Ensure thread safety in phone parsing logic.

SignalServiceKit/src/Contacts/PhoneNumber.m

@@ -40,7 +40,7 @@ static NSString *const RPDefaultsKeyPhoneNumberCanonical = @"RPDefaultsKeyPhoneN
     OWSAssert(text != nil);
     OWSAssert(regionCode != nil);
 
-    PhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedUtil];
+    PhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedThreadLocal];
 
     NSError *parseError   = nil;
     NBPhoneNumber *number = [phoneUtil parse:text defaultRegion:regionCode error:&parseError];
@@ -71,7 +71,7 @@ static NSString *const RPDefaultsKeyPhoneNumberCanonical = @"RPDefaultsKeyPhoneN
 
     NSString *_Nullable countryCode = nil;
 #if TARGET_OS_IPHONE
-    countryCode = [[PhoneNumberUtil sharedUtil].nbPhoneNumberUtil countryCodeByCarrier];
+    countryCode = [[PhoneNumberUtil sharedThreadLocal].nbPhoneNumberUtil countryCodeByCarrier];
 
     if ([countryCode isEqualToString:@"ZZ"]) {
         countryCode = [locale objectForKey:NSLocaleCountryCode];
@@ -164,7 +164,7 @@ static NSString *const RPDefaultsKeyPhoneNumberCanonical = @"RPDefaultsKeyPhoneN
 }
 
 + (NSString *)regionCodeFromCountryCodeString:(NSString *)countryCodeString {
-    NBPhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedUtil].nbPhoneNumberUtil;
+    NBPhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedThreadLocal].nbPhoneNumberUtil;
     NSString *regionCode =
         [phoneUtil getRegionCodeForCountryCode:@([[countryCodeString substringFromIndex:1] integerValue])];
     return regionCode;
@@ -381,11 +381,11 @@ static NSString *const RPDefaultsKeyPhoneNumberCanonical = @"RPDefaultsKeyPhoneN
 }
 
 - (BOOL)isValid {
-    return [[PhoneNumberUtil sharedUtil].nbPhoneNumberUtil isValidNumber:self.phoneNumber];
+    return [[PhoneNumberUtil sharedThreadLocal].nbPhoneNumberUtil isValidNumber:self.phoneNumber];
 }
 
 - (NSString *)localizedDescriptionForUser {
-    NBPhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedUtil].nbPhoneNumberUtil;
+    NBPhoneNumberUtil *phoneUtil = [PhoneNumberUtil sharedThreadLocal].nbPhoneNumberUtil;
 
     NSError *formatError = nil;
     NSString *pretty =

SignalServiceKit/src/Contacts/PhoneNumberUtil.h

@@ -1,14 +1,18 @@
 //
-//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
-#import <libPhoneNumber_iOS/NBPhoneNumberUtil.h>
 #import "PhoneNumber.h"
+#import <libPhoneNumber_iOS/NBPhoneNumberUtil.h>
 
 @interface PhoneNumberUtil : NSObject
 
 @property (nonatomic, retain) NBPhoneNumberUtil *nbPhoneNumberUtil;
 
+- (instancetype)init NS_UNAVAILABLE;
+
++ (instancetype)sharedThreadLocal;
+
 + (BOOL)name:(NSString *)nameString matchesQuery:(NSString *)queryString;
 
 + (NSString *)callingCodeFromCountryCode:(NSString *)countryCode;
@@ -28,8 +32,6 @@
 
 + (NSString *)examplePhoneNumberForCountryCode:(NSString *)countryCode;
 
-+ (instancetype)sharedUtil;
-
 - (NBPhoneNumber *)parse:(NSString *)numberToParse defaultRegion:(NSString *)defaultRegion error:(NSError **)error;
 - (NSString *)format:(NBPhoneNumber *)phoneNumber
         numberFormat:(NBEPhoneNumberFormat)numberFormat

SignalServiceKit/src/Contacts/PhoneNumberUtil.m

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
 #import "PhoneNumberUtil.h"
@@ -18,13 +18,28 @@
 
 @implementation PhoneNumberUtil
 
-+ (instancetype)sharedUtil {
++ (NSObject *)sharedLock
+{
     static dispatch_once_t onceToken;
-    static id sharedInstance = nil;
+    static NSObject *lock = nil;
     dispatch_once(&onceToken, ^{
-      sharedInstance = [self.class new];
+        lock = [NSObject new];
     });
-    return sharedInstance;
+    return lock;
+}
+
++ (PhoneNumberUtil *)sharedThreadLocal
+{
+    @synchronized(self.sharedLock)
+    {
+        NSString *key = PhoneNumberUtil.logTag;
+        PhoneNumberUtil *_Nullable threadLocal = NSThread.currentThread.threadDictionary[key];
+        if (!threadLocal) {
+            threadLocal = [PhoneNumberUtil new];
+            NSThread.currentThread.threadDictionary[key] = threadLocal;
+        }
+        return threadLocal;
+    }
 }
 
 - (instancetype)init {
@@ -138,9 +153,10 @@
         return @"+1";
     }
 
-    NSString *callingCode = [NSString stringWithFormat:@"%@%@",
+    NSString *callingCode =
+        [NSString stringWithFormat:@"%@%@",
                   COUNTRY_CODE_PREFIX,
-                                      [[[self sharedUtil] nbPhoneNumberUtil] getCountryCodeForRegion:countryCode]];
+                  [[[self sharedThreadLocal] nbPhoneNumberUtil] getCountryCodeForRegion:countryCode]];
     return callingCode;
 }
 
@@ -578,25 +594,23 @@
 
 + (NSString *)examplePhoneNumberForCountryCode:(NSString *)countryCode
 {
+    PhoneNumberUtil *sharedUtil = [self sharedThreadLocal];
+
     // Signal users are very likely using mobile devices, so prefer that kind of example.
     NSError *error;
     NBPhoneNumber *nbPhoneNumber =
-        [[[self sharedUtil] nbPhoneNumberUtil] getExampleNumberForType:countryCode
+        [sharedUtil.nbPhoneNumberUtil getExampleNumberForType:countryCode type:NBEPhoneNumberTypeMOBILE error:&error];
-                                                                  type:NBEPhoneNumberTypeMOBILE
-                                                                 error:&error];
     OWSAssert(!error);
     if (!nbPhoneNumber) {
         // For countries that with similar mobile and land lines, use "line or mobile"
         // examples.
-        nbPhoneNumber =
+        nbPhoneNumber = [sharedUtil.nbPhoneNumberUtil getExampleNumberForType:countryCode
-            [[[self sharedUtil] nbPhoneNumberUtil] getExampleNumberForType:countryCode
                                                                          type:NBEPhoneNumberTypeFIXED_LINE_OR_MOBILE
                                                                         error:&error];
         OWSAssert(!error);
     }
-    NSString *result = (nbPhoneNumber ? [[[self sharedUtil] nbPhoneNumberUtil] format:nbPhoneNumber
+    NSString *result = (nbPhoneNumber
-                                                                         numberFormat:NBEPhoneNumberFormatE164
+            ? [sharedUtil.nbPhoneNumberUtil format:nbPhoneNumber numberFormat:NBEPhoneNumberFormatE164 error:&error]
-                                                                                error:&error]
             : nil);
     OWSAssert(!error);
     return result;