OSAtomicCompareAndSwap64Barrier crash when creating default Realm on iPhone 4s

[mitchctodd]

Goals

Create a default Realm instance.

Expected Results

A default Realm instance is created without crashing.

Actual Results

When I try to create the default Realm instance, I experience a crash on my iPhone 4s test device (not using simulator) perhaps related to being a 32-bit device.
#0 0x25ae7c78 in OSAtomicCompareAndSwap64Barrier$VARIANT$mp ()
#1 0x25aec7c6 in _pthread_cond_signal ()
#2 0x002012ba in realm::SharedGroup::low_level_commit(unsigned long long) ()
#3 0x00200e74 in realm::SharedGroup::do_commit() ()
#4 0x002014a2 in realm::SharedGroup::commit_and_continue_as_read() ()
#5 0x00143ea2 in realm::_impl::SharedGroupFriend::commit_and_continue_as_read(realm::SharedGroup&) [inlined] at /Users/realm/workspace/objc_ios/tightdb_objc/core/include/realm/group_shared.hpp:1108
#6 0x00143e9e in realm::LangBindHelper::commit_and_continue_as_read(realm::SharedGroup&) [inlined] at /Users/realm/workspace/objc_ios/tightdb_objc/core/include/realm/lang_bind_helper.hpp:372
#7 0x00143e9e in realm::_impl::transaction::commit(realm::SharedGroup&, realm::BindingContext*) at /Users/realm/workspace/objc_ios/tightdb_objc/Realm/ObjectStore/impl/transact_log_handler.cpp:451
#8 0x00141d28 in realm::Realm::commit_transaction() at /Users/realm/workspace/objc_ios/tightdb_objc/Realm/ObjectStore/shared_realm.cpp:318
#9 0x00141772 in realm::Realm::update_schema(std::__1::unique_ptr<realm::Schema, std::__1::default_deleterealm::Schema >, unsigned long long) at /Users/realm/workspace/objc_ios/tightdb_objc/Realm/ObjectStore/shared_realm.cpp:254
#10 0x0012bcf0 in +[RLMRealm realmWithConfiguration:error:] at /Users/realm/workspace/objc_ios/tightdb_objc/Realm/RLMRealm.mm:374
#11 0x0012a8fc in +[RLMRealm defaultRealm] at /Users/realm/workspace/objc_ios/tightdb_objc/Realm/RLMRealm.mm:162
#12 0x0009b0aa in -[ViewController viewDidLoad] at /Users/mitch/Documents/Personal/Moto/test/RealmTest/RealmTest/ViewController.m:22

Steps to Reproduce

1. Create new Single View Application project in Xcode
2. Follow Realm's 'Getting Started' instructions for Static Framework use (same issue experienced with Dynamic Framework)
3. Try and create default Realm instance in viewDidLoad

Code Sample

this is all my code:

@implementation ViewController

RLMRealm* realmInstance;

• (void)viewDidLoad {
  [super viewDidLoad];

  realmInstance = [RLMRealm defaultRealm];
  }

@EnD

Version of Realm and Tooling

Realm: 0.98.4
Xcode: 7.2
OS X: 10.10.5
Device: iOS 9.2.1 on iPhone 4s

[bdash]

Thanks for the report, @mitchctodd. We're tracking this issue as #3321, and hope to have a fix released in the next couple of hours.