Merge pull request #43 from 4brunu/feature/avoid-deadlock

Avoid deadlock by using NSRecursiveLock

Observable/Classes/Lock.swift

@@ -8,18 +8,4 @@ internal protocol Lock {
     func unlock()
 }
 
-internal final class Mutex: Lock {
-    private var mutex: pthread_mutex_t = {
-        var mutex = pthread_mutex_t()
-        pthread_mutex_init(&mutex, nil)
-        return mutex
-    }()
-
-    func lock() {
-        pthread_mutex_lock(&mutex)
-    }
-
-    func unlock() {
-        pthread_mutex_unlock(&mutex)
-    }
-}
+extension NSRecursiveLock: Lock {}

Observable/Classes/Observable.swift

@@ -10,7 +10,7 @@ public class Observable<T> {
     private var observers: [Int: (Observer, DispatchQueue?)] = [:]
     private var uniqueID = (0...).makeIterator()
 
-    fileprivate let lock: Lock = Mutex()
+    fileprivate let lock: Lock = NSRecursiveLock()
 
     fileprivate var _value: T {
         didSet {

Observable/Tests/Observable_Tests.swift

@@ -220,6 +220,25 @@ class Observable_Tests: XCTestCase {
         XCTAssert(true)
     }
 
+    func test_whenUpdatingValueFromObserver_shouldNotDeadLock() {
+        let exp = expectation(description: "")
+        exp.expectedFulfillmentCount = 4
+        let observable = MutableObservable(0)
+        var lastValueResult: Int?
+
+        observable.observe { newValue, _ in
+            lastValueResult = newValue
+            exp.fulfill()
+            if newValue < 3 {
+                observable.wrappedValue = newValue + 1
+            }
+        }.add(to: &disposal)
+
+        wait(for: [exp], timeout: 1.0)
+        XCTAssertEqual(lastValueResult, 3)
+        XCTAssert(true)
+    }
+
     // MARK: - Using Singleton
     func test_whenUsingDispatchMain_shouldSucceed() {
         let exp = expectation(description: "")