Versions of .NET

Release 3.6.0

  • Released on 2014-08-12

Release notes


Mono 3.6.0 has 878 commits since the last release. This is the work of 66 contributors since March 10 2014. Out of those, 22 have done their first contribution. 112 bugs were fixed.


  • Runtime performance counters have been integrated into the profiler allowing the performance counter information to be surfaced to profiling tools and in particular Xamarin's upcoming profiler.
  • The profiler now produces backtraces for statistical mode. The profiler's tracing mode now works on ARM.
  • We now distribute nuget on mac.


  • The debugger now support line and column ranges. pdb2mdb supports it. Note: the rest of our toolchain still needs to be updated.
  • The debugger now supports changing the current line in the top frame.
  • Lots of bugfixes and performance improvements.
  • The debugger now support reading simple properties without calling their getter, this is done by having a lightweight IL interpreter for small pieces of code. This allows more properties to be inspected while the process is completely stopped and without having to temporarily resume execution of the target to execute the property code.
  • Added buffered response mode to improve network efficiency on high latency links such as USB.

Garbage Collection

  • The GC bridge got a lot of performance work. There are now two new modes that can significantly improve some workloads.

Class libraries

  • Multiple http stack improvements: some leaks in the stack have been fixed, as well as solving some long-standing bugs involving asynchronous operations and proxies. We have introduced a more comprehensive test harness to ensure that those bugs do not surface again.
  • System.IO.Compression is now implemented
  • System.Security.Claims is now implemented. It resides in the System assembly (existed before in the Identity stack, but now we track the new home from the .NET 4.5 API).


  • Reworked locking to drop a hot lock in method lookup.
  • Use fine grained locking instead of a big hot lock.
  • Better hashing of some runtime internal items to avoid some corner-case slowdowns with generics.


  • The profiler is now able to produces backtraces in statistical mode.
  • Added periodical flushing that should help interactive users. This means that the profiling will send data over the profiling even if the application is not currently sending data (this is there to support the upcoming new profiler UI).
  • It now collects and reports performance counter information. See mprof-report's man page.


  • Fixed the handling of the volatile. CIL prefix.
  • We now distribute IKVM's ikdasm tool. This is a reliable disassembler that does not have the limitation of monodis of requiring a complete set of assemblies that are compatible to disassemble. This will disassemble even files that do not have their dependencies available.
  • Optimized EqualityComparer for more types.
  • Mono.Unix.Native.Syscall.getxattr() can now return Errno.ENOATTR on OS X.
  • Our msbuild implementation can now build Project K and Roslyn
  • Optimized EqualityComparer for more types.

Bug fixes

C# Compiler

  • [mcs] Flow analysis of nested binary expressions inside anonymous methods was missing on left/right reset. Fixes #18417
  • [mcs] Fix betterness logic for default vs params parameters. Fixes #19754
  • [mcs] Flow analysis of binary expressions not using logical operators. Fixes #20086
  • [mcs] Emit unmanaged version info from AssemblyFileVersion. Fixes #20057
  • [mcs] Fix expression tree conversion type for lifted enum equality comparisons. Fixes #19938
  • [mcs] Report error when named argument for param parameter is given but not all formal parameters are provided. Fixes #19878
  • [mcs] Unify reachable label lookup. Fixes #19887
  • [mcs] Don't release field address copy before it's used. Fixes #20040
  • [mcs] Fix error reporting propagation for loop statements. Fixes #20034
  • [mcs] Emit better code for null coalescing operator with nullable return type. Fixes #19702
  • [mcs] Add explicit array conversion involving type parameters. Fixes #18474

Other Bug fixes

  • Add System.ServiceModel.Security assembly. Fixes #20108
  • [sdb] Avoid clearing event requests if they reference an assembly which is unloaded. Instead, remove the assembly reference from the event request so it stays active. Fixes #19924
  • Rename -> Based on PR #976
  • [System] Fix parsing of IPv6 addresses. Fixes #18574
  • [Http] Cleanup chained async operations. Fixes #19161
  • [corlib] Add Guid hex format parsing with whitespaces. Fixes #19915
  • [System.Net.Http] Parsing productinfo like headers with missing version. Fixes #19881
  • [System] Throw IOE in more cases when dealing with an invalid Process object. Fixes #19864
  • [bcl] Fix Process.PrivateMemorySize64 on osx, we now return task_baic_info.resident_size. Fixes #19738
  • Clean up the usage of FILETIME structures, avoid accessing them as gint64 since that would lead to alignment problems. Fixes #19739
  • [sdb] Avoid stack overflows when a boxed vtype recursively references itself using fields. Fixes #18914
  • [profiler] Filter more event types in mprof-report based on time. Fixes #11904
  • [profiler] In mprof-report fix handling of the time filter when starting from 0. Fixes #11904
  • [http] Convert string output data using BOM header when available. Fixes #19667
  • [] Fix encoding of Content-MD5. Based on patch by nberardi. Fixes #19644
  • [sdb] Avoid placing implicit sequence points at offsets where the IL stack is empty when using symbol file based sequence points. Fixes #13640
  • [eglib] Remove test-glib code, we don't have to maintain compatibility with glib any more. Fixes #19638
  • [corlib] Rethrow user not initialization exception when lazy initialization throws. Fixes #19564
  • [mcs] Don't report interface implementation errors for optional implementations. Fixes #18030
  • [mcs] Include more unicode categories in parsing identifier part character. Fixes #18229
  • [mcs] Emit null constant value for default parameters of generic types to indicate not missing value. Fixes #19033
  • [mcs] Do type parameter conversion involving type parameters using dependency rules. Fixes #18473
  • [mcs] Emit all method like members in same order as they appear in source code. Fixes #19509
  • [mcs] Convert extended underlying enum constants to their underlying type. Fixes #18866
  • [mcs] Don't apply reference type is optimization for dynamic expressions. Fixes #19423
  • [mcs] Inflate anonymymous method with correct type arguments when async this requires hoisting in parent type. Fixes #19176
  • [mcs] Fix using type relationship check for type parameters. Fixes #18639
  • [mcs] Caching of type argument types should not happen under error conditions. Fixes #18282
  • [linq] Use hashtable lookup instead of linear scan for groupby keys. Fixes #18673
  • [mcs] Private member can still have base members when in nested types. Fixes #19378
  • [mcs] Make unused event warning reporting consistent to csc. Fixes #19095
  • [mcs] Add parent storey reference only when this is not captured directly. Fixes #19077
  • [mcs] Fix recursive resolving of crefs. Fixes #18511
  • [mcs] Adding unit test for #18511
  • [mcs] Emit field initializer with expression tree in all user constructors. Fixes #18308
  • [dlr] Emit correct code for convert of nullable types. Fixes #19500


  • [runtime] Fix decoding of jagged arrays in custom attributes. Fixes #19825
  • [runtime] Avoid calling mono_thread_current () in sgen_thread_detach (), since it can construct objects. Fixes #19755
  • [runtime] Avoid passing commands to lldb using the python api, it doesn't seem to work well in script files. Fixes #19732
  • [runtime] Fix Process.TotalProcessorTime becoming negative. Fixes #19739
  • [runtime] Clean up an #ifdef block
  • [jit] Make generic ctor calls made out of gsharedvt methods indirect, since they cannot be patched. Fixes #18634
  • [jit] Fix rethrowing of exceptions in thumb mode. Fixes #18448
  • [jit] Fix the lookup of the AOT version of Interlocked.Exchange<T> in full-aot mode. Fixes #19070
  • [jit] Fix an unreachable code part in mini_emit_memset (). Fixes #19083
  • [llvm] Fix a few problems with longs on 32 bit platforms. Fixes #18925
  • [runtime] Improve the hashing of MONO_TYPE_VAR/MONO_TYPE_MVAR. Fixes #18880
  • [interpreter] Disable fast call invocation using methodinfo delegates due to aot limitation. Fixes #18688
  • [runtime] Improve the hashing of MONO_TYPE_VAR/MONO_TYPE_MVAR. Fixes #18880
  • [sgen] Restore hazard pointers in suspend signal handler. Fixes #15695

Core Libraries

  • [corlib] Fix extra await context switch when custom SynchronizationContext does not change. Fixes #17878
  • [corlib] Add SortVersion. Fixes #18770
  • [corlib] Make invariant NumberFormatter thread static too as it has internal static state. Fixes #18599
  • [corlib] Filter out any right-to-left sign characters. Fixes #18522
  • [corlib] Fix localized resource loading bug. Fixes #14987
  • [corlib] Optimize EqualityComparer for common value types. Fixes #18400
  • [system] Don't terminate response reading on bad cookie value. Fixes #18868
  • DataRowView indexer should not break on "completed" added rows (any rows other than the IsNew one). Fixes #18898 (Novell #595899)
  • [corlib] Defer TypeInfo instantiation logic in DefinedTypes. Fixes #19082
  • [Mono.Security] Send all the certificates (except the root) from an SSL/TLS 'Server certificate' message (7.4.2 in RFC2246). Fixes #16974
  • [System.Core] Don't auto increment when trimming hashset. Fixes #18687
  • [] Close service-point slot on explicit dispose. Fixes #18848
  • [Fix] System.Runtime.Caching.MemoryCache doesn't honor SlidingExpiration. Fixes #18213
  • [System.Xml.Linq] Fix XNamespace.GetName locking to not be racy. Fixes #18564
  • [System.Net.Http] Incomplete byte ranges parsing. Fixes #18494
  • [System.ServiceModel.Web] Fix JsonQueryStringConverter.ConvertValueToString to work when running on any culture. Fixes #18437
  • System.Runtime.Caching.MemoryCache doesn't order expirable items correctly. Fixes #18235
  • ConcurrentQueue<T>.TryPeek() is not thread safe. Fixes #18182
  • System/PCL: Implement HttpWebRequest.SupportsCookieContainer, WebRequest.CreateHttp. Fixes #18378
  • [interpreter] Implement simple quote expression. Fixes #18248
  • mdbrebase: use File.Move instead of FileInfo.MoveTo. Fixes #18361
  • Add unit test for Novell bug #497562
  • System.Runtime.MemoryCache.GetValues() throws LockRecursionException with expired items - GetValues() calls MemoryCacheContainer.GetEntry() which now gets an EnterUpgradeableReadLock needed by ExpireIfNeeded() - Added a test case. Fixes #18245
  • [Sys.Data] Fix Novell Bug #519648
  • [Sys.Data] Add unit tests for Novell bug #519648
  • [System.XML] Fix handling of space in XSL value-of elements. Fixes #18113
  • [System.XML] Fix XSL node-set bug. Fixes #18114
  • [System.XML] Fix handling of global variables in XSLs. Fixes #18118
  • [System.XML] Do not reset document schema when reading an element. Fixes #9541


  • Fix setter of TableLayoutPanel.LayoutSettings throws unwanted exception. Fixes Novell #497562
  • [MWF] Fix opacity of form. Fixes #19856
  • [MWF] Fix ComboBox list to not display offscreen. Fixes #15462
  • [MWF] Fix Screen.FromRectangle. Fixes #8271
  • [MWF] Implement multi-display support on Linux. Fixes #325669
  • [MWF] Clear currentCell before disposing. Fixes #19567
  • [MWF] Unit test for DataGridView bug. Fixes #19567
  • [MWF] Don't try to remove non-child control. Fixes #19818
  • [MWF] Add unit test for #19818
  • [MWF] Fix AutoSize behavior of FlowLayoutPanel. Fixes #2912
  • [MWF] Fix crash from null control in ContainerControl. Fixes #10537
  • [MWF] Fix TableLayoutPanel layout bug. Fixes #8907
  • [MWF] Fix clipping of last line of dropdown. Fixes #2462
  • [MWF] Release capture when clicking LinkLabel. Fixes #2787
  • [MWF] Fix text position on buttons. Fixes #463149
  • [MWF] Fix crash when setting Row.Height. Fixes #2394
  • [MWF] Unit test for Row.Height/MinimumHeight bug. Fixes #2394
  • [MWF] Fix size of text area on message box. Fixes #2090
  • [MWF] Fix hang if clipboard source application closes down. Fixes #674098
  • [Printing] Improve reported printer settings. Fixes #602934
  • [Printing] Add unit test for Novell bug #602934


Aaron Bockover, Alan McGovern, Alex Rønne Petersen, Alexander
Köplinger, Alexis Christoforides, Alice, Andrea Canciani, Antoine
Cailliau, Atsushi Eno, BrandonLWhite, Craig Minihan, Damien Daspit,
David Karlaš, David Moore, David Schmitt, Eberhard Beilharz, Eduardo
Burgos, Enrico Sada, Etienne CHAMPETIER, Fabian König, INADA Naoki,
Jeffrey Stedfast, Joao Matos, Joel Martinez, Jonathan Chambers,
Jonathan Pryor, Jose Donizetti, Jérémie Laval, Kimura Youichi, Lex Li,
Ludovic Henry, Marcus von Appen, Marek Habersack, Marek Safar, Marius
Ungureanu, Mark Probst, Martin Baulig, Michael Hutchinson, Miguel
Ferreira, Miguel de Icaza, Mika Aalto, NN, Neale Ferguson, Paolo
Molaro, Piotr Zierhoffer, Richard Cook, Richard Meyer, Robert
Pickering, Rodrigo Kumpera, Rolf Bjarne Kvinge, Sebastien Pouliot,
Seth Jackson, Stephen McConnel, Tammo 'kb' Hinrichs, Timotheus
Pokorra, Tom Hindle, Tom Philpot, Vincent Povirk, Virgile Bello,
Zoltan Varga, drummerhu, godFather89, ninjarobot, xplicit.