From e1b87288d03e152214e224c5b9b099a83a0b97e9 Mon Sep 17 00:00:00 2001
From: James J Kalafus <kalafus@pm.me>
Date: Sun, 4 Feb 2024 18:14:22 -0500
Subject: [PATCH] array thread safety wrapper to fix racing condition causing
 `Fatal error: UnsafeMutablePointer.moveUpdate(from:) with negative count` at
 `self?.streamingSessions.removeAll(where: { $0 == object })`

---
 Sources/OpenAI/OpenAI.swift                   |  2 +-
 .../Utilities/ArrayWithThreadSafety.swift     | 26 +++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 Sources/OpenAI/Public/Utilities/ArrayWithThreadSafety.swift

diff --git a/Sources/OpenAI/OpenAI.swift b/Sources/OpenAI/OpenAI.swift
index cfb1e9d1..182fced1 100644
--- a/Sources/OpenAI/OpenAI.swift
+++ b/Sources/OpenAI/OpenAI.swift
@@ -35,7 +35,7 @@ final public class OpenAI: OpenAIProtocol {
     }
     
     private let session: URLSessionProtocol
-    private var streamingSessions: [NSObject] = []
+    private var streamingSessions = ArrayWithThreadSafety<NSObject>()
     
     public let configuration: Configuration
 
diff --git a/Sources/OpenAI/Public/Utilities/ArrayWithThreadSafety.swift b/Sources/OpenAI/Public/Utilities/ArrayWithThreadSafety.swift
new file mode 100644
index 00000000..a0c4db64
--- /dev/null
+++ b/Sources/OpenAI/Public/Utilities/ArrayWithThreadSafety.swift
@@ -0,0 +1,26 @@
+//
+//  ArrayWithThreadSafety.swift
+//
+//
+//  Created by James J Kalafus on 2024-02-01.
+//
+
+import Foundation
+
+internal class ArrayWithThreadSafety<Element> {
+    private var array = [Element]()
+    private let queue = DispatchQueue(label: "us.kalaf.OpenAI.threadSafeArray", attributes: .concurrent)
+
+    @inlinable public func append(_ element: Element) {
+        queue.async(flags: .barrier) {
+            self.array.append(element)
+        }
+    }
+
+    @inlinable public func removeAll(where shouldBeRemoved: @escaping (Element) throws -> Bool) rethrows {
+        try queue.sync(flags: .barrier) {
+            try self.array.removeAll(where: shouldBeRemoved)
+        }
+    }
+}
+