1 files changed, 103 insertions, 0 deletions
diff --git a/Menes/yieldToSelector.mm b/Menes/yieldToSelector.mm
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+++ b/Menes/yieldToSelector.mm
@@ -0,0 +1,103 @@
+/* Cydia - iPhone UIKit Front-End for Debian APT
+ * Copyright (C) 2008-2011  Jay Freeman (saurik)
+*/
+
+/* Modified BSD License {{{ */
+/*
+ *        Redistribution and use in source and binary
+ * forms, with or without modification, are permitted
+ * provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the
+ *    above copyright notice, this list of conditions
+ *    and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the
+ *    above copyright notice, this list of conditions
+ *    and the following disclaimer in the documentation
+ *    and/or other materials provided with the
+ *    distribution.
+ * 3. The name of the author may not be used to endorse
+ *    or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+ * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+/* }}} */
+
+#include "Menes/yieldToSelector.h"
+
+@implementation NSObject (MenesYieldToSelector)
+
+- (void) doNothing {
+}
+
+- (void) _yieldToContext:(NSMutableArray *)context {
+    NSAutoreleasePool *pool([[NSAutoreleasePool alloc] init]);
+
+    SEL selector(reinterpret_cast<SEL>([[context objectAtIndex:0] pointerValue]));
+    id object([[context objectAtIndex:1] nonretainedObjectValue]);
+    volatile bool &stopped(*reinterpret_cast<bool *>([[context objectAtIndex:2] pointerValue]));
+
+    /* XXX: deal with exceptions */
+    id value([self performSelector:selector withObject:object]);
+
+    NSMethodSignature *signature([self methodSignatureForSelector:selector]);
+    [context removeAllObjects];
+    if ([signature methodReturnLength] != 0 && value != nil)
+        [context addObject:value];
+
+    stopped = true;
+
+    [self
+        performSelectorOnMainThread:@selector(doNothing)
+        withObject:nil
+        waitUntilDone:NO
+    ];
+
+    [pool release];
+}
+
+- (id) yieldToSelector:(SEL)selector withObject:(id)object {
+    volatile bool stopped(false);
+
+    NSMutableArray *context([NSMutableArray arrayWithObjects:
+        [NSValue valueWithPointer:selector],
+        [NSValue valueWithNonretainedObject:object],
+        [NSValue valueWithPointer:const_cast<bool *>(&stopped)],
+    nil]);
+
+    NSThread *thread([[[NSThread alloc]
+        initWithTarget:self
+        selector:@selector(_yieldToContext:)
+        object:context
+    ] autorelease]);
+
+    [thread start];
+
+    NSRunLoop *loop([NSRunLoop currentRunLoop]);
+    NSDate *future([NSDate distantFuture]);
+    NSString *mode([loop currentMode] ?: NSDefaultRunLoopMode);
+
+    while (!stopped && [loop runMode:mode beforeDate:future]);
+
+    return [context count] == 0 ? nil : [context objectAtIndex:0];
+}
+
+- (id) yieldToSelector:(SEL)selector {
+    return [self yieldToSelector:selector withObject:nil];
+}
+
+@end