Open Radar

 
Summary:
The Thread Sanitizer reports an issue in NSXPCConnection during normal use.

Steps to Reproduce:
1) Create project using NSXPCConnection.
2) Turn on Thread Sanitizer.
3) Build and Run.

Expected Results:
No message from Thread Sanitizer.

Actual Results:
Thread Sanitizer breaks and a "thread info -s" unveils this:
thread #3: tid = 0x13792f, 0x0000000106c272a0 libclang_rt.tsan_osx_dynamic.dylib`__tsan_on_report, queue = 'com.apple.NSXPCConnection.user.32952', stop reason = Use of an uninitialized or destroyed mutex detected

{
  "all_addresses_are_same" : true,
  "description" : "Use of an uninitialized or destroyed mutex",
  "global_address" : 140735264319824,
  "global_name" : "sModesLock",
  "instrumentation_class" : "ThreadSanitizer",
  "issue_type" : "mutex-invalid-access",
  "location_description" : "'sModesLock' is a global variable (0x7fff7b6fe950)",
  "locs" : [
    {
      "address" : 140735264319824,
      "file_descriptor" : 0,
      "index" : 0,
      "size" : 0,
      "start" : 0,
      "suppressable" : 1,
      "thread_id" : 0,
      "trace" : [

      ],
      "type" : "global"
    }
  ],
  "memory_address" : 0,
  "mops" : [

  ],
  "mutexes" : [
    {
      "address" : 140735264319824,
      "destroyed" : 0,
      "index" : 0,
      "mutex_id" : 1297,
      "trace" : [
        4408230431,
        140735806956101,
        4407928661,
        4407929659,
        140735575779948
      ]
    }
  ],
  "report_count" : 0,
  "sleep_trace" : [

  ],
  "stacks" : [
    {
      "index" : 0,
      "thread_id" : 3,
      "trace" : [
        4408230431,
        140735806956101,
        4407928661,
        4407929659,
        140735575779948
      ]
    }
  ],
  "stop_description" : "Use of an uninitialized or destroyed mutex detected",
  "summary" : "Use of an uninitialized or destroyed mutex in AdjustCGSSourceInRunLoop(void (*)(__CFRunLoop*, __CFRunLoopSource*, __CFString const*), __CFRunLoop*, __CFRunLoopSource*) at sModesLock",
  "threads" : [

  ],
  "unique_tids" : [

  ]
}

Regression:
-

Notes:
-