Menes/yieldToSelector.mm

   1 /* Cydia - iPhone UIKit Front-End for Debian APT
   2  * Copyright (C) 2008-2015  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU General Public License, Version 3 {{{ */
   6 /*
   7  * Cydia is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation, either version 3 of the License,
  10  * or (at your option) any later version.
  11  *
  12  * Cydia is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with Cydia.  If not, see <http://www.gnu.org/licenses/>.
  19 **/
  20 /* }}} */
  21
  22 #include "Menes/yieldToSelector.h"
  23
  24 @implementation NSObject (MenesYieldToSelector)
  25
  26 - (void) doNothing {
  27 }
  28
  29 - (void) _yieldToContext:(NSMutableArray *)context {
  30     NSAutoreleasePool *pool([[NSAutoreleasePool alloc] init]);
  31
  32     SEL selector(reinterpret_cast<SEL>([[context objectAtIndex:0] pointerValue]));
  33     id object([[context objectAtIndex:1] nonretainedObjectValue]);
  34     volatile bool &stopped(*reinterpret_cast<bool *>([[context objectAtIndex:2] pointerValue]));
  35
  36     /* XXX: deal with exceptions */
  37     id value([self performSelector:selector withObject:object]);
  38
  39     NSMethodSignature *signature([self methodSignatureForSelector:selector]);
  40     [context removeAllObjects];
  41     if ([signature methodReturnLength] != 0 && value != nil)
  42         [context addObject:value];
  43
  44     stopped = true;
  45
  46     [self
  47         performSelectorOnMainThread:@selector(doNothing)
  48         withObject:nil
  49         waitUntilDone:NO
  50     ];
  51
  52     [pool release];
  53 }
  54
  55 - (id) yieldToSelector:(SEL)selector withObject:(id)object {
  56     volatile bool stopped(false);
  57
  58     NSMutableArray *context([NSMutableArray arrayWithObjects:
  59         [NSValue valueWithPointer:selector],
  60         [NSValue valueWithNonretainedObject:object],
  61         [NSValue valueWithPointer:const_cast<bool *>(&stopped)],
  62     nil]);
  63
  64     NSThread *thread([[[NSThread alloc]
  65         initWithTarget:self
  66         selector:@selector(_yieldToContext:)
  67         object:context
  68     ] autorelease]);
  69
  70     [thread start];
  71
  72     NSRunLoop *loop([NSRunLoop currentRunLoop]);
  73     NSDate *future([NSDate distantFuture]);
  74     NSString *mode([loop currentMode] ?: NSDefaultRunLoopMode);
  75
  76     while (!stopped && [loop runMode:mode beforeDate:future]);
  77
  78     return [context count] == 0 ? nil : [context objectAtIndex:0];
  79 }
  80
  81 - (id) yieldToSelector:(SEL)selector {
  82     return [self yieldToSelector:selector withObject:nil];
  83 }
  84
  85 @end