- Add a new SPMainThreadTrampoline NSObject category, allowing all NSObjects to easily proxy commands onto the main thread with any number and type of arguments.

 - Use the new trampoline and other thread safety tweaks to hopefully address a number of what appear to be threading issues:
     http://log.sequelpro.com/view/20
     http://log.sequelpro.com/view/32
     http://log.sequelpro.com/view/41
     http://log.sequelpro.com/view/42
     http://log.sequelpro.com/view/55
     http://log.sequelpro.com/view/64
     http://log.sequelpro.com/view/65
     http://log.sequelpro.com/view/66

1 files changed, 153 insertions, 0 deletions

diff --git a/Source/SPMainThreadTrampoline.m b/Source/SPMainThreadTrampoline.m
new file mode 100644
index 00000000..381e42ee
--- /dev/null
+++ b/Source/SPMainThreadTrampoline.m
@@ -0,0 +1,153 @@
+//
+//  $Id$
+//
+//  SPMainThreadTrampoline.m
+//  sequel-pro
+//
+//  Created by Rowan Beentje on 20/03/2010.
+//  Copyright 2010 Rowan Beentje. All rights reserved.
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+//  More info at <http://code.google.com/p/sequel-pro/>
+//
+
+#import "SPMainThreadTrampoline.h"
+
+@implementation NSObject (SPMainThreadTrampoline)
+
+/**
+ * Provide a category on all NSObjects to return a trampoline for that
+ * object on the main thread.
+ * This cannot be retained or released.
+ */
+- (id) onMainThread
+{
+
+	// Return an autoreleased trampoline object
+	return [[[SPMainThreadTrampoline alloc] initWithObject:self] autorelease];
+}
+
+/**
+ * Provide a retained version of the category
+ */
+- (id) retainedOnMainThread
+{
+	return [[SPMainThreadTrampoline alloc] initWithObject:self];
+}
+
+@end
+
+
+@implementation SPMainThreadTrampoline
+
+/**
+ * The master initiliasation - the category implementation calls this
+ * with the requested object.
+ */
+- (id) initWithObject:(id)theObject
+{
+	if (self = [super init]) {
+		trampolineObject = theObject;
+	}
+	return self;
+}
+
+/**
+ * Delegate unrecognised methods to the trampolined objects, thanks to the magic
+ * of NSInvocation (see forwardInvocation: docs for background). Must be paired
+ * with methodSignationForSelector:.
+ */
+- (void) forwardInvocation:(NSInvocation *)theInvocation
+{
+	SEL theSelector = [theInvocation selector];
+	if (![trampolineObject respondsToSelector:theSelector]) [self doesNotRecognizeSelector:theSelector];
+
+	// Retain the arguments and object for the call for safety
+	[theInvocation retainArguments];
+	[trampolineObject retain];
+	[theInvocation performSelectorOnMainThread:@selector(invokeWithTarget:) withObject:trampolineObject waitUntilDone:YES];
+	[trampolineObject release];
+}
+
+/**
+ * Return the correct method signatures for the trampolined object if
+ * NSObject doesn't implement the requested methods.
+ */
+- (NSMethodSignature *) methodSignatureForSelector:(SEL)theSelector
+{
+	NSMethodSignature *defaultSignature = [super methodSignatureForSelector:theSelector];
+	if (defaultSignature) return defaultSignature;
+
+	return [trampolineObject methodSignatureForSelector:theSelector];
+}
+
+/**
+ * Override the default repondsToSelector:, returning true if either NSObject
+ * or the trampolined object supports the selector.
+ */
+- (BOOL) respondsToSelector:(SEL)theSelector
+{	
+	return ([super respondsToSelector:theSelector] || [trampolineObject respondsToSelector:theSelector]);
+}
+
+/**
+ * Override the default performSelector:, again either using NSObject defaults
+ * or performing the selector on the trampolined object.
+ * Note that the return value from the trampolined object is not preserved in this case.
+ */
+- (id) performSelector:(SEL)theSelector
+{
+	if ([super respondsToSelector:theSelector]) return [super performSelector:theSelector];
+
+	if (![trampolineObject respondsToSelector:theSelector]) [self doesNotRecognizeSelector:theSelector];
+
+	// Retain the object while performing calls on it
+	[trampolineObject retain];
+	[trampolineObject performSelectorOnMainThread:theSelector withObject:nil waitUntilDone:YES];
+	[trampolineObject release];
+
+	return nil;
+}
+
+/**
+ * Override the default performSelector:withObject: - see performSelector:
+ * Note that the return value from the trampolined object is not preserved in this case.
+ */
+- (id) performSelector:(SEL)theSelector withObject:(id)theObject
+{
+	if ([super respondsToSelector:theSelector]) return [super performSelector:theSelector withObject:theObject];
+
+	if (![trampolineObject respondsToSelector:theSelector]) [self doesNotRecognizeSelector:theSelector];
+
+	// Retain the trampolined object, and the argument object, while performing calls
+	[trampolineObject retain];
+	[theObject retain];
+	[trampolineObject performSelectorOnMainThread:theSelector withObject:theObject waitUntilDone:YES];
+	[theObject release];
+	[trampolineObject release];
+
+	return nil;
+}
+
+/**
+ * If the trampoline is sent the onMainThread category, just return the trampoline directly.
+ */
+- (id) onMainThread
+{
+	return self;
+}
+
+@end
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