[Core] Add logging level getter to FIRConfiguration

FirebaseCore/Sources/FIRConfiguration.m

@@ -17,6 +17,11 @@
 #import "FirebaseCore/Sources/FIRAnalyticsConfiguration.h"
 
 extern void FIRSetLoggerLevel(FIRLoggerLevel loggerLevel);
+extern FIRLoggerLevel FIRGetLoggerLevel(void);
+
+@interface FIRConfiguration ()
+@property(nonatomic, readonly) dispatch_queue_t queue;
+@end
 
 @implementation FIRConfiguration
 
@@ -32,6 +37,7 @@ + (instancetype)sharedInstance {
 - (instancetype)init {
   self = [super init];
   if (self) {
+    _queue = dispatch_queue_create("com.firebase.FIRConfiguration", DISPATCH_QUEUE_SERIAL);
     _analyticsConfiguration = [FIRAnalyticsConfiguration sharedInstance];
   }
   return self;
@@ -40,7 +46,17 @@ - (instancetype)init {
 - (void)setLoggerLevel:(FIRLoggerLevel)loggerLevel {
   NSAssert(loggerLevel <= FIRLoggerLevelMax && loggerLevel >= FIRLoggerLevelMin,
            @"Invalid logger level, %ld", (long)loggerLevel);
-  FIRSetLoggerLevel(loggerLevel);
+  dispatch_sync(self.queue, ^{
+    FIRSetLoggerLevel(loggerLevel);
+  });
+}
+
+- (FIRLoggerLevel)loggerLevel {
+  __block FIRLoggerLevel level;
+  dispatch_sync(self.queue, ^{
+    level = FIRGetLoggerLevel();
+  });
+  return level;
 }
 
 @end

FirebaseCore/Sources/FIRLogger.m

@@ -87,6 +87,7 @@ void FIRLoggerInitialize(void) {
 }
 
 FIRLoggerLevel FIRGetLoggerLevel(void) {
+  FIRLoggerInitialize();
   return (FIRLoggerLevel)GULGetLoggerLevel();
 }
 

FirebaseCore/Sources/Public/FirebaseCore/FIRConfiguration.h

@@ -40,6 +40,9 @@ NS_SWIFT_NAME(FirebaseConfiguration)
  */
 - (void)setLoggerLevel:(FIRLoggerLevel)loggerLevel;
 
+/// Returns the logging level for internal Firebase logging.
+- (FIRLoggerLevel)loggerLevel;
+
 @end
 
 NS_ASSUME_NONNULL_END

FirebaseCore/Tests/Unit/FIRConfigurationTest.m

@@ -28,4 +28,47 @@ - (void)testSharedInstance {
   XCTAssertNotNil(config.analyticsConfiguration);
 }
 
+- (void)testGetDefaultLevel {
+  FIRConfiguration *config = [FIRConfiguration sharedInstance];
+  FIRLoggerLevel defaultLevel = [config loggerLevel];
+  XCTAssertEqual(defaultLevel, FIRLoggerLevelNotice);
+}
+
+- (void)testSetAndGet {
+  FIRConfiguration *config = [FIRConfiguration sharedInstance];
+  for (FIRLoggerLevel level = FIRLoggerLevelMin; level <= FIRLoggerLevelMax; level++) {
+    [config setLoggerLevel:level];
+    XCTAssertEqual([config loggerLevel], level);
+  }
+}
+
+- (void)testSynchronizedAccess {
+  FIRConfiguration *config = [FIRConfiguration sharedInstance];
+
+  __block BOOL raceConditionExists = NO;
+
+  // Dispatch to a concurrent queue to simulate concurrent access.
+  dispatch_queue_t queue = dispatch_get_global_queue(QOS_CLASS_UTILITY, 0);
+  for (int i = 0; i < 1000000; i++) {
+    dispatch_async(queue, ^{
+      // Get the current logging level.
+      FIRLoggerLevel currentLevel = [config loggerLevel];
+
+      // Set a new logging level.
+      FIRLoggerLevel nextLevel =
+          (currentLevel + 1 > FIRLoggerLevelMax) ? FIRLoggerLevelMin : currentLevel + 1;
+      [config setLoggerLevel:nextLevel];
+
+      // Confirm that the new logging level is retrieved.
+      if (nextLevel != [config loggerLevel]) {
+        raceConditionExists = YES;
+      }
+    });
+  }
+
+  dispatch_sync(queue, ^{/* Drain queue before proceeding. */});
+
+  XCTAssertEqual(raceConditionExists, NO);
+}
+
 @end