Storage lock fix (#10468)

* Revert "Include subheaders in script output (#10212)"

This reverts commit 11313da.

* Use a dedicated sync object

* Revert "Revert "Include subheaders in script output (#10212)""

This reverts commit 41fe302.

* Add changelog and tests

* Revert "Include subheaders in script output (#10212)"

This reverts commit 11313da.

* Revert "Revert "Include subheaders in script output (#10212)""

This reverts commit 472e3f9.

* style

Author: morganchen12

FirebaseStorage/CHANGELOG.md

@@ -1,5 +1,6 @@
 # 10.2.0
-- [fixed] Fix a race condition where a download size could exceed the value of the `maxSize` parameter. (#10358)
+- [fixed] Fixed an issue where using Storage with more than one FirebaseApp instance caused non-default Storage instances to deadlock (#10463).
+- [fixed] Fixed a race condition where a download size could exceed the value of the `maxSize` parameter. (#10358)
 
 # 10.1.0
 - [fixed] Fixed a 10.0.0 regression where metadata passed to `putFile` was not properly initialized. (#10353)

FirebaseStorage/Sources/Storage.swift

@@ -302,6 +302,7 @@ import FirebaseAuthInterop
   }
 
   /// Map of apps to a dictionary of buckets to GTMSessionFetcherService.
+  private static let fetcherServiceLock = NSObject()
   private static var fetcherServiceMap: [String: [String: GTMSessionFetcherService]] = [:]
   private static var retryWhenOffline: GTMSessionFetcherRetryBlock = {
     (suggestedWillRetry: Bool,
@@ -321,8 +322,8 @@ import FirebaseAuthInterop
                                                _ auth: AuthInterop,
                                                _ appCheck: AppCheckInterop)
     -> GTMSessionFetcherService {
-    objc_sync_enter(fetcherServiceMap)
-    defer { objc_sync_exit(fetcherServiceMap) }
+    objc_sync_enter(fetcherServiceLock)
+    defer { objc_sync_exit(fetcherServiceLock) }
     var bucketMap = fetcherServiceMap[app.name]
     if bucketMap == nil {
       bucketMap = [:]

FirebaseStorage/Tests/Integration/StorageIntegration.swift

@@ -137,6 +137,24 @@ class StorageResultTests: StorageIntegrationCommon {
     waitForExpectations()
   }
 
+  func testNoDeadlocks() throws {
+    let storage2 = Storage.storage(url: "")
+
+    let expectation1 = expectation(description: #function)
+    let expectation2 = expectation(description: #function)
+    let ref = storage.reference(withPath: "ios/public/testBytesUpload")
+    let data = try XCTUnwrap("Hello Swift World".data(using: .utf8), "Data construction failed")
+    ref.putData(data) { result in
+      expectation1.fulfill()
+
+      let ref2 = storage2.reference(withPath: "ios/public/testBytesUpload")
+      ref2.putData(data) { result in
+        expectation2.fulfill()
+      }
+    }
+    waitForExpectations(timeout: 30)
+  }
+
   func testSimplePutSpecialCharacter() throws {
     let expectation = self.expectation(description: #function)
     let ref = storage.reference(withPath: "ios/public/-._~!$'()*,=:@&+;")