3 .\" Copyright 2003 Ximian, Inc.
4 .\" Copyright 2004-2011 Novell, Inc.
5 .\" Copyright 2011-2012 Xamarin Inc
6 .\" Copyright 2013 7digital Media Ltd.
8 .\" Miguel de Icaza (miguel@gnu.org)
12 mono \- Mono's ECMA-CLI native code generator (Just-in-Time and Ahead-of-Time)
15 .B mono [options] file [arguments...]
17 .B mono-sgen [options] file [arguments...]
19 \fImono\fP is a runtime implementation of the ECMA Common Language
20 Infrastructure. This can be used to run ECMA and .NET applications.
22 The runtime contains a native code generator that transforms the
23 Common Intermediate Language into native code.
25 The code generator can operate in two modes: just in time compilation
26 (JIT) or ahead of time compilation (AOT). Since code can be
27 dynamically loaded, the runtime environment and the JIT are always
28 present, even if code is compiled ahead of time.
30 The runtime loads the specified
37 is an ECMA assembly. They typically have a .exe or .dll extension.
39 The runtime provides a number of configuration options for running
40 applications, for developing and debugging, and for testing and
41 debugging the runtime itself.
43 The \fImono\fP command uses the Boehm conservative garbage collector
44 while the \fImono-sgen\fP command uses a moving and generational
47 On Unix-based systems, Mono provides a mechanism to emulate the
48 Windows-style file access, this includes providing a case insensitive
49 view of the file system, directory separator mapping (from \\ to /) and
50 stripping the drive letters.
52 This functionality is enabled by setting the
54 environment variable to one of
59 See the description for
61 in the environment variables section for more details.
63 The following options are available:
65 \fB--aot\fR, \fB--aot[=options]\fR
66 This option is used to precompile the CIL code in the specified
67 assembly to native code. The generated code is stored in a file with
68 the extension .so. This file will be automatically picked up by the
69 runtime when the assembly is executed.
71 Ahead-of-Time compilation is most useful if you use it in combination
72 with the -O=all,-shared flag which enables all of the optimizations in
73 the code generator to be performed. Some of those optimizations are
74 not practical for Just-in-Time compilation since they might be very
77 Unlike the .NET Framework, Ahead-of-Time compilation will not generate
78 domain independent code: it generates the same code that the
79 Just-in-Time compiler would produce. Since most applications use a
80 single domain, this is fine. If you want to optimize the generated
81 code for use in multi-domain applications, consider using the
84 This pre-compiles the methods, but the original assembly is still
85 required to execute as this one contains the metadata and exception
86 information which is not available on the generated file. When
87 precompiling code, you might want to compile with all optimizations
88 (-O=all). Pre-compiled code is position independent code.
90 Pre compilation is just a mechanism to reduce startup time, increase
91 code sharing across multiple mono processes and avoid just-in-time
92 compilation program startup costs. The original assembly must still
93 be present, as the metadata is contained there.
95 AOT code typically can not be moved from one computer to another
96 (CPU-specific optimizations that are detected at runtime) so you
97 should not try to move the pre-generated assemblies or package the
98 pre-generated assemblies for deployment.
100 A few options are available as a parameter to the
102 command line option. The options are separated by commas, and more
103 than one can be specified:
108 The AOT compiler will emit a (ELF only) library initializer to automatically
109 register the aot compiled module with the runtime. This is only useful in static
113 Instructs the AOT compiler to output assembly code instead of an
116 .I bind-to-runtime-version
118 If specified, forces the generated AOT files to be bound to the
119 runtime version of the compiling Mono. This will prevent the AOT
120 files from being consumed by a different Mono runtime.
123 This is currently an experimental feature as it is not complete.
124 This instructs Mono to precompile code that has historically not been
125 precompiled with AOT.
129 When this option is specified, P/Invoke methods are invoked directly
130 instead of going through the operating system symbol lookup operation.
132 .I llvm-path=<PREFIX>
133 Same for the llvm tools 'opt' and 'llc'.
136 Use the GNU style target triple <TRIPLE> to determine some code generation options, i.e.
137 --mtriple=armv7-linux-gnueabi will generate code that targets ARMv7. This is currently
138 only supported by the ARM backend. In LLVM mode, this triple is passed on to the LLVM
141 .I nimt-trampolines=[number]
142 When compiling in full aot mode, the IMT trampolines must be precreated
143 in the AOT image. You can add additional method trampolines with this argument.
147 Instructs the AOT compiler to not output any debugging information.
150 This prevents the AOT compiler from generating a direct calls to a
151 method. The AOT compiler usually generates direct calls for certain
152 methods that do not require going through the PLT (for example,
153 methods that are known to not require a hook like a static
154 constructor) or call into simple internal calls.
157 Instructs the AOT compiler to emit DWARF debugging information. When
158 used together with the nodebug option, only DWARF debugging
159 information is emitted, but not the information that can be used at
162 .I nrgctx-trampolines=[number]
163 When compiling in full aot mode, the generic sharing trampolines must be precreated
164 in the AOT image. You can add additional method trampolines with this argument.
167 .I ntrampolines=[number]
168 When compiling in full aot mode, the method trampolines must be precreated
169 in the AOT image. You can add additional method trampolines with this argument.
172 .I outfile=[filename]
173 Instructs the AOT compiler to save the output to the specified file.
175 .I print-skipped-methods
176 If the AOT compiler cannot compile a method for any reason, enabling this flag
177 will output the skipped methods to the console.
179 .I readonly-value=namespace.typename.fieldname=type/value
180 Override the value of a static readonly field. Usually, during JIT
181 compilation, the static constructor is ran eagerly, so the value of
182 a static readonly field is known at compilation time and the compiler
183 can do a number of optimizations based on it. During AOT, instead, the static
184 constructor can't be ran, so this option can be used to set the value of such
185 a field and enable the same set of optimizations.
186 Type can be any of i1, i2, i4 for integers of the respective sizes (in bytes).
187 Note that signed/unsigned numbers do not matter here, just the storage size.
188 This option can be specified multiple times and it doesn't prevent the static
189 constructor for the type defining the field to execute with the usual rules
190 at runtime (hence possibly computing a different value for the field).
193 .I save-temps,keep-temps
194 Instructs the AOT compiler to keep temporary files.
197 This instructs the compiler to generate sequence point checks that
198 allow Mono's soft debugger to debug applications even on systems where
199 it is not possible to set breakpoints or to single step (certain
200 hardware configurations like the cell phones and video gaming
204 Create an ELF object file (.o) or .s file which can be statically linked into an
205 executable when embedding the mono runtime. When this option is used, the object file
206 needs to be registered with the embedded runtime using the mono_aot_register_module
207 function which takes as its argument the mono_aot_module_<ASSEMBLY NAME>_info global
208 symbol from the object file:
211 extern void *mono_aot_module_hello_info;
213 mono_aot_register_module (mono_aot_module_hello_info);
218 Print various stats collected during AOT compilation.
221 This is an experimental option for the AOT compiler to use multiple threads
222 when compiling the methods.
224 .I tool-prefix=<PREFIX>
225 Prepends <PREFIX> to the name of tools ran by the AOT compiler, i.e. 'as'/'ld'. For
226 example, --tool=prefix=arm-linux-gnueabi- will make the AOT compiler run
227 'arm-linux-gnueabi-as' instead of 'as'.
230 Instructs the AOT compiler to emit debug symbol information.
232 For more information about AOT, see: http://www.mono-project.com/docs/advanced/aot/
235 \fB--attach=[options]\fR
236 Currently the only option supported by this command line argument is
237 \fBdisable\fR which disables the attach functionality.
239 \fB--config filename\fR
240 Load the specified configuration file instead of the default one(s).
241 The default files are /etc/mono/config and ~/.mono/config or the file
242 specified in the MONO_CONFIG environment variable, if set. See the
243 mono-config(5) man page for details on the format of this file.
245 \fB--debugger-agent=[options]\fR
246 This instructs the Mono runtime to
247 start a debugging agent inside the Mono runtime and connect it to a
248 client user interface will control the Mono process.
249 This option is typically used by IDEs, like the MonoDevelop IDE.
251 The configuration is specified using one of more of the following options:
257 Use this option to specify the IP address where your debugger client is
262 Specifies the diagnostics log level for
266 Used to specify the file where the log will be stored, it defaults to
270 Defaults to no, with the default option Mono will actively connect to the
271 host/port configured with the \fBaddress\fR option. If you set it to 'y', it
272 instructs the Mono runtime to start debugging in server mode, where Mono
273 actively waits for the debugger front end to connect to the Mono process.
274 Mono will print out to stdout the IP address and port where it is listening.
277 If set to yes, Mono will call \fBsetpgid(0, 0)\fB on startup, if that function
278 is available on the system. This is useful for ensuring that signals delivered
279 to a process that is executing the debuggee are not propagated to the debuggee,
280 e.g. when Ctrl-C sends \fBSIGINT\fB to the \fBsdb\fB tool.
283 Defaults to yes, with the default option Mono will suspend the vm on startup
284 until it connects successfully to a debugger front end. If you set it to 'n', in
285 conjunction with \fBserver=y\fR, it instructs the Mono runtime to run as normal,
286 while caching metadata to send to the debugger front end on connection..
288 .I transport=transport_name
290 This is used to specify the transport that the debugger will use to
291 communicate. It must be specified and currently requires this to
297 Configures the virtual machine to be better suited for desktop
298 applications. Currently this sets the GC system to avoid expanding
299 the heap as much as possible at the expense of slowing down garbage
303 This is an experimental flag that instructs the Mono runtime to not
304 generate any code at runtime and depend exclusively on the code
305 generated from using mono --aot=full previously. This is useful for
306 platforms that do not permit dynamic code generation.
308 Notice that this feature will abort execution at runtime if a codepath
309 in your program, or Mono's class libraries attempts to generate code
310 dynamically. You should test your software upfront and make sure that
311 you do not use any dynamic features.
313 \fB--gc=boehm\fR, \fB--gc=sgen\fR
314 Selects the Garbage Collector engine for Mono to use, Boehm or SGen.
315 Currently this merely ensures that you are running either the
316 \fImono\fR or \fImono-sgen\fR commands. This flag can be set in the
317 \fBMONO_ENV_OPTIONS\fR environment variable to force all of your child
318 processes to use one particular kind of GC with the Mono runtime.
320 \fB--help\fR, \fB-h\fR
321 Displays usage instructions.
324 If the Mono runtime has been compiled with LLVM support (not available
325 in all configurations), Mono will use the LLVM optimization and code
326 generation engine to JIT or AOT compile.
328 For more information, consult: http://www.mono-project.com/docs/advanced/mono-llvm/
331 When using a Mono that has been compiled with LLVM support, it forces
332 Mono to fallback to its JIT engine and not use the LLVM backend.
334 \fB--optimize=MODE\fR, \fB-O=MODE\fR
335 MODE is a comma separated list of optimizations. They also allow
336 optimizations to be turned off by prefixing the optimization name with
339 In general, Mono has been tuned to use the default set of flags,
340 before using these flags for a deployment setting, you might want to
341 actually measure the benefits of using them.
343 The following optimizations are implemented:
345 all Turn on all optimizations
346 peephole Peephole postpass
347 branch Branch optimizations
348 inline Inline method calls
349 cfold Constant folding
350 consprop Constant propagation
351 copyprop Copy propagation
352 deadce Dead code elimination
353 linears Linear scan global reg allocation
354 cmov Conditional moves [arch-dependency]
355 shared Emit per-domain code
356 sched Instruction scheduling
357 intrins Intrinsic method implementations
358 tailc Tail recursion and tail calls
359 loop Loop related optimizations
360 fcmov Fast x86 FP compares [arch-dependency]
361 leaf Leaf procedures optimizations
362 aot Usage of Ahead Of Time compiled code
363 precomp Precompile all methods before executing Main
364 abcrem Array bound checks removal
365 ssapre SSA based Partial Redundancy Elimination
366 sse2 SSE2 instructions on x86 [arch-dependency]
367 gshared Enable generic code sharing.
370 For example, to enable all the optimization but dead code
371 elimination and inlining, you can use:
373 -O=all,-deadce,-inline
376 The flags that are flagged with [arch-dependency] indicate that the
377 given option if used in combination with Ahead of Time compilation
378 (--aot flag) would produce pre-compiled code that will depend on the
379 current CPU and might not be safely moved to another computer.
381 \fB--runtime=VERSION\fR
382 Mono supports different runtime versions. The version used depends on the program
383 that is being run or on its configuration file (named program.exe.config). This option
384 can be used to override such autodetection, by forcing a different runtime version
385 to be used. Note that this should only be used to select a later compatible runtime
386 version than the one the program was compiled against. A typical usage is for
387 running a 1.1 program on a 2.0 version:
389 mono --runtime=v2.0.50727 program.exe
392 \fB--security\fR, \fB--security=mode\fR
393 Activate the security manager, a currently experimental feature in
394 Mono and it is OFF by default. The new code verifier can be enabled
395 with this option as well.
399 Using security without parameters is equivalent as calling it with the
402 The following modes are supported:
405 This allows mono to support declarative security attributes,
406 e.g. execution of Code Access Security (CAS) or non-CAS demands.
409 Enables the core-clr security system, typically used for
410 Moonlight/Silverlight applications. It provides a much simpler
411 security system than CAS, see http://www.mono-project.com/docs/web/moonlight/
412 for more details and links to the descriptions of this new system.
415 Enables the new verifier and performs basic verification for code
416 validity. In this mode, unsafe code and P/Invoke are allowed. This
417 mode provides a better safety guarantee but it is still possible
418 for managed code to crash Mono.
421 Enables the new verifier and performs full verification of the code
422 being executed. It only allows verifiable code to be executed.
423 Unsafe code is not allowed but P/Invoke is. This mode should
424 not allow managed code to crash mono. The verification is not as
425 strict as ECMA 335 standard in order to stay compatible with the MS
428 The security system acts on user code: code contained in mscorlib or
429 the global assembly cache is always trusted.
434 Configures the virtual machine to be better suited for server
435 operations (currently, allows a heavier threadpool initialization).
438 Verifies mscorlib and assemblies in the global
439 assembly cache for valid IL, and all user code for IL
442 This is different from \fB--security\fR's verifiable
443 or validil in that these options only check user code and skip
444 mscorlib and assemblies located on the global assembly cache.
446 \fB-V\fR, \fB--version\fR
447 Prints JIT version information (system configuration, release number
448 and branch names if available).
451 .SH DEVELOPMENT OPTIONS
452 The following options are used to help when developing a JITed application.
454 \fB--debug\fR, \fB--debug=OPTIONS\fR
455 Turns on the debugging mode in the runtime. If an assembly was
456 compiled with debugging information, it will produce line number
457 information for stack traces.
461 The optional OPTIONS argument is a comma separated list of debugging
462 options. These options are turned off by default since they generate
463 much larger and slower code at runtime.
465 The following options are supported:
468 Produces a detailed error when throwing a InvalidCastException. This
469 option needs to be enabled as this generates more verbose code at
473 Disable some JIT optimizations which are usually only disabled when
474 running inside the debugger. This can be helpful if you want to attach
475 to the running process with mdb.
478 Generate and register debugging information with gdb. This is only supported on some
479 platforms, and only when using gdb 7.0 or later.
483 \fB--profile[=profiler[:profiler_args]]\fR
484 Turns on profiling. For more information about profiling applications
485 and code coverage see the sections "PROFILING" and "CODE COVERAGE"
488 This option can be used multiple times, each time will load an
489 additional profiler. This allows developers to use modules that
490 extend the JIT through the Mono profiling interface.
492 \fB--trace[=expression]\fR
493 Shows method names as they are invoked. By default all methods are
496 The trace can be customized to include or exclude methods, classes or
497 assemblies. A trace expression is a comma separated list of targets,
498 each target can be prefixed with a minus sign to turn off a particular
499 target. The words `program', `all' and `disabled' have special
500 meaning. `program' refers to the main program being executed, and
501 `all' means all the method calls.
503 The `disabled' option is used to start up with tracing disabled. It
504 can be enabled at a later point in time in the program by sending the
505 SIGUSR2 signal to the runtime.
507 Assemblies are specified by their name, for example, to trace all
508 calls in the System assembly, use:
511 mono --trace=System app.exe
514 Classes are specified with the T: prefix. For example, to trace all
515 calls to the System.String class, use:
518 mono --trace=T:System.String app.exe
521 And individual methods are referenced with the M: prefix, and the
522 standard method notation:
525 mono --trace=M:System.Console:WriteLine app.exe
528 Exceptions can also be traced, it will cause a stack trace to be
529 printed every time an exception of the specified type is thrown.
530 The exception type can be specified with or without the namespace,
531 and to trace all exceptions, specify 'all' as the type name.
534 mono --trace=E:System.Exception app.exe
537 As previously noted, various rules can be specified at once:
540 mono --trace=T:System.String,T:System.Random app.exe
543 You can exclude pieces, the next example traces calls to
544 System.String except for the System.String:Concat method.
547 mono --trace=T:System.String,-M:System.String:Concat
550 You can trace managed to unmanaged transitions using
551 the wrapper qualifier:
554 mono --trace=wrapper app.exe
557 Finally, namespaces can be specified using the N: prefix:
560 mono --trace=N:System.Xml
564 \fB--no-x86-stack-align\fR
565 Don't align stack frames on the x86 architecture. By default, Mono
566 aligns stack frames to 16 bytes on x86, so that local floating point
567 and SIMD variables can be properly aligned. This option turns off the
568 alignment, which usually saves one intruction per call, but might
569 result in significantly lower floating point and SIMD performance.
572 Generate a JIT method map in a /tmp/perf-PID.map file. This file is then
573 used, for example, by the perf tool included in recent Linux kernels.
574 Each line in the file has:
577 HEXADDR HEXSIZE methodname
580 Currently this option is only supported on Linux.
581 .SH JIT MAINTAINER OPTIONS
582 The maintainer options are only used by those developing the runtime
583 itself, and not typically of interest to runtime users or developers.
586 Inserts a breakpoint before the method whose name is `method'
587 (namespace.class:methodname). Use `Main' as method name to insert a
588 breakpoint on the application's main method. You can use it also with
589 generics, for example "System.Collections.Generic.Queue`1:Peek"
592 Inserts a breakpoint on exceptions. This allows you to debug your
593 application with a native debugger when an exception is thrown.
596 This compiles a method (namespace.name:methodname), this is used for
597 testing the compiler performance or to examine the output of the code
601 Compiles all the methods in an assembly. This is used to test the
602 compiler performance or to examine the output of the code generator
604 \fB--graph=TYPE METHOD\fR
605 This generates a postscript file with a graph with the details about
606 the specified method (namespace.name:methodname). This requires `dot'
607 and ghostview to be installed (it expects Ghostview to be called
610 The following graphs are available:
612 cfg Control Flow Graph (CFG)
614 code CFG showing code
615 ssa CFG showing code after SSA translation
616 optcode CFG showing code after IR optimizations
619 Some graphs will only be available if certain optimizations are turned
623 Instruct the runtime on the number of times that the method specified
624 by --compile (or all the methods if --compileall is used) to be
625 compiled. This is used for testing the code generator performance.
628 Displays information about the work done by the runtime during the
629 execution of an application.
631 \fB--wapi=hps|semdel\fR
632 Perform maintenance of the process shared data.
634 semdel will delete the global semaphore.
636 hps will list the currently used handles.
638 \fB-v\fR, \fB--verbose\fR
639 Increases the verbosity level, each time it is listed, increases the
640 verbosity level to include more information (including, for example,
641 a disassembly of the native code produced, code selector info etc.).
643 The Mono runtime allows external processes to attach to a running
644 process and load assemblies into the running program. To attach to
645 the process, a special protocol is implemented in the Mono.Management
648 With this support it is possible to load assemblies that have an entry
649 point (they are created with -target:exe or -target:winexe) to be
650 loaded and executed in the Mono process.
652 The code is loaded into the root domain, and it starts execution on
653 the special runtime attach thread. The attached program should
654 create its own threads and return after invocation.
656 This support allows for example debugging applications by having the
657 csharp shell attach to running processes.
659 The mono runtime includes a profiler that can be used to explore
660 various performance related problems in your application. The
661 profiler is activated by passing the --profile command line argument
662 to the Mono runtime, the format is:
665 --profile[=profiler[:profiler_args]]
668 Mono has a built-in profiler called 'default' (and is also the default
669 if no arguments are specified), but developers can write custom
670 profilers, see the section "CUSTOM PROFILERS" for more details.
674 is not specified, the default profiler is used.
678 is a profiler-specific string of options for the profiler itself.
680 The default profiler accepts the following options 'alloc' to profile
681 memory consumption by the application; 'time' to profile the time
682 spent on each routine; 'jit' to collect time spent JIT-compiling methods
683 and 'stat' to perform sample statistical profiling.
684 If no options are provided the default is 'alloc,time,jit'.
687 profile data is printed to stdout: to change this, use the 'file=filename'
688 option to output the data to filename.
693 mono --profile program.exe
697 That will run the program with the default profiler and will do time
698 and allocation profiling.
702 mono --profile=default:stat,alloc,file=prof.out program.exe
705 Will do sample statistical profiling and allocation profiling on
706 program.exe. The profile data is put in prof.out.
708 Note that the statistical profiler has a very low overhead and should
709 be the preferred profiler to use (for better output use the full path
710 to the mono binary when running and make sure you have installed the
711 addr2line utility that comes from the binutils package).
713 This is the most advanced profiler.
715 The Mono \f[I]log\f[] profiler can be used to collect a lot of
716 information about a program running in the Mono runtime.
717 This data can be used (both while the process is running and later)
718 to do analyses of the program behaviour, determine resource usage,
719 performance issues or even look for particular execution patterns.
721 This is accomplished by logging the events provided by the Mono
722 runtime through the profiling interface and periodically writing
723 them to a file which can be later inspected with the mprof-report(1)
726 More information about how to use the log profiler is available on the
727 mprof-report(1) page.
729 Mono provides a mechanism for loading other profiling modules which in
730 the form of shared libraries. These profiling modules can hook up to
731 various parts of the Mono runtime to gather information about the code
734 To use a third party profiler you must pass the name of the profiler
738 mono --profile=custom program.exe
742 In the above sample Mono will load the user defined profiler from the
743 shared library `mono-profiler-custom.so'. This profiler module must
744 be on your dynamic linker library path.
746 A list of other third party profilers is available from Mono's web
747 site (www.mono-project.com/docs/advanced/performance-tips/)
749 Custom profiles are written as shared libraries. The shared library
750 must be called `mono-profiler-NAME.so' where `NAME' is the name of
753 For a sample of how to write your own custom profiler look in the
754 Mono source tree for in the samples/profiler.c.
756 Mono ships with a code coverage module. This module is activated by
757 using the Mono --profile=cov option. The format is:
758 \fB--profile=cov[:assembly-name[/namespace]] test-suite.exe\fR
760 By default code coverage will default to all the assemblies loaded,
761 you can limit this by specifying the assembly name, for example to
762 perform code coverage in the routines of your program use, for example
763 the following command line limits the code coverage to routines in the
767 mono --profile=cov:demo demo.exe
773 does not include the extension.
775 You can further restrict the code coverage output by specifying a
779 mono --profile=cov:demo/My.Utilities demo.exe
783 Which will only perform code coverage in the given assembly and
786 Typical output looks like this:
789 Not covered: Class:.ctor ()
790 Not covered: Class:A ()
791 Not covered: Driver:.ctor ()
792 Not covered: Driver:method ()
793 Partial coverage: Driver:Main ()
798 The offsets displayed are IL offsets.
800 A more powerful coverage tool is available in the module `monocov'.
801 See the monocov(1) man page for details.
803 To debug managed applications, you can use the
805 command, a command line debugger.
807 It is possible to obtain a stack trace of all the active threads in
808 Mono by sending the QUIT signal to Mono, you can do this from the
809 command line, like this:
815 Where pid is the Process ID of the Mono process you want to examine.
816 The process will continue running afterwards, but its state is not
820 this is a last-resort mechanism for debugging applications and should
821 not be used to monitor or probe a production application. The
822 integrity of the runtime after sending this signal is not guaranteed
823 and the application might crash or terminate at any given point
826 The \fB--debug=casts\fR option can be used to get more detailed
827 information for Invalid Cast operations, it will provide information
828 about the types involved.
830 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
831 to get verbose debugging output about the execution of your
832 application within Mono.
836 environment variable if set, the logging level is changed to the set
837 value. Possible values are "error", "critical", "warning", "message",
838 "info", "debug". The default value is "error". Messages with a logging
839 level greater then or equal to the log level will be printed to
842 Use "info" to track the dynamic loading of assemblies.
847 environment variable to limit the extent of the messages you get:
848 If set, the log mask is changed to the set value. Possible values are
849 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
850 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
851 "security" (e.g. Moonlight CoreCLR support) and "all".
852 The default value is "all". Changing the mask value allows you to display only
853 messages for a certain component. You can use multiple masks by comma
854 separating them. For example to see config file messages and assembly loader
855 messages set you mask to "asm,cfg".
857 The following is a common use to track down problems with P/Invoke:
860 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
864 .SH DEBUGGING WITH LLDB
865 If you are using LLDB, you can use the
867 script to print some internal data structures with it. To use this,
872 command script import $PREFIX/lib/mono/lldb/mono.py
875 Where $PREFIX is the prefix value that you used when you configured
876 Mono (typically /usr).
878 Once this is done, then you can inspect some Mono Runtime data structures,
883 (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
886 Mono's XML serialization engine by default will use a reflection-based
887 approach to serialize which might be slow for continuous processing
888 (web service applications). The serialization engine will determine
889 when a class must use a hand-tuned serializer based on a few
890 parameters and if needed it will produce a customized C# serializer
891 for your types at runtime. This customized serializer then gets
892 dynamically loaded into your application.
894 You can control this with the MONO_XMLSERIALIZER_THS environment
897 The possible values are
899 to disable the use of a C# customized
900 serializer, or an integer that is the minimum number of uses before
901 the runtime will produce a custom serializer (0 will produce a
902 custom serializer on the first access, 50 will produce a serializer on
903 the 50th use). Mono will fallback to an interpreted serializer if the
904 serializer generation somehow fails. This behavior can be disabled
905 by setting the option
907 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
908 .SH ENVIRONMENT VARIABLES
911 Turns off the garbage collection in Mono. This should be only used
912 for debugging purposes
915 When Mono is compiled with LLVM support, this instructs the runtime to
916 stop using LLVM after the specified number of methods are JITed.
917 This is a tool used in diagnostics to help isolate problems in the
918 code generation backend. For example \fBLLVM_COUNT=10\fR would only
919 compile 10 methods with LLVM and then switch to the Mono JIT engine.
920 \fBLLVM_COUNT=0\fR would disable the LLVM engine altogether.
923 If set, this variable will instruct Mono to ahead-of-time compile new
924 assemblies on demand and store the result into a cache in
927 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
928 Mono contains a feature which allows modifying settings in the .config files shipped
929 with Mono by using config section mappers. The mappers and the mapping rules are
930 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
931 settings.map file found in the top-level directory of your ASP.NET application.
932 Both files are read by System.Web on application startup, if they are found at the
933 above locations. If you don't want the mapping to be performed you can set this
934 variable in your environment before starting the application and no action will
937 \fBMONO_ASPNET_WEBCONFIG_CACHESIZE\fR
938 Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager
939 queries. Its default size is 100 items, and when more items are needed, cache
940 evictions start happening. If evictions are too frequent this could impose
941 unnecessary overhead, which could be avoided by using this environment variable
942 to set up a higher cache size (or to lower memory requirements by decreasing it).
944 \fBMONO_CAIRO_DEBUG_DISPOSE\fR
945 If set, causes Mono.Cairo to collect stack traces when objects are allocated,
946 so that the finalization/Dispose warnings include information about the
950 If set, this variable overrides the default system configuration directory
951 ($PREFIX/etc). It's used to locate machine.config file.
954 Sets the style of COM interop. If the value of this variable is "MS"
955 Mono will use string marhsalling routines from the liboleaut32 for the
956 BSTR type library, any other values will use the mono-builtin BSTR
960 If set, this variable overrides the default runtime configuration file
961 ($PREFIX/etc/mono/config). The --config command line options overrides the
962 environment variable.
965 Override the automatic cpu detection mechanism. Currently used only on arm.
966 The format of the value is as follows:
972 where V is the architecture number 4, 5, 6, 7 and the options can be currently be
973 "thumb" or "thumb2". Example:
976 MONO_CPU_ARCH="armv4 thumb" mono ...
980 \fBMONO_ARM_FORCE_SOFT_FLOAT\fR
981 When Mono is built with a soft float fallback on ARM and this variable is set to
982 "1", Mono will always emit soft float code, even if a VFP unit is detected.
984 \fBMONO_DISABLE_AIO\fR
985 If set, tells mono NOT to attempt using native asynchronous I/O services. In
986 that case, a default select/poll implementation is used. Currently only epoll()
989 \fBMONO_DISABLE_MANAGED_COLLATION\fR
990 If this environment variable is `yes', the runtime uses unmanaged
991 collation (which actually means no culture-sensitive collation). It
992 internally disables managed collation functionality invoked via the
993 members of System.Globalization.CompareInfo class. Collation is
996 \fBMONO_DISABLE_SHM\fR
997 Unix only: If set, disables the shared memory files used for
998 cross-process handles: process have only private handles. This means
999 that process and thread handles are not available to other processes,
1000 and named mutexes, named events and named semaphores are not visible
1003 This is can also be enabled by default by passing the
1004 "--disable-shared-handles" option to configure.
1006 This is the default from mono 2.8 onwards.
1008 \fBMONO_DISABLE_SHARED_AREA\fR
1009 Unix only: If set, disable usage of shared memory for exposing
1010 performance counters. This means it will not be possible to both
1011 externally read performance counters from this processes or read
1012 those of external processes.
1015 When set, enables the use of a fully managed DNS resolver instead of the
1016 regular libc functions. This resolver performs much better when multiple
1017 queries are run in parallel.
1019 Note that /etc/nsswitch.conf will be ignored.
1021 \fBMONO_EGD_SOCKET\fR
1022 For platforms that do not otherwise have a way of obtaining random bytes
1023 this can be set to the name of a file system socket on which an egd or
1024 prngd daemon is listening.
1026 \fBMONO_ENABLE_SHM\fR
1027 Unix only: Enable support for cross-process handles. Cross-process
1028 handles are used to expose process handles, thread handles, named
1029 mutexes, named events and named semaphores across Unix processes.
1031 \fBMONO_ENV_OPTIONS\fR
1032 This environment variable allows you to pass command line arguments to
1033 a Mono process through the environment. This is useful for example
1034 to force all of your Mono processes to use LLVM or SGEN without having
1035 to modify any launch scripts.
1037 \fBMONO_ENV_OPTIONS\fR
1038 Used to pass extra options to the debugger agent in the runtime, as they were passed
1039 using --debugger-agent=.
1041 \fBMONO_EVENTLOG_TYPE\fR
1042 Sets the type of event log provider to use (for System.Diagnostics.EventLog).
1044 Possible values are:
1049 Persists event logs and entries to the local file system.
1051 The directory in which to persist the event logs, event sources and entries
1052 can be specified as part of the value.
1054 If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog"
1055 on unix and "%APPDATA%\mono\eventlog" on Windows.
1060 Uses the native win32 API to write events and registers event logs and
1061 event sources in the registry. This is only available on Windows.
1063 On Unix, the directory permission for individual event log and event source
1064 directories is set to 777 (with +t bit) allowing everyone to read and write
1065 event log entries while only allowing entries to be deleted by the user(s)
1070 Silently discards any events.
1073 The default is "null" on Unix (and versions of Windows before NT), and
1074 "win32" on Windows NT (and higher).
1077 \fBMONO_EXTERNAL_ENCODINGS\fR
1078 If set, contains a colon-separated list of text encodings to try when
1079 turning externally-generated text (e.g. command-line arguments or
1080 filenames) into Unicode. The encoding names come from the list
1081 provided by iconv, and the special case "default_locale" which refers
1082 to the current locale's default encoding.
1084 When reading externally-generated text strings UTF-8 is tried first,
1085 and then this list is tried in order with the first successful
1086 conversion ending the search. When writing external text (e.g. new
1087 filenames or arguments to new processes) the first item in this list
1088 is used, or UTF-8 if the environment variable is not set.
1090 The problem with using MONO_EXTERNAL_ENCODINGS to process your
1091 files is that it results in a problem: although its possible to get
1092 the right file name it is not necessarily possible to open the file.
1093 In general if you have problems with encodings in your filenames you
1094 should use the "convmv" program.
1096 \fBMONO_GC_PARAMS\fR
1097 When using Mono with the SGen garbage collector this variable controls
1098 several parameters of the collector. The variable's value is a comma
1099 separated list of words.
1103 \fBnursery-size=\fIsize\fR
1104 Sets the size of the nursery. The size is specified in bytes and must
1105 be a power of two. The suffixes `k', `m' and `g' can be used to
1106 specify kilo-, mega- and gigabytes, respectively. The nursery is the
1107 first generation (of two). A larger nursery will usually speed up the
1108 program but will obviously use more memory. The default nursery size
1111 \fBmajor=\fIcollector\fR Specifies which major collector to use.
1112 Options are `marksweep' for the Mark&Sweep collector, and
1113 `marksweep-conc' for concurrent Mark&Sweep. The non-concurrent
1114 Mark&Sweep collector is the default.
1116 \fBsoft-heap-limit=\fIsize\fR
1117 Once the heap size gets larger than this size, ignore what the default
1118 major collection trigger metric says and only allow four nursery size's
1119 of major heap growth between major collections.
1121 \fBevacuation-threshold=\fIthreshold\fR
1122 Sets the evacuation threshold in percent. This option is only available
1123 on the Mark&Sweep major collectors. The value must be an
1124 integer in the range 0 to 100. The default is 66. If the sweep phase of
1125 the collection finds that the occupancy of a specific heap block type is
1126 less than this percentage, it will do a copying collection for that block
1127 type in the next major collection, thereby restoring occupancy to close
1128 to 100 percent. A value of 0 turns evacuation off.
1130 \fB(no-)lazy-sweep\fR
1131 Enables or disables lazy sweep for the Mark&Sweep collector. If
1132 enabled, the sweeping of individual major heap blocks is done
1133 piecemeal whenever the need arises, typically during nursery
1134 collections. Lazy sweeping is enabled by default.
1136 \fB(no-)concurrent-sweep\fR
1137 Enables or disables concurrent sweep for the Mark&Sweep collector. If
1138 enabled, the iteration of all major blocks to determine which ones can
1139 be freed and which ones have to be kept and swept, is done
1140 concurrently with the running program. Concurrent sweeping is enabled
1143 \fBstack-mark=\fImark-mode\fR
1144 Specifies how application threads should be scanned. Options are
1145 `precise` and `conservative`. Precise marking allow the collector
1146 to know what values on stack are references and what are not.
1147 Conservative marking threats all values as potentially references
1148 and leave them untouched. Precise marking reduces floating garbage
1149 and can speed up nursery collection and allocation rate, it has
1150 the downside of requiring a significant extra memory per compiled
1151 method. The right option, unfortunately, requires experimentation.
1153 \fBsave-target-ratio=\fIratio\fR
1154 Specifies the target save ratio for the major collector. The collector
1155 lets a given amount of memory to be promoted from the nursery due to
1156 minor collections before it triggers a major collection. This amount
1157 is based on how much memory it expects to free. It is represented as
1158 a ratio of the size of the heap after a major collection.
1159 Valid values are between 0.1 and 2.0. The default is 0.5.
1160 Smaller values will keep the major heap size smaller but will trigger
1161 more major collections. Likewise, bigger values will use more memory
1162 and result in less frequent major collections.
1163 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1165 \fBdefault-allowance-ratio=\fIratio\fR
1166 Specifies the default allocation allowance when the calculated size
1167 is too small. The allocation allowance is how much memory the collector
1168 let be promoted before triggered a major collection.
1169 It is a ratio of the nursery size.
1170 Valid values are between 1.0 and 10.0. The default is 4.0.
1171 Smaller values lead to smaller heaps and more frequent major collections.
1172 Likewise, bigger values will allow the heap to grow faster but use
1173 more memory when it reaches a stable size.
1174 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1176 \fBminor=\fIminor-collector\fR
1177 Specifies which minor collector to use. Options are 'simple' which
1178 promotes all objects from the nursery directly to the old generation
1179 and 'split' which lets object stay longer on the nursery before promoting.
1181 \fBalloc-ratio=\fIratio\fR
1182 Specifies the ratio of memory from the nursery to be use by the alloc space.
1183 This only can only be used with the split minor collector.
1184 Valid values are integers between 1 and 100. Default is 60.
1186 \fBpromotion-age=\fIage\fR
1187 Specifies the required age of an object must reach inside the nursery before
1188 been promoted to the old generation. This only can only be used with the
1189 split minor collector.
1190 Valid values are integers between 1 and 14. Default is 2.
1192 \fB(no-)cementing\fR
1193 Enables or disables cementing. This can dramatically shorten nursery
1194 collection times on some benchmarks where pinned objects are referred
1195 to from the major heap.
1200 When using Mono with the SGen garbage collector this environment
1201 variable can be used to turn on various debugging features of the
1202 collector. The value of this variable is a comma separated list of
1203 words. Do not use these options in production.
1208 Sets the debug level to the specified number.
1210 \fBprint-allowance\fR
1211 After each major collection prints memory consumption for before and
1212 after the collection and the allowance for the minor collector, i.e. how
1213 much the heap is allowed to grow from minor collections before the next
1214 major collection is triggered.
1217 Gathers statistics on the classes whose objects are pinned in the
1218 nursery and for which global remset entries are added. Prints those
1219 statistics when shutting down.
1221 \fBcollect-before-allocs\fR
1223 \fBcheck-at-minor-collections\fR
1224 This performs a consistency check on minor collections and also clears
1225 the nursery at collection time, instead of the default, when buffers
1226 are allocated (clear-at-gc). The consistency check ensures that
1227 there are no major to minor references that are not on the remembered
1230 \fBmod-union-consistency-check\fR
1231 Checks that the mod-union cardtable is consistent before each
1232 finishing major collection pause. This check is only applicable to
1233 concurrent major collectors.
1235 \fBcheck-mark-bits\fR
1236 Checks that mark bits in the major heap are consistent at the end of
1237 each major collection. Consistent mark bits mean that if an object is
1238 marked, all objects that it had references to must also be marked.
1240 \fBcheck-nursery-pinned\fR
1241 After nursery collections, and before starting concurrent collections,
1242 check whether all nursery objects are pinned, or not pinned -
1243 depending on context. Does nothing when the split nursery collector
1246 \fBxdomain-checks\fR
1247 Performs a check to make sure that no references are left to an
1250 \fBclear-at-tlab-creation\fR
1251 Clears the nursery incrementally when the thread local allocation
1252 buffers (TLAB) are created. The default setting clears the whole
1255 \fBdebug-clear-at-tlab-creation\fR
1256 Clears the nursery incrementally when the thread local allocation
1257 buffers (TLAB) are created, but at GC time fills it with the byte
1258 `0xff`, which should result in a crash more quickly if
1259 `clear-at-tlab-creation` doesn't work properly.
1262 This clears the nursery at GC time instead of doing it when the thread
1263 local allocation buffer (TLAB) is created. The default is to clear
1264 the nursery at TLAB creation time.
1267 Don't do minor collections. If the nursery is full, a major collection
1268 is triggered instead, unless it, too, is disabled.
1271 Don't do major collections.
1273 \fBconservative-stack-mark\fR
1274 Forces the GC to scan the stack conservatively, even if precise
1275 scanning is available.
1277 \fBno-managed-allocator\fR
1278 Disables the managed allocator.
1280 \fBcheck-scan-starts\fR
1281 If set, does a plausibility check on the scan_starts before and after each collection
1283 \fBverify-nursery-at-minor-gc\fR
1284 If set, does a complete object walk of the nursery at the start of each minor collection.
1286 \fBdump-nursery-at-minor-gc\fR
1287 If set, dumps the contents of the nursery at the start of each minor collection. Requires
1288 verify-nursery-at-minor-gc to be set.
1290 \fBheap-dump=\fIfile\fR
1291 Dumps the heap contents to the specified file. To visualize the
1292 information, use the mono-heapviz tool.
1294 \fBbinary-protocol=\fIfile\fR
1295 Outputs the debugging output to the specified file. For this to
1296 work, Mono needs to be compiled with the BINARY_PROTOCOL define on
1297 sgen-gc.c. You can then use this command to explore the output
1299 sgen-grep-binprot 0x1234 0x5678 < file
1302 \fBnursery-canaries\fR
1303 If set, objects allocated in the nursery are suffixed with a canary (guard)
1304 word, which is checked on each minor collection. Can be used to detect/debug
1305 heap corruption issues.
1308 \fBdo-not-finalize\fR
1309 If enabled, finalizers will not be run. Everything else will be
1310 unaffected: finalizable objects will still be put into the
1311 finalization queue where they survive until they're scheduled to
1312 finalize. Once they're not in the queue anymore they will be
1313 collected regularly.
1316 \fBlog-finalizers\fR
1317 Log verbosely around the finalization process to aid debugging.
1321 \fBMONO_GAC_PREFIX\fR
1322 Provides a prefix the runtime uses to look for Global Assembly Caches.
1323 Directories are separated by the platform path separator (colons on
1324 unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
1325 install. Or to the directory provided in the gacutil /gacdir command. Example:
1326 .B /home/username/.mono:/usr/local/mono/
1329 Enables some filename rewriting support to assist badly-written
1330 applications that hard-code Windows paths. Set to a colon-separated
1331 list of "drive" to strip drive letters, or "case" to do
1332 case-insensitive file matching in every directory in a path. "all"
1333 enables all rewriting methods. (Backslashes are always mapped to
1334 slashes if this variable is set to a valid option).
1337 For example, this would work from the shell:
1340 MONO_IOMAP=drive:case
1344 If you are using mod_mono to host your web applications, you can use
1347 directive instead, like this:
1350 MonoIOMAP <appalias> all
1353 See mod_mono(8) for more details.
1355 Additionally. Mono includes a profiler module which allows one to track what
1356 adjustements to file paths IOMAP code needs to do. The tracking code reports
1357 the managed location (full stack trace) from which the IOMAP-ed call was made and,
1358 on process exit, the locations where all the IOMAP-ed strings were created in
1359 managed code. The latter report is only approximate as it is not always possible
1360 to estimate the actual location where the string was created. The code uses simple
1361 heuristics - it analyzes stack trace leading back to the string allocation location
1362 and ignores all the managed code which lives in assemblies installed in GAC as well as in the
1363 class libraries shipped with Mono (since they are assumed to be free of case-sensitivity
1364 issues). It then reports the first location in the user's code - in most cases this will be
1365 the place where the string is allocated or very close to the location. The reporting code
1366 is implemented as a custom profiler module (see the "PROFILING" section) and can be loaded
1367 in the following way:
1372 mono --profile=iomap yourapplication.exe
1375 Note, however, that Mono currently supports only one profiler module
1379 When Mono is using the LLVM code generation backend you can use this
1380 environment variable to pass code generation options to the LLVM
1383 \fBMONO_MANAGED_WATCHER\fR
1384 If set to "disabled", System.IO.FileSystemWatcher will use a file watcher
1385 implementation which silently ignores all the watching requests.
1386 If set to any other value, System.IO.FileSystemWatcher will use the default
1387 managed implementation (slow). If unset, mono will try to use inotify, FAM,
1388 Gamin, kevent under Unix systems and native API calls on Windows, falling
1389 back to the managed implementation on error.
1391 \fBMONO_MESSAGING_PROVIDER\fR
1392 Mono supports a plugin model for its implementation of System.Messaging making
1393 it possible to support a variety of messaging implementations (e.g. AMQP, ActiveMQ).
1394 To specify which messaging implementation is to be used the evironement variable
1395 needs to be set to the full class name for the provider. E.g. to use the RabbitMQ based
1396 AMQP implementation the variable should be set to:
1399 Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
1402 If set causes the mono process to be bound to a single processor. This may be
1403 useful when debugging or working around race conditions.
1406 Disable inlining of thread local accesses. Try setting this if you get a segfault
1407 early on in the execution of mono.
1410 Provides a search path to the runtime where to look for library
1411 files. This is a tool convenient for debugging applications, but
1412 should not be used by deployed applications as it breaks the assembly
1413 loader in subtle ways.
1415 Directories are separated by the platform path separator (colons on unix). Example:
1416 .B /home/username/lib:/usr/local/mono/lib
1418 Relative paths are resolved based on the launch-time current directory.
1420 Alternative solutions to MONO_PATH include: installing libraries into
1421 the Global Assembly Cache (see gacutil(1)) or having the dependent
1422 libraries side-by-side with the main executable.
1424 For a complete description of recommended practices for application
1426 http://www.mono-project.com/docs/getting-started/application-deployment/
1429 Experimental RTC support in the statistical profiler: if the user has
1430 the permission, more accurate statistics are gathered. The MONO_RTC
1431 value must be restricted to what the Linux rtc allows: power of two
1432 from 64 to 8192 Hz. To enable higher frequencies like 4096 Hz, run as root:
1435 echo 4096 > /proc/sys/dev/rtc/max-user-freq
1442 MONO_RTC=4096 mono --profiler=default:stat program.exe
1446 \fBMONO_SHARED_DIR\fR
1447 If set its the directory where the ".wapi" handle state is stored.
1448 This is the directory where the Windows I/O Emulation layer stores its
1449 shared state data (files, events, mutexes, pipes). By default Mono
1450 will store the ".wapi" directory in the users's home directory.
1452 \fBMONO_SHARED_HOSTNAME\fR
1453 Uses the string value of this variable as a replacement for the host name when
1454 creating file names in the ".wapi" directory. This helps if the host name of
1455 your machine is likely to be changed when a mono application is running or if
1456 you have a .wapi directory shared among several different computers.
1458 Mono typically uses the hostname to create the files that are used to
1459 share state across multiple Mono processes. This is done to support
1460 home directories that might be shared over the network.
1462 \fBMONO_STRICT_IO_EMULATION\fR
1463 If set, extra checks are made during IO operations. Currently, this
1464 includes only advisory locks around file writes.
1467 The name of the theme to be used by Windows.Forms. Available themes today
1468 include "clearlooks", "nice" and "win32".
1470 The default is "win32".
1472 \fBMONO_THREAPOOL\fR
1473 This environment variable can be used to choose the implementation of
1474 the ThreadPool used at runtime. By default this uses the long term
1475 Mono threadpool implementation. But a new "microsoft" value switches
1476 the threadpool implementation to Microsoft's CoreCLR/ReferenceSource implementation.
1478 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1479 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1480 avoid a new negotiation between the client and a server. Negotiation are very
1481 CPU intensive so an application-specific custom value may prove useful for
1482 small embedded systems.
1484 The default is 180 seconds.
1486 \fBMONO_THREADS_PER_CPU\fR
1487 The minimum number of threads in the general threadpool will be
1488 MONO_THREADS_PER_CPU * number of CPUs. The default value for this
1491 \fBMONO_XMLSERIALIZER_THS\fR
1492 Controls the threshold for the XmlSerializer to produce a custom
1493 serializer for a given class instead of using the Reflection-based
1494 interpreter. The possible values are `no' to disable the use of a
1495 custom serializer or a number to indicate when the XmlSerializer
1496 should start serializing. The default value is 50, which means that
1497 the a custom serializer will be produced on the 50th use.
1499 \fBMONO_X509_REVOCATION_MODE\fR
1500 Sets the revocation mode used when validating a X509 certificate chain (https,
1501 ftps, smtps...). The default is 'nocheck', which performs no revocation check
1502 at all. The other possible values are 'offline', which performs CRL check (not
1503 implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
1504 status (not implemented yet).
1505 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1507 \fBMONO_ASPNET_NODELETE\fR
1508 If set to any value, temporary source files generated by ASP.NET support
1509 classes will not be removed. They will be kept in the user's temporary
1513 If set, enables some features of the runtime useful for debugging.
1514 This variable should contain a comma separated list of debugging options.
1515 Currently, the following options are supported:
1519 \fBbreak-on-unverified\fR
1520 If this variable is set, when the Mono VM runs into a verification
1521 problem, instead of throwing an exception it will break into the
1522 debugger. This is useful when debugging verifier problems
1525 This option can be used to get more detailed information from
1526 InvalidCast exceptions, it will provide information about the types
1529 \fBcollect-pagefault-stats\fR
1530 Collects information about pagefaults. This is used internally to
1531 track the number of page faults produced to load metadata. To display
1532 this information you must use this option with "--stats" command line
1535 \fBdont-free-domains\fR
1536 This is an Optimization for multi-AppDomain applications (most
1537 commonly ASP.NET applications). Due to internal limitations Mono,
1538 Mono by default does not use typed allocations on multi-appDomain
1539 applications as they could leak memory when a domain is unloaded.
1541 Although this is a fine default, for applications that use more than
1542 on AppDomain heavily (for example, ASP.NET applications) it is worth
1543 trading off the small leaks for the increased performance
1544 (additionally, since ASP.NET applications are not likely going to
1545 unload the application domains on production systems, it is worth
1546 using this feature).
1548 \fBdyn-runtime-invoke\fR
1549 Instructs the runtime to try to use a generic runtime-invoke wrapper
1550 instead of creating one invoke wrapper.
1553 Equivalent to setting the \fBMONO_XDEBUG\fR variable, this emits
1554 symbols into a shared library as the code is JITed that can be loaded
1555 into GDB to inspect symbols.
1557 \fBgen-seq-points\fR
1558 Automatically generates sequence points where the
1559 IL stack is empty. These are places where the debugger can set a
1562 \fBexplicit-null-checks\fR
1563 Makes the JIT generate an explicit NULL check on variable dereferences
1564 instead of depending on the operating system to raise a SIGSEGV or
1565 another form of trap event when an invalid memory location is
1569 Captures the interrupt signal (Control-C) and displays a stack trace
1570 when pressed. Useful to find out where the program is executing at a
1571 given point. This only displays the stack trace of a single thread.
1574 Instructs the runtime to initialize the stack with
1575 some known values (0x2a on x86-64) at the start of a method to assist
1576 in debuggin the JIT engine.
1578 \fBkeep-delegates\fR
1579 This option will leak delegate trampolines that are no longer
1580 referenced as to present the user with more information about a
1581 delegate misuse. Basically a delegate instance might be created,
1582 passed to unmanaged code, and no references kept in managed code,
1583 which will garbage collect the code. With this option it is possible
1584 to track down the source of the problems.
1586 \fBreverse-pinvoke-exceptions
1587 This option will cause mono to abort with a descriptive message when
1588 during stack unwinding after an exception it reaches a native stack
1589 frame. This happens when a managed delegate is passed to native code,
1590 and the managed delegate throws an exception. Mono will normally try
1591 to unwind the stack to the first (managed) exception handler, and it
1592 will skip any native stack frames in the process. This leads to
1593 undefined behaviour (since mono doesn't know how to process native
1594 frames), leaks, and possibly crashes too.
1596 \fBno-gdb-backtrace\fR
1597 This option will disable the GDB backtrace emitted by the runtime
1598 after a SIGSEGV or SIGABRT in unmanaged code.
1600 \fBsuspend-on-sigsegv\fR
1601 This option will suspend the program when a native SIGSEGV is received.
1602 This is useful for debugging crashes which do not happen under gdb,
1603 since a live process contains more information than a core file.
1605 \fBcheck-pinvoke-callconv\fR
1606 This option causes the runtime to check for calling convention
1607 mismatches when using pinvoke, i.e. mixing cdecl/stdcall. It only
1608 works on windows. If a mismatch is detected, an
1609 ExecutionEngineException is thrown.
1613 \fBMONO_LOG_LEVEL\fR
1614 The logging level, possible values are `error', `critical', `warning',
1615 `message', `info' and `debug'. See the DEBUGGING section for more
1619 Controls the domain of the Mono runtime that logging will apply to.
1620 If set, the log mask is changed to the set value. Possible values are
1621 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1622 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
1623 "security" (e.g. Moonlight CoreCLR support) and "all".
1624 The default value is "all". Changing the mask value allows you to display only
1625 messages for a certain component. You can use multiple masks by comma
1626 separating them. For example to see config file messages and assembly loader
1627 messages set you mask to "asm,cfg".
1630 Used for runtime tracing of method calls. The format of the comma separated
1639 disabled Trace output off upon start.
1642 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1644 \fBMONO_TRACE_LISTENER\fR
1645 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1646 print the output of the System.Diagnostics Trace and Debug classes.
1647 It can be set to a filename, and to Console.Out or Console.Error to display
1648 output to standard output or standard error, respectively. If it's set to
1649 Console.Out or Console.Error you can append an optional prefix that will
1650 be used when writing messages like this: Console.Error:MyProgramName.
1651 See the System.Diagnostics.DefaultTraceListener documentation for more
1654 \fBMONO_WCF_TRACE\fR
1655 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.
1657 \fBMONO_XEXCEPTIONS\fR
1658 This throws an exception when a X11 error is encountered; by default a
1659 message is displayed but execution continues
1661 \fBMONO_XMLSERIALIZER_DEBUG\fR
1662 Set this value to 1 to prevent the serializer from removing the
1663 temporary files that are created for fast serialization; This might
1664 be useful when debugging.
1667 This is used in the System.Windows.Forms implementation when running
1668 with the X11 backend. This is used to debug problems in Windows.Forms
1669 as it forces all of the commands send to X11 server to be done
1670 synchronously. The default mode of operation is asynchronous which
1671 makes it hard to isolate the root of certain problems.
1673 \fBMONO_GENERIC_SHARING\fR
1674 This environment variable controls the kind of generic sharing used.
1675 This variable is used by internal JIT developers and should not be
1676 changed in production. Do not use it.
1678 The variable controls which classes will have generic code sharing
1681 Permissible values are:
1685 All generated code can be shared.
1688 Only the classes in System.Collections.Generic will have its code
1689 shared (this is the default value).
1692 Only code in corlib will have its code shared.
1695 No generic code sharing will be performed.
1698 Generic code sharing by default only applies to collections. The
1699 Mono JIT by default turns this on.
1702 When the the MONO_XDEBUG env var is set, debugging info for JITted
1703 code is emitted into a shared library, loadable into gdb. This enables,
1704 for example, to see managed frame names on gdb backtraces.
1706 \fBMONO_VERBOSE_METHOD\fR
1707 Enables the maximum JIT verbosity for the specified method. This is
1708 very helpfull to diagnose a miscompilation problems of a specific
1711 \fBMONO_VERBOSE_HWCAP\fR
1712 If set, makes the JIT output information about detected CPU features
1713 (such as SSE, CMOV, FCMOV, etc) to stdout.
1715 \fBMONO_CONSERVATIVE_HWCAP\fR
1716 If set, the JIT will not perform any hardware capability detection. This
1717 may be useful to pinpoint the cause of JIT issues. This is the default
1718 when Mono is built as an AOT cross compiler, so that the generated code
1719 will run on most hardware.
1721 If you want to use Valgrind, you will find the file `mono.supp'
1722 useful, it contains the suppressions for the GC which trigger
1723 incorrect warnings. Use it like this:
1725 valgrind --suppressions=mono.supp mono ...
1728 On some platforms, Mono can expose a set of DTrace probes (also known
1729 as user-land statically defined, USDT Probes).
1731 They are defined in the file `mono.d'.
1733 .B ves-init-begin, ves-init-end
1735 Begin and end of runtime initialization.
1737 .B method-compile-begin, method-compile-end
1739 Begin and end of method compilation.
1740 The probe arguments are class name, method name and signature,
1741 and in case of method-compile-end success or failure of compilation.
1745 Begin and end of Garbage Collection.
1747 To verify the availability of the probes, run:
1749 dtrace -P mono'$target' -l -c mono
1752 Mono's Ping implementation for detecting network reachability can
1753 create the ICMP packets itself without requiring the system ping
1754 command to do the work. If you want to enable this on Linux for
1755 non-root users, you need to give the Mono binary special permissions.
1757 As root, run this command:
1759 # setcap cap_net_raw=+ep /usr/bin/mono
1762 On Unix assemblies are loaded from the installation lib directory. If you set
1763 `prefix' to /usr, the assemblies will be located in /usr/lib. On
1764 Windows, the assemblies are loaded from the directory where mono and
1767 .B ~/.mono/aot-cache
1769 The directory for the ahead-of-time compiler demand creation
1770 assemblies are located.
1772 .B /etc/mono/config, ~/.mono/config
1774 Mono runtime configuration file. See the mono-config(5) manual page
1775 for more information.
1777 .B ~/.config/.mono/certs, /usr/share/.mono/certs
1779 Contains Mono certificate stores for users / machine. See the certmgr(1)
1780 manual page for more information on managing certificate stores and
1781 the mozroots(1) page for information on how to import the Mozilla root
1782 certificates into the Mono certificate store.
1784 .B ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
1786 Files in this directory allow a user to customize the configuration
1787 for a given system assembly, the format is the one described in the
1788 mono-config(5) page.
1790 .B ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
1792 Contains Mono cryptographic keypairs for users / machine. They can be
1793 accessed by using a CspParameters object with DSACryptoServiceProvider
1794 and RSACryptoServiceProvider classes.
1796 .B ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
1798 Contains Mono isolated storage for non-roaming users, roaming users and
1799 local machine. Isolated storage can be accessed using the classes from
1800 the System.IO.IsolatedStorage namespace.
1802 .B <assembly>.config
1804 Configuration information for individual assemblies is loaded by the
1805 runtime from side-by-side files with the .config files, see the
1806 http://www.mono-project.com/Config for more information.
1808 .B Web.config, web.config
1810 ASP.NET applications are configured through these files, the
1811 configuration is done on a per-directory basis. For more information
1812 on this subject see the http://www.mono-project.com/Config_system.web
1815 Mailing lists are listed at the
1816 http://www.mono-project.com/community/help/mailing-lists/
1818 http://www.mono-project.com
1821 certmgr(1), csharp(1), mcs(1), mdb(1), monocov(1), monodis(1),
1822 mono-config(5), mozroots(1), mprof-report(1), pdb2mdb(1), xsp(1), mod_mono(8).
1824 For more information on AOT:
1825 http://www.mono-project.com/docs/advanced/aot/
1827 For ASP.NET-related documentation, see the xsp(1) manual page
projects / mono.git / blob