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.
127 .I data-outfile=FILE.dll.aotdata
129 This instructs the AOT code generator to output certain data
130 constructs into a separate file. This can reduce the executable
131 images some five to twenty percent. Developers need to then ship the
132 resulting aotdata as a resource and register a hook to load the data
133 on demand by using the
134 .I mono_install_load_aot_data_hook
139 When this option is specified, P/Invoke methods are invoked directly
140 instead of going through the operating system symbol lookup operation.
142 .I llvm-path=<PREFIX>
143 Same for the llvm tools 'opt' and 'llc'.
146 Use the GNU style target triple <TRIPLE> to determine some code generation options, i.e.
147 --mtriple=armv7-linux-gnueabi will generate code that targets ARMv7. This is currently
148 only supported by the ARM backend. In LLVM mode, this triple is passed on to the LLVM
151 .I nimt-trampolines=[number]
152 When compiling in full aot mthis data at startup
153 usingode, the IMT trampolines must be precreated
154 in the AOT image. You can add additional method trampolines with this argument.
158 Instructs the AOT compiler to not output any debugging information.
161 This prevents the AOT compiler from generating a direct calls to a
162 method. The AOT compiler usually generates direct calls for certain
163 methods that do not require going through the PLT (for example,
164 methods that are known to not require a hook like a static
165 constructor) or call into simple internal calls.
168 Instructs the AOT compiler to emit DWARF debugging information. When
169 used together with the nodebug option, only DWARF debugging
170 information is emitted, but not the information that can be used at
173 .I nrgctx-trampolines=[number]
174 When compiling in full aot mode, the generic sharing trampolines must be precreated
175 in the AOT image. You can add additional method trampolines with this argument.
178 .I ntrampolines=[number]
179 When compiling in full aot mode, the method trampolines must be precreated
180 in the AOT image. You can add additional method trampolines with this argument.
183 .I outfile=[filename]
184 Instructs the AOT compiler to save the output to the specified file.
186 .I print-skipped-methods
187 If the AOT compiler cannot compile a method for any reason, enabling this flag
188 will output the skipped methods to the console.
190 .I readonly-value=namespace.typename.fieldname=type/value
191 Override the value of a static readonly field. Usually, during JIT
192 compilation, the static constructor is ran eagerly, so the value of
193 a static readonly field is known at compilation time and the compiler
194 can do a number of optimizations based on it. During AOT, instead, the static
195 constructor can't be ran, so this option can be used to set the value of such
196 a field and enable the same set of optimizations.
197 Type can be any of i1, i2, i4 for integers of the respective sizes (in bytes).
198 Note that signed/unsigned numbers do not matter here, just the storage size.
199 This option can be specified multiple times and it doesn't prevent the static
200 constructor for the type defining the field to execute with the usual rules
201 at runtime (hence possibly computing a different value for the field).
204 .I save-temps,keep-temps
205 Instructs the AOT compiler to keep temporary files.
208 This instructs the compiler to generate sequence point checks that
209 allow Mono's soft debugger to debug applications even on systems where
210 it is not possible to set breakpoints or to single step (certain
211 hardware configurations like the cell phones and video gaming
215 Create an ELF object file (.o) or .s file which can be statically linked into an
216 executable when embedding the mono runtime. When this option is used, the object file
217 needs to be registered with the embedded runtime using the mono_aot_register_module
218 function which takes as its argument the mono_aot_module_<ASSEMBLY NAME>_info global
219 symbol from the object file:
222 extern void *mono_aot_module_hello_info;
224 mono_aot_register_module (mono_aot_module_hello_info);
229 Print various stats collected during AOT compilation.
232 This is an experimental option for the AOT compiler to use multiple threads
233 when compiling the methods.
235 .I tool-prefix=<PREFIX>
236 Prepends <PREFIX> to the name of tools ran by the AOT compiler, i.e. 'as'/'ld'. For
237 example, --tool=prefix=arm-linux-gnueabi- will make the AOT compiler run
238 'arm-linux-gnueabi-as' instead of 'as'.
241 Instructs the AOT compiler to emit debug symbol information.
243 For more information about AOT, see: http://www.mono-project.com/docs/advanced/aot/
246 \fB--attach=[options]\fR
247 Currently the only option supported by this command line argument is
248 \fBdisable\fR which disables the attach functionality.
250 \fB--config filename\fR
251 Load the specified configuration file instead of the default one(s).
252 The default files are /etc/mono/config and ~/.mono/config or the file
253 specified in the MONO_CONFIG environment variable, if set. See the
254 mono-config(5) man page for details on the format of this file.
256 \fB--debugger-agent=[options]\fR
257 This instructs the Mono runtime to
258 start a debugging agent inside the Mono runtime and connect it to a
259 client user interface will control the Mono process.
260 This option is typically used by IDEs, like the MonoDevelop IDE.
262 The configuration is specified using one of more of the following options:
268 Use this option to specify the IP address where your debugger client is
273 Specifies the diagnostics log level for
277 Used to specify the file where the log will be stored, it defaults to
281 Defaults to no, with the default option Mono will actively connect to the
282 host/port configured with the \fBaddress\fR option. If you set it to 'y', it
283 instructs the Mono runtime to start debugging in server mode, where Mono
284 actively waits for the debugger front end to connect to the Mono process.
285 Mono will print out to stdout the IP address and port where it is listening.
288 If set to yes, Mono will call \fBsetpgid(0, 0)\fB on startup, if that function
289 is available on the system. This is useful for ensuring that signals delivered
290 to a process that is executing the debuggee are not propagated to the debuggee,
291 e.g. when Ctrl-C sends \fBSIGINT\fB to the \fBsdb\fB tool.
294 Defaults to yes, with the default option Mono will suspend the vm on startup
295 until it connects successfully to a debugger front end. If you set it to 'n', in
296 conjunction with \fBserver=y\fR, it instructs the Mono runtime to run as normal,
297 while caching metadata to send to the debugger front end on connection..
299 .I transport=transport_name
301 This is used to specify the transport that the debugger will use to
302 communicate. It must be specified and currently requires this to
308 Configures the virtual machine to be better suited for desktop
309 applications. Currently this sets the GC system to avoid expanding
310 the heap as much as possible at the expense of slowing down garbage
314 This is an experimental flag that instructs the Mono runtime to not
315 generate any code at runtime and depend exclusively on the code
316 generated from using mono --aot=full previously. This is useful for
317 platforms that do not permit dynamic code generation.
319 Notice that this feature will abort execution at runtime if a codepath
320 in your program, or Mono's class libraries attempts to generate code
321 dynamically. You should test your software upfront and make sure that
322 you do not use any dynamic features.
324 \fB--gc=boehm\fR, \fB--gc=sgen\fR
325 Selects the Garbage Collector engine for Mono to use, Boehm or SGen.
326 Currently this merely ensures that you are running either the
327 \fImono\fR or \fImono-sgen\fR commands. This flag can be set in the
328 \fBMONO_ENV_OPTIONS\fR environment variable to force all of your child
329 processes to use one particular kind of GC with the Mono runtime.
331 \fB--arch=32\fR, \fB--arch=64\fR
332 (Mac OS X only): Selects the bitness of the Mono binary used, if
333 available. If the binary used is already for the selected bitness, nothing
334 changes. If not, the execution switches to a binary with the selected
335 bitness suffix installed side by side (for example, '/bin/mono --arch=64'
336 will switch to '/bin/mono64' iff '/bin/mono' is a 32-bit build).
338 \fB--help\fR, \fB-h\fR
339 Displays usage instructions.
342 If the Mono runtime has been compiled with LLVM support (not available
343 in all configurations), Mono will use the LLVM optimization and code
344 generation engine to JIT or AOT compile.
346 For more information, consult: http://www.mono-project.com/docs/advanced/mono-llvm/
349 When using a Mono that has been compiled with LLVM support, it forces
350 Mono to fallback to its JIT engine and not use the LLVM backend.
352 \fB--optimize=MODE\fR, \fB-O=MODE\fR
353 MODE is a comma separated list of optimizations. They also allow
354 optimizations to be turned off by prefixing the optimization name with
357 In general, Mono has been tuned to use the default set of flags,
358 before using these flags for a deployment setting, you might want to
359 actually measure the benefits of using them.
361 The following optimization flags are implemented in the core engine:
363 abcrem Array bound checks removal
364 all Turn on all optimizations
365 aot Usage of Ahead Of Time compiled code
366 branch Branch optimizations
367 cfold Constant folding
368 cmov Conditional moves [arch-dependency]
369 deadce Dead code elimination
370 consprop Constant propagation
371 copyprop Copy propagation
372 fcmov Fast x86 FP compares [arch-dependency]
373 float32 Perform 32-bit float arithmetic using 32-bit operations
374 gshared Enable generic code sharing.
375 inline Inline method calls
376 intrins Intrinsic method implementations
377 linears Linear scan global reg allocation
378 leaf Leaf procedures optimizations
379 loop Loop related optimizations
380 peephole Peephole postpass
381 precomp Precompile all methods before executing Main
382 sched Instruction scheduling
383 shared Emit per-domain code
384 sse2 SSE2 instructions on x86 [arch-dependency]
385 tailc Tail recursion and tail calls
388 For example, to enable all the optimization but dead code
389 elimination and inlining, you can use:
391 -O=all,-deadce,-inline
394 The flags that are flagged with [arch-dependency] indicate that the
395 given option if used in combination with Ahead of Time compilation
396 (--aot flag) would produce pre-compiled code that will depend on the
397 current CPU and might not be safely moved to another computer.
401 The following optimizations are supported
404 Requests that the runtime performn 32-bit floating point operations
405 using only 32-bits. By default the Mono runtime tries to use the
406 highest precision available for floating point operations, but while
407 this might render better results, the code might run slower. This
408 options also affects the code generated by the LLVM backend.
411 Controls whether the runtime should attempt to inline (the default),
412 or not inline methods invocations
416 \fB--runtime=VERSION\fR
417 Mono supports different runtime versions. The version used depends on the program
418 that is being run or on its configuration file (named program.exe.config). This option
419 can be used to override such autodetection, by forcing a different runtime version
420 to be used. Note that this should only be used to select a later compatible runtime
421 version than the one the program was compiled against. A typical usage is for
422 running a 1.1 program on a 2.0 version:
424 mono --runtime=v2.0.50727 program.exe
427 \fB--security\fR, \fB--security=mode\fR
428 Activate the security manager, a currently experimental feature in
429 Mono and it is OFF by default. The new code verifier can be enabled
430 with this option as well.
434 Using security without parameters is equivalent as calling it with the
437 The following modes are supported:
440 Enables the core-clr security system, typically used for
441 Moonlight/Silverlight applications. It provides a much simpler
442 security system than CAS, see http://www.mono-project.com/docs/web/moonlight/
443 for more details and links to the descriptions of this new system.
446 Enables the new verifier and performs basic verification for code
447 validity. In this mode, unsafe code and P/Invoke are allowed. This
448 mode provides a better safety guarantee but it is still possible
449 for managed code to crash Mono.
452 Enables the new verifier and performs full verification of the code
453 being executed. It only allows verifiable code to be executed.
454 Unsafe code is not allowed but P/Invoke is. This mode should
455 not allow managed code to crash mono. The verification is not as
456 strict as ECMA 335 standard in order to stay compatible with the MS
459 The security system acts on user code: code contained in mscorlib or
460 the global assembly cache is always trusted.
465 Configures the virtual machine to be better suited for server
466 operations (currently, allows a heavier threadpool initialization).
469 Verifies mscorlib and assemblies in the global
470 assembly cache for valid IL, and all user code for IL
473 This is different from \fB--security\fR's verifiable
474 or validil in that these options only check user code and skip
475 mscorlib and assemblies located on the global assembly cache.
477 \fB-V\fR, \fB--version\fR
478 Prints JIT version information (system configuration, release number
479 and branch names if available).
482 .SH DEVELOPMENT OPTIONS
483 The following options are used to help when developing a JITed application.
485 \fB--debug\fR, \fB--debug=OPTIONS\fR
486 Turns on the debugging mode in the runtime. If an assembly was
487 compiled with debugging information, it will produce line number
488 information for stack traces.
492 The optional OPTIONS argument is a comma separated list of debugging
493 options. These options are turned off by default since they generate
494 much larger and slower code at runtime.
496 The following options are supported:
499 Produces a detailed error when throwing a InvalidCastException. This
500 option needs to be enabled as this generates more verbose code at
504 Disable some JIT optimizations which are usually only disabled when
505 running inside the debugger. This can be helpful if you want to attach
506 to the running process with mdb.
509 Generate and register debugging information with gdb. This is only supported on some
510 platforms, and only when using gdb 7.0 or later.
514 \fB--profile[=profiler[:profiler_args]]\fR
515 Turns on profiling. For more information about profiling applications
516 and code coverage see the sections "PROFILING" and "CODE COVERAGE"
519 This option can be used multiple times, each time will load an
520 additional profiler. This allows developers to use modules that
521 extend the JIT through the Mono profiling interface.
523 \fB--trace[=expression]\fR
524 Shows method names as they are invoked. By default all methods are
527 The trace can be customized to include or exclude methods, classes or
528 assemblies. A trace expression is a comma separated list of targets,
529 each target can be prefixed with a minus sign to turn off a particular
530 target. The words `program', `all' and `disabled' have special
531 meaning. `program' refers to the main program being executed, and
532 `all' means all the method calls.
534 The `disabled' option is used to start up with tracing disabled. It
535 can be enabled at a later point in time in the program by sending the
536 SIGUSR2 signal to the runtime.
538 Assemblies are specified by their name, for example, to trace all
539 calls in the System assembly, use:
542 mono --trace=System app.exe
545 Classes are specified with the T: prefix. For example, to trace all
546 calls to the System.String class, use:
549 mono --trace=T:System.String app.exe
552 And individual methods are referenced with the M: prefix, and the
553 standard method notation:
556 mono --trace=M:System.Console:WriteLine app.exe
559 Exceptions can also be traced, it will cause a stack trace to be
560 printed every time an exception of the specified type is thrown.
561 The exception type can be specified with or without the namespace,
562 and to trace all exceptions, specify 'all' as the type name.
565 mono --trace=E:System.Exception app.exe
568 As previously noted, various rules can be specified at once:
571 mono --trace=T:System.String,T:System.Random app.exe
574 You can exclude pieces, the next example traces calls to
575 System.String except for the System.String:Concat method.
578 mono --trace=T:System.String,-M:System.String:Concat
581 You can trace managed to unmanaged transitions using
582 the wrapper qualifier:
585 mono --trace=wrapper app.exe
588 Finally, namespaces can be specified using the N: prefix:
591 mono --trace=N:System.Xml
595 \fB--no-x86-stack-align\fR
596 Don't align stack frames on the x86 architecture. By default, Mono
597 aligns stack frames to 16 bytes on x86, so that local floating point
598 and SIMD variables can be properly aligned. This option turns off the
599 alignment, which usually saves one intruction per call, but might
600 result in significantly lower floating point and SIMD performance.
603 Generate a JIT method map in a /tmp/perf-PID.map file. This file is then
604 used, for example, by the perf tool included in recent Linux kernels.
605 Each line in the file has:
608 HEXADDR HEXSIZE methodname
611 Currently this option is only supported on Linux.
612 .SH JIT MAINTAINER OPTIONS
613 The maintainer options are only used by those developing the runtime
614 itself, and not typically of interest to runtime users or developers.
617 Inserts a breakpoint before the method whose name is `method'
618 (namespace.class:methodname). Use `Main' as method name to insert a
619 breakpoint on the application's main method. You can use it also with
620 generics, for example "System.Collections.Generic.Queue`1:Peek"
623 Inserts a breakpoint on exceptions. This allows you to debug your
624 application with a native debugger when an exception is thrown.
627 This compiles a method (namespace.name:methodname), this is used for
628 testing the compiler performance or to examine the output of the code
632 Compiles all the methods in an assembly. This is used to test the
633 compiler performance or to examine the output of the code generator
635 \fB--graph=TYPE METHOD\fR
636 This generates a postscript file with a graph with the details about
637 the specified method (namespace.name:methodname). This requires `dot'
638 and ghostview to be installed (it expects Ghostview to be called
641 The following graphs are available:
643 cfg Control Flow Graph (CFG)
645 code CFG showing code
646 ssa CFG showing code after SSA translation
647 optcode CFG showing code after IR optimizations
650 Some graphs will only be available if certain optimizations are turned
654 Instruct the runtime on the number of times that the method specified
655 by --compile (or all the methods if --compileall is used) to be
656 compiled. This is used for testing the code generator performance.
659 Displays information about the work done by the runtime during the
660 execution of an application.
662 \fB--wapi=hps|semdel\fR
663 Perform maintenance of the process shared data.
665 semdel will delete the global semaphore.
667 hps will list the currently used handles.
669 \fB-v\fR, \fB--verbose\fR
670 Increases the verbosity level, each time it is listed, increases the
671 verbosity level to include more information (including, for example,
672 a disassembly of the native code produced, code selector info etc.).
674 The Mono runtime allows external processes to attach to a running
675 process and load assemblies into the running program. To attach to
676 the process, a special protocol is implemented in the Mono.Management
679 With this support it is possible to load assemblies that have an entry
680 point (they are created with -target:exe or -target:winexe) to be
681 loaded and executed in the Mono process.
683 The code is loaded into the root domain, and it starts execution on
684 the special runtime attach thread. The attached program should
685 create its own threads and return after invocation.
687 This support allows for example debugging applications by having the
688 csharp shell attach to running processes.
690 The mono runtime includes a profiler that can be used to explore
691 various performance related problems in your application. The
692 profiler is activated by passing the --profile command line argument
693 to the Mono runtime, the format is:
696 --profile[=profiler[:profiler_args]]
699 Mono has a built-in profiler called 'default' (and is also the default
700 if no arguments are specified), but developers can write custom
701 profilers, see the section "CUSTOM PROFILERS" for more details.
705 is not specified, the default profiler is used.
709 is a profiler-specific string of options for the profiler itself.
711 The default profiler accepts the following options 'alloc' to profile
712 memory consumption by the application; 'time' to profile the time
713 spent on each routine; 'jit' to collect time spent JIT-compiling methods
714 and 'stat' to perform sample statistical profiling.
715 If no options are provided the default is 'alloc,time,jit'.
718 profile data is printed to stdout: to change this, use the 'file=filename'
719 option to output the data to filename.
724 mono --profile program.exe
728 That will run the program with the default profiler and will do time
729 and allocation profiling.
733 mono --profile=default:stat,alloc,file=prof.out program.exe
736 Will do sample statistical profiling and allocation profiling on
737 program.exe. The profile data is put in prof.out.
739 Note that the statistical profiler has a very low overhead and should
740 be the preferred profiler to use (for better output use the full path
741 to the mono binary when running and make sure you have installed the
742 addr2line utility that comes from the binutils package).
744 This is the most advanced profiler.
746 The Mono \f[I]log\f[] profiler can be used to collect a lot of
747 information about a program running in the Mono runtime.
748 This data can be used (both while the process is running and later)
749 to do analyses of the program behaviour, determine resource usage,
750 performance issues or even look for particular execution patterns.
752 This is accomplished by logging the events provided by the Mono
753 runtime through the profiling interface and periodically writing
754 them to a file which can be later inspected with the mprof-report(1)
757 More information about how to use the log profiler is available on the
758 mprof-report(1) page.
760 Mono provides a mechanism for loading other profiling modules which in
761 the form of shared libraries. These profiling modules can hook up to
762 various parts of the Mono runtime to gather information about the code
765 To use a third party profiler you must pass the name of the profiler
769 mono --profile=custom program.exe
773 In the above sample Mono will load the user defined profiler from the
774 shared library `mono-profiler-custom.so'. This profiler module must
775 be on your dynamic linker library path.
777 A list of other third party profilers is available from Mono's web
778 site (www.mono-project.com/docs/advanced/performance-tips/)
780 Custom profiles are written as shared libraries. The shared library
781 must be called `mono-profiler-NAME.so' where `NAME' is the name of
784 For a sample of how to write your own custom profiler look in the
785 Mono source tree for in the samples/profiler.c.
787 Mono ships with a code coverage module. This module is activated by
788 using the Mono --profile=cov option. The format is:
789 \fB--profile=cov[:assembly-name[/namespace]] test-suite.exe\fR
791 By default code coverage will default to all the assemblies loaded,
792 you can limit this by specifying the assembly name, for example to
793 perform code coverage in the routines of your program use, for example
794 the following command line limits the code coverage to routines in the
798 mono --profile=cov:demo demo.exe
804 does not include the extension.
806 You can further restrict the code coverage output by specifying a
810 mono --profile=cov:demo/My.Utilities demo.exe
814 Which will only perform code coverage in the given assembly and
817 Typical output looks like this:
820 Not covered: Class:.ctor ()
821 Not covered: Class:A ()
822 Not covered: Driver:.ctor ()
823 Not covered: Driver:method ()
824 Partial coverage: Driver:Main ()
829 The offsets displayed are IL offsets.
831 A more powerful coverage tool is available in the module `monocov'.
832 See the monocov(1) man page for details.
834 To debug managed applications, you can use the
836 command, a command line debugger.
838 It is possible to obtain a stack trace of all the active threads in
839 Mono by sending the QUIT signal to Mono, you can do this from the
840 command line, like this:
846 Where pid is the Process ID of the Mono process you want to examine.
847 The process will continue running afterwards, but its state is not
851 this is a last-resort mechanism for debugging applications and should
852 not be used to monitor or probe a production application. The
853 integrity of the runtime after sending this signal is not guaranteed
854 and the application might crash or terminate at any given point
857 The \fB--debug=casts\fR option can be used to get more detailed
858 information for Invalid Cast operations, it will provide information
859 about the types involved.
861 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
862 to get verbose debugging output about the execution of your
863 application within Mono.
867 environment variable if set, the logging level is changed to the set
868 value. Possible values are "error", "critical", "warning", "message",
869 "info", "debug". The default value is "error". Messages with a logging
870 level greater then or equal to the log level will be printed to
873 Use "info" to track the dynamic loading of assemblies.
878 environment variable to limit the extent of the messages you get:
879 If set, the log mask is changed to the set value. Possible values are
880 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
881 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
882 "security" (e.g. Moonlight CoreCLR support) and "all".
883 The default value is "all". Changing the mask value allows you to display only
884 messages for a certain component. You can use multiple masks by comma
885 separating them. For example to see config file messages and assembly loader
886 messages set you mask to "asm,cfg".
888 The following is a common use to track down problems with P/Invoke:
891 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
895 .SH DEBUGGING WITH LLDB
896 If you are using LLDB, you can use the
898 script to print some internal data structures with it. To use this,
903 command script import $PREFIX/lib/mono/lldb/mono.py
906 Where $PREFIX is the prefix value that you used when you configured
907 Mono (typically /usr).
909 Once this is done, then you can inspect some Mono Runtime data structures,
914 (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
917 Mono's XML serialization engine by default will use a reflection-based
918 approach to serialize which might be slow for continuous processing
919 (web service applications). The serialization engine will determine
920 when a class must use a hand-tuned serializer based on a few
921 parameters and if needed it will produce a customized C# serializer
922 for your types at runtime. This customized serializer then gets
923 dynamically loaded into your application.
925 You can control this with the MONO_XMLSERIALIZER_THS environment
928 The possible values are
930 to disable the use of a C# customized
931 serializer, or an integer that is the minimum number of uses before
932 the runtime will produce a custom serializer (0 will produce a
933 custom serializer on the first access, 50 will produce a serializer on
934 the 50th use). Mono will fallback to an interpreted serializer if the
935 serializer generation somehow fails. This behavior can be disabled
936 by setting the option
938 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
939 .SH ENVIRONMENT VARIABLES
942 Turns off the garbage collection in Mono. This should be only used
943 for debugging purposes
946 (Also \fBhttp_proxy\fR) If set, web requests using the Mono
947 Class Library will be automatically proxied through the given URL.
948 Not supported on Windows, Mac OS, iOS or Android. See also \fBNO_PROXY\fR.
951 When Mono is compiled with LLVM support, this instructs the runtime to
952 stop using LLVM after the specified number of methods are JITed.
953 This is a tool used in diagnostics to help isolate problems in the
954 code generation backend. For example \fBLLVM_COUNT=10\fR would only
955 compile 10 methods with LLVM and then switch to the Mono JIT engine.
956 \fBLLVM_COUNT=0\fR would disable the LLVM engine altogether.
959 If set, this variable will instruct Mono to ahead-of-time compile new
960 assemblies on demand and store the result into a cache in
963 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
964 Mono contains a feature which allows modifying settings in the .config files shipped
965 with Mono by using config section mappers. The mappers and the mapping rules are
966 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
967 settings.map file found in the top-level directory of your ASP.NET application.
968 Both files are read by System.Web on application startup, if they are found at the
969 above locations. If you don't want the mapping to be performed you can set this
970 variable in your environment before starting the application and no action will
973 \fBMONO_ASPNET_WEBCONFIG_CACHESIZE\fR
974 Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager
975 queries. Its default size is 100 items, and when more items are needed, cache
976 evictions start happening. If evictions are too frequent this could impose
977 unnecessary overhead, which could be avoided by using this environment variable
978 to set up a higher cache size (or to lower memory requirements by decreasing it).
980 \fBMONO_CAIRO_DEBUG_DISPOSE\fR
981 If set, causes Mono.Cairo to collect stack traces when objects are allocated,
982 so that the finalization/Dispose warnings include information about the
986 If set, this variable overrides the default system configuration directory
987 ($PREFIX/etc). It's used to locate machine.config file.
990 Sets the style of COM interop. If the value of this variable is "MS"
991 Mono will use string marhsalling routines from the liboleaut32 for the
992 BSTR type library, any other values will use the mono-builtin BSTR
996 If set, this variable overrides the default runtime configuration file
997 ($PREFIX/etc/mono/config). The --config command line options overrides the
998 environment variable.
1001 Override the automatic cpu detection mechanism. Currently used only on arm.
1002 The format of the value is as follows:
1008 where V is the architecture number 4, 5, 6, 7 and the options can be currently be
1009 "thumb" or "thumb2". Example:
1012 MONO_CPU_ARCH="armv4 thumb" mono ...
1016 \fBMONO_ARM_FORCE_SOFT_FLOAT\fR
1017 When Mono is built with a soft float fallback on ARM and this variable is set to
1018 "1", Mono will always emit soft float code, even if a VFP unit is
1021 \fBMONO_DARWIN_WATCHER_MAXFDS\fR
1022 This is a debugging aid used to force limits on the FileSystemWatcher
1023 implementation in Darwin. There is no limit by default.
1025 \fBMONO_DISABLE_AIO\fR
1026 If set, tells mono NOT to attempt using native asynchronous I/O services. In
1027 that case, a default select/poll implementation is used. Currently only epoll()
1030 \fBMONO_DISABLE_MANAGED_COLLATION\fR
1031 If this environment variable is `yes', the runtime uses unmanaged
1032 collation (which actually means no culture-sensitive collation). It
1033 internally disables managed collation functionality invoked via the
1034 members of System.Globalization.CompareInfo class. Collation is
1037 \fBMONO_DISABLE_SHM\fR
1038 Unix only: If set, disables the shared memory files used for
1039 cross-process handles: process have only private handles. This means
1040 that process and thread handles are not available to other processes,
1041 and named mutexes, named events and named semaphores are not visible
1044 This is can also be enabled by default by passing the
1045 "--disable-shared-handles" option to configure.
1047 This is the default from mono 2.8 onwards.
1049 \fBMONO_DISABLE_SHARED_AREA\fR
1050 Unix only: If set, disable usage of shared memory for exposing
1051 performance counters. This means it will not be possible to both
1052 externally read performance counters from this processes or read
1053 those of external processes.
1056 When set, enables the use of a fully managed DNS resolver instead of the
1057 regular libc functions. This resolver performs much better when multiple
1058 queries are run in parallel.
1060 Note that /etc/nsswitch.conf will be ignored.
1062 \fBMONO_EGD_SOCKET\fR
1063 For platforms that do not otherwise have a way of obtaining random bytes
1064 this can be set to the name of a file system socket on which an egd or
1065 prngd daemon is listening.
1067 \fBMONO_ENABLE_COOP\fR
1068 This makes the Mono runtime and the SGen garbage collector run in cooperative
1069 mode as opposed to run on preemptive mode. Preemptive mode is the mode
1070 that Mono has used historically, going back to the Boehm days, where the
1071 garbage collector would run at any point and suspend execution of all
1072 threads as required to perform a garbage collection. The cooperative mode
1073 on the other hand requires the cooperation of all threads to stop at a
1074 safe point. This makes for an easier to debug garbage collector. As
1075 of Mono 4.3.0 it is a work in progress, and while it works, it has not
1076 been used extensively. This option enabled the feature and allows us to
1077 find spots that need to be tuned for this mode of operation. Alternatively,
1078 this mode can be enabled at compile time by using the --with-cooperative-gc
1079 flag when calling configure.
1081 \fBMONO_ENABLE_SHM\fR
1082 Unix only: Enable support for cross-process handles. Cross-process
1083 handles are used to expose process handles, thread handles, named
1084 mutexes, named events and named semaphores across Unix processes.
1086 \fBMONO_ENV_OPTIONS\fR
1087 This environment variable allows you to pass command line arguments to
1088 a Mono process through the environment. This is useful for example
1089 to force all of your Mono processes to use LLVM or SGEN without having
1090 to modify any launch scripts.
1092 \fBMONO_ENV_OPTIONS\fR
1093 Used to pass extra options to the debugger agent in the runtime, as they were passed
1094 using --debugger-agent=.
1096 \fBMONO_EVENTLOG_TYPE\fR
1097 Sets the type of event log provider to use (for System.Diagnostics.EventLog).
1099 Possible values are:
1104 Persists event logs and entries to the local file system.
1106 The directory in which to persist the event logs, event sources and entries
1107 can be specified as part of the value.
1109 If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog"
1110 on unix and "%APPDATA%\mono\eventlog" on Windows.
1115 Uses the native win32 API to write events and registers event logs and
1116 event sources in the registry. This is only available on Windows.
1118 On Unix, the directory permission for individual event log and event source
1119 directories is set to 777 (with +t bit) allowing everyone to read and write
1120 event log entries while only allowing entries to be deleted by the user(s)
1125 Silently discards any events.
1128 The default is "null" on Unix (and versions of Windows before NT), and
1129 "win32" on Windows NT (and higher).
1132 \fBMONO_EXTERNAL_ENCODINGS\fR
1133 If set, contains a colon-separated list of text encodings to try when
1134 turning externally-generated text (e.g. command-line arguments or
1135 filenames) into Unicode. The encoding names come from the list
1136 provided by iconv, and the special case "default_locale" which refers
1137 to the current locale's default encoding.
1139 When reading externally-generated text strings UTF-8 is tried first,
1140 and then this list is tried in order with the first successful
1141 conversion ending the search. When writing external text (e.g. new
1142 filenames or arguments to new processes) the first item in this list
1143 is used, or UTF-8 if the environment variable is not set.
1145 The problem with using MONO_EXTERNAL_ENCODINGS to process your
1146 files is that it results in a problem: although its possible to get
1147 the right file name it is not necessarily possible to open the file.
1148 In general if you have problems with encodings in your filenames you
1149 should use the "convmv" program.
1151 \fBMONO_GC_PARAMS\fR
1152 When using Mono with the SGen garbage collector this variable controls
1153 several parameters of the collector. The variable's value is a comma
1154 separated list of words.
1158 \fBmax-heap-size=\fIsize\fR
1159 Sets the maximum size of the heap. The size is specified in bytes and must
1160 be a power of two. The suffixes `k', `m' and `g' can be used to
1161 specify kilo-, mega- and gigabytes, respectively. The limit is the sum
1162 of the nursery, major heap and large object heap. Once the limit is reached
1163 the application will receive OutOfMemoryExceptions when trying to allocate.
1164 Not the full extent of memory set in max-heap-size could be available to
1165 satisfy a single allocation due to internal fragmentation. By default heap
1166 limits is disabled and the GC will try to use all available memory.
1168 \fBnursery-size=\fIsize\fR
1169 Sets the size of the nursery. The size is specified in bytes and must
1170 be a power of two. The suffixes `k', `m' and `g' can be used to
1171 specify kilo-, mega- and gigabytes, respectively. The nursery is the
1172 first generation (of two). A larger nursery will usually speed up the
1173 program but will obviously use more memory. The default nursery size
1176 \fBmajor=\fIcollector\fR Specifies which major collector to use.
1177 Options are `marksweep' for the Mark&Sweep collector, and
1178 `marksweep-conc' for concurrent Mark&Sweep. The non-concurrent
1179 Mark&Sweep collector is the default.
1181 \fBsoft-heap-limit=\fIsize\fR
1182 Once the heap size gets larger than this size, ignore what the default
1183 major collection trigger metric says and only allow four nursery size's
1184 of major heap growth between major collections.
1186 \fBevacuation-threshold=\fIthreshold\fR
1187 Sets the evacuation threshold in percent. This option is only available
1188 on the Mark&Sweep major collectors. The value must be an
1189 integer in the range 0 to 100. The default is 66. If the sweep phase of
1190 the collection finds that the occupancy of a specific heap block type is
1191 less than this percentage, it will do a copying collection for that block
1192 type in the next major collection, thereby restoring occupancy to close
1193 to 100 percent. A value of 0 turns evacuation off.
1195 \fB(no-)lazy-sweep\fR
1196 Enables or disables lazy sweep for the Mark&Sweep collector. If
1197 enabled, the sweeping of individual major heap blocks is done
1198 piecemeal whenever the need arises, typically during nursery
1199 collections. Lazy sweeping is enabled by default.
1201 \fB(no-)concurrent-sweep\fR
1202 Enables or disables concurrent sweep for the Mark&Sweep collector. If
1203 enabled, the iteration of all major blocks to determine which ones can
1204 be freed and which ones have to be kept and swept, is done
1205 concurrently with the running program. Concurrent sweeping is enabled
1208 \fBstack-mark=\fImark-mode\fR
1209 Specifies how application threads should be scanned. Options are
1210 `precise` and `conservative`. Precise marking allow the collector
1211 to know what values on stack are references and what are not.
1212 Conservative marking threats all values as potentially references
1213 and leave them untouched. Precise marking reduces floating garbage
1214 and can speed up nursery collection and allocation rate, it has
1215 the downside of requiring a significant extra memory per compiled
1216 method. The right option, unfortunately, requires experimentation.
1218 \fBsave-target-ratio=\fIratio\fR
1219 Specifies the target save ratio for the major collector. The collector
1220 lets a given amount of memory to be promoted from the nursery due to
1221 minor collections before it triggers a major collection. This amount
1222 is based on how much memory it expects to free. It is represented as
1223 a ratio of the size of the heap after a major collection.
1224 Valid values are between 0.1 and 2.0. The default is 0.5.
1225 Smaller values will keep the major heap size smaller but will trigger
1226 more major collections. Likewise, bigger values will use more memory
1227 and result in less frequent major collections.
1228 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1230 \fBdefault-allowance-ratio=\fIratio\fR
1231 Specifies the default allocation allowance when the calculated size
1232 is too small. The allocation allowance is how much memory the collector
1233 let be promoted before triggered a major collection.
1234 It is a ratio of the nursery size.
1235 Valid values are between 1.0 and 10.0. The default is 4.0.
1236 Smaller values lead to smaller heaps and more frequent major collections.
1237 Likewise, bigger values will allow the heap to grow faster but use
1238 more memory when it reaches a stable size.
1239 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1241 \fBminor=\fIminor-collector\fR
1242 Specifies which minor collector to use. Options are 'simple' which
1243 promotes all objects from the nursery directly to the old generation
1244 and 'split' which lets object stay longer on the nursery before promoting.
1246 \fBalloc-ratio=\fIratio\fR
1247 Specifies the ratio of memory from the nursery to be use by the alloc space.
1248 This only can only be used with the split minor collector.
1249 Valid values are integers between 1 and 100. Default is 60.
1251 \fBpromotion-age=\fIage\fR
1252 Specifies the required age of an object must reach inside the nursery before
1253 been promoted to the old generation. This only can only be used with the
1254 split minor collector.
1255 Valid values are integers between 1 and 14. Default is 2.
1257 \fB(no-)cementing\fR
1258 Enables or disables cementing. This can dramatically shorten nursery
1259 collection times on some benchmarks where pinned objects are referred
1260 to from the major heap.
1262 \fBallow-synchronous-major\fR
1263 This forbids the major collector from performing synchronous major collections.
1264 The major collector might want to do a synchronous collection due to excessive
1265 fragmentation. Disabling this might trigger OutOfMemory error in situations that
1266 would otherwise not happen.
1271 When using Mono with the SGen garbage collector this environment
1272 variable can be used to turn on various debugging features of the
1273 collector. The value of this variable is a comma separated list of
1274 words. Do not use these options in production.
1279 Sets the debug level to the specified number.
1281 \fBprint-allowance\fR
1282 After each major collection prints memory consumption for before and
1283 after the collection and the allowance for the minor collector, i.e. how
1284 much the heap is allowed to grow from minor collections before the next
1285 major collection is triggered.
1288 Gathers statistics on the classes whose objects are pinned in the
1289 nursery and for which global remset entries are added. Prints those
1290 statistics when shutting down.
1292 \fBcollect-before-allocs\fR
1294 \fBcheck-at-minor-collections\fR
1295 This performs a consistency check on minor collections and also clears
1296 the nursery at collection time, instead of the default, when buffers
1297 are allocated (clear-at-gc). The consistency check ensures that
1298 there are no major to minor references that are not on the remembered
1301 \fBmod-union-consistency-check\fR
1302 Checks that the mod-union cardtable is consistent before each
1303 finishing major collection pause. This check is only applicable to
1304 concurrent major collectors.
1306 \fBcheck-mark-bits\fR
1307 Checks that mark bits in the major heap are consistent at the end of
1308 each major collection. Consistent mark bits mean that if an object is
1309 marked, all objects that it had references to must also be marked.
1311 \fBcheck-nursery-pinned\fR
1312 After nursery collections, and before starting concurrent collections,
1313 check whether all nursery objects are pinned, or not pinned -
1314 depending on context. Does nothing when the split nursery collector
1317 \fBxdomain-checks\fR
1318 Performs a check to make sure that no references are left to an
1321 \fBclear-at-tlab-creation\fR
1322 Clears the nursery incrementally when the thread local allocation
1323 buffers (TLAB) are created. The default setting clears the whole
1326 \fBdebug-clear-at-tlab-creation\fR
1327 Clears the nursery incrementally when the thread local allocation
1328 buffers (TLAB) are created, but at GC time fills it with the byte
1329 `0xff`, which should result in a crash more quickly if
1330 `clear-at-tlab-creation` doesn't work properly.
1333 This clears the nursery at GC time instead of doing it when the thread
1334 local allocation buffer (TLAB) is created. The default is to clear
1335 the nursery at TLAB creation time.
1338 Don't do minor collections. If the nursery is full, a major collection
1339 is triggered instead, unless it, too, is disabled.
1342 Don't do major collections.
1344 \fBconservative-stack-mark\fR
1345 Forces the GC to scan the stack conservatively, even if precise
1346 scanning is available.
1348 \fBno-managed-allocator\fR
1349 Disables the managed allocator.
1351 \fBcheck-scan-starts\fR
1352 If set, does a plausibility check on the scan_starts before and after each collection
1354 \fBverify-nursery-at-minor-gc\fR
1355 If set, does a complete object walk of the nursery at the start of each minor collection.
1357 \fBdump-nursery-at-minor-gc\fR
1358 If set, dumps the contents of the nursery at the start of each minor collection. Requires
1359 verify-nursery-at-minor-gc to be set.
1361 \fBheap-dump=\fIfile\fR
1362 Dumps the heap contents to the specified file. To visualize the
1363 information, use the mono-heapviz tool.
1365 \fBbinary-protocol=\fIfile\fR
1366 Outputs the debugging output to the specified file. For this to
1367 work, Mono needs to be compiled with the BINARY_PROTOCOL define on
1368 sgen-gc.c. You can then use this command to explore the output
1370 sgen-grep-binprot 0x1234 0x5678 < file
1373 \fBnursery-canaries\fR
1374 If set, objects allocated in the nursery are suffixed with a canary (guard)
1375 word, which is checked on each minor collection. Can be used to detect/debug
1376 heap corruption issues.
1379 \fBdo-not-finalize(=\fIclasses\fB)\fR
1380 If enabled, finalizers will not be run. Everything else will be
1381 unaffected: finalizable objects will still be put into the
1382 finalization queue where they survive until they're scheduled to
1383 finalize. Once they're not in the queue anymore they will be
1384 collected regularly. If a list of comma-separated class names is
1385 given, only objects from those classes will not be finalized.
1388 \fBlog-finalizers\fR
1389 Log verbosely around the finalization process to aid debugging.
1393 \fBMONO_GAC_PREFIX\fR
1394 Provides a prefix the runtime uses to look for Global Assembly Caches.
1395 Directories are separated by the platform path separator (colons on
1396 unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
1397 install. Or to the directory provided in the gacutil /gacdir command. Example:
1398 .B /home/username/.mono:/usr/local/mono/
1401 Enables some filename rewriting support to assist badly-written
1402 applications that hard-code Windows paths. Set to a colon-separated
1403 list of "drive" to strip drive letters, or "case" to do
1404 case-insensitive file matching in every directory in a path. "all"
1405 enables all rewriting methods. (Backslashes are always mapped to
1406 slashes if this variable is set to a valid option).
1409 For example, this would work from the shell:
1412 MONO_IOMAP=drive:case
1416 If you are using mod_mono to host your web applications, you can use
1419 directive instead, like this:
1422 MonoIOMAP <appalias> all
1425 See mod_mono(8) for more details.
1427 Additionally. Mono includes a profiler module which allows one to track what
1428 adjustements to file paths IOMAP code needs to do. The tracking code reports
1429 the managed location (full stack trace) from which the IOMAP-ed call was made and,
1430 on process exit, the locations where all the IOMAP-ed strings were created in
1431 managed code. The latter report is only approximate as it is not always possible
1432 to estimate the actual location where the string was created. The code uses simple
1433 heuristics - it analyzes stack trace leading back to the string allocation location
1434 and ignores all the managed code which lives in assemblies installed in GAC as well as in the
1435 class libraries shipped with Mono (since they are assumed to be free of case-sensitivity
1436 issues). It then reports the first location in the user's code - in most cases this will be
1437 the place where the string is allocated or very close to the location. The reporting code
1438 is implemented as a custom profiler module (see the "PROFILING" section) and can be loaded
1439 in the following way:
1444 mono --profile=iomap yourapplication.exe
1447 Note, however, that Mono currently supports only one profiler module
1451 When Mono is using the LLVM code generation backend you can use this
1452 environment variable to pass code generation options to the LLVM
1455 \fBMONO_MANAGED_WATCHER\fR
1456 If set to "disabled", System.IO.FileSystemWatcher will use a file watcher
1457 implementation which silently ignores all the watching requests.
1458 If set to any other value, System.IO.FileSystemWatcher will use the default
1459 managed implementation (slow). If unset, mono will try to use inotify, FAM,
1460 Gamin, kevent under Unix systems and native API calls on Windows, falling
1461 back to the managed implementation on error.
1463 \fBMONO_MESSAGING_PROVIDER\fR
1464 Mono supports a plugin model for its implementation of System.Messaging making
1465 it possible to support a variety of messaging implementations (e.g. AMQP, ActiveMQ).
1466 To specify which messaging implementation is to be used the evironement variable
1467 needs to be set to the full class name for the provider. E.g. to use the RabbitMQ based
1468 AMQP implementation the variable should be set to:
1471 Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
1474 If set causes the mono process to be bound to a single processor. This may be
1475 useful when debugging or working around race conditions.
1478 Disable inlining of thread local accesses. Try setting this if you get a segfault
1479 early on in the execution of mono.
1482 Provides a search path to the runtime where to look for library
1483 files. This is a tool convenient for debugging applications, but
1484 should not be used by deployed applications as it breaks the assembly
1485 loader in subtle ways.
1487 Directories are separated by the platform path separator (colons on unix). Example:
1488 .B /home/username/lib:/usr/local/mono/lib
1490 Relative paths are resolved based on the launch-time current directory.
1492 Alternative solutions to MONO_PATH include: installing libraries into
1493 the Global Assembly Cache (see gacutil(1)) or having the dependent
1494 libraries side-by-side with the main executable.
1496 For a complete description of recommended practices for application
1498 http://www.mono-project.com/docs/getting-started/application-deployment/
1501 Experimental RTC support in the statistical profiler: if the user has
1502 the permission, more accurate statistics are gathered. The MONO_RTC
1503 value must be restricted to what the Linux rtc allows: power of two
1504 from 64 to 8192 Hz. To enable higher frequencies like 4096 Hz, run as root:
1507 echo 4096 > /proc/sys/dev/rtc/max-user-freq
1514 MONO_RTC=4096 mono --profiler=default:stat program.exe
1518 \fBMONO_SHARED_DIR\fR
1519 If set its the directory where the ".wapi" handle state is stored.
1520 This is the directory where the Windows I/O Emulation layer stores its
1521 shared state data (files, events, mutexes, pipes). By default Mono
1522 will store the ".wapi" directory in the users's home directory.
1524 \fBMONO_SHARED_HOSTNAME\fR
1525 Uses the string value of this variable as a replacement for the host name when
1526 creating file names in the ".wapi" directory. This helps if the host name of
1527 your machine is likely to be changed when a mono application is running or if
1528 you have a .wapi directory shared among several different computers.
1530 Mono typically uses the hostname to create the files that are used to
1531 share state across multiple Mono processes. This is done to support
1532 home directories that might be shared over the network.
1534 \fBMONO_STRICT_IO_EMULATION\fR
1535 If set, extra checks are made during IO operations. Currently, this
1536 includes only advisory locks around file writes.
1539 The name of the theme to be used by Windows.Forms. Available themes today
1540 include "clearlooks", "nice" and "win32".
1542 The default is "win32".
1544 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1545 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1546 avoid a new negotiation between the client and a server. Negotiation are very
1547 CPU intensive so an application-specific custom value may prove useful for
1548 small embedded systems.
1550 The default is 180 seconds.
1552 \fBMONO_THREADS_PER_CPU\fR
1553 The minimum number of threads in the general threadpool will be
1554 MONO_THREADS_PER_CPU * number of CPUs. The default value for this
1557 \fBMONO_XMLSERIALIZER_THS\fR
1558 Controls the threshold for the XmlSerializer to produce a custom
1559 serializer for a given class instead of using the Reflection-based
1560 interpreter. The possible values are `no' to disable the use of a
1561 custom serializer or a number to indicate when the XmlSerializer
1562 should start serializing. The default value is 50, which means that
1563 the a custom serializer will be produced on the 50th use.
1565 \fBMONO_X509_REVOCATION_MODE\fR
1566 Sets the revocation mode used when validating a X509 certificate chain (https,
1567 ftps, smtps...). The default is 'nocheck', which performs no revocation check
1568 at all. The other possible values are 'offline', which performs CRL check (not
1569 implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
1570 status (not implemented yet).
1573 (Also \fBno_proxy\fR) If both \fBHTTP_PROXY\fR and \fBNO_PROXY\fR are
1574 set, \fBNO_PROXY\fR will be treated as a comma-separated list of "bypass" domains
1575 which will not be sent through the proxy. Domains in \fBNO_PROXY\fR may contain
1576 wildcards, as in "*.mono-project.com" or "build????.local". Not supported on
1577 Windows, Mac OS, iOS or Android.
1578 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1580 \fBMONO_ASPNET_NODELETE\fR
1581 If set to any value, temporary source files generated by ASP.NET support
1582 classes will not be removed. They will be kept in the user's temporary
1586 If set, enables some features of the runtime useful for debugging.
1587 This variable should contain a comma separated list of debugging options.
1588 Currently, the following options are supported:
1592 \fBalign-small-structs\fR
1593 Enables small structs alignment to 4/8 bytes.
1595 \fBarm-use-fallback-tls\fR
1596 When this option is set on ARM, a fallback TLS will be used instead
1597 of the default fast TLS.
1599 \fBbreak-on-unverified\fR
1600 If this variable is set, when the Mono VM runs into a verification
1601 problem, instead of throwing an exception it will break into the
1602 debugger. This is useful when debugging verifier problems
1605 This option can be used to get more detailed information from
1606 InvalidCast exceptions, it will provide information about the types
1609 \fBcheck-pinvoke-callconv\fR
1610 This option causes the runtime to check for calling convention
1611 mismatches when using pinvoke, i.e. mixing cdecl/stdcall. It only
1612 works on windows. If a mismatch is detected, an
1613 ExecutionEngineException is thrown.
1615 \fBcollect-pagefault-stats\fR
1616 Collects information about pagefaults. This is used internally to
1617 track the number of page faults produced to load metadata. To display
1618 this information you must use this option with "--stats" command line
1621 \fBdebug-domain-unload\fR
1622 When this option is set, the runtime will invalidate the domain memory
1623 pool instead of destroying it.
1625 \fBdont-free-domains\fR
1626 This is an Optimization for multi-AppDomain applications (most
1627 commonly ASP.NET applications). Due to internal limitations Mono,
1628 Mono by default does not use typed allocations on multi-appDomain
1629 applications as they could leak memory when a domain is unloaded.
1631 Although this is a fine default, for applications that use more than
1632 on AppDomain heavily (for example, ASP.NET applications) it is worth
1633 trading off the small leaks for the increased performance
1634 (additionally, since ASP.NET applications are not likely going to
1635 unload the application domains on production systems, it is worth
1636 using this feature).
1638 \fBdyn-runtime-invoke\fR
1639 Instructs the runtime to try to use a generic runtime-invoke wrapper
1640 instead of creating one invoke wrapper.
1642 \fBexplicit-null-checks\fR
1643 Makes the JIT generate an explicit NULL check on variable dereferences
1644 instead of depending on the operating system to raise a SIGSEGV or
1645 another form of trap event when an invalid memory location is
1649 Equivalent to setting the \fBMONO_XDEBUG\fR variable, this emits
1650 symbols into a shared library as the code is JITed that can be loaded
1651 into GDB to inspect symbols.
1653 \fBgen-seq-points\fR
1654 Automatically generates sequence points where the
1655 IL stack is empty. These are places where the debugger can set a
1658 \fBgen-compact-seq-points\fR
1659 This option generates sequence points data that maps native offsets to
1660 IL offsets. Sequence point data is used to display IL offset in
1661 stacktraces. Stacktraces with IL offsets can be symbolicated using
1662 mono-symbolicate tool.
1665 Captures the interrupt signal (Control-C) and displays a stack trace
1666 when pressed. Useful to find out where the program is executing at a
1667 given point. This only displays the stack trace of a single thread.
1670 Instructs the runtime to initialize the stack with
1671 some known values (0x2a on x86-64) at the start of a method to assist
1672 in debuggin the JIT engine.
1674 \fBkeep-delegates\fR
1675 This option will leak delegate trampolines that are no longer
1676 referenced as to present the user with more information about a
1677 delegate misuse. Basically a delegate instance might be created,
1678 passed to unmanaged code, and no references kept in managed code,
1679 which will garbage collect the code. With this option it is possible
1680 to track down the source of the problems.
1682 \fBno-gdb-backtrace\fR
1683 This option will disable the GDB backtrace emitted by the runtime
1684 after a SIGSEGV or SIGABRT in unmanaged code.
1686 \fBpartial-sharing\fR
1687 When this option is set, the runtime can share generated code between
1688 generic types effectively reducing the amount of code generated.
1690 \fBreverse-pinvoke-exceptions
1691 This option will cause mono to abort with a descriptive message when
1692 during stack unwinding after an exception it reaches a native stack
1693 frame. This happens when a managed delegate is passed to native code,
1694 and the managed delegate throws an exception. Mono will normally try
1695 to unwind the stack to the first (managed) exception handler, and it
1696 will skip any native stack frames in the process. This leads to
1697 undefined behaviour (since mono doesn't know how to process native
1698 frames), leaks, and possibly crashes too.
1700 \fBsingle-imm-size\fR
1701 This guarantees that each time managed code is compiled the same
1702 instructions and registers are used, regardless of the size of used
1705 \fBsoft-breakpoints\fR
1706 This option allows using single-steps and breakpoints in hardware
1707 where we cannot do it with signals.
1709 \fBsuspend-on-sigsegv\fR
1710 This option will suspend the program when a native SIGSEGV is received.
1711 This is useful for debugging crashes which do not happen under gdb,
1712 since a live process contains more information than a core file.
1714 \fBsuspend-on-exception\fR
1715 This option will suspend the program when an exception occurs.
1717 \fBsuspend-on-unhandled\fR
1718 This option will suspend the program when an unhadled exception occurs.
1722 \fBMONO_LOG_LEVEL\fR
1723 The logging level, possible values are `error', `critical', `warning',
1724 `message', `info' and `debug'. See the DEBUGGING section for more
1728 Controls the domain of the Mono runtime that logging will apply to.
1729 If set, the log mask is changed to the set value. Possible values are
1730 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1731 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
1732 "security" (e.g. Moonlight CoreCLR support) and "all".
1733 The default value is "all". Changing the mask value allows you to display only
1734 messages for a certain component. You can use multiple masks by comma
1735 separating them. For example to see config file messages and assembly loader
1736 messages set you mask to "asm,cfg".
1739 Used for runtime tracing of method calls. The format of the comma separated
1748 disabled Trace output off upon start.
1751 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1753 \fBMONO_TRACE_LISTENER\fR
1754 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1755 print the output of the System.Diagnostics Trace and Debug classes.
1756 It can be set to a filename, and to Console.Out or Console.Error to display
1757 output to standard output or standard error, respectively. If it's set to
1758 Console.Out or Console.Error you can append an optional prefix that will
1759 be used when writing messages like this: Console.Error:MyProgramName.
1760 See the System.Diagnostics.DefaultTraceListener documentation for more
1763 \fBMONO_WCF_TRACE\fR
1764 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.
1766 \fBMONO_XEXCEPTIONS\fR
1767 This throws an exception when a X11 error is encountered; by default a
1768 message is displayed but execution continues
1770 \fBMONO_XMLSERIALIZER_DEBUG\fR
1771 Set this value to 1 to prevent the serializer from removing the
1772 temporary files that are created for fast serialization; This might
1773 be useful when debugging.
1776 This is used in the System.Windows.Forms implementation when running
1777 with the X11 backend. This is used to debug problems in Windows.Forms
1778 as it forces all of the commands send to X11 server to be done
1779 synchronously. The default mode of operation is asynchronous which
1780 makes it hard to isolate the root of certain problems.
1783 When the the MONO_XDEBUG env var is set, debugging info for JITted
1784 code is emitted into a shared library, loadable into gdb. This enables,
1785 for example, to see managed frame names on gdb backtraces.
1787 \fBMONO_VERBOSE_METHOD\fR
1788 Enables the maximum JIT verbosity for the specified method. This is
1789 very helpfull to diagnose a miscompilation problems of a specific
1792 \fBMONO_VERBOSE_HWCAP\fR
1793 If set, makes the JIT output information about detected CPU features
1794 (such as SSE, CMOV, FCMOV, etc) to stdout.
1796 \fBMONO_CONSERVATIVE_HWCAP\fR
1797 If set, the JIT will not perform any hardware capability detection. This
1798 may be useful to pinpoint the cause of JIT issues. This is the default
1799 when Mono is built as an AOT cross compiler, so that the generated code
1800 will run on most hardware.
1802 If you want to use Valgrind, you will find the file `mono.supp'
1803 useful, it contains the suppressions for the GC which trigger
1804 incorrect warnings. Use it like this:
1806 valgrind --suppressions=mono.supp mono ...
1809 On some platforms, Mono can expose a set of DTrace probes (also known
1810 as user-land statically defined, USDT Probes).
1812 They are defined in the file `mono.d'.
1814 .B ves-init-begin, ves-init-end
1816 Begin and end of runtime initialization.
1818 .B method-compile-begin, method-compile-end
1820 Begin and end of method compilation.
1821 The probe arguments are class name, method name and signature,
1822 and in case of method-compile-end success or failure of compilation.
1826 Begin and end of Garbage Collection.
1828 To verify the availability of the probes, run:
1830 dtrace -P mono'$target' -l -c mono
1833 Mono's Ping implementation for detecting network reachability can
1834 create the ICMP packets itself without requiring the system ping
1835 command to do the work. If you want to enable this on Linux for
1836 non-root users, you need to give the Mono binary special permissions.
1838 As root, run this command:
1840 # setcap cap_net_raw=+ep /usr/bin/mono
1843 On Unix assemblies are loaded from the installation lib directory. If you set
1844 `prefix' to /usr, the assemblies will be located in /usr/lib. On
1845 Windows, the assemblies are loaded from the directory where mono and
1848 .B ~/.mono/aot-cache
1850 The directory for the ahead-of-time compiler demand creation
1851 assemblies are located.
1853 .B /etc/mono/config, ~/.mono/config
1855 Mono runtime configuration file. See the mono-config(5) manual page
1856 for more information.
1858 .B ~/.config/.mono/certs, /usr/share/.mono/certs
1860 Contains Mono certificate stores for users / machine. See the certmgr(1)
1861 manual page for more information on managing certificate stores and
1862 the mozroots(1) page for information on how to import the Mozilla root
1863 certificates into the Mono certificate store.
1865 .B ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
1867 Files in this directory allow a user to customize the configuration
1868 for a given system assembly, the format is the one described in the
1869 mono-config(5) page.
1871 .B ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
1873 Contains Mono cryptographic keypairs for users / machine. They can be
1874 accessed by using a CspParameters object with DSACryptoServiceProvider
1875 and RSACryptoServiceProvider classes.
1877 .B ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
1879 Contains Mono isolated storage for non-roaming users, roaming users and
1880 local machine. Isolated storage can be accessed using the classes from
1881 the System.IO.IsolatedStorage namespace.
1883 .B <assembly>.config
1885 Configuration information for individual assemblies is loaded by the
1886 runtime from side-by-side files with the .config files, see the
1887 http://www.mono-project.com/Config for more information.
1889 .B Web.config, web.config
1891 ASP.NET applications are configured through these files, the
1892 configuration is done on a per-directory basis. For more information
1893 on this subject see the http://www.mono-project.com/Config_system.web
1896 Mailing lists are listed at the
1897 http://www.mono-project.com/community/help/mailing-lists/
1899 http://www.mono-project.com
1902 certmgr(1), csharp(1), mcs(1), mdb(1), monocov(1), monodis(1),
1903 mono-config(5), mozroots(1), mprof-report(1), pdb2mdb(1), xsp(1), mod_mono(8).
1905 For more information on AOT:
1906 http://www.mono-project.com/docs/advanced/aot/
1908 For ASP.NET-related documentation, see the xsp(1) manual page
projects / mono.git / blob