removed force unwrap

Author: tgymnich

Sources/TSCBasic/FileSystem.swift

@@ -10,7 +10,6 @@
 
 import TSCLibc
 import Foundation
-import Dispatch
 
 public enum FileSystemError: Swift.Error {
     /// Access to the path is denied.
@@ -515,8 +514,6 @@ public class InMemoryFileSystem: FileSystem {
 
     /// The root filesytem.
     private var root: Node
-    /// A dispatch queue for accessing the lock map in a thread safe manner.
-    private let lockMapQueue = DispatchQueue(label: "org.swift.swiftpm.\(InMemoryFileSystem.self).lockQueue")
     /// A map that keeps weak references to all locked files.
     private let lockMap = NSMapTable<NSString, ReadWriteLock>(keyOptions: .copyIn, valueOptions: .weakMemory)
 
@@ -779,17 +776,19 @@ public class InMemoryFileSystem: FileSystem {
     }
 
     public func withLock<T>(on path: AbsolutePath, type: LockType = .exclusive, _ body: () throws -> T) throws -> T {
-        var fileLock: ReadWriteLock?
-        
-        lockMapQueue.sync {
-            if let lock = lockMap.object(forKey: path.pathString as NSString) {
-                fileLock = lock
-            } else {
-                fileLock = ReadWriteLock()
-                lockMap.setObject(fileLock, forKey: path.pathString as NSString)
-            }
+        let lock = Lock()
+        var fileLock: ReadWriteLock
+
+        lock.lock()
+        if let lock = lockMap.object(forKey: path.pathString as NSString) {
+            fileLock = lock
+        } else {
+            fileLock = ReadWriteLock()
+            lockMap.setObject(fileLock, forKey: path.pathString as NSString)
         }
-        return try fileLock!.withLock(type: type, body)
+        lock.unlock()
+
+        return try fileLock.withLock(type: type, body)
     }
 }
 

Sources/TSCBasic/Lock.swift

@@ -24,10 +24,18 @@ public struct Lock {
     public init() {
     }
 
+    func lock() {
+        _lock.lock()
+    }
+
+    func unlock() {
+        _lock.unlock()
+    }
+
     /// Execute the given block while holding the lock.
     public func withLock<T> (_ body: () throws -> T) rethrows -> T {
-        _lock.lock()
-        defer { _lock.unlock() }
+        lock()
+        defer { unlock() }
         return try body()
     }
 }