Provided by: mono-runtime-common_3.2.8+dfsg-4ubuntu1_amd64 bug

NAME

       mono - Mono's ECMA-CLI native code generator (Just-in-Time and Ahead-of-Time)

SYNOPSIS

       mono [options] file [arguments...]

       mono-sgen [options] file [arguments...]

DESCRIPTION

       mono  is a runtime implementation of the ECMA Common Language Infrastructure.  This can be
       used to run ECMA and .NET applications.

       The runtime contains a native code  generator  that  transforms  the  Common  Intermediate
       Language into native code.

       The  code  generator  can operate in two modes: just in time compilation (JIT) or ahead of
       time compilation (AOT).  Since code can be dynamically loaded, the runtime environment and
       the JIT are always present, even if code is compiled ahead of time.

       The  runtime loads the specified file and optionally passes the arguments to it.  The file
       is an ECMA assembly.  They typically have a .exe or .dll extension.

       The runtime provides a number of  configuration  options  for  running  applications,  for
       developing and debugging, and for testing and debugging the runtime itself.

       The mono command uses the Boehm conservative garbage collector while the mono-sgen command
       uses a moving and generational garbage collector.

PORTABILITY

       On Unix-based systems, Mono provides a mechanism to emulate the Windows-style file access,
       this  includes  providing  a case insensitive view of the file system, directory separator
       mapping (from \ to /) and stripping the drive letters.

       This functionality is enabled by setting the MONO_IOMAP environment  variable  to  one  of
       all, drive and case.

       See the description for MONO_IOMAP in the environment variables section for more details.

RUNTIME OPTIONS

       The following options are available:

       --aot, --aot[=options]
              This  option is used to precompile the CIL code in the specified assembly to native
              code.  The generated code is stored in a file with the extension  .so.   This  file
              will  be  automatically  picked  up  by  the runtime when the assembly is executed.
              Ahead-of-Time compilation is most useful if you use  it  in  combination  with  the
              -O=all,-shared flag which enables all of the optimizations in the code generator to
              be performed.  Some of those  optimizations  are  not  practical  for  Just-in-Time
              compilation  since  they  might be very time consuming.  Unlike the .NET Framework,
              Ahead-of-Time compilation will not generate domain independent code:  it  generates
              the   same  code  that  the  Just-in-Time  compiler  would  produce.    Since  most
              applications use a single domain, this is fine.    If  you  want  to  optimize  the
              generated  code  for use in multi-domain applications, consider using the -O=shared
              flag.  This pre-compiles the methods, but the original assembly is  still  required
              to execute as this one contains the metadata and exception information which is not
              available on the generated file.  When precompiling code, you might want to compile
              with  all  optimizations (-O=all).  Pre-compiled code is position independent code.
              Pre compilation is just a mechanism to reduce startup time, increase  code  sharing
              across  multiple  mono processes and avoid just-in-time compilation program startup
              costs.  The original assembly must still be present, as the metadata  is  contained
              there.   AOT  code  typically  can  not be moved from one computer to another (CPU-
              specific optimizations that are detected at runtime) so you should not try to  move
              the   pre-generated   assemblies   or  package  the  pre-generated  assemblies  for
              deployment.  A few options are available as a parameter to the --aot  command  line
              option.   The options are separated by commas, and more than one can be specified:

              autoreg
                     The AOT compiler will emit a (ELF only) library initializer to automatically
                     register the aot compiled module with the runtime.  This is only  useful  in
                     static mode

              asmonly
                     Instructs  the  AOT  compiler  to  output assembly code instead of an object
                     file.

              bind-to-runtime-version
                     If specified, forces the generated AOT files to  be  bound  to  the  runtime
                     version  of the compiling Mono.   This will prevent the AOT files from being
                     consumed  by  a  different  Mono  runtime.   full  This  is   currently   an
                     experimental  feature  as  it  is  not  complete.   This  instructs  Mono to
                     precompile code that has historically not been precompiled with AOT.

              direct-pinvoke
                     When this option is specified, P/Invoke methods are invoked directly instead
                     of going through the operating system symbol lookup operation.

              llvm-path=<PREFIX>
                     Same for the llvm tools 'opt' and 'llc'.

              mtriple=<TRIPLE>
                     Use  the  GNU style target triple <TRIPLE> to determine some code generation
                     options, i.e.  --mtriple=armv7-linux-gnueabi will generate code that targets
                     ARMv7.  This  is  currently only supported by the ARM backend. In LLVM mode,
                     this triple is passed on to the LLVM llc compiler.

              nimt-trampolines=[number]
                     When compiling in full aot mode, the IMT trampolines must be  precreated  in
                     the  AOT  image.   You  can  add  additional  method  trampolines  with this
                     argument.  Defaults to 128.

              nodebug
                     Instructs the AOT compiler to not output any debugging information.

              dwarfdebug
                     Instructs the AOT compiler to emit DWARF debugging  information.  When  used
                     together  with  the  nodebug  option,  only  DWARF  debugging information is
                     emitted, but not the information that can be used at runtime.

              nrgctx-trampolines=[number]
                     When compiling in full aot mode, the generic  sharing  trampolines  must  be
                     precreated in the AOT image.  You can add additional method trampolines with
                     this argument.  Defaults to 1024.

              ntrampolines=[number]
                     When compiling in full aot mode, the method trampolines must  be  precreated
                     in  the  AOT  image.   You  can  add additional method trampolines with this
                     argument.  Defaults to 1024.

              outfile=[filename]
                     Instructs the AOT compiler to save the output to the specified file.

              print-skipped-methods
                     If the AOT compiler cannot compile a method for any  reason,  enabling  this
                     flag will output the skipped methods to the console.

              readonly-value=namespace.typename.fieldname=type/value
                     Override  the  value  of  a  static  readonly  field.  Usually,  during  JIT
                     compilation, the static constructor is ran eagerly, so the value of a static
                     readonly field is known at compilation time and the compiler can do a number
                     of optimizations based on it. During AOT, instead,  the  static  constructor
                     can't  be  ran,  so this option can be used to set the value of such a field
                     and enable the same set of optimizations.  Type can be any of i1, i2, i4 for
                     integers  of  the  respective  sizes  (in bytes).  Note that signed/unsigned
                     numbers do not matter here, just the  storage  size.   This  option  can  be
                     specified  multiple  times and it doesn't prevent the static constructor for
                     the type defining the field to execute  with  the  usual  rules  at  runtime
                     (hence possibly computing a different value for the field).

              save-temps,keep-temps
                     Instructs the AOT compiler to keep temporary files.

              soft-debug
                     This  instructs  the  compiler  to generate sequence point checks that allow
                     Mono's soft debugger to debug applications even on systems where it  is  not
                     possible   to   set   breakpoints   or  to  single  step  (certain  hardware
                     configurations like the cell phones and video gaming consoles).

              static Create an ELF object file (.o) or .s file which  can  be  statically  linked
                     into  an  executable  when  embedding  the mono runtime. When this option is
                     used, the object file needs to be registered with the embedded runtime using
                     the  mono_aot_register_module  function  which  takes  as  its  argument the
                     mono_aot_module_<ASSEMBLY NAME>_info global symbol from the object file:

                     extern void *mono_aot_module_hello_info;

                     mono_aot_register_module (mono_aot_module_hello_info);

              stats  Print various stats collected during AOT compilation.

              threads=[number]
                     This is an experimental option for the AOT compiler to use multiple  threads
                     when compiling the methods.

              tool-prefix=<PREFIX>
                     Prepends  <PREFIX>  to  the  name  of  tools  ran  by the AOT compiler, i.e.
                     'as'/'ld'. For example, --tool=prefix=arm-linux-gnueabi- will make  the  AOT
                     compiler run

              write-symbols
                     Instructs the AOT compiler to emit debug symbol information.

              For more information about AOT, see: http://www.mono-project.com/AOT

       --attach=[options]
              Currently  the only option supported by this command line argument is disable which
              disables the attach functionality.

       --config filename
              Load the specified configuration file instead of the default one(s).   The  default
              files  are  /etc/mono/config  and  ~/.mono/config  or  the  file  specified  in the
              MONO_CONFIG environment variable, if set.  See  the  mono-config(5)  man  page  for
              details on the format of this file.

       --debugger-agent=[options]
              This  instructs the Mono runtime to start a debugging agent inside the Mono runtime
              and connect it to a client user interface will  control  the  Mono  process.   This
              option is typically used by IDEs, like the MonoDevelop IDE.

       The configuration is specified using one of more of the following options:

              address=host:port
                     Use  this  option  to  specify  the IP address where your debugger client is
                     listening to.

              loglevel=LEVEL
                     Specifies the diagnostics log level for

              logfile=filename
                     Used to specify the file where the  log  will  be  stored,  it  defaults  to
                     standard output.

              server=[y/n]
                     Defaults  to  no,  with the default option Mono will actively connect to the
                     host/port configured with the address option.  If you  set  it  to  'y',  it
                     instructs  the  Mono  runtime  to start debugging in server mode, where Mono
                     actively waits for the debugger front end to connect to  the  Mono  process.
                     Mono will print out to stdout the IP address and port where it is listening.

              setpgid=[y/n]
                     If  set to yes, Mono will call setpgid(0, 0) on startup, if that function is
                     available on the system. This is useful for ensuring that signals  delivered
                     to  a  process  that  is  executing  the  debuggee are not propagated to the
                     debuggee, e.g. when Ctrl-C sends SIGINT to the sdb tool.

              suspend=[y/n]
                     Defaults to yes, with the default option Mono will suspend the vm on startup
                     until  it  connects  successfully to a debugger front end.  If you set it to
                     'n', in conjunction with server=y, it instructs the Mono runtime to  run  as
                     normal,  while  caching  metadata  to  send  to  the  debugger  front end on
                     connection..

              transport=transport_name
                     This is used to  specify  the  transport  that  the  debugger  will  use  to
                     communicate.    It  must  be  specified  and  currently  requires this to be
                     'dt_socket'.

       --desktop
              Configures the virtual machine  to  be  better  suited  for  desktop  applications.
              Currently  this  sets the GC system to avoid expanding the heap as much as possible
              at the expense of slowing down garbage collection a bit.

       --full-aot
              This is an experimental flag that instructs the Mono runtime to  not  generate  any
              code  at  runtime  and  depend  exclusively  on  the code generated from using mono
              --aot=full previously.   This is useful for platforms that do  not  permit  dynamic
              code  generation.   Notice  that  this feature will abort execution at runtime if a
              codepath in your program, or Mono's  class  libraries  attempts  to  generate  code
              dynamically.   You  should test your software upfront and make sure that you do not
              use any dynamic features.

       --gc=boehm, --gc=sgen
              Selects the Garbage Collector engine for Mono to use,  Boehm  or  SGen.   Currently
              this  merely  ensures  that  you are running either the mono or mono-sgen commands.
              This flag can be set in the MONO_ENV_OPTIONS environment variable to force  all  of
              your child processes to use one particular kind of GC with the Mono runtime.

       --help, -h
              Displays usage instructions.

       --llvm If  the  Mono  runtime  has  been  compiled with LLVM support (not available in all
              configurations), Mono will use the LLVM optimization and code generation engine  to
              JIT   or   AOT   compile.    For   more   information,   consult:  http://www.mono-
              project.com/Mono_LLVM

       --nollvm
              When using a Mono that has been compiled with  LLVM  support,  it  forces  Mono  to
              fallback to its JIT engine and not use the LLVM backend.

       --optimize=MODE, -O=MODE
              MODE  is a comma separated list of optimizations.  They also allow optimizations to
              be turned off by prefixing the optimization name with a minus  sign.   In  general,
              Mono has been tuned to use the default set of flags, before using these flags for a
              deployment setting, you might want to actually measure the benefits of using  them.
              The following optimizations are implemented:
                           all        Turn on all optimizations
                           peephole   Peephole postpass
                           branch     Branch optimizations
                           inline     Inline method calls
                           cfold      Constant folding
                           consprop   Constant propagation
                           copyprop   Copy propagation
                           deadce     Dead code elimination
                           linears    Linear scan global reg allocation
                           cmov       Conditional moves [arch-dependency]
                           shared     Emit per-domain code
                           sched      Instruction scheduling
                           intrins    Intrinsic method implementations
                           tailc      Tail recursion and tail calls
                           loop       Loop related optimizations
                           fcmov      Fast x86 FP compares [arch-dependency]
                           leaf       Leaf procedures optimizations
                           aot        Usage of Ahead Of Time compiled code
                           precomp    Precompile all methods before executing Main
                           abcrem     Array bound checks removal
                           ssapre     SSA based Partial Redundancy Elimination
                           sse2       SSE2 instructions on x86 [arch-dependency]
                           gshared    Enable generic code sharing.
              For example, to enable all the optimization but dead code elimination and inlining,
              you can use:
                   -O=all,-deadce,-inline
              The flags that are flagged with [arch-dependency] indicate that the given option if
              used  in combination with Ahead of Time compilation (--aot flag) would produce pre-
              compiled code that will depend on the current CPU and might not be safely moved  to
              another computer.

       --runtime=VERSION
              Mono  supports  different runtime versions. The version used depends on the program
              that is being run or on its configuration  file  (named  program.exe.config).  This
              option  can  be used to override such autodetection, by forcing a different runtime
              version to be used. Note that this should only be used to select a later compatible
              runtime  version  than the one the program was compiled against. A typical usage is
              for running a 1.1 program on a 2.0 version:
                       mono --runtime=v2.0.50727 program.exe

       --security, --security=mode
              Activate the security manager, a currently experimental feature in Mono and  it  is
              OFF by default. The new code verifier can be enabled with this option as well.

              Using  security  without  parameters  is  equivalent  as  calling it with the "cas"
              parameter.

              The following modes are supported:

              cas    This allows mono to support declarative security attributes, e.g.  execution
                     of Code Access Security (CAS) or non-CAS demands.

              core-clr
                     Enables    the    core-clr    security    system,    typically    used   for
                     Moonlight/Silverlight applications.  It provides  a  much  simpler  security
                     system  than CAS, see http://www.mono-project.com/Moonlight for more details
                     and links to the descriptions of this new system.

              validil
                     Enables the new verifier and performs basic verification for code  validity.
                     In  this  mode,  unsafe  code and P/Invoke are allowed. This mode provides a
                     better safety guarantee but it is still possible for managed code  to  crash
                     Mono.

              verifiable
                     Enables  the  new  verifier and performs full verification of the code being
                     executed.  It only allows verifiable code to be executed.   Unsafe  code  is
                     not  allowed  but  P/Invoke  is.  This mode should not allow managed code to
                     crash mono.  The verification is not as strict as ECMA 335 standard in order
                     to stay compatible with the MS runtime.

              The  security  system  acts  on user code: code contained in mscorlib or the global
              assembly cache is always trusted.

       --server
              Configures  the  virtual  machine  to  be  better  suited  for  server   operations
              (currently, allows a heavier threadpool initialization).

       --verify-all
              Verifies mscorlib and assemblies in the global assembly cache for valid IL, and all
              user code for IL verifiability.

              This is different from --security's verifiable or validil  in  that  these  options
              only  check  user  code  and  skip  mscorlib  and  assemblies located on the global
              assembly cache.

       -V, --version
              Prints JIT version information (system configuration,  release  number  and  branch
              names if available).

DEVELOPMENT OPTIONS

       The following options are used to help when developing a JITed application.

       --debug, --debug=OPTIONS
              Turns  on  the  debugging  mode  in  the runtime.  If an assembly was compiled with
              debugging information, it will produce line number information for stack traces.

              The optional OPTIONS argument is a  comma  separated  list  of  debugging  options.
              These  options are turned off by default since they generate much larger and slower
              code at runtime.

              The following options are supported:

              casts  Produces a detailed  error  when  throwing  a  InvalidCastException.    This
                     option  needs to be enabled as this generates more verbose code at execution
                     time.

              mdb-optimizations
                     Disable some JIT optimizations which are usually only disabled when  running
                     inside  the  debugger.   This  can  be  helpful if you want to attach to the
                     running process with mdb.

              gdb    Generate and register debugging information with gdb. This is only supported
                     on some platforms, and only when using gdb 7.0 or later.

       --profile[=profiler[:profiler_args]]
              Turns  on  profiling.   For  more information about profiling applications and code
              coverage see the sections "PROFILING" and "CODE COVERAGE" below.

       This option can be used multiple times, each time will load an
              additional profiler.   This allows developers to use modules that  extend  the  JIT
              through the Mono profiling interface.

       --trace[=expression]
              Shows  method  names  as they are invoked.  By default all methods are traced.  The
              trace can be customized to include or exclude methods, classes  or  assemblies.   A
              trace  expression is a comma separated list of targets, each target can be prefixed
              with a minus sign to turn off a particular target.  The words `program', `all'  and
              `disabled'  have  special  meaning.   `program'  refers  to  the main program being
              executed, and `all' means all the method calls.  The `disabled' option is  used  to
              start  up with tracing disabled.  It can be enabled at a later point in time in the
              program by sending the SIGUSR2 signal to the runtime.  Assemblies are specified  by
              their name, for example, to trace all calls in the System assembly, use:

                   mono --trace=System app.exe

              Classes  are  specified with the T: prefix.  For example, to trace all calls to the
              System.String class, use:

                   mono --trace=T:System.String app.exe

              And individual methods are referenced with the M: prefix, and the  standard  method
              notation:

                   mono --trace=M:System.Console:WriteLine app.exe

              Exceptions can also be traced, it will cause a stack trace to be printed every time
              an exception of the specified type is thrown.  The exception type can be  specified
              with  or  without  the namespace, and to trace all exceptions, specify 'all' as the
              type name.

                   mono --trace=E:System.Exception app.exe

              As previously noted, various rules can be specified at once:

                   mono --trace=T:System.String,T:System.Random app.exe

              You can exclude pieces, the next example traces calls to System.String  except  for
              the System.String:Concat method.

                   mono --trace=T:System.String,-M:System.String:Concat

              You can trace managed to unmanaged transitions using the wrapper qualifier:

                   mono --trace=wrapper app.exe

              Finally, namespaces can be specified using the N: prefix:

                   mono --trace=N:System.Xml

       --no-x86-stack-align
              Don't  align  stack  frames on the x86 architecture.  By default, Mono aligns stack
              frames to 16 bytes on x86, so that local floating point and SIMD variables  can  be
              properly  aligned.   This  option  turns off the alignment, which usually saves one
              intruction per call, but might result in significantly  lower  floating  point  and
              SIMD performance.

       --jitmap
              Generate  a JIT method map in a /tmp/perf-PID.map file. This file is then used, for
              example, by the perf tool included in recent Linux kernels.  Each line in the  file
              has:

                   HEXADDR HEXSIZE methodname

              Currently this option is only supported on Linux.

JIT MAINTAINER OPTIONS

       The  maintainer  options  are  only  used  by those developing the runtime itself, and not
       typically of interest to runtime users or developers.

       --break method
              Inserts   a   breakpoint   before   the   method    whose    name    is    `method'
              (namespace.class:methodname).   Use `Main' as method name to insert a breakpoint on
              the application's main method.  You can use it  also  with  generics,  for  example
              "System.Collections.Generic.Queue`1:Peek"

       --breakonex
              Inserts a breakpoint on exceptions.  This allows you to debug your application with
              a native debugger when an exception is thrown.

       --compile name
              This compiles a method (namespace.name:methodname), this is used  for  testing  the
              compiler performance or to examine the output of the code generator.

       --compileall
              Compiles  all  the  methods  in  an  assembly.   This  is used to test the compiler
              performance or to examine the output of the code generator

       --graph=TYPE METHOD
              This generates a postscript file with a graph with the details about the  specified
              method  (namespace.name:methodname).   This  requires  `dot'  and  ghostview  to be
              installed (it expects Ghostview to be  called  "gv").   The  following  graphs  are
              available:
                        cfg        Control Flow Graph (CFG)
                        dtree      Dominator Tree
                        code       CFG showing code
                        ssa        CFG showing code after SSA translation
                        optcode    CFG showing code after IR optimizations
              Some graphs will only be available if certain optimizations are turned on.

       --ncompile
              Instruct  the runtime on the number of times that the method specified by --compile
              (or all the methods if --compileall is used) to be  compiled.   This  is  used  for
              testing the code generator performance.

       --stats
              Displays  information about the work done by the runtime during the execution of an
              application.

       --wapi=hps|semdel
              Perform maintenance of the process shared data.   semdel  will  delete  the  global
              semaphore.  hps will list the currently used handles.

       -v, --verbose
              Increases  the  verbosity  level,  each  time it is listed, increases the verbosity
              level to include more information (including, for example,  a  disassembly  of  the
              native code produced, code selector info etc.).

ATTACH SUPPORT

       The  Mono  runtime  allows  external  processes  to  attach  to a running process and load
       assemblies into the running program.   To attach to the process,  a  special  protocol  is
       implemented in the Mono.Management assembly.

       With  this  support  it  is possible to load assemblies that have an entry point (they are
       created with -target:exe or -target:winexe) to be loaded and executed in the Mono process.

       The code is loaded into the root domain, and it starts execution on  the  special  runtime
       attach  thread.     The  attached  program  should create its own threads and return after
       invocation.

       This support allows for example debugging applications by having the csharp  shell  attach
       to running processes.

PROFILING

       The  mono  runtime  includes  a  profiler  that can be used to explore various performance
       related problems in your application.  The profiler is activated by passing the  --profile
       command line argument to the Mono runtime, the format is:

            --profile[=profiler[:profiler_args]]

       Mono has a built-in profiler called 'default' (and is also the default if no arguments are
       specified), but developers can write custom profilers, see the section "CUSTOM  PROFILERS"
       for more details.

       If  a  profiler  is  not  specified, the default profiler is used.  The profiler_args is a
       profiler-specific string of options for the profiler itself.  The default profiler accepts
       the  following options 'alloc' to profile memory consumption by the application; 'time' to
       profile the time spent on each routine; 'jit' to collect time spent JIT-compiling  methods
       and  'stat'  to  perform  sample  statistical  profiling.   If no options are provided the
       default is 'alloc,time,jit'.

       By default the profile data is printed to stdout: to change this, use the  'file=filename'
       option to output the data to filename.  For example:

            mono --profile program.exe

       That  will  run  the  program  with  the  default profiler and will do time and allocation
       profiling.

            mono --profile=default:stat,alloc,file=prof.out program.exe

       Will do  sample statistical profiling and allocation profiling on program.exe. The profile
       data  is  put in prof.out.  Note that the statistical profiler has a very low overhead and
       should be the preferred profiler to use (for better output use the full path to  the  mono
       binary when running and make sure you have installed the addr2line utility that comes from
       the binutils package).

LOG PROFILER

       This is the most advanced profiler.

       The Mono log profiler can be used to collect a lot of information about a program  running
       in  the Mono runtime.  This data can be used (both while the process is running and later)
       to do analyses of the program behaviour, determine resource usage, performance  issues  or
       even look for particular execution patterns.

       This  is  accomplished  by  logging  the  events  provided by the Mono runtime through the
       profiling interface and periodically writing them to a file which can be  later  inspected
       with the mprof-report(1) tool.

       More  information  about  how  to use the log profiler is available on the mprof-report(1)
       page.

CUSTOM PROFILERS

       Mono provides a mechanism for loading other profiling modules which in the form of  shared
       libraries.   These  profiling  modules can hook up to various parts of the Mono runtime to
       gather information about the code being executed.

       To use a third party profiler you must pass the name of the profiler to Mono, like this:

            mono --profile=custom program.exe

       In the above sample Mono will load the user  defined  profiler  from  the  shared  library
       `mono-profiler-custom.so'.   This  profiler  module must be on your dynamic linker library
       path.

       A list of other third party  profilers  is  available  from  Mono's  web  site  (www.mono-
       project.com/Performance_Tips)

       Custom profiles are written as shared libraries.  The shared library must be called `mono-
       profiler-NAME.so' where `NAME' is the name of your profiler.

       For a sample of how to write your own custom profiler look in the Mono source tree for  in
       the samples/profiler.c.

CODE COVERAGE

       Mono  ships  with  a  code  coverage  module.   This module is activated by using the Mono
       --profile=cov option.   The  format  is:  --profile=cov[:assembly-name[/namespace]]  test-
       suite.exe

       By  default code coverage will default to all the assemblies loaded, you can limit this by
       specifying the assembly name, for example to perform code coverage in the routines of your
       program  use,  for example the following command line limits the code coverage to routines
       in the "demo" assembly:

            mono --profile=cov:demo demo.exe

       Notice that the assembly-name does not include the extension.

       You can further restrict the code coverage output by specifying a namespace:

            mono --profile=cov:demo/My.Utilities demo.exe

       Which will only perform code coverage in the given assembly and namespace.

       Typical output looks like this:

            Not covered: Class:.ctor ()
            Not covered: Class:A ()
            Not covered: Driver:.ctor ()
            Not covered: Driver:method ()
            Partial coverage: Driver:Main ()
                 offset 0x000a

       The offsets displayed are IL offsets.

       A more powerful coverage tool is available in the module `monocov'.   See  the  monocov(1)
       man page for details.

DEBUGGING AIDS

       To debug managed applications, you can use the mdb command, a command line debugger.

       It  is  possible  to obtain a stack trace of all the active threads in Mono by sending the
       QUIT signal to Mono, you can do this from the command line, like this:

            kill -QUIT pid

       Where pid is the Process ID of the Mono process you want to  examine.   The  process  will
       continue running afterwards, but its state is not guaranteed.

       Important:  this  is  a last-resort mechanism for debugging applications and should not be
       used to monitor or probe a production application.  The integrity  of  the  runtime  after
       sending  this signal is not guaranteed and the application might crash or terminate at any
       given point afterwards.

       The --debug=casts option can be used to get more detailed  information  for  Invalid  Cast
       operations, it will provide information about the types involved.

       You  can  use  the  MONO_LOG_LEVEL  and MONO_LOG_MASK environment variables to get verbose
       debugging output about the execution of your application within Mono.

       The MONO_LOG_LEVEL environment variable if set, the logging level is changed  to  the  set
       value. Possible values are "error", "critical", "warning", "message", "info", "debug". The
       default value is "error". Messages with a logging level greater then or equal to  the  log
       level will be printed to stdout/stderr.

       Use "info" to track the dynamic loading of assemblies.

       Use the MONO_LOG_MASK environment variable to limit the extent of the messages you get: If
       set, the log mask is changed to  the  set  value.  Possible  values  are  "asm"  (assembly
       loader),  "type",  "dll"  (native library loader), "gc" (garbage collector), "cfg" (config
       file loader), "aot" (precompiler), "security" (e.g. Moonlight CoreCLR support) and  "all".
       The  default  value  is "all". Changing the mask value allows you to display only messages
       for a certain component. You can use multiple masks by comma separating them. For  example
       to see config file messages and assembly loader messages set you mask to "asm,cfg".

       The following is a common use to track down problems with P/Invoke:

            $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe

SERIALIZATION

       Mono's  XML  serialization  engine  by  default  will  use  a reflection-based approach to
       serialize which might be slow for continuous processing (web service  applications).   The
       serialization engine will determine when a class must use a hand-tuned serializer based on
       a few parameters and if needed it will produce a customized C# serializer for  your  types
       at   runtime.    This  customized  serializer  then  gets  dynamically  loaded  into  your
       application.

       You can control this with the MONO_XMLSERIALIZER_THS environment variable.

       The possible values are `no' to disable the use of  a  C#  customized  serializer,  or  an
       integer  that  is  the  minimum  number  of  uses before the runtime will produce a custom
       serializer (0 will produce a custom serializer on the first  access,  50  will  produce  a
       serializer  on  the  50th  use).  Mono  will  fallback to an interpreted serializer if the
       serializer generation somehow fails. This behavior can be disabled by setting  the  option
       `nofallback' (for example: MONO_XMLSERIALIZER_THS=0,nofallback).

ENVIRONMENT VARIABLES

       GC_DONT_GC
              Turns  off  the garbage collection in Mono.  This should be only used for debugging
              purposes

       LVM_COUNT
              When Mono is compiled with LLVM support, this instructs the runtime to  stop  using
              LLVM  after  the  specified  number  of  methods are JITed.  This is a tool used in
              diagnostics to help isolate problems in the code generation backend.   For  example
              LLVM_COUNT=10  would  only compile 10 methods with LLVM and then switch to the Mono
              JIT engine.  LLVM_COUNT=0 would disable the LLVM engine altogether.

       MONO_AOT_CACHE
              If set, this variable will instruct Mono to ahead-of-time compile new assemblies on
              demand and store the result into a cache in ~/.mono/aot-cache.

       MONO_ASPNET_INHIBIT_SETTINGSMAP
              Mono  contains  a  feature  which  allows  modifying  settings in the .config files
              shipped with Mono by using config section mappers.  The  mappers  and  the  mapping
              rules are defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in
              the settings.map file found in the top-level directory of your ASP.NET application.
              Both  files are read by System.Web on application startup, if they are found at the
              above locations. If you don't want the mapping to be performed  you  can  set  this
              variable  in your environment before starting the application and no action will be
              taken.

       MONO_ASPNET_WEBCONFIG_CACHESIZE
              Mono has a cache of ConfigSection objects for speeding  up  WebConfigurationManager
              queries.  Its  default  size  is  100  items, and when more items are needed, cache
              evictions start  happening.  If  evictions  are  too  frequent  this  could  impose
              unnecessary  overhead, which could be avoided by using this environment variable to
              set up a higher cache size (or to lower memory requirements by decreasing it).

       MONO_CAIRO_DEBUG_DISPOSE
              If set, causes Mono.Cairo to collect stack traces when objects  are  allocated,  so
              that  the  finalization/Dispose  warnings  include information about the instance's
              origin.

       MONO_CFG_DIR
              If  set,  this  variable  overrides  the  default  system  configuration  directory
              ($PREFIX/etc). It's used to locate machine.config file.

       MONO_COM
              Sets the style of COM interop.  If the value of this variable is "MS" Mono will use
              string marhsalling routines from the liboleaut32 for the  BSTR  type  library,  any
              other values will use the mono-builtin BSTR string marshalling.

       MONO_CONFIG
              If   set,   this   variable   overrides  the  default  runtime  configuration  file
              ($PREFIX/etc/mono/config).  The  --config  command  line  options   overrides   the
              environment variable.

       MONO_CPU_ARCH
              Override  the  automatic  cpu detection mechanism. Currently used only on arm.  The
              format of the value is as follows:

                   "armvV [thumb]"

              where V is the architecture number 4, 5, 6, 7 and the options can be  currently  be
              "thunb". Example:

                   MONO_CPU_ARCH="armv4 thumb" mono ...

       MONO_DISABLE_AIO
              If  set,  tells mono NOT to attempt using native asynchronous I/O services. In that
              case, a default select/poll implementation  is  used.  Currently  only  epoll()  is
              supported.

       MONO_DISABLE_MANAGED_COLLATION
              If  this environment variable is `yes', the runtime uses unmanaged collation (which
              actually means no culture-sensitive  collation).  It  internally  disables  managed
              collation functionality invoked via the members of System.Globalization.CompareInfo
              class. Collation is enabled by default.

       MONO_DISABLE_SHM
              Unix only: If set, disables the shared memory files used for cross-process handles:
              process  have only private handles.  This means that process and thread handles are
              not available to other  processes,  and  named  mutexes,  named  events  and  named
              semaphores  are  not  visible  between  processes.   This is can also be enabled by
              default by passing the "--disable-shared-handles" option to configure.  This is the
              default from mono 2.8 onwards.

       MONO_DISABLE_SHARED_AREA
              Unix  only:  If  set,  disable  usage  of  shared  memory  for exposing performance
              counters. This means it will not be possible to both  externally  read  performance
              counters from this processes or read those of external processes.

       MONO_DNS
              When  set,  enables  the use of a fully managed DNS resolver instead of the regular
              libc functions. This resolver performs much better when multiple queries are run in
              parallel.

              Note that /etc/nsswitch.conf will be ignored.

       MONO_EGD_SOCKET
              For  platforms  that do not otherwise have a way of obtaining random bytes this can
              be set to the name of a file system socket on which  an  egd  or  prngd  daemon  is
              listening.

       MONO_ENABLE_SHM
              Unix  only:  Enable  support  for cross-process handles.  Cross-process handles are
              used to expose process handles, thread handles, named  mutexes,  named  events  and
              named semaphores across Unix processes.

       MONO_ENV_OPTIONS
              This  environment  variable  allows  you  to  pass command line arguments to a Mono
              process through the environment.   This is useful for example to force all of  your
              Mono processes to use LLVM or SGEN without having to modify any launch scripts.

       MONO_ENV_OPTIONS
              Used  to  pass  extra  options  to  the debugger agent in the runtime, as they were
              passed using --debugger-agent=.

       MONO_EVENTLOG_TYPE
              Sets the type of event  log  provider  to  use  (for  System.Diagnostics.EventLog).
              Possible values are:

              local[:path]
                     Persists  event logs and entries to the local file system.  The directory in
                     which to persist the event logs, event sources and entries can be  specified
                     as  part  of  the  value.  If the path is not explicitly set, it defaults to
                     "/var/lib/mono/eventlog" on unix and "%APPDATA%no\ventlog" on Windows.

              win32  Uses the native win32 API to write events and registers event logs and event
                     sources  in the registry.   This is only available on Windows.  On Unix, the
                     directory permission for individual event log and event  source  directories
                     is  set  to  777 (with +t bit) allowing everyone to read and write event log
                     entries while only allowing entries  to  be  deleted  by  the  user(s)  that
                     created them.

              null   Silently discards any events.

              The  default  is "null" on Unix (and versions of Windows before NT), and "win32" on
              Windows NT (and higher).

       MONO_EXTERNAL_ENCODINGS
              If set, contains a colon-separated list of  text  encodings  to  try  when  turning
              externally-generated  text (e.g. command-line arguments or filenames) into Unicode.
              The encoding names come from the list provided  by  iconv,  and  the  special  case
              "default_locale" which refers to the current locale's default encoding.

              When  reading externally-generated text strings UTF-8 is tried first, and then this
              list is tried in order with the first  successful  conversion  ending  the  search.
              When  writing  external text (e.g. new filenames or arguments to new processes) the
              first item in this list is used, or UTF-8 if the environment variable is not set.

              The problem with using MONO_EXTERNAL_ENCODINGS to process your  files  is  that  it
              results  in  a  problem: although its possible to get the right file name it is not
              necessarily possible to open the file.   In  general  if  you  have  problems  with
              encodings in your filenames you should use the "convmv" program.

       MONO_GC_PARAMS
              When  using  Mono  with  the  SGen garbage collector this variable controls several
              parameters of the collector.  The variable's value is a  comma  separated  list  of
              words.

              nursery-size=size
                     Sets  the size of the nursery.  The size is specified in bytes and must be a
                     power of two.  The suffixes `k', `m' and `g' can be used to  specify  kilo-,
                     mega-  and gigabytes, respectively.  The nursery is the first generation (of
                     two).  A larger nursery will usually speed up the program but will obviously
                     use more memory.  The default nursery size 4 MB.

              major=collector
                     Specifies  which  major  collector  to use.  Options are `marksweep' for the
                     Mark&Sweep   collector,   `marksweep-conc'   for   concurrent    Mark&Sweep,
                     `marksweep-par'  for  parallel  Mark&Sweep, `marksweep-fixed' for Mark&Sweep
                     with a fixed heap, and `marksweep-fixed-par' for parallel Mark&Sweep with  a
                     fixed heap. The Mark&Sweep collector is the default.

              major-heap-size=size
                     Sets  the  size of the major heap (not including the large object space) for
                     the fixed-heap Mark&Sweep collector (i.e. `marksweep-fixed' and  `marksweep-
                     fixed-par').   The size is in bytes, with optional suffixes `k', `m' and `g'
                     to specify kilo-, mega- and gigabytes, respectively.   The  default  is  512
                     megabytes.

              soft-heap-limit=size
                     Once the heap size gets larger than this size, ignore what the default major
                     collection trigger metric says and only allow four nursery size's  of  major
                     heap growth between major collections.

              evacuation-threshold=threshold
                     Sets  the evacuation threshold in percent.  This option is only available on
                     the Mark&Sweep major collectors.  The value must be an integer in the  range
                     0  to  100.   The default is 66.  If the sweep phase of the collection finds
                     that the occupancy  of  a  specific  heap  block  type  is  less  than  this
                     percentage,  it will do a copying collection for that block type in the next
                     major collection, thereby restoring occupancy to close to  100  percent.   A
                     value of 0 turns evacuation off.

              (no-)lazy-sweep
                     Enables  or  disables  lazy sweep for the Mark&Sweep collector.  If enabled,
                     the sweep phase of the garbage collection is  done  piecemeal  whenever  the
                     need arises, typically during nursery collections.  Lazy sweeping is enabled
                     by default.

              stack-mark=mark-mode
                     Specifies how application threads should be scanned. Options  are  `precise`
                     and  `conservative`. Precise marking allow the collector to know what values
                     on stack are references and what are not.  Conservative marking threats  all
                     values  as  potentially references and leave them untouched. Precise marking
                     reduces floating garbage and can speed up nursery collection and  allocation
                     rate,  it  has  the  downside  of  requiring  a significant extra memory per
                     compiled method. The right option, unfortunately, requires experimentation.

              save-target-ratio=ratio
                     Specifies the target save ratio for the major collector. The collector  lets
                     a  given  amount  of  memory  to  be  promoted from the nursery due to minor
                     collections before it triggers a major collection. This amount is  based  on
                     how much memory it expects to free. It is represented as a ratio of the size
                     of the heap after a major collection.  Valid values are between 0.1 and 2.0.
                     The  default  is  0.5.  Smaller values will keep the major heap size smaller
                     but will trigger more major collections. Likewise, bigger  values  will  use
                     more  memory  and result in less frequent major collections.  This option is
                     EXPERIMENTAL, so it might disappear in later versions of mono.

              default-allowance-ratio=ratio
                     Specifies the default allocation allowance when the calculated size  is  too
                     small.  The  allocation  allowance  is  how much memory the collector let be
                     promoted before triggered a major collection.  It is a ratio of the  nursery
                     size.   Valid  values are between 1.0 and 10.0. The default is 4.0.  Smaller
                     values lead to smaller heaps and more frequent major collections.  Likewise,
                     bigger values will allow the heap to grow faster but use more memory when it
                     reaches a stable size.  This option is EXPERIMENTAL, so it  might  disappear
                     in later versions of mono.

              minor=minor-collector
                     Specifies  which minor collector to use. Options are 'simple' which promotes
                     all objects from the nursery directly to  the  old  generation  and  'split'
                     which lets object stay longer on the nursery before promoting.

              alloc-ratio=ratio
                     Specifies the ratio of memory from the nursery to be use by the alloc space.
                     This only can only be used with the split minor collector.  Valid values are
                     integers between 1 and 100. Default is 60.

              promotion-age=age
                     Specifies the required age of an object must reach inside the nursery before
                     been promoted to the old generation. This only can only  be  used  with  the
                     split  minor collector.  Valid values are integers between 1 and 14. Default
                     is 2.

              (no-)cementing
                     Enables or  disables  cementing.   This  can  dramatically  shorten  nursery
                     collection  times  on  some  benchmarks where pinned objects are referred to
                     from the major heap.

       MONO_GC_DEBUG
              When using Mono with the SGen garbage collector this environment  variable  can  be
              used  to  turn  on  various debugging features of the collector.  The value of this
              variable is a comma  separated  list  of  words.   Do  not  use  these  options  in
              production.

              number Sets the debug level to the specified number.

              print-allowance
                     After  each  major collection prints memory consumption for before and after
                     the collection and the allowance for the minor collector, i.e. how much  the
                     heap  is  allowed  to  grow  from  minor  collections  before the next major
                     collection is triggered.

              print-pinning
                     Gathers statistics on the classes whose objects are pinned  in  the  nursery
                     and for which global remset entries are added.  Prints those statistics when
                     shutting down.

              collect-before-allocs

              check-at-minor-collections
                     This performs a consistency check on minor collections and also  clears  the
                     nursery  at  collection  time,  instead  of  the  default,  when buffers are
                     allocated (clear-at-gc).   The consistency check ensures that there  are  no
                     major to minor references that are not on the remembered sets.

              mod-union-consistency-check
                     Checks  that  the  mod-union  cardtable  is consistent before each finishing
                     major collection pause.  This check is only applicable to  concurrent  major
                     collectors.

              check-mark-bits
                     Checks  that  mark  bits in the major heap are consistent at the end of each
                     major collection.  Consistent mark bits mean that if an  object  is  marked,
                     all objects that it had references to must also be marked.

              check-nursery-pinned
                     After nursery collections, and before starting concurrent collections, check
                     whether all nursery objects  are  pinned,  or  not  pinned  -  depending  on
                     context.  Does nothing when the split nursery collector is used.

              xdomain-checks
                     Performs  a  check  to  make sure that no references are left to an unloaded
                     AppDomain.

              clear-at-gc
                     This clears the nursery at GC time instead of doing it when the thread local
                     allocation buffer (TLAB) is created.  The default is to clear the nursery at
                     TLAB creation time.

              disable-minor
                     Don't do minor collections.  If the nursery is full, a major  collection  is
                     triggered instead, unless it, too, is disabled.

              disable-major
                     Don't do major collections.

              conservative-stack-mark
                     Forces  the GC to scan the stack conservatively, even if precise scanning is
                     available.

              no-managed-allocator
                     Disables the managed allocator.

              check-scan-starts
                     If set, does a plausibility check on the scan_starts before and  after  each
                     collection

              verify-nursery-at-minor-gc
                     If  set,  does  a  complete  object walk of the nursery at the start of each
                     minor collection.

              dump-nursery-at-minor-gc
                     If set, dumps the contents of  the  nursery  at  the  start  of  each  minor
                     collection. Requires verify-nursery-at-minor-gc to be set.

              heap-dump=file
                     Dumps   the  heap  contents  to  the  specified  file.    To  visualize  the
                     information, use the mono-heapviz tool.

              binary-protocol=file
                     Outputs the debugging output to the specified file.   For this to work, Mono
                     needs to be compiled with the BINARY_PROTOCOL define on sgen-gc.c.   You can
                     then use this command to explore the output
                                     sgen-grep-binprot 0x1234 0x5678 < file

       MONO_GAC_PREFIX
              Provides a prefix the runtime uses to look for Global Assembly Caches.  Directories
              are  separated  by  the  platform  path separator (colons on unix). MONO_GAC_PREFIX
              should point to the top directory of  a  prefixed  install.  Or  to  the  directory
              provided       in       the       gacutil       /gacdir      command.      Example:
              /home/username/.mono:/usr/local/mono/

       MONO_IOMAP
              Enables some filename rewriting support to assist badly-written  applications  that
              hard-code  Windows  paths.  Set to a colon-separated list of "drive" to strip drive
              letters, or "case" to do case-insensitive file matching in  every  directory  in  a
              path.   "all"  enables  all  rewriting  methods.  (Backslashes are always mapped to
              slashes if this variable is set to a valid option).
              For example, this would work from the shell:

                   MONO_IOMAP=drive:case
                   export MONO_IOMAP

              If you are using mod_mono to host your web applications, you can use the  MonoIOMAP
              directive instead, like this:

                   MonoIOMAP <appalias> all

              See mod_mono(8) for more details.

              Additionally.  Mono  includes  a  profiler  module  which  allows one to track what
              adjustements to file paths IOMAP code needs to do. The tracking  code  reports  the
              managed  location  (full stack trace) from which the IOMAP-ed call was made and, on
              process exit, the locations where all the IOMAP-ed strings were created in  managed
              code.  The  latter  report  is  only  approximate  as  it is not always possible to
              estimate the actual location where the string was created.  The  code  uses  simple
              heuristics - it analyzes stack trace leading back to the string allocation location
              and ignores all the managed code which lives in assemblies installed in GAC as well
              as  in  the class libraries shipped with Mono (since they are assumed to be free of
              case-sensitivity issues). It then reports the first location in the user's  code  -
              in most cases this will be the place where the string is allocated or very close to
              the location. The reporting code is implemented as a custom  profiler  module  (see
              the "PROFILING" section) and can be loaded in the following way:

                   mono --profile=iomap yourapplication.exe

              Note, however, that Mono currently supports only one profiler module at a time.

       MONO_LLVM
              When  Mono  is  using the LLVM code generation backend you can use this environment
              variable to pass code generation options to the LLVM compiler.

       MONO_MANAGED_WATCHER
              If  set  to  "disabled",  System.IO.FileSystemWatcher  will  use  a  file   watcher
              implementation  which  silently  ignores  all the watching requests.  If set to any
              other   value,   System.IO.FileSystemWatcher   will   use   the   default   managed
              implementation  (slow).  If unset, mono will try to use inotify, FAM, Gamin, kevent
              under Unix systems and native API calls on Windows, falling  back  to  the  managed
              implementation on error.

       MONO_MESSAGING_PROVIDER
              Mono  supports  a plugin model for its implementation of System.Messaging making it
              possible to support a variety of messaging implementations (e.g.  AMQP,  ActiveMQ).
              To  specify  which  messaging implementation is to be used the evironement variable
              needs to be set to the full class name for the provider.  E.g. to use the  RabbitMQ
              based AMQP implementation the variable should be set to:

              Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ

       MONO_NO_SMP
              If set causes the mono process to be bound to a single processor. This may be
              useful when debugging or working around race conditions.

       MONO_NO_TLS
              Disable inlining of thread local accesses. Try setting this if you get a segfault
              early on in the execution of mono.

       MONO_PATH
              Provides a search path to the runtime where to look for library
              files.   This is a tool convenient for debugging applications, but
              should not be used by deployed applications as it breaks the assembly
              loader in subtle ways.
              Directories are separated by the platform path separator (colons on unix). Example:
              /home/username/lib:/usr/local/mono/lib
              Alternative solutions to MONO_PATH include: installing libraries into
              the Global Assembly Cache (see gacutil(1)) or having the dependent
              libraries side-by-side with the main executable.
              For a complete description of recommended practices for application
              deployment, see
              http://www.mono-project.com/Guidelines:Application_Deployment

       MONO_RTC
              Experimental RTC support in the statistical profiler: if the user has
              the permission, more accurate statistics are gathered.  The MONO_RTC
              value must be restricted to what the Linux rtc allows: power of two
              from 64 to 8192 Hz. To enable higher frequencies like 4096 Hz, run as root:

                   echo 4096 > /proc/sys/dev/rtc/max-user-freq

              For example:

                   MONO_RTC=4096 mono --profiler=default:stat program.exe

       MONO_SHARED_DIR
              If  set  its  the  directory where the ".wapi" handle state is stored.  This is the
              directory where the Windows I/O  Emulation  layer  stores  its  shared  state  data
              (files,  events, mutexes, pipes).  By default Mono will store the ".wapi" directory
              in the users's home directory.

       MONO_SHARED_HOSTNAME
              Uses the string value of this variable as a replacement  for  the  host  name  when
              creating  file  names in the ".wapi" directory. This helps if the host name of your
              machine is likely to be changed when a mono application is running or if you have a
              .wapi  directory shared among several different computers.  Mono typically uses the
              hostname to create the files that are used to  share  state  across  multiple  Mono
              processes.   This is done to support home directories that might be shared over the
              network.

       MONO_STRICT_IO_EMULATION
              If set, extra checks are made during IO operations.  Currently, this includes  only
              advisory locks around file writes.

       MONO_THEME
              The name of the theme to be used by Windows.Forms.   Available themes today include
              "clearlooks", "nice" and "win32".  The default is "win32".

       MONO_TLS_SESSION_CACHE_TIMEOUT
              The time, in seconds, that the SSL/TLS session cache will keep it's entry to  avoid
              a  new  negotiation  between  the  client  and  a  server. Negotiation are very CPU
              intensive so an application-specific  custom  value  may  prove  useful  for  small
              embedded systems.  The default is 180 seconds.

       MONO_THREADS_PER_CPU
              The   maximum   number   of  threads  in  the  general  threadpool  will  be  20  +
              (MONO_THREADS_PER_CPU * number of CPUs). The default value for this variable is 10.

       MONO_XMLSERIALIZER_THS
              Controls the threshold for the XmlSerializer to produce a custom serializer  for  a
              given class instead of using the Reflection-based interpreter.  The possible values
              are `no' to disable the use of a custom serializer or a number to indicate when the
              XmlSerializer should start serializing.   The default value is 50, which means that
              the a custom serializer will be produced on the 50th use.

       MONO_X509_REVOCATION_MODE
              Sets the revocation mode used when validating  a  X509  certificate  chain  (https,
              ftps,  smtps...).   The default is 'nocheck', which performs no revocation check at
              all. The other possible  values  are  'offline',  which  performs  CRL  check  (not
              implemented  yet)  and  'online'  which  uses OCSP and CRL to verify the revocation
              status (not implemented yet).

ENVIRONMENT VARIABLES FOR DEBUGGING

       MONO_ASPNET_NODELETE
              If set to any value, temporary source files generated by  ASP.NET  support  classes
              will not be removed. They will be kept in the user's temporary directory.

       MONO_DEBUG
              If  set,  enables some features of the runtime useful for debugging.  This variable
              should contain a  comma  separated  list  of  debugging  options.   Currently,  the
              following options are supported:

              break-on-unverified
                     If  this variable is set, when the Mono VM runs into a verification problem,
                     instead of throwing an exception it will break into the debugger.   This  is
                     useful when debugging verifier problems

              casts  This  option  can  be used to get more detailed information from InvalidCast
                     exceptions, it will provide information about the types involved.

              collect-pagefault-stats
                     Collects information about pagefaults.   This is used  internally  to  track
                     the  number  of  page  faults  produced  to  load metadata.  To display this
                     information you must use this option with "--stats" command line option.

              dont-free-domains
                     This is an Optimization  for  multi-AppDomain  applications  (most  commonly
                     ASP.NET  applications).   Due  to internal limitations Mono, Mono by default
                     does not use typed allocations on multi-appDomain applications as they could
                     leak memory when a domain is unloaded.  Although this is a fine default, for
                     applications that use more than on AppDomain heavily (for  example,  ASP.NET
                     applications)  it  is  worth  trading  off the small leaks for the increased
                     performance (additionally, since ASP.NET applications are not  likely  going
                     to  unload  the application domains on production systems, it is worth using
                     this feature).

              dyn-runtime-invoke
                     Instructs the runtime to try to use a generic runtime-invoke wrapper instead
                     of creating one invoke wrapper.

              gdb    Equivalent  to  setting  the MONO_XDEBUG variable, this emits symbols into a
                     shared library as the code is JITed that can be loaded into GDB  to  inspect
                     symbols.

              gen-seq-points
                     Automatically  generates sequence points where the IL stack is empty.  These
                     are places where the debugger can set a breakpoint.

              explicit-null-checks
                     Makes the JIT generate an  explicit  NULL  check  on  variable  dereferences
                     instead  of  depending on the operating system to raise a SIGSEGV or another
                     form of trap event when an invalid memory location is accessed.

              handle-sigint
                     Captures the interrupt signal (Control-C) and displays a  stack  trace  when
                     pressed.   Useful  to  find  out  where  the program is executing at a given
                     point.  This only displays the stack trace of a single thread.

              init-stacks
                     Instructs the runtime to initialize the stack with some known  values  (0x2a
                     on x86-64) at the start of a method to assist in debuggin the JIT engine.

              keep-delegates
                     This  option will leak delegate trampolines that are no longer referenced as
                     to  present  the  user  with  more  information  about  a  delegate  misuse.
                     Basically  a  delegate  instance might be created, passed to unmanaged code,
                     and no references kept in managed code, which will garbage collect the code.
                     With this option it is possible to track down the source of the problems.

              reverse-pinvoke-exceptions
                     This  option will cause mono to abort with a descriptive message when during
                     stack unwinding after an exception it reaches a  native  stack  frame.  This
                     happens  when  a  managed delegate is passed to native code, and the managed
                     delegate throws an exception. Mono will normally try to unwind the stack  to
                     the  first  (managed)  exception  handler, and it will skip any native stack
                     frames in the process. This leads to undefined behaviour (since mono doesn't
                     know how to process native frames), leaks, and possibly crashes too.

              no-gdb-backtrace
                     This  option  will  disable the GDB backtrace emitted by the runtime after a
                     SIGSEGV or SIGABRT in unmanaged code.

              suspend-on-sigsegv
                     This option will suspend the program when  a  native  SIGSEGV  is  received.
                     This  is useful for debugging crashes which do not happen under gdb, since a
                     live process contains more information than a core file.

       MONO_LOG_LEVEL
              The logging level, possible values are `error', `critical',  `warning',  `message',
              `info' and `debug'.  See the DEBUGGING section for more details.

       MONO_LOG_MASK
              Controls  the  domain  of the Mono runtime that logging will apply to.  If set, the
              log mask is changed to the set value. Possible values are "asm" (assembly  loader),
              "type", "dll" (native library loader), "gc" (garbage collector), "cfg" (config file
              loader), "aot" (precompiler),  "security"  (e.g.  Moonlight  CoreCLR  support)  and
              "all".   The  default value is "all". Changing the mask value allows you to display
              only messages for a  certain  component.  You  can  use  multiple  masks  by  comma
              separating  them.  For  example  to  see  config  file messages and assembly loader
              messages set you mask to "asm,cfg".

       MONO_TRACE
              Used for runtime tracing of method calls. The format of the comma  separated  trace
              options is:

                   [-]M:method name
                   [-]N:namespace
                   [-]T:class name
                   [-]all
                   [-]program
                   disabled       Trace output off upon start.

              You can toggle trace output on/off sending a SIGUSR2 signal to the program.

       MONO_TRACE_LISTENER
              If  set,  enables the System.Diagnostics.DefaultTraceListener, which will print the
              output of the System.Diagnostics Trace and Debug classes.   It  can  be  set  to  a
              filename,  and to Console.Out or Console.Error to display output to standard output
              or standard error, respectively. If it's set to Console.Out  or  Console.Error  you
              can  append  an  optional prefix that will be used when writing messages like this:
              Console.Error:MyProgramName.    See   the   System.Diagnostics.DefaultTraceListener
              documentation for more information.

       MONO_WCF_TRACE
              This  eases  WCF  diagnostics functionality by simply outputs all log messages from
              WCF engine to "stdout", "stderr" or any file passed to this  environment  variable.
              The log format is the same as usual diagnostic output.

       MONO_XEXCEPTIONS
              This  throws  an exception when a X11 error is encountered; by default a message is
              displayed but execution continues

       MONO_XMLSERIALIZER_DEBUG
              Set this value to 1 to prevent the serializer from  removing  the  temporary  files
              that are created for fast serialization;  This might be useful when debugging.

       MONO_XSYNC
              This  is  used in the System.Windows.Forms implementation when running with the X11
              backend.  This is used to debug problems in Windows.Forms as it forces all  of  the
              commands  send  to  X11  server  to  be  done  synchronously.   The default mode of
              operation is asynchronous which makes it  hard  to  isolate  the  root  of  certain
              problems.

       MONO_GENERIC_SHARING
              This environment variable controls the kind of generic sharing used.  This variable
              is used by internal JIT developers and should not be changed in production.  Do not
              use  it.   The  variable  controls  which  classes  will  have generic code sharing
              enabled.  Permissible values are:

              all    All generated code can be shared.

              collections
                     Only the classes in System.Collections.Generic will  have  its  code  shared
                     (this is the default value).

              corlib Only code in corlib will have its code shared.

              none   No generic code sharing will be performed.
       Generic  code  sharing  by  default only applies to collections.   The Mono JIT by default
       turns this on.

       MONO_XDEBUG
              When the the MONO_XDEBUG env var is set, debugging info for JITted code is  emitted
              into a shared library, loadable into gdb. This enables, for example, to see managed
              frame names on gdb backtraces.

       MONO_VERBOSE_METHOD
              Enables the maximum JIT verbosity for the specified method. This is  very  helpfull
              to diagnose a miscompilation problems of a specific method.

       MONO_VERBOSE_HWCAP
              If  set, makes the JIT output information about detected CPU features (such as SSE,
              CMOV, FCMOV, etc) to stdout.

VALGRIND

       If you want to use Valgrind, you will find the file `mono.supp' useful,  it  contains  the
       suppressions for the GC which trigger incorrect warnings.  Use it like this:
           valgrind --suppressions=mono.supp mono ...

DTRACE

       On  some  platforms,  Mono  can  expose  a  set  of DTrace probes (also known as user-land
       statically defined, USDT Probes).

       They are defined in the file `mono.d'.

       ves-init-begin, ves-init-end
              Begin and end of runtime initialization.

       method-compile-begin, method-compile-end
              Begin and end of method compilation.  The probe arguments are  class  name,  method
              name  and  signature,  and  in  case  of  method-compile-end  success or failure of
              compilation.

       gc-begin, gc-end
              Begin and end of Garbage Collection.

       To verify the availability of the probes, run:
                  dtrace -P mono'$target' -l -c mono

PERMISSIONS

       Mono's Ping implementation for detecting network reachability can create the ICMP  packets
       itself  without  requiring  the system ping command to do the work.  If you want to enable
       this on Linux for non-root users, you need to give the Mono binary special permissions.

       As root, run this command:
          # setcap cap_net_raw=+ep /usr/bin/mono

FILES

       On Unix assemblies are loaded from the installation lib directory.  If you set `prefix' to
       /usr,  the  assemblies will be located in /usr/lib.  On Windows, the assemblies are loaded
       from the directory where mono and mint live.

       ~/.mono/aot-cache
              The directory  for  the  ahead-of-time  compiler  demand  creation  assemblies  are
              located.

       /etc/mono/config, ~/.mono/config
              Mono  runtime  configuration  file.   See  the  mono-config(5) manual page for more
              information.

       ~/.config/.mono/certs, /usr/share/.mono/certs
              Contains Mono certificate stores for users / machine.  See  the  certmgr(1)  manual
              page  for  more information on managing certificate stores and the mozroots(1) page
              for information on how to import  the  Mozilla  root  certificates  into  the  Mono
              certificate store.

       ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
              Files  in  this  directory  allow a user to customize the configuration for a given
              system assembly, the format is the one described in the mono-config(5) page.

       ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
              Contains Mono cryptographic keypairs for users / machine. They can be  accessed  by
              using     a     CspParameters     object    with    DSACryptoServiceProvider    and
              RSACryptoServiceProvider classes.

       ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
              Contains Mono isolated storage for  non-roaming  users,  roaming  users  and  local
              machine.   Isolated   storage   can   be   accessed  using  the  classes  from  the
              System.IO.IsolatedStorage namespace.

       <assembly>.config
              Configuration information for individual assemblies is loaded by the  runtime  from
              side-by-side   files   with   the   .config   files,   see   the   http://www.mono-
              project.com/Config for more information.

       Web.config, web.config
              ASP.NET applications are configured through these files, the configuration is  done
              on   a  per-directory  basis.   For  more  information  on  this  subject  see  the
              http://www.mono-project.com/Config_system.web page.

MAILING LISTS

       Mailing lists are listed at the http://www.mono-project.com/Mailing_Lists

WEB SITE

       http://www.mono-project.com

SEE ALSO

       certmgr(1),   csharp(1),   mcs(1),   mdb(1),   monocov(1),   monodis(1),   mono-config(5),
       mozroots(1), mprof-report(1), pdb2mdb(1), xsp(1), mod_mono(8).

       For more information on AOT: http://www.mono-project.com/AOT

       For ASP.NET-related documentation, see the xsp(1) manual page

                                                                                   Mono(Mono 3.0)