/Users/awniemel/Notepad-SVN/svn/trunk/CatNiP/CatNiP/UncaughtExceptionHandler.m

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#import "UncaughtExceptionHandler.h"
#include <libkern/OSAtomic.h>
#include <execinfo.h>

NSString * const UncaughtExceptionHandlerSignalExceptionName = @"UncaughtExceptionHandlerSignalExceptionName";
NSString * const UncaughtExceptionHandlerSignalKey = @"UncaughtExceptionHandlerSignalKey";
NSString * const UncaughtExceptionHandlerAddressesKey = @"UncaughtExceptionHandlerAddressesKey";

volatile int32_t UncaughtExceptionCount = 0;
const int32_t UncaughtExceptionMaximum = 10;

const NSInteger UncaughtExceptionHandlerSkipAddressCount = 4;
const NSInteger UncaughtExceptionHandlerReportAddressCount = 5;

@implementation UncaughtExceptionHandler

+ (NSArray *)backtrace
{
         void* callstack[128];
         int frames = backtrace(callstack, 128);
         char **strs = backtrace_symbols(callstack, frames);
         
         int i;
         NSMutableArray *backtrace = [NSMutableArray arrayWithCapacity:frames];
         for (
                i = UncaughtExceptionHandlerSkipAddressCount;
                i < UncaughtExceptionHandlerSkipAddressCount +
                        UncaughtExceptionHandlerReportAddressCount;
                i++)
         {
                [backtrace addObject:[NSString stringWithUTF8String:strs[i]]];
         }
         free(strs);
         
         return backtrace;
}

- (void)alertView:(UIAlertView *)anAlertView clickedButtonAtIndex:(NSInteger)anIndex
{
        if (anIndex == 0)
        {
                dismissed = YES;
        }
}

- (void)validateAndSaveCriticalApplicationData
{
        
}

- (void)handleException:(NSException *)exception
{
        [self validateAndSaveCriticalApplicationData];
        
        UIAlertView *alert =
                [[[UIAlertView alloc]
                        initWithTitle:NSLocalizedString(@"Unhandled exception", nil)
                        message:[NSString stringWithFormat:NSLocalizedString(
                                @"You can try to continue but the application may be unstable.\n\n"
                                @"Debug details follow:\n%@\n%@", nil),
                                [exception reason],
                                [[exception userInfo] objectForKey:UncaughtExceptionHandlerAddressesKey]]
                        delegate:self
                        cancelButtonTitle:NSLocalizedString(@"Quit", nil)
                        otherButtonTitles:NSLocalizedString(@"Continue", nil), nil]
                autorelease];
        [alert show];
        
        CFRunLoopRef runLoop = CFRunLoopGetCurrent();
        CFArrayRef allModes = CFRunLoopCopyAllModes(runLoop);
        
        while (!dismissed)
        {
                for (NSString *mode in (NSArray *)allModes)
                {
                        CFRunLoopRunInMode((CFStringRef)mode, 0.001, false);
                }
        }
        
        CFRelease(allModes);

        NSSetUncaughtExceptionHandler(NULL);
        signal(SIGABRT, SIG_DFL);
        signal(SIGILL, SIG_DFL);
        signal(SIGSEGV, SIG_DFL);
        signal(SIGFPE, SIG_DFL);
        signal(SIGBUS, SIG_DFL);
        signal(SIGPIPE, SIG_DFL);
        
        if ([[exception name] isEqual:UncaughtExceptionHandlerSignalExceptionName])
        {
                kill(getpid(), [[[exception userInfo] objectForKey:UncaughtExceptionHandlerSignalKey] intValue]);
        }
        else
        {
                [exception raise];
        }
}

@end

void HandleException(NSException *exception)
{
        int32_t exceptionCount = OSAtomicIncrement32(&UncaughtExceptionCount);
        if (exceptionCount > UncaughtExceptionMaximum)
        {
                return;
        }
        
        NSArray *callStack = [UncaughtExceptionHandler backtrace];
        NSMutableDictionary *userInfo =
                [NSMutableDictionary dictionaryWithDictionary:[exception userInfo]];
        [userInfo
                setObject:callStack
                forKey:UncaughtExceptionHandlerAddressesKey];
        
        [[[[UncaughtExceptionHandler alloc] init] autorelease]
                performSelectorOnMainThread:@selector(handleException:)
                withObject:
                        [NSException
                                exceptionWithName:[exception name]
                                reason:[exception reason]
                                userInfo:userInfo]
                waitUntilDone:YES];
}

void SignalHandler(int signal)
{
        int32_t exceptionCount = OSAtomicIncrement32(&UncaughtExceptionCount);
        if (exceptionCount > UncaughtExceptionMaximum)
        {
                return;
        }
        
        NSMutableDictionary *userInfo =
                [NSMutableDictionary
                        dictionaryWithObject:[NSNumber numberWithInt:signal]
                        forKey:UncaughtExceptionHandlerSignalKey];

        NSArray *callStack = [UncaughtExceptionHandler backtrace];
        [userInfo
                setObject:callStack
                forKey:UncaughtExceptionHandlerAddressesKey];
        
        [[[[UncaughtExceptionHandler alloc] init] autorelease]
                performSelectorOnMainThread:@selector(handleException:)
                withObject:
                        [NSException
                                exceptionWithName:UncaughtExceptionHandlerSignalExceptionName
                                reason:
                                        [NSString stringWithFormat:
                                                NSLocalizedString(@"Signal %d was raised.", nil),
                                                signal]
                                userInfo:
                                        [NSDictionary
                                                dictionaryWithObject:[NSNumber numberWithInt:signal]
                                                forKey:UncaughtExceptionHandlerSignalKey]]
                waitUntilDone:YES];
}

void InstallUncaughtExceptionHandler()
{
        NSSetUncaughtExceptionHandler(&HandleException);
        signal(SIGABRT, SignalHandler);
        signal(SIGILL, SignalHandler);
        signal(SIGSEGV, SignalHandler);
        signal(SIGFPE, SignalHandler);
        signal(SIGBUS, SignalHandler);
        signal(SIGPIPE, SignalHandler);
}