Can I close file descriptors for currently unused UIAppFonts?

Question 1

If not, is there an alternative way of keeping local fonts available to UIWebView without resorting to @font-face which is slow?

Turns out, there is.

We solved the problem by registering fonts using CTFontManagerRegisterFontsForURL and unregistering them with CTFontManagerUnregisterFontsForURL. This keeps them available for UIWebView, given that you always register fonts before using them in font-family.

Question 2

I was having trouble with closing file descriptors associated with a Sprite Kit action,

playSoundFileNamed:

They never close. So they eat up file descriptors until the app crashes. I figured out a way to close them. I don't see why it wouldn't work for your UIAppFonts.

I modified the snippet you referenced in your question. This is my modified version,

#import <sys/types.h>
#import <fcntl.h>
#import <errno.h>
#import <sys/param.h>


-(void)closeFileDescriptorsForSounds
{
    int flags;
    int fd;
    char buf[MAXPATHLEN+1] ;
    int n = 1 ;

    for (fd = 0; fd < (int) FD_SETSIZE; fd++) {
        errno = 0;
        flags = fcntl(fd, F_GETFD, 0);
        if (flags == -1 && errno) {
            if (errno != EBADF) {
                return ;
            }
            else
                continue;
        }
        fcntl(fd , F_GETPATH, buf ) ;
        NSLog( @"File Descriptor %d number %d in use for: %s",fd,n , buf ) ;
        ++n ;

// My modifications to the snippet...

        NSString *str = [NSString stringWithUTF8String:buf];
        NSString *theFileName = [str lastPathComponent];

        if ([theFileName isEqualToString:@"LoudBang.mp3"])
        {
            NSLog(@"FD is LoudBang");
            NSFileHandle *loudBangHandle = [[NSFileHandle alloc] initWithFileDescriptor:fd closeOnDealloc:YES];
        }
        else if ([theFileName isEqualToString:@"QuietBang.mp3"])
        {
            NSLog(@"FD is QuietBang");
            NSFileHandle *quietBangHandle = [[NSFileHandle alloc] initWithFileDescriptor:fd closeOnDealloc:YES];
        }
    }
}

I converted buf to a string and then isolated the file name. Then I compared the file name to a known file I want to close. When a file I want to close is found the code creates an NSFileHandle around the file descriptor using the following,

NSFileHandle *loudBangHandle = [[NSFileHandle alloc] initWithFileDescriptor:fd closeOnDealloc:YES];

This init specifically closes the file descriptor on dealloc of the NSFileHandle (which will be almost immediately).

Let us know if it works for your UIAppFonts.