5
我一直有NSURLConnection请求在我们的iPhone应用程序超时的间歇性问题。这似乎是最近发生的事情。一旦进入这种状态，它就会保持这种状态。唯一的解决方案似乎是杀死应用程序并重新启动它。NSURLConnection超时
观察：
- 执行该NSURLConnection的核心代码没有改变（除了最近添加一些自定义用户代理代码）。
- 还没有找到可重复使用的情况，但超时后似乎应用程序已经坐在后台一段时间，特别是如果运行在3G（没有WiFi）。
- 服务器上的Apache在遇到这些超时时没有记录来自客户端的请求。
- 一些迹象表明其他应用程序（如Mail和Safari）受到影响（即遇到超时），但并不一致。
- 3G覆盖是坚实的，我在，不排除一个短暂的问题触发问题（假设不太可能）。
- 所有请求都发送到我们自己的API服务器，并且是平稳的POST请求。
- 由于timeoutInterval和POST请求的问题，我们使用自己的基于NSTimer的超时。我尝试过增加超时值来解决问题 - 问题仍然存在。
其他杂物：
- 应用最近被转化为ARC。
- 在iOS 5.1.1下运行应用程序。
- 应用程序使用最新版本的UrbanAirship，TestFlight和Flurry SDK。
- 同样使用TouchXML的ARC分支来分析响应。
正如您在下面看到的，代码在主线程上运行。我认为在该线程上阻塞了某些东西，但是暂停应用程序时看到的堆栈跟踪表明主线程正常。我认为NSURLConnection使用自己的线程并且必须被阻止。
#define relnil(v) (v = nil)
- (id) initWebRequestController
{
self = [super init];
if (self)
{
//setup a queue to execute all web requests on synchronously
dispatch_queue_t aQueue = dispatch_queue_create("com.myapp.webqueue", NULL);
[self setWebQueue:aQueue];
}
return self;
}
- (void) getStuffFromServer
{
dispatch_queue_t aQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(aQueue, ^{
dispatch_sync([self webQueue], ^{
error_block_t errorBlock = ^(MyAppAPIStatusCode code, NSError * error){
dispatch_async(dispatch_get_main_queue(), ^{
[[self delegate] webRequestController:self didEncounterErrorGettingPointsWithCode:code andOptionalError:error];
});
};
parsing_block_t parsingBlock = ^(CXMLDocument * doc, error_block_t errorHandler){
NSError * error = nil;
CXMLNode * node = [doc nodeForXPath:@"apiResult/data/stuff" error:&error];
if (error || !node) {
errorHandler(MyAppAPIStatusCodeFailedToParse, error);
}
else {
stuffString = [node stringValue];
}
if (stuffString) {
dispatch_async(dispatch_get_main_queue(), ^{
[[self delegate] webRequestController:self didFinishGettingStuff:stuffString];
});
}
else {
errorHandler(MyAppAPIStatusCodeFailedToParse, error);
}
};
NSURL * url = [[NSURL alloc] initWithString:[NSString stringWithFormat:MyAppURLFormat_MyAppAPI, @"stuff/getStuff"]];
NSMutableURLRequest * urlRequest = [[NSMutableURLRequest alloc] initWithURL:url];
NSMutableDictionary * postDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:
[[NSUserDefaults standardUserDefaults] objectForKey:MyAppKey_Token], @"token",
origin, @"from",
destination, @"to",
transitTypeString, @"mode",
time, @"time",
nil];
NSString * postString = [WebRequestController httpBodyFromDictionary:postDictionary];
[urlRequest setHTTPBody:[postString dataUsingEncoding:NSUTF8StringEncoding]];
[urlRequest setHTTPMethod:@"POST"];
if (urlRequest)
{
[self performAPIRequest:urlRequest withRequestParameters:postDictionary parsing:parsingBlock errorHandling:errorBlock timeout:kTimeout_Standard];
}
else
{
errorBlock(MyAppAPIStatusCodeInvalidRequest, nil);
}
relnil(url);
relnil(urlRequest);
});
});
}
- (void) performAPIRequest: (NSMutableURLRequest *) request
withRequestParameters: (NSMutableDictionary *) requestParameters
parsing: (parsing_block_t) parsingBlock
errorHandling: (error_block_t) errorBlock
timeout: (NSTimeInterval) timeout
{
NSAssert([self apiConnection] == nil, @"Requesting before previous request has completed");
NSString * postString = [WebRequestController httpBodyFromDictionary:requestParameters];
[request setHTTPBody:[postString dataUsingEncoding:NSUTF8StringEncoding]];
NSString * erVersion = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];
NSString * erBuildVersion = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];
if ([erBuildVersion isEqualToString:erVersion] || [erBuildVersion isEqualToString:@""]) {
erBuildVersion = @"";
} else {
erBuildVersion = [NSString stringWithFormat:@"(%@)", erBuildVersion];
}
NSString * iosVersion = [[UIDevice currentDevice] systemVersion];
NSString * userAgent = [NSString stringWithFormat:@"MyApp/%@%@ iOS/%@", erVersion, erBuildVersion, iosVersion];
[request setValue:userAgent forHTTPHeaderField:@"User-Agent"];
[request setTimeoutInterval:(timeout-3.0f)];
dispatch_sync(dispatch_get_main_queue(), ^{
NSURLConnection * urlConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:NO];
if (urlConnection)
{
[self setApiConnection:urlConnection];
requestParseBlock = [parsingBlock copy];
requestErrorBlock = [errorBlock copy];
NSMutableData * aMutableData = [[NSMutableData alloc] init];
[self setReceivedData:aMutableData];
relnil(aMutableData);
[urlConnection scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
[urlConnection start];
relnil(urlConnection);
NSTimer * aTimer = [NSTimer scheduledTimerWithTimeInterval:timeout target:self selector:@selector(timeoutTimerFired:) userInfo:nil repeats:NO];
[self setTimeoutTimer:aTimer];
}
else
{
errorBlock(MyAppAPIStatusCodeInvalidRequest, nil);
}
});
//we want the web requests to appear synchronous from outside of this interface
while ([self apiConnection] != nil)
{
[NSThread sleepForTimeInterval:.25];
}
}
- (void) timeoutTimerFired: (NSTimer *) timer
{
[[self apiConnection] cancel];
relnil(apiConnection);
relnil(receivedData);
[self requestErrorBlock](MyAppAPIStatusCodeTimeout, nil);
requestErrorBlock = nil;
requestParseBlock = nil;
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
[self requestErrorBlock](MyAppAPIStatusCodeFailedToConnect, error);
relnil(apiConnection);
relnil(receivedData);
[[self timeoutTimer] invalidate];
relnil(timeoutTimer);
requestErrorBlock = nil;
requestParseBlock = nil;
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
[receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[receivedData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
MyAppAPIStatusCode status = MyAppAPIStatusCodeFailedToParse;
CXMLDocument *doc = [[self receivedData] length] ? [[CXMLDocument alloc] initWithData:[self receivedData] options:0 error:nil] : nil;
DLog(@"response:\n%@", doc);
if (doc)
{
NSError * error = nil;
CXMLNode * node = [doc nodeForXPath:@"apiResult/result" error:&error];
if (!error && node)
{
status = [[node stringValue] intValue];
if (status == MyAppAPIStatusCodeOK)
{
[self requestParseBlock](doc, [self requestErrorBlock]);
}
else if (status == MyAppAPIStatusCodeTokenMissingInvalidOrExpired)
{
[Definitions setToken:nil];
[self requestMyAppTokenIfNotPresent];
[Definitions logout];
dispatch_async(dispatch_get_main_queue(), ^{
[[self delegate] webRequestControllerDidRecivedExpiredTokenError:self];
});
}
else
{
[self requestErrorBlock](status, nil);
}
}
else
{
[self requestErrorBlock](status, nil);
}
}
else
{
status = MyAppAPIStatusCodeUnexpectedResponse;
[self requestErrorBlock](status, nil);
}
relnil(doc);
relnil(apiConnection);
relnil(receivedData);
[[self timeoutTimer] invalidate];
relnil(timeoutTimer);
requestErrorBlock = nil;
requestParseBlock = nil;
}
下面的URL是应用程序处于有问题状态时队列/线程的一些屏幕截图。请注意，我相信线程10与在上一次超时时执行的取消有关，尽管互斥等待很好奇。此外，线程22中关于Flurry的位在其他场合遇到问题时并不一致。
堆栈跟踪截图：
http://img27.imageshack.us/img27/5614/screenshot20120529at236.png http://img198.imageshack.us/img198/5614/screenshot20120529at236.png
也许我忽视的东西显然是错误的那些痕迹，因为我是比较新的的iOS /苹果的发展。
所有这一切都将是非常简单的解决，如果我有NSURLConnection的和相关代码的源代码，但如它，我在这一点上采取刺在黑暗中。
您发布的信息太多，但可能还不够。什么是错误信息？ – Mundi
没有错误信息 - 就是这样。 NSURLConnection开始，但从未完成，我们的NSTimer开始取消它。 – mackinra
想到我到处搜索类似的问题后，我只是无意中发现了这个问题：http://stackoverflow.com/questions/10149811/why-does-nsurlconnection-fail-to-reach-the-backend我认为它可能只是我悲痛的原因。将尝试撕掉TestFlight，看看会发生什么。 – mackinra