Source/DebuggerConnection.m

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2007 - 2010, 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 "DebuggerConnection.h"
  18
  19 #import <sys/socket.h>
  20 #import <netinet/in.h>
  21
  22 #import "AppDelegate.h"
  23 #import "LoggingController.h"
  24
  25 // DebuggerConnection (Private) ////////////////////////////////////////////////
  26
  27 @interface DebuggerConnection ()
  28
  29 @property (assign) CFSocketRef socket;
  30 @property (assign) CFReadStreamRef readStream;
  31 @property NSUInteger lastReadTransaction;
  32 @property (retain) NSMutableString* currentPacket;
  33 @property (assign) CFWriteStreamRef writeStream;
  34 @property NSUInteger lastWrittenTransaction;
  35 @property (retain) NSMutableArray* queuedWrites;
  36
  37 @end
  38
  39 // CFNetwork Callbacks /////////////////////////////////////////////////////////
  40
  41 void ReadStreamCallback(CFReadStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  42 {
  43         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
  44         switch (eventType)
  45         {
  46                 case kCFStreamEventHasBytesAvailable:
  47                         [connection readStreamHasData];
  48                         break;
  49
  50                 case kCFStreamEventErrorOccurred:
  51                 {
  52                         CFErrorRef error = CFReadStreamCopyError(stream);
  53                         CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  54                         CFReadStreamClose(stream);
  55                         CFRelease(stream);
  56                         [connection errorEncountered:[[(NSError*)error autorelease] description]];
  57                         break;
  58                 }
  59
  60                 case kCFStreamEventEndEncountered:
  61                         CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  62                         CFReadStreamClose(stream);
  63                         CFRelease(stream);
  64                         [connection socketDisconnected];
  65                         break;
  66         };
  67 }
  68
  69 void WriteStreamCallback(CFWriteStreamRef stream, CFStreamEventType eventType, void* connectionRaw)
  70 {
  71         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
  72         switch (eventType)
  73         {
  74                 case kCFStreamEventCanAcceptBytes:
  75                         [connection sendQueuedWrites];
  76                         break;
  77
  78                 case kCFStreamEventErrorOccurred:
  79                 {
  80                         CFErrorRef error = CFWriteStreamCopyError(stream);
  81                         CFWriteStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  82                         CFWriteStreamClose(stream);
  83                         CFRelease(stream);
  84                         [connection errorEncountered:[[(NSError*)error autorelease] description]];
  85                         break;
  86                 }
  87
  88                 case kCFStreamEventEndEncountered:
  89                         CFWriteStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
  90                         CFWriteStreamClose(stream);
  91                         CFRelease(stream);
  92                         [connection socketDisconnected];
  93                         break;
  94         }
  95 }
  96
  97 void SocketAcceptCallback(CFSocketRef socket,
  98                                                                                                         CFSocketCallBackType callbackType,
  99                                                                                                         CFDataRef address,
 100                                                                                                         const void* data,
 101                                                                                                         void* connectionRaw)
 102 {
 103         assert(callbackType == kCFSocketAcceptCallBack);
 104         NSLog(@"SocketAcceptCallback()");
 105
 106         DebuggerConnection* connection = (DebuggerConnection*)connectionRaw;
 107
 108         CFReadStreamRef readStream;
 109         CFWriteStreamRef writeStream;
 110
 111         // Create the streams on the socket.
 112         CFStreamCreatePairWithSocket(kCFAllocatorDefault,
 113                                                                                                                          *(CFSocketNativeHandle*)data,  // Socket handle.
 114                                                                                                                          &readStream,  // Read stream in-pointer.
 115                                                                                                                          &writeStream);  // Write stream in-pointer.
 116
 117         // Create struct to register callbacks for the stream.
 118         CFStreamClientContext context;
 119         context.version = 0;
 120         context.info = connection;
 121         context.retain = NULL;
 122         context.release = NULL;
 123         context.copyDescription = NULL;
 124
 125         // Set the client of the read stream.
 126         CFOptionFlags readFlags =
 127         kCFStreamEventOpenCompleted |
 128         kCFStreamEventHasBytesAvailable |
 129         kCFStreamEventErrorOccurred |
 130         kCFStreamEventEndEncountered;
 131         if (CFReadStreamSetClient(readStream, readFlags, ReadStreamCallback, &context))
 132                 // Schedule in run loop to do asynchronous communication with the engine.
 133                 CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 134         else
 135                 return;
 136
 137         // Open the stream now that it's scheduled on the run loop.
 138         if (!CFReadStreamOpen(readStream))
 139         {
 140                 CFStreamError error = CFReadStreamGetError(readStream);
 141                 NSLog(@"error! %@", error);
 142                 return;
 143         }
 144
 145         // Set the client of the write stream.
 146         CFOptionFlags writeFlags =
 147         kCFStreamEventOpenCompleted |
 148         kCFStreamEventCanAcceptBytes |
 149         kCFStreamEventErrorOccurred |
 150         kCFStreamEventEndEncountered;
 151         if (CFWriteStreamSetClient(writeStream, writeFlags, WriteStreamCallback, &context))
 152                 // Schedule it in the run loop to receive error information.
 153                 CFWriteStreamScheduleWithRunLoop(writeStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 154         else
 155                 return;
 156
 157         // Open the write stream.
 158         if (!CFWriteStreamOpen(writeStream))
 159         {
 160                 CFStreamError error = CFWriteStreamGetError(writeStream);
 161                 NSLog(@"error! %@", error);
 162                 return;
 163         }
 164
 165         connection.readStream = readStream;
 166         connection.writeStream = writeStream;
 167         [connection socketDidAccept];
 168 }
 169
 170 ////////////////////////////////////////////////////////////////////////////////
 171
 172 @implementation DebuggerConnection
 173
 174 @synthesize socket = socket_;
 175 @synthesize readStream = readStream_;
 176 @synthesize lastReadTransaction = lastReadTransaction_;
 177 @synthesize currentPacket = currentPacket_;
 178 @synthesize writeStream = writeStream_;
 179 @synthesize lastWrittenTransaction = lastWrittenTransaction_;
 180 @synthesize queuedWrites = queuedWrites_;
 181
 182 - (void)dealloc
 183 {
 184         self.currentPacket = nil;
 185         [super dealloc];
 186 }
 187
 188 /**
 189  * Called by SocketWrapper after the connection is successful. This immediately calls
 190  * -[SocketWrapper receive] to clear the way for communication, though the information
 191  * could be useful server information that we don't use right now.
 192  */
 193 - (void)socketDidAccept
 194 {
 195         connected = YES;
 196         transactionID = 1;
 197         self.queuedWrites = [NSMutableArray array];
 198         writeQueueLock_ = [NSRecursiveLock new];
 199         callTable_ = [NSMutableDictionary new];
 200 }
 201
 202 /**
 203  * Receives errors from the SocketWrapper and updates the display
 204  */
 205 - (void)errorEncountered:(NSString*)error
 206 {
 207         [delegate_ errorEncountered:error];
 208 }
 209
 210 /**
 211  * Creates, connects to, and schedules a CFSocket.
 212  */
 213 - (void)connect
 214 {
 215         // Pass ourselves to the callback so we don't have to use ugly globals.
 216         CFSocketContext context;
 217         context.version = 0;
 218         context.info = self;
 219         context.retain = NULL;
 220         context.release = NULL;
 221         context.copyDescription = NULL;
 222
 223         // Create the address structure.
 224         struct sockaddr_in address;
 225         memset(&address, 0, sizeof(address));
 226         address.sin_len = sizeof(address);
 227         address.sin_family = AF_INET;
 228         address.sin_port = htons(port);
 229         address.sin_addr.s_addr = htonl(INADDR_ANY);
 230
 231         // Create the socket signature.
 232         CFSocketSignature signature;
 233         signature.protocolFamily = PF_INET;
 234         signature.socketType = SOCK_STREAM;
 235         signature.protocol = IPPROTO_TCP;
 236         signature.address = (CFDataRef)[NSData dataWithBytes:&address length:sizeof(address)];
 237
 238         socket_ = CFSocketCreateWithSocketSignature(kCFAllocatorDefault,
 239                                                                                                                                                                                         &signature,  // Socket signature.
 240                                                                                                                                                                                         kCFSocketAcceptCallBack,  // Callback types.
 241                                                                                                                                                                                         SocketAcceptCallback,  // Callout function pointer.
 242                                                                                                                                                                                         &context);  // Context to pass to callout.
 243         if (!socket_)
 244         {
 245                 [self errorEncountered:@"Could not open socket."];
 246                 return;
 247         }
 248
 249         // Allow old, yet-to-be recycled sockets to be reused.
 250         BOOL yes = YES;
 251         setsockopt(CFSocketGetNative(socket_), SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(BOOL));
 252
 253         // Schedule the socket on the run loop.
 254         CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket_, 0);
 255         CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopCommonModes);
 256         CFRelease(source);
 257 }
 258
 259 /**
 260  * Closes a socket and releases the ref.
 261  */
 262 - (void)close
 263 {
 264         // The socket goes down, so do the streams, which clean themselves up.
 265         CFSocketInvalidate(socket_);
 266         CFRelease(socket_);
 267         self.queuedWrites = nil;
 268         [writeQueueLock_ release];
 269         [callTable_ release];
 270 }
 271
 272 /**
 273  * Notification that the socket disconnected.
 274  */
 275 - (void)socketDisconnected
 276 {
 277         [self close];
 278         [delegate_ debuggerDisconnected];
 279 }
 280
 281 /**
 282  * Callback from the CFReadStream that there is data waiting to be read.
 283  */
 284 - (void)readStreamHasData
 285 {
 286         const NSUInteger kBufferSize = 1024;
 287         UInt8 buffer[kBufferSize];
 288         CFIndex bufferOffset = 0;  // Starting point in |buffer| to work with.
 289         CFIndex bytesRead = CFReadStreamRead(readStream_, buffer, kBufferSize);
 290         const char* charBuffer = (const char*)buffer;
 291
 292         // The read loop works by going through the buffer until all the bytes have
 293         // been processed.
 294         while (bufferOffset < bytesRead)
 295         {
 296                 // Find the NULL separator, or the end of the string.
 297                 NSUInteger partLength = 0;
 298                 for (NSUInteger i = bufferOffset; i < bytesRead && charBuffer[i] != '\0'; ++i, ++partLength) ;
 299
 300                 // If there is not a current packet, set some state.
 301                 if (!self.currentPacket)
 302                 {
 303                         // Read the message header: the size.  This will be |partLength| bytes.
 304                         packetSize_ = atoi(charBuffer + bufferOffset);
 305                         currentPacketIndex_ = 0;
 306                         self.currentPacket = [NSMutableString stringWithCapacity:packetSize_];
 307                         bufferOffset += partLength + 1;  // Pass over the NULL byte.
 308                         continue;  // Spin the loop to begin reading actual data.
 309                 }
 310
 311                 // Substring the byte stream and append it to the packet string.
 312                 CFStringRef bufferString = CFStringCreateWithBytes(kCFAllocatorDefault,
 313                                                                                                                                                                                                                          buffer + bufferOffset,  // Byte pointer, offset by start index.
 314                                                                                                                                                                                                                          partLength,  // Length.
 315                                                                                                                                                                                                                          kCFStringEncodingUTF8,
 316                                                                                                                                                                                                                          true);
 317                 [self.currentPacket appendString:(NSString*)bufferString];
 318                 CFRelease(bufferString);
 319
 320                 // Advance counters.
 321                 currentPacketIndex_ += partLength;
 322                 bufferOffset += partLength + 1;
 323
 324                 // If this read finished the packet, handle it and reset.
 325                 NSLog(@"cpi %d ps %d br %d ds %d", currentPacketIndex_, packetSize_, bytesRead, partLength);
 326                 if (currentPacketIndex_ >= packetSize_)
 327                 {
 328                         [self handlePacket:[[currentPacket_ retain] autorelease]];
 329                         self.currentPacket = nil;
 330                         packetSize_ = 0;
 331                         currentPacketIndex_ = 0;
 332                 }
 333         }
 334 }
 335
 336 /**
 337  * Performs the packet handling of a raw string XML packet. From this point on,
 338  * the packets are associated with a transaction and are then dispatched.
 339  */
 340 - (void)handlePacket:(NSString*)packet
 341 {
 342         // Test if we can convert it into an NSXMLDocument.
 343         NSError* error = nil;
 344         NSXMLDocument* xmlTest = [[NSXMLDocument alloc] initWithXMLString:currentPacket_ options:NSXMLDocumentTidyXML error:&error];
 345
 346         // Try to recover if we encountered an error.
 347         if (!xmlTest)
 348         {
 349                 // We do not want to starve the write queue, so manually parse out the
 350                 // transaction ID.
 351                 NSRange location = [currentPacket_ rangeOfString:@"transaction_id"];
 352                 if (location.location != NSNotFound)
 353                 {
 354                         NSUInteger start = location.location + location.length;
 355                         NSUInteger end = start;
 356
 357                         NSCharacterSet* numericSet = [NSCharacterSet decimalDigitCharacterSet];
 358
 359                         // Loop over the characters after the attribute name to extract the ID.
 360                         while (end < [currentPacket_ length])
 361                         {
 362                                 unichar c = [currentPacket_ characterAtIndex:end];
 363                                 if ([numericSet characterIsMember:c])
 364                                 {
 365                                         // If this character is numeric, extend the range to substring.
 366                                         ++end;
 367                                 }
 368                                 else
 369                                 {
 370                                         if (start == end)
 371                                         {
 372                                                 // If this character is nonnumeric and we have nothing in the
 373                                                 // range, skip this character.
 374                                                 ++start;
 375                                                 ++end;
 376                                         }
 377                                         else
 378                                         {
 379                                                 // We've moved past the numeric ID so we should stop searching.
 380                                                 break;
 381                                         }
 382                                 }
 383                         }
 384
 385                         // If we were able to extract the transaction ID, update the last read.
 386                         NSRange substringRange = NSMakeRange(start, end - start);
 387                         NSString* transactionStr = [currentPacket_ substringWithRange:substringRange];
 388                         if ([transactionStr length])
 389                                 lastReadTransaction_ = [transactionStr intValue];
 390                 }
 391
 392                 // Otherwise, assume +1 and hope it works.
 393                 ++lastReadTransaction_;
 394         }
 395         else
 396         {
 397                 // See if the transaction can be parsed out.
 398                 NSInteger transaction = [self transactionIDFromResponse:xmlTest];
 399                 if (transaction < lastReadTransaction_)
 400                 {
 401                         NSLog(@"tx = %d vs %d", transaction, lastReadTransaction_);
 402                         NSLog(@"out of date transaction %@", packet);
 403                         return;
 404                 }
 405
 406                 if (transaction != lastWrittenTransaction_)
 407                         NSLog(@"txn %d <> %d last written, %d last read", transaction, lastWrittenTransaction_, lastReadTransaction_);
 408
 409                 lastReadTransaction_ = transaction;
 410         }
 411
 412         // Log this receive event.
 413         LoggingController* logger = [(AppDelegate*)[NSApp delegate] loggingController];
 414         LogEntry* log = [logger recordReceive:currentPacket_];
 415         log.error = error;
 416         log.lastWrittenTransactionID = lastWrittenTransaction_;
 417         log.lastReadTransactionID = lastReadTransaction_;
 418
 419         // Finally, dispatch the handler for this response.
 420         [self handleResponse:[xmlTest autorelease]];
 421 }
 422
 423 /**
 424  * Writes a command into the write stream. If the stream is ready for writing,
 425  * we do so immediately. If not, the command is queued and will be written
 426  * when the stream is ready.
 427  */
 428 - (void)send:(NSString*)command
 429 {
 430         if (lastReadTransaction_ >= lastWrittenTransaction_ && CFWriteStreamCanAcceptBytes(writeStream_))
 431                 [self performSend:command];
 432         else
 433                 [queuedWrites_ addObject:command];
 434         [self sendQueuedWrites];
 435 }
 436
 437 /**
 438  * This performs a blocking send. This should ONLY be called when we know we
 439  * have write access to the stream. We will busy wait in case we don't do a full
 440  * send.
 441  */
 442 - (void)performSend:(NSString*)command
 443 {
 444         // If this is an out-of-date transaction, do not bother sending it.
 445         NSInteger transaction = [self transactionIDFromCommand:command];
 446         if (transaction != NSNotFound && transaction < lastWrittenTransaction_)
 447                 return;
 448
 449         BOOL done = NO;
 450
 451         char* string = (char*)[command UTF8String];
 452         int stringLength = strlen(string);
 453
 454         // Busy wait while writing. BAADD. Should background this operation.
 455         while (!done)
 456         {
 457                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 458                 {
 459                         // Include the NULL byte in the string when we write.
 460                         int bytesWritten = CFWriteStreamWrite(writeStream_, (UInt8*)string, stringLength + 1);
 461                         if (bytesWritten < 0)
 462                         {
 463                                 NSLog(@"write error");
 464                         }
 465                         // Incomplete write.
 466                         else if (bytesWritten < strlen(string))
 467                         {
 468                                 // Adjust the buffer and wait for another chance to write.
 469                                 stringLength -= bytesWritten;
 470                                 memmove(string, string + bytesWritten, stringLength);
 471                         }
 472                         else
 473                         {
 474                                 done = YES;
 475
 476                                 // We need to scan the string to find the transactionID.
 477                                 if (transaction == NSNotFound)
 478                                 {
 479                                         NSLog(@"sent %@ without a transaction ID", command);
 480                                         continue;
 481                                 }
 482                                 lastWrittenTransaction_ = transaction;
 483                         }
 484                 }
 485         }
 486
 487         // Log this trancation.
 488         LoggingController* logger = [(AppDelegate*)[NSApp delegate] loggingController];
 489         LogEntry* log = [logger recordSend:command];
 490         log.lastWrittenTransactionID = lastWrittenTransaction_;
 491         log.lastReadTransactionID = lastReadTransaction_;
 492 }
 493
 494 - (void)handleResponse:(NSXMLDocument*)response
 495 {
 496         // Check and see if there's an error.
 497         NSArray* error = [[response rootElement] elementsForName:@"error"];
 498         if ([error count] > 0)
 499         {
 500                 NSLog(@"Xdebug error: %@", error);
 501                 [delegate_ errorEncountered:[[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue]];
 502         }
 503
 504         if ([[[response rootElement] name] isEqualToString:@"init"])
 505         {
 506                 [self initReceived:response];
 507                 return;
 508         }
 509
 510         NSString* callbackStr = [callTable_ objectForKey:[NSNumber numberWithInt:lastReadTransaction_]];
 511         if (callbackStr)
 512         {
 513                 SEL callback = NSSelectorFromString(callbackStr);
 514                 [self performSelector:callback withObject:response];
 515         }
 516
 517         [self sendQueuedWrites];
 518 }
 519
 520 #pragma mark Private
 521
 522 /**
 523  * This will send a command to the debugger engine. It will append the
 524  * transaction ID automatically. It accepts a NSString command along with a
 525  * a variable number of arguments to substitute into the command, a la
 526  * +[NSString stringWithFormat:]. Returns the transaction ID as a NSNumber.
 527  */
 528 - (NSNumber*)sendCommandWithCallback:(SEL)callback format:(NSString*)format, ...
 529 {
 530         // Collect varargs and format command.
 531         va_list args;
 532         va_start(args, format);
 533         NSString* command = [[NSString alloc] initWithFormat:format arguments:args];
 534         va_end(args);
 535
 536         NSNumber* callbackKey = [NSNumber numberWithInt:transactionID++];
 537         if (callback)
 538                 [callTable_ setObject:NSStringFromSelector(callback) forKey:callbackKey];
 539
 540         [self send:[NSString stringWithFormat:@"%@ -i %@", [command autorelease], callbackKey]];
 541
 542         return callbackKey;
 543 }
 544
 545 /**
 546  * Checks if there are unsent commands in the |queuedWrites_| queue and sends
 547  * them if it's OK to do so. This will not block.
 548  */
 549 - (void)sendQueuedWrites
 550 {
 551         if (!connected)
 552                 return;
 553
 554         [writeQueueLock_ lock];
 555         if (lastReadTransaction_ >= lastWrittenTransaction_ && [queuedWrites_ count] > 0)
 556         {
 557                 NSString* command = [queuedWrites_ objectAtIndex:0];
 558
 559                 // We don't want to block because this is called from the main thread.
 560                 // |-performSend:| busy waits when the stream is not ready. Bail out
 561                 // before we do that becuase busy waiting is BAD.
 562                 if (CFWriteStreamCanAcceptBytes(writeStream_))
 563                 {
 564                         [self performSend:command];
 565                         [queuedWrites_ removeObjectAtIndex:0];
 566                 }
 567         }
 568         [writeQueueLock_ unlock];
 569 }
 570
 571
 572 /**
 573  * Returns the transaction_id from an NSXMLDocument.
 574  */
 575 - (NSInteger)transactionIDFromResponse:(NSXMLDocument*)response
 576 {
 577         return [[[[response rootElement] attributeForName:@"transaction_id"] stringValue] intValue];
 578 }
 579
 580 /**
 581  * Scans a command string for the transaction ID component. If it is not found,
 582  * returns NSNotFound.
 583  */
 584 - (NSInteger)transactionIDFromCommand:(NSString*)command
 585 {
 586         NSRange occurrence = [command rangeOfString:@"-i "];
 587         if (occurrence.location == NSNotFound)
 588                 return NSNotFound;
 589         NSString* transaction = [command substringFromIndex:occurrence.location + occurrence.length];
 590         return [transaction intValue];
 591 }
 592
 593 @end