Mac OSX上的Newtonsoft JSON.NET 6.0.8和Mono以辉煌的方式失败了

Question

我构建了一个大量使用JSON的分布式系统应用程序。该应用程序在Windows（在7、8、8.1、Server 2008、Server 2012上测试）和带有Mono 的Ubuntu 14.04上运行良好

然而，当我试图在OSX Yosemite 10.10.2（可能是其他版本）上运行该应用程序时，它以一种光荣的方式失败了。我已经隔离了对Newtonsoft JSON.NET的一些调用，并在一个独立的沙盒应用程序中运行它们，永远无法重现这个问题。我粘贴了下面的调试信息，希望有人在堆栈跟踪中看到一些东西，或者其他可能指向明显问题的东西。

Stacktrace:
  at <unknown> <0xffffffff>
  at (wrapper managed-to-native) object.__icall_wrapper_mono_gc_alloc_vector (intptr,intptr,intptr) <0xffffffff>
  at (wrapper alloc) object.AllocVector (intptr,intptr) <0xffffffff>
  at System.Reflection.Emit.DynamicMethod.AddRef (object) <0x00077>
  at System.Reflection.Emit.DynamicMethodTokenGenerator.GetToken (System.Reflection.MemberInfo,bool) <0x0001b>
  at System.Reflection.Emit.ILGenerator.Emit (System.Reflection.Emit.OpCode,System.Type) <0x000ee>
  at Newtonsoft.Json.Utilities.ILGeneratorExtensions.BoxIfNeeded (System.Reflection.Emit.ILGenerator,System.Type) <0x0007a>
  at Newtonsoft.Json.Utilities.DynamicReflectionDelegateFactory.GenerateCreateGetPropertyIL (System.Reflection.PropertyInfo,System.Reflection.Emit.ILGenerator) <0x0009b>
  at Newtonsoft.Json.Utilities.DynamicReflectionDelegateFactory.CreateGet<T> (System.Reflection.PropertyInfo) <0x000bf>
  at Newtonsoft.Json.Utilities.ReflectionDelegateFactory.CreateGet<T> (System.Reflection.MemberInfo) <0x0007d>
  at Newtonsoft.Json.Serialization.DynamicValueProvider.GetValue (object) <0x0003f>
  at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CalculatePropertyValues (Newtonsoft.Json.JsonWriter,object,Newtonsoft.Json.Serialization.JsonContainerContract,Newtonsoft.Json.Serialization.JsonProperty,Newtonsoft.Json.Serialization.JsonProperty,Newtonsoft.Json.Serialization.JsonContract&,object&) <0x000fe>
  at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject (Newtonsoft.Json.JsonWriter,object,Newtonsoft.Json.Serialization.JsonObjectContract,Newtonsoft.Json.Serialization.JsonProperty,Newtonsoft.Json.Serialization.JsonContainerContract,Newtonsoft.Json.Serialization.JsonProperty) <0x00197>
  at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue (Newtonsoft.Json.JsonWriter,object,Newtonsoft.Json.Serialization.JsonContract,Newtonsoft.Json.Serialization.JsonProperty,Newtonsoft.Json.Serialization.JsonContainerContract,Newtonsoft.Json.Serialization.JsonProperty) <0x0015f>
  at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize (Newtonsoft.Json.JsonWriter,object,System.Type) <0x000bf>
  at Newtonsoft.Json.JsonSerializer.SerializeInternal (Newtonsoft.Json.JsonWriter,object,System.Type) <0x0053b>
  at Newtonsoft.Json.JsonSerializer.Serialize (Newtonsoft.Json.JsonWriter,object,System.Type) <0x00019>
  at Newtonsoft.Json.JsonConvert.SerializeObjectInternal (object,System.Type,Newtonsoft.Json.JsonSerializer) <0x000e7>
  at Newtonsoft.Json.JsonConvert.SerializeObject (object,System.Type,Newtonsoft.Json.Formatting,Newtonsoft.Json.JsonSerializerSettings) <0x0003f>
  at Newtonsoft.Json.JsonConvert.SerializeObject (object,Newtonsoft.Json.Formatting,Newtonsoft.Json.JsonSerializerSettings) <0x00017>
  at kvpbase.kvpserver.serialize_json (object) <0x000e7>
  at kvpbase.kvpserver.obj_write (System.Net.HttpListenerContext,kvpbase.request_metadata,kvpbase.obj) <0x01bd7>
  at kvpbase.kvpserver.put_handler (System.Net.HttpListenerContext,kvpbase.request_metadata) <0x00f4f>
  at kvpbase.kvpserver.user_api (System.Net.HttpListenerContext,kvpbase.request_metadata) <0x0062f>
  at kvpbase.kvpserver.processor (System.Net.HttpListenerContext,kvpbase.http_request) <0x0103b>
  at kvpbase.kvpserver.conn_handler (System.IAsyncResult) <0x005a7>
  at System.Net.ListenerAsyncResult.InvokeCallback (object) <0x00051>
  at (wrapper runtime-invoke) <Module>.runtime_invoke_void__this___object (object,intptr,intptr,intptr) <0xffffffff>
Native stacktrace:

Debug info from gdb:
(lldb) command source -s 0 '/tmp/mono-gdb-commands.1s6ayI'
Executing commands in '/private/tmp/mono-gdb-commands.1s6ayI'.
(lldb) process attach --pid 4136
Process 4136 stopped
Executable module set to "/usr/bin/mono".
Architecture set to: i386-apple-macosx.
(lldb) thread list
Process 4136 stopped

为了简洁起见，我删除了一堆与线程相关的数据。全文如下：https://gist.github.com/jchristn/677c53abc3c3028d804f

serialize_json方法如下（非常简单）：

public static string serialize_json(object obj)
{
  return JsonConvert.SerializeObject(obj, Newtonsoft.Json.Formatting.Indented, new JsonSerializerSettings { });
}

和单声道版本：

sh-3.2# mono --version
Mono JIT compiler version 3.10.0 ((detached/e204655 Mon Oct 13 08:50:28 EDT 2014)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
    TLS:           normal
    SIGSEGV:       altstack
    Notification:  kqueue
    Architecture:  x86
    Disabled:      none
    Misc:          softdebug 
    LLVM:          yes(3.4svn-mono-(detached/e656cac)
    GC:            sgen

有问题的JSON字符串看起来像：

{
  "url": "http://localhost/root/home/foo",
  "user_guid": "root",
  "container_name": "home",
  "size": 3259,
  "num_objects": 1,
  "container_path": [],
  "child_containers": [
    "abcd",
    "foo",
    "large-dir"
  ],
  "obj_metadata": [
    {
      "key": "foo",
      "size": 3259,
      "created": "2014-10-24T07:44:24.5773422Z",
      "last_update": "2014-10-24T07:44:24.5773422Z",
      "last_access": "2014-10-24T07:44:24.5773422Z"
    }
  ]
}

及其定义：

public class dir_info
{
    public string url { get; set; }
    public string user_guid { get; set; }
    public string container_name { get; set; }
    public long size { get; set; }
    public int num_objects { get; set; }
    public List<string> container_path { get; set; }
    public List<string> child_containers { get; set; }
    public List<obj_info> obj_metadata { get; set; }
}

这是在一个旧的Macbook Pro上，但它有一个酷睿2双核和8GB的RAM。机器上没有其他东西在运行。

还尝试将Mono更新到3.12.1，但也出现了同样的问题。

sh-3.2# which mono
/usr/bin/mono
sh-3.2# mono --version
Mono JIT compiler version 3.12.1 ((detached/b7764aa Fri Mar  6 15:32:47 EST 2015)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
    TLS:           normal
    SIGSEGV:       altstack
    Notification:  kqueue
    Architecture:  x86
    Disabled:      none
    Misc:          softdebug 
    LLVM:          yes(3.6.0svn-mono-(detached/5486eb2)
    GC:            sgen

我也尝试过在Windows上的Mono中运行，但问题没有出现（v3.12.1）。

Answer 1

我在iOS开发中也有过类似的奇怪经历。（使用多任务处理和JSON时出现这样的异常）我发现将这些添加到mtouch AOT选项解决了我的问题：

nrgctx蹦床=8096，nimt蹦床=896，ntrmpolines=4048

希望它也能帮助你（也许还有其他开发者）。