Open Radar

 
Summary:
I've been working on storing some logging info using ASL in our iPhone app, and have come across a problem where my ASL search just doesn't seem to be able to find records that I have previously logged using asl_log(). At its most basic level, this is the code I am using:

        const char *facility = "blah";
        NSString *message = @"hi there";

        // write an entry
        aslmsg msg = asl_new(ASL_TYPE_MSG);
        asl_set(msg, ASL_KEY_FACILITY, facility);
        asl_log(NULL, msg, ASL_LEVEL_CRIT, [message UTF8String], nil);
       
        // try to read
        aslmsg query = asl_new(ASL_TYPE_QUERY);
        asl_set_query(query, ASL_KEY_FACILITY, facility, ASL_QUERY_OP_EQUAL);
        aslresponse response = asl_search(NULL, query);
        while (NULL != (msg = aslresponse_next(response))) {
            const char *m = asl_get(msg, ASL_KEY_MSG);
            NSLog(@"XXX %s", m);
        }
        NSLog(@"Done");


If I run this code on Mac OS X or in the simulator, it works perfectly.  If I run it on my device, no entries are output (other than the "Done" at the end).

Note that I am not attempting to read entries written by other applications.  I am attempting to read back my own log entries.


Steps to Reproduce:
Execute the above snippet of code in an application running on a device.

Expected Results:
The application should display:
  XXX hi there
  Done

Actual Results:
The application displays:
  Done

Regression:

Notes:
I posted a question on the dev forums about this, and had several others also saying they had the same problem.  I got some good feedback from Quinn (DTS) saying that ASL probably isn't a good choice for logging due to some undocumented differences between platforms (I've raised a documentation radar - 14461411), however, I haven't seen any statements saying that asl_search shouldn't actually work within the confines of the limitations that Quinn spells out.

Note that I've classified as Crash/Hang/Data Loss.  It doesn't actually Crash or Hang, but we definitely lose data.