @synthesize delegate = delegate_;
  39 @synthesize lastReadTransaction = lastReadTransaction_;
  40 @synthesize currentPacket = currentPacket_;
  41 @synthesize lastWrittenTransaction = lastWrittenTransaction_;
  42 @synthesize queuedWrites = queuedWrites_;
  43
  44 - (id)initWithPort:(NSUInteger)aPort
  45 {
  46   if (self = [super init]) {
  47     port_ = aPort;
  48   }
  49   return self;
  50 }
  51
  52 - (void)dealloc
  53 {
  54   self.currentPacket = nil;
  55   [super dealloc];
  56 }
  57
  58 /**
  59  * Kicks off the socket on another thread.
  60  */
  61 - (void)connect
  62 {
  63   if (thread_ && !connected_) {
  64     // A thread has been detached but the socket has yet to connect. Do not
  65     // spawn a new thread otherwise multiple threads will be blocked on the same
  66     // socket.
  67     return;
  68   }
  69   [NSThread detachNewThreadSelector:@selector(runNetworkThread) toTarget:self withObject:nil];
  70 }
  71
  72 /**
  73  * Creates, connects to, and schedules a CFSocket.
  74  */
  75 - (void)runNetworkThread
  76 {
  77   NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  78
  79   thread_ = [NSThread currentThread];
  80   runLoop_ = [NSRunLoop currentRunLoop];
  81   callbackController_ = new NetworkCallbackController(self);
  82
  83   // Create a source that is used to quit.
  84   CFRunLoopSourceContext quitContext = { 0 };
  85   quitContext.info = self;
  86   quitContext.perform = PerformQuitSignal;
  87   quitSource_ = CFRunLoopSourceCreate(kCFAllocatorDefault, 0, &quitContext);
  88   CFRunLoopAddSource([runLoop_ getCFRunLoop], quitSource_, kCFRunLoopCommonModes);
  89
  90   callbackController_->OpenConnection(port_);
  91
  92   CFRunLoopRun();
  93
  94   thread_ = nil;
  95   runLoop_ = nil;
  96   delete callbackController_;
  97   callbackController_ = NULL;
  98
  99   CFRunLoopSourceInvalidate(quitSource_);
 100   CFRelease(quitSource_);
 101   quitSource_ = NULL;
 102
 103   [pool release];
 104 }
 105
 106 /**
 107  * Called by SocketWrapper after the connection is successful. This immediately calls
 108  * -[SocketWrapper receive] to clear the way for communication, though the information
 109  * could be useful server information that we don't use right now.
 110  */
 111 - (void)socketDidAccept
 112 {
 113   connected_ = YES;
 114   transactionID = 1;
 115   lastReadTransaction_ = 0;
 116   lastWrittenTransaction_ = 0;
 117   self.queuedWrites = [NSMutableArray array];
 118   writeQueueLock_ = [NSRecursiveLock new];
 119   if ([delegate_ respondsToSelector:@selector(connectionDidAccept:)])
 120     [delegate_ performSelectorOnMainThread:@selector(connectionDidAccept:)
 121                                 withObject:self
 122                              waitUntilDone:NO];
 123 }
 124
 125 /**
 126  * Closes a socket and releases the ref.
 127  */
 128 - (void)close
 129 {
 130   if (thread_) {
 131     [thread_ cancel];
 132   }
 133   if (runLoop_ && quitSource_) {
 134     CFRunLoopSourceSignal(quitSource_);
 135     CFRunLoopWakeUp([runLoop_ getCFRunLoop]);
 136   }
 137 }
 138
 139 /**
 140  * Quits the run loop and stops the thread.
 141  */
 142 - (void)performQuitSignal
 143 {
 144   self.queuedWrites = nil;
 145   connected_ = NO;
 146   [writeQueueLock_ release];
 147
 148   if (runLoop_) {
 149     CFRunLoopStop([runLoop_ getCFRunLoop]);
 150   }
 151
 152   callbackController_->CloseConnection();
 153 }
 154
 155 /**
 156  * Notification that the socket disconnected.
 157  */
 158 - (void)socketDisconnected
 159 {
 160   if ([delegate_ respondsToSelector:@selector(connectionDidClose:)])
 161     [delegate_ connectionDidClose:self];
 162 }
 163
 164 /**
 165  * Writes a command into the write stream. If the stream is ready for writing,
 166  * we do so immediately. If not, the command is queued and will be written
 167  * when the stream is ready.
 168  */
 169 - (void)send:(NSString*)command
 170 {
 171   if (lastReadTransaction_ >= lastWrittenTransaction_ && callbackController_->WriteStreamCanAcceptBytes()) {
 172     [self performSend:command];
 173   } else {
 174     [writeQueueLock_ lock];
 175     [queuedWrites_ addObject:command];
 176     [writeQueueLock_ unlock];
 177   }
 178   [self sendQueuedWrites];
 179 }
 180
 181 /**
 182  * This will send a command to the debugger engine. It will append the
 183  * transaction ID automatically. It accepts a NSString command along with a
 184  * a variable number of arguments to substitute into the command, a la
 185  * +[NSString stringWithFormat:]. Returns the transaction ID as a NSNumber.
 186  */
 187 - (NSNumber*)sendCommandWithFormat:(NSString*)format, ...
 188 {
 189   // Collect varargs and format command.
 190   va_list args;
 191   va_start(args, format);
 192   NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
 193   va_end(args);
 194
 195   NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 196   NSString* taggedCommand = [NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey];
 197   [self performSelector:@selector(send:)
 198                onThread:thread_
 199              withObject:taggedCommand
 200           waitUntilDone:connected_];
 201
 202   return callbackKey;
 203 }
 204
 205 /**
 206  * Certain commands expect encoded data to be the the last, unnamed parameter
 207  * of the command. In these cases, inserting the transaction ID at the end is
 208  * incorrect, so clients use this method to have |{txn}| replaced with the
 209  * transaction ID.
 210  */
 211 - (NSNumber*)sendCustomCommandWithFormat:(NSString*)format, ...
 212 {
 213   // Collect varargs and format command.
 214   va_list args;
 215   va_start(args, format);
 216   NSString* command = [[[NSString alloc] initWithFormat:format arguments:args] autorelease];
 217   va_end(args);
 218
 219   NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 220   NSString* taggedCommand = [command stringByReplacingOccurrencesOfString:@"{txn}"
 221                                                                withString:[callbackKey stringValue]];
 222   [self performSelector:@selector(send:)
 223                onThread:thread_
 224              withObject:taggedCommand
 225           waitUntilDone:connected_];
 226
 227   return callbackKey;
 228 }
 229
 230 /**
 231  * Given a file path, this returns a file:// URI and escapes any spaces for the
 232  * debugger engine.
 233  */
 234 - (NSString*)escapedURIPath:(NSString*)path
 235 {
 236   // Custon GDBp paths are fine.
 237   if ([[path substringToIndex:4] isEqualToString:@"gdbp"])
 238     return path;
 239
 240   // Create a temporary URL that will escape all the nasty characters.
 241   NSURL* url = [NSURL fileURLWithPath:path];
 242   NSString* urlString = [url absoluteString];
 243
 244   // Remove the host because this is a file:// URL;
 245   urlString = [urlString stringByReplacingOccurrencesOfString:[url host] withString:@""];
 246
 247   // Escape % for use in printf-style NSString formatters.
 248   urlString = [urlString stringByReplacingOccurrencesOfString:@"%" withString:@"%%"];
 249   return urlString;
 250 }
 251
 252 /**
 253  * Returns the transaction_id from an NSXMLDocument.
 254  */
 255 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response
 256 {
 257   return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
 258 }
 259
 260 /**
 261  * Scans a command string for the transaction ID component. If it is not found,
 262  * returns NSNotFound.
 263  */
 264 - (NSInteger)transactionIDFromCommand:(NSString*)command
 265 {
 266   NSRange occurrence = [command rangeOfString:@"-i "];
 267   if (occurrence.location == NSNotFound)
 268     return NSNotFound;
 269   NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
 270   return [transaction intValue];
 271 }
 272
 273 // Private /////////////////////////////////////////////////////////////////////
 274 #pragma mark Private
 275
 276 // Delegate Thread-Safe Wrappers ///////////////////////////////////////////////
 277
 278 /**
 279  * Receives errors from the SocketWrapper and updates the display
 280  */
 281 - (void)errorEncountered:(NSString*)error
 282 {
 283   if (![delegate_ respondsToSelector:@selector(errorEncountered:)])
 284     return;
 285   [delegate_ performSelectorOnMainThread:@selector(errorEncountered:)
 286                               withObject:error
 287                            waitUntilDone:NO];
 288 }
 289
 290 - (LogEntry*)recordSend:(NSString*)command
 291 {
 292   LoggingController* logger = [[AppDelegate instance] loggingController];
 293   LogEntry* entry = [LogEntry newSendEntry:command];
 294   entry.lastReadTransactionID = lastReadTransaction_;
 295   entry.lastWrittenTransactionID = lastWrittenTransaction_;
 296   [logger performSelectorOnMainThread:@selector(recordEntry:)
 297                            withObject:entry
 298                         waitUntilDone:NO];
 299   return [entry autorelease];
 300 }
 301
 302 - (LogEntry*)recordReceive:(NSString*)command
 303 {
 304   LoggingController* logger = [[AppDelegate instance] loggingController];
 305   LogEntry* entry = [LogEntry newReceiveEntry:command];
 306   entry.lastReadTransactionID = lastReadTransaction_;
 307   entry.lastWrittenTransactionID = lastWrittenTransaction_;
 308   [logger performSelectorOnMainThread:@selector(recordEntry:)
 309                            withObject:entry
 310                         waitUntilDone:NO];
 311   return [entry autorelease];
 312 }
 313
 314 // Stream Managers /////////////////////////////////////////////////////////////
 315
 316 /**
 317  * Callback from the CFReadStream that there is data waiting to be read.
 318  */
 319 - (void)readStreamHasData:(CFReadStreamRef)stream
 320 {
 321   const NSUInteger kBufferSize = 1024;
 322   UInt8 buffer[kBufferSize];
 323   CFIndex bufferOffset = 0;  // Starting point in |buffer| to work with.
 324   CFIndex bytesRead = CFReadStreamRead(stream, buffer, kBufferSize);
 325   const char* charBuffer = (const char*)buffer;
 326
 327   // The read loop works by going through the buffer until all the bytes have
 328   // been processed.
 329   while (bufferOffset < bytesRead) {
 330     // Find the NULL separator, or the end of the string.
 331     NSUInteger partLength = 0;
 332     for (CFIndex i = bufferOffset; i < bytesRead && charBuffer[i] != '\0'; ++i, ++partLength) ;
 333
 334     // If there is not a current packet, set some state.
 335     if (!self.currentPacket) {
 336       // Read the message header: the size.  This will be |partLength| bytes.
 337       packetSize_ = atoi(charBuffer + bufferOffset);
 338       currentPacketIndex_ = 0;
 339       self.currentPacket = [NSMutableString stringWithCapacity:packetSize_];
 340       bufferOffset += partLength + 1;  // Pass over the NULL byte.
 341       continue;  // Spin the loop to begin reading actual data.
 342     }
 343
 344     // Substring the byte stream and append it to the packet string.
 345     CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 346                                                        buffer + bufferOffset,  // Byte pointer, offset by start index.
 347                                                        partLength,  // Length.
 348                                                        kCFStringEncodingUTF8,
 349                                                        true);
 350     [self.currentPacket appendString:(NSString*)bufferString];
 351     CFRelease(bufferString);
 352
 353     // Advance counters.
 354     currentPacketIndex_ += partLength;
 355     bufferOffset += partLength + 1;
 356
 357     // If this read finished the packet, handle it and reset.
 358     if (currentPacketIndex_ >= packetSize_) {
 359       [self handlePacket:[[currentPacket_ retain] autorelease]];
 360       self.currentPacket = nil;
 361       packetSize_ = 0;
 362       currentPacketIndex_ = 0;
 363     }
 364   }
 365 }
 366
 367 /**
 368  * Performs the packet handling of a raw string XML packet. From this point on,
 369  * the packets are associated with a transaction and are then dispatched.
 370  */
 371 - (void)handlePacket:(NSString*)packet
 372 {
 373   // Test if we can convert it into an NSXMLDocument.
 374   NSError* error = nil;
 375   NSXMLDocument* xml = [[NSXMLDocument alloc] initWithXMLString:currentPacket_
 376                                                         options:NSXMLDocumentTidyXML
 377                                                           error:&error];
 378   // TODO: Remove this assert before stable release. Flush out any possible
 379   // issues during testing.
 380   assert(xml);
 381
 382   // Validate the transaction.
 383   NSInteger transaction = [self transactionIDFromResponse:xml];
 384   if (transaction < lastReadTransaction_) {
 385     NSLog(@"Transaction #%d is out of date (lastRead = %d). Dropping packet: %@",
 386         transaction, lastReadTransaction_, packet);
 387     return;
 388   }
 389   if (transaction != lastWrittenTransaction_) {
 390     NSLog(@"Transaction #%d received out of order. lastRead = %d, lastWritten = %d. Continuing.",
 391         transaction, lastReadTransaction_, lastWrittenTransaction_);
 392   }
 393
 394   lastReadTransaction_ = transaction;
 395
 396   // Log this receive event.
 397   LogEntry* log = [self recordReceive:currentPacket_];
 398   log.error = error;
 399
 400   // Finally, dispatch the handler for this response.
 401   [self handleResponse:[xml autorelease]];
 402 }
 403
 404 - (void)handleResponse:(NSXMLDocument*)response
 405 {
 406   // Check and see if there's an error.
 407   NSArray* error = [[response rootElement] elementsForName:@"error"];
 408   if ([error count] > 0) {
 409     NSLog(@"Xdebug error: %@", error);
 410     NSString* errorMessage = [[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue];
 411     [self errorEncountered:errorMessage];
 412   }
 413
 414   if ([[[response rootElement] name] isEqualToString:@"init"]) {
 415     connected_ = YES;
 416     [delegate_ performSelectorOnMainThread:@selector(handleInitialResponse:)
 417                                 withObject:response
 418                              waitUntilDone:NO];
 419     return;
 420   }
 421
 422   if ([delegate_ respondsToSelector:@selector(handleResponse:)])
 423     [delegate_ performSelectorOnMainThread:@selector(handleResponse:)
 424                                 withObject:response
 425                              waitUntilDone:NO];
 426
 427   [self sendQueuedWrites];
 428 }
 429
 430 /**
 431  * This performs a blocking send. This should ONLY be called when we know we
 432  * have write access to the stream. We will busy wait in case we don't do a full
 433  * send.
 434  */
 435 - (void)performSend:(NSString*)command
 436 {
 437   // If this is an out-of-date transaction, do not bother sending it.
 438   NSInteger transaction = [self transactionIDFromCommand:command];
 439   if (transaction != NSNotFound && transaction < lastWrittenTransaction_)
 440     return;
 441
 442   if (callbackController_->WriteString(command)) {
 443     // We need to scan the string to find the transactionID.
 444     if (transaction == NSNotFound) {
 445       NSLog(@"sent %@ without a transaction ID", command);
 446     }
 447     lastWrittenTransaction_ = transaction;
 448   }
 449
 450   // Log this trancation.
 451   [self recordSend:command];
 452 }
 453
 454 /**
 455  * Checks if there are unsent commands in the |queuedWrites_| queue and sends
 456  * them if it's OK to do so. This will not block.
 457  */
 458 - (void)sendQueuedWrites
 459 {
 460   if (!connected_)
 461     return;
 462
 463   [writeQueueLock_ lock];
 464   if (lastReadTransaction_ >= lastWrittenTransaction_ && [queuedWrites_ count] > 0) {
 465     NSString* command = [queuedWrites_ objectAtIndex:0];
 466
 467     // We don't want to block because this is called from the main thread.
 468     // |-performSend:| busy waits when the stream is not ready. Bail out
 469     // before we do that becuase busy waiting is BAD.
 470     if (callbackController_->WriteStreamCanAcceptBytes()) {
 471       [self performSend:command];
 472       [queuedWrites_ removeObjectAtIndex:0];
 473     }
 474   }
 475   [writeQueueLock_ unlock];
 476 }
 477
 478 @end