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 Instructs the AOT compiler to generate offline sequence points .msym files.
147 The generated .msym files will be stored into a subfolder of <PATH> named as the
151 Use the GNU style target triple <TRIPLE> to determine some code generation options, i.e.
152 --mtriple=armv7-linux-gnueabi will generate code that targets ARMv7. This is currently
153 only supported by the ARM backend. In LLVM mode, this triple is passed on to the LLVM
156 .I nimt-trampolines=[number]
157 When compiling in full aot mode, the IMT trampolines must be precreated
158 in the AOT image. You can add additional method trampolines with this argument.
162 Instructs the AOT compiler to not output any debugging information.
165 This prevents the AOT compiler from generating a direct calls to a
166 method. The AOT compiler usually generates direct calls for certain
167 methods that do not require going through the PLT (for example,
168 methods that are known to not require a hook like a static
169 constructor) or call into simple internal calls.
172 Instructs the AOT compiler to emit DWARF debugging information. When
173 used together with the nodebug option, only DWARF debugging
174 information is emitted, but not the information that can be used at
177 .I nrgctx-trampolines=[number]
178 When compiling in full aot mode, the generic sharing trampolines must be precreated
179 in the AOT image. You can add additional method trampolines with this argument.
182 .I ntrampolines=[number]
183 When compiling in full aot mode, the method trampolines must be precreated
184 in the AOT image. You can add additional method trampolines with this argument.
187 .I outfile=[filename]
188 Instructs the AOT compiler to save the output to the specified file.
190 .I print-skipped-methods
191 If the AOT compiler cannot compile a method for any reason, enabling this flag
192 will output the skipped methods to the console.
194 .I readonly-value=namespace.typename.fieldname=type/value
195 Override the value of a static readonly field. Usually, during JIT
196 compilation, the static constructor is ran eagerly, so the value of
197 a static readonly field is known at compilation time and the compiler
198 can do a number of optimizations based on it. During AOT, instead, the static
199 constructor can't be ran, so this option can be used to set the value of such
200 a field and enable the same set of optimizations.
201 Type can be any of i1, i2, i4 for integers of the respective sizes (in bytes).
202 Note that signed/unsigned numbers do not matter here, just the storage size.
203 This option can be specified multiple times and it doesn't prevent the static
204 constructor for the type defining the field to execute with the usual rules
205 at runtime (hence possibly computing a different value for the field).
208 .I save-temps,keep-temps
209 Instructs the AOT compiler to keep temporary files.
212 This instructs the compiler to generate sequence point checks that
213 allow Mono's soft debugger to debug applications even on systems where
214 it is not possible to set breakpoints or to single step (certain
215 hardware configurations like the cell phones and video gaming
219 Create an ELF object file (.o) or .s file which can be statically linked into an
220 executable when embedding the mono runtime. When this option is used, the object file
221 needs to be registered with the embedded runtime using the mono_aot_register_module
222 function which takes as its argument the mono_aot_module_<ASSEMBLY NAME>_info global
223 symbol from the object file:
226 extern void *mono_aot_module_hello_info;
228 mono_aot_register_module (mono_aot_module_hello_info);
233 Print various stats collected during AOT compilation.
236 This is an experimental option for the AOT compiler to use multiple threads
237 when compiling the methods.
239 .I tool-prefix=<PREFIX>
240 Prepends <PREFIX> to the name of tools ran by the AOT compiler, i.e. 'as'/'ld'. For
241 example, --tool=prefix=arm-linux-gnueabi- will make the AOT compiler run
242 'arm-linux-gnueabi-as' instead of 'as'.
245 Instructs the AOT compiler to emit debug symbol information.
247 For more information about AOT, see: http://www.mono-project.com/docs/advanced/aot/
250 \fB--attach=[options]\fR
251 Currently the only option supported by this command line argument is
252 \fBdisable\fR which disables the attach functionality.
254 \fB--config filename\fR
255 Load the specified configuration file instead of the default one(s).
256 The default files are /etc/mono/config and ~/.mono/config or the file
257 specified in the MONO_CONFIG environment variable, if set. See the
258 mono-config(5) man page for details on the format of this file.
260 \fB--aot-path=PATH\fR
261 List of additional directories to search for AOT images.
263 \fB--debugger-agent=[options]\fR
264 This instructs the Mono runtime to
265 start a debugging agent inside the Mono runtime and connect it to a
266 client user interface will control the Mono process.
267 This option is typically used by IDEs, like the MonoDevelop IDE.
269 The configuration is specified using one of more of the following options:
275 Use this option to specify the IP address where your debugger client is
280 Specifies the diagnostics log level for
284 Used to specify the file where the log will be stored, it defaults to
288 Defaults to no, with the default option Mono will actively connect to the
289 host/port configured with the \fBaddress\fR option. If you set it to 'y', it
290 instructs the Mono runtime to start debugging in server mode, where Mono
291 actively waits for the debugger front end to connect to the Mono process.
292 Mono will print out to stdout the IP address and port where it is listening.
295 If set to yes, Mono will call \fBsetpgid(0, 0)\fB on startup, if that function
296 is available on the system. This is useful for ensuring that signals delivered
297 to a process that is executing the debuggee are not propagated to the debuggee,
298 e.g. when Ctrl-C sends \fBSIGINT\fB to the \fBsdb\fB tool.
301 Defaults to yes, with the default option Mono will suspend the vm on startup
302 until it connects successfully to a debugger front end. If you set it to 'n', in
303 conjunction with \fBserver=y\fR, it instructs the Mono runtime to run as normal,
304 while caching metadata to send to the debugger front end on connection..
306 .I transport=transport_name
308 This is used to specify the transport that the debugger will use to
309 communicate. It must be specified and currently requires this to
315 Configures the virtual machine to be better suited for desktop
316 applications. Currently this sets the GC system to avoid expanding
317 the heap as much as possible at the expense of slowing down garbage
321 This is an experimental flag that instructs the Mono runtime to not
322 generate any code at runtime and depend exclusively on the code
323 generated from using mono --aot=full previously. This is useful for
324 platforms that do not permit dynamic code generation.
326 Notice that this feature will abort execution at runtime if a codepath
327 in your program, or Mono's class libraries attempts to generate code
328 dynamically. You should test your software upfront and make sure that
329 you do not use any dynamic features.
331 \fB--gc=boehm\fR, \fB--gc=sgen\fR
332 Selects the Garbage Collector engine for Mono to use, Boehm or SGen.
333 Currently this merely ensures that you are running either the
334 \fImono\fR or \fImono-sgen\fR commands. This flag can be set in the
335 \fBMONO_ENV_OPTIONS\fR environment variable to force all of your child
336 processes to use one particular kind of GC with the Mono runtime.
338 \fB--gc-debug=[options]\fR
339 Command line equivalent of the \fBMONO_GC_DEBUG\fR environment variable.
341 \fB--gc-params=[options]\fR
342 Command line equivalent of the \fBMONO_GC_PARAMS\fR environment variable.
344 \fB--arch=32\fR, \fB--arch=64\fR
345 (Mac OS X only): Selects the bitness of the Mono binary used, if
346 available. If the binary used is already for the selected bitness, nothing
347 changes. If not, the execution switches to a binary with the selected
348 bitness suffix installed side by side (for example, '/bin/mono --arch=64'
349 will switch to '/bin/mono64' iff '/bin/mono' is a 32-bit build).
351 \fB--help\fR, \fB-h\fR
352 Displays usage instructions.
355 If the Mono runtime has been compiled with LLVM support (not available
356 in all configurations), Mono will use the LLVM optimization and code
357 generation engine to JIT or AOT compile.
359 For more information, consult: http://www.mono-project.com/docs/advanced/mono-llvm/
362 When using a Mono that has been compiled with LLVM support, it forces
363 Mono to fallback to its JIT engine and not use the LLVM backend.
365 \fB--optimize=MODE\fR, \fB-O=MODE\fR
366 MODE is a comma separated list of optimizations. They also allow
367 optimizations to be turned off by prefixing the optimization name with
370 In general, Mono has been tuned to use the default set of flags,
371 before using these flags for a deployment setting, you might want to
372 actually measure the benefits of using them.
374 The following optimization flags are implemented in the core engine:
376 abcrem Array bound checks removal
377 all Turn on all optimizations
378 aot Usage of Ahead Of Time compiled code
379 branch Branch optimizations
380 cfold Constant folding
381 cmov Conditional moves [arch-dependency]
382 deadce Dead code elimination
383 consprop Constant propagation
384 copyprop Copy propagation
385 fcmov Fast x86 FP compares [arch-dependency]
386 float32 Perform 32-bit float arithmetic using 32-bit operations
387 gshared Enable generic code sharing.
388 inline Inline method calls
389 intrins Intrinsic method implementations
390 linears Linear scan global reg allocation
391 leaf Leaf procedures optimizations
392 loop Loop related optimizations
393 peephole Peephole postpass
394 precomp Precompile all methods before executing Main
395 sched Instruction scheduling
396 shared Emit per-domain code
397 sse2 SSE2 instructions on x86 [arch-dependency]
398 tailc Tail recursion and tail calls
401 For example, to enable all the optimization but dead code
402 elimination and inlining, you can use:
404 -O=all,-deadce,-inline
407 The flags that are flagged with [arch-dependency] indicate that the
408 given option if used in combination with Ahead of Time compilation
409 (--aot flag) would produce pre-compiled code that will depend on the
410 current CPU and might not be safely moved to another computer.
414 The following optimizations are supported
417 Requests that the runtime performn 32-bit floating point operations
418 using only 32-bits. By default the Mono runtime tries to use the
419 highest precision available for floating point operations, but while
420 this might render better results, the code might run slower. This
421 options also affects the code generated by the LLVM backend.
424 Controls whether the runtime should attempt to inline (the default),
425 or not inline methods invocations
429 \fB--runtime=VERSION\fR
430 Mono supports different runtime versions. The version used depends on the program
431 that is being run or on its configuration file (named program.exe.config). This option
432 can be used to override such autodetection, by forcing a different runtime version
433 to be used. Note that this should only be used to select a later compatible runtime
434 version than the one the program was compiled against. A typical usage is for
435 running a 1.1 program on a 2.0 version:
437 mono --runtime=v2.0.50727 program.exe
440 \fB--security\fR, \fB--security=mode\fR
441 Activate the security manager, a currently experimental feature in
442 Mono and it is OFF by default. The new code verifier can be enabled
443 with this option as well.
447 Using security without parameters is equivalent as calling it with the
450 The following modes are supported:
453 Enables the core-clr security system, typically used for
454 Moonlight/Silverlight applications. It provides a much simpler
455 security system than CAS, see http://www.mono-project.com/docs/web/moonlight/
456 for more details and links to the descriptions of this new system.
459 Enables the new verifier and performs basic verification for code
460 validity. In this mode, unsafe code and P/Invoke are allowed. This
461 mode provides a better safety guarantee but it is still possible
462 for managed code to crash Mono.
465 Enables the new verifier and performs full verification of the code
466 being executed. It only allows verifiable code to be executed.
467 Unsafe code is not allowed but P/Invoke is. This mode should
468 not allow managed code to crash mono. The verification is not as
469 strict as ECMA 335 standard in order to stay compatible with the MS
472 The security system acts on user code: code contained in mscorlib or
473 the global assembly cache is always trusted.
478 Configures the virtual machine to be better suited for server
479 operations (currently, allows a heavier threadpool initialization).
482 Verifies mscorlib and assemblies in the global
483 assembly cache for valid IL, and all user code for IL
486 This is different from \fB--security\fR's verifiable
487 or validil in that these options only check user code and skip
488 mscorlib and assemblies located on the global assembly cache.
490 \fB-V\fR, \fB--version\fR
491 Prints JIT version information (system configuration, release number
492 and branch names if available).
495 .SH DEVELOPMENT OPTIONS
496 The following options are used to help when developing a JITed application.
498 \fB--debug\fR, \fB--debug=OPTIONS\fR
499 Turns on the debugging mode in the runtime. If an assembly was
500 compiled with debugging information, it will produce line number
501 information for stack traces.
505 The optional OPTIONS argument is a comma separated list of debugging
506 options. These options are turned off by default since they generate
507 much larger and slower code at runtime.
509 The following options are supported:
512 Produces a detailed error when throwing a InvalidCastException. This
513 option needs to be enabled as this generates more verbose code at
517 Disable some JIT optimizations which are usually only disabled when
518 running inside the debugger. This can be helpful if you want to attach
519 to the running process with mdb.
522 Generate and register debugging information with gdb. This is only supported on some
523 platforms, and only when using gdb 7.0 or later.
527 \fB--profile[=profiler[:profiler_args]]\fR
528 Turns on profiling. For more information about profiling applications
529 and code coverage see the sections "PROFILING" and "CODE COVERAGE"
532 This option can be used multiple times, each time will load an
533 additional profiler. This allows developers to use modules that
534 extend the JIT through the Mono profiling interface.
536 \fB--trace[=expression]\fR
537 Shows method names as they are invoked. By default all methods are
540 The trace can be customized to include or exclude methods, classes or
541 assemblies. A trace expression is a comma separated list of targets,
542 each target can be prefixed with a minus sign to turn off a particular
543 target. The words `program', `all' and `disabled' have special
544 meaning. `program' refers to the main program being executed, and
545 `all' means all the method calls.
547 The `disabled' option is used to start up with tracing disabled. It
548 can be enabled at a later point in time in the program by sending the
549 SIGUSR2 signal to the runtime.
551 Assemblies are specified by their name, for example, to trace all
552 calls in the System assembly, use:
555 mono --trace=System app.exe
558 Classes are specified with the T: prefix. For example, to trace all
559 calls to the System.String class, use:
562 mono --trace=T:System.String app.exe
565 And individual methods are referenced with the M: prefix, and the
566 standard method notation:
569 mono --trace=M:System.Console:WriteLine app.exe
572 Exceptions can also be traced, it will cause a stack trace to be
573 printed every time an exception of the specified type is thrown.
574 The exception type can be specified with or without the namespace,
575 and to trace all exceptions, specify 'all' as the type name.
578 mono --trace=E:System.Exception app.exe
581 As previously noted, various rules can be specified at once:
584 mono --trace=T:System.String,T:System.Random app.exe
587 You can exclude pieces, the next example traces calls to
588 System.String except for the System.String:Concat method.
591 mono --trace=T:System.String,-M:System.String:Concat
594 You can trace managed to unmanaged transitions using
595 the wrapper qualifier:
598 mono --trace=wrapper app.exe
601 Finally, namespaces can be specified using the N: prefix:
604 mono --trace=N:System.Xml
608 \fB--no-x86-stack-align\fR
609 Don't align stack frames on the x86 architecture. By default, Mono
610 aligns stack frames to 16 bytes on x86, so that local floating point
611 and SIMD variables can be properly aligned. This option turns off the
612 alignment, which usually saves one intruction per call, but might
613 result in significantly lower floating point and SIMD performance.
616 Generate a JIT method map in a /tmp/perf-PID.map file. This file is then
617 used, for example, by the perf tool included in recent Linux kernels.
618 Each line in the file has:
621 HEXADDR HEXSIZE methodname
624 Currently this option is only supported on Linux.
625 .SH JIT MAINTAINER OPTIONS
626 The maintainer options are only used by those developing the runtime
627 itself, and not typically of interest to runtime users or developers.
629 \fB--bisect=optimization:filename\fR
630 This flag is used by the automatic optimization bug bisector. It
631 takes an optimization flag and a filename of a file containing a list
632 of full method names, one per line. When it compiles one of the
633 methods in the file it will use the optimization given, in addition to
634 the optimizations that are otherwise enabled. Note that if the
635 optimization is enabled by default, you should disable it with `-O`,
636 otherwise it will just apply to every method, whether it's in the file
640 Inserts a breakpoint before the method whose name is `method'
641 (namespace.class:methodname). Use `Main' as method name to insert a
642 breakpoint on the application's main method. You can use it also with
643 generics, for example "System.Collections.Generic.Queue`1:Peek"
646 Inserts a breakpoint on exceptions. This allows you to debug your
647 application with a native debugger when an exception is thrown.
650 This compiles a method (namespace.name:methodname), this is used for
651 testing the compiler performance or to examine the output of the code
655 Compiles all the methods in an assembly. This is used to test the
656 compiler performance or to examine the output of the code generator
658 \fB--graph=TYPE METHOD\fR
659 This generates a postscript file with a graph with the details about
660 the specified method (namespace.name:methodname). This requires `dot'
661 and ghostview to be installed (it expects Ghostview to be called
664 The following graphs are available:
666 cfg Control Flow Graph (CFG)
668 code CFG showing code
669 ssa CFG showing code after SSA translation
670 optcode CFG showing code after IR optimizations
673 Some graphs will only be available if certain optimizations are turned
677 Instruct the runtime on the number of times that the method specified
678 by --compile (or all the methods if --compileall is used) to be
679 compiled. This is used for testing the code generator performance.
682 Displays information about the work done by the runtime during the
683 execution of an application.
685 \fB--wapi=hps|semdel\fR
686 Perform maintenance of the process shared data.
688 semdel will delete the global semaphore.
690 hps will list the currently used handles.
692 \fB-v\fR, \fB--verbose\fR
693 Increases the verbosity level, each time it is listed, increases the
694 verbosity level to include more information (including, for example,
695 a disassembly of the native code produced, code selector info etc.).
697 The Mono runtime allows external processes to attach to a running
698 process and load assemblies into the running program. To attach to
699 the process, a special protocol is implemented in the Mono.Management
702 With this support it is possible to load assemblies that have an entry
703 point (they are created with -target:exe or -target:winexe) to be
704 loaded and executed in the Mono process.
706 The code is loaded into the root domain, and it starts execution on
707 the special runtime attach thread. The attached program should
708 create its own threads and return after invocation.
710 This support allows for example debugging applications by having the
711 csharp shell attach to running processes.
713 The mono runtime includes a profiler that can be used to explore
714 various performance related problems in your application. The
715 profiler is activated by passing the --profile command line argument
716 to the Mono runtime, the format is:
719 --profile[=profiler[:profiler_args]]
722 Mono has a built-in profiler called 'default' (and is also the default
723 if no arguments are specified), but developers can write custom
724 profilers, see the section "CUSTOM PROFILERS" for more details.
728 is not specified, the default profiler is used.
732 is a profiler-specific string of options for the profiler itself.
734 The default profiler accepts the following options 'alloc' to profile
735 memory consumption by the application; 'time' to profile the time
736 spent on each routine; 'jit' to collect time spent JIT-compiling methods
737 and 'stat' to perform sample statistical profiling.
738 If no options are provided the default is 'alloc,time,jit'.
741 profile data is printed to stdout: to change this, use the 'file=filename'
742 option to output the data to filename.
747 mono --profile program.exe
751 That will run the program with the default profiler and will do time
752 and allocation profiling.
756 mono --profile=default:stat,alloc,file=prof.out program.exe
759 Will do sample statistical profiling and allocation profiling on
760 program.exe. The profile data is put in prof.out.
762 Note that the statistical profiler has a very low overhead and should
763 be the preferred profiler to use (for better output use the full path
764 to the mono binary when running and make sure you have installed the
765 addr2line utility that comes from the binutils package).
767 This is the most advanced profiler.
769 The Mono \f[I]log\f[] profiler can be used to collect a lot of
770 information about a program running in the Mono runtime.
771 This data can be used (both while the process is running and later)
772 to do analyses of the program behaviour, determine resource usage,
773 performance issues or even look for particular execution patterns.
775 This is accomplished by logging the events provided by the Mono
776 runtime through the profiling interface and periodically writing
777 them to a file which can be later inspected with the mprof-report(1)
780 More information about how to use the log profiler is available on the
781 mprof-report(1) page.
783 Mono provides a mechanism for loading other profiling modules which in
784 the form of shared libraries. These profiling modules can hook up to
785 various parts of the Mono runtime to gather information about the code
788 To use a third party profiler you must pass the name of the profiler
792 mono --profile=custom program.exe
796 In the above sample Mono will load the user defined profiler from the
797 shared library `mono-profiler-custom.so'. This profiler module must
798 be on your dynamic linker library path.
800 A list of other third party profilers is available from Mono's web
801 site (www.mono-project.com/docs/advanced/performance-tips/)
803 Custom profiles are written as shared libraries. The shared library
804 must be called `mono-profiler-NAME.so' where `NAME' is the name of
807 For a sample of how to write your own custom profiler look in the
808 Mono source tree for in the samples/profiler.c.
810 Mono ships with a code coverage module. This module is activated by
811 using the Mono --profile=cov option. The format is:
812 \fB--profile=cov[:assembly-name[/namespace]] test-suite.exe\fR
814 By default code coverage will default to all the assemblies loaded,
815 you can limit this by specifying the assembly name, for example to
816 perform code coverage in the routines of your program use, for example
817 the following command line limits the code coverage to routines in the
821 mono --profile=cov:demo demo.exe
827 does not include the extension.
829 You can further restrict the code coverage output by specifying a
833 mono --profile=cov:demo/My.Utilities demo.exe
837 Which will only perform code coverage in the given assembly and
840 Typical output looks like this:
843 Not covered: Class:.ctor ()
844 Not covered: Class:A ()
845 Not covered: Driver:.ctor ()
846 Not covered: Driver:method ()
847 Partial coverage: Driver:Main ()
852 The offsets displayed are IL offsets.
854 A more powerful coverage tool is available in the module `monocov'.
855 See the monocov(1) man page for details.
857 You can improve startup performance by using the AOT profiler.
859 Typically the AOT compiler (\fBmono --aot\fR) will not generate code
860 for generic instantiations. To solve this, you can run Mono with the
861 AOT profiler to find out all the generic instantiations that are used,
862 and then instructing the AOT compiler to produce code for these.
864 This command will run the specified app.exe and produce the
865 \fBout.aotprof\fR file with the data describing the generic
866 instantiations that are needed:
868 $ mono --profile=aot:output=out.aotprof app.exe
871 Once you have this data, you can pass this to Mono's AOT compiler to
872 instruct it to generate code for it:
874 $ mono --aot=profile=out.aotprof
877 To debug managed applications, you can use the
879 command, a command line debugger.
881 It is possible to obtain a stack trace of all the active threads in
882 Mono by sending the QUIT signal to Mono, you can do this from the
883 command line, like this:
889 Where pid is the Process ID of the Mono process you want to examine.
890 The process will continue running afterwards, but its state is not
894 this is a last-resort mechanism for debugging applications and should
895 not be used to monitor or probe a production application. The
896 integrity of the runtime after sending this signal is not guaranteed
897 and the application might crash or terminate at any given point
900 The \fB--debug=casts\fR option can be used to get more detailed
901 information for Invalid Cast operations, it will provide information
902 about the types involved.
904 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
905 to get verbose debugging output about the execution of your
906 application within Mono.
910 environment variable if set, the logging level is changed to the set
911 value. Possible values are "error", "critical", "warning", "message",
912 "info", "debug". The default value is "error". Messages with a logging
913 level greater then or equal to the log level will be printed to
916 Use "info" to track the dynamic loading of assemblies.
921 environment variable to limit the extent of the messages you get:
922 If set, the log mask is changed to the set value. Possible values are
923 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
924 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
925 "security" (e.g. Moonlight CoreCLR support), "threadpool" (thread pool generic),
926 "io-threadpool" (thread pool I/O), "io-layer" (I/O layer - sockets, handles, shared memory etc)
928 The default value is "all". Changing the mask value allows you to display only
929 messages for a certain component. You can use multiple masks by comma
930 separating them. For example to see config file messages and assembly loader
931 messages set you mask to "asm,cfg".
933 The following is a common use to track down problems with P/Invoke:
936 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
940 .SH DEBUGGING WITH LLDB
941 If you are using LLDB, you can use the
943 script to print some internal data structures with it. To use this,
948 command script import $PREFIX/lib/mono/lldb/mono.py
951 Where $PREFIX is the prefix value that you used when you configured
952 Mono (typically /usr).
954 Once this is done, then you can inspect some Mono Runtime data structures,
959 (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
962 Mono's XML serialization engine by default will use a reflection-based
963 approach to serialize which might be slow for continuous processing
964 (web service applications). The serialization engine will determine
965 when a class must use a hand-tuned serializer based on a few
966 parameters and if needed it will produce a customized C# serializer
967 for your types at runtime. This customized serializer then gets
968 dynamically loaded into your application.
970 You can control this with the MONO_XMLSERIALIZER_THS environment
973 The possible values are
975 to disable the use of a C# customized
976 serializer, or an integer that is the minimum number of uses before
977 the runtime will produce a custom serializer (0 will produce a
978 custom serializer on the first access, 50 will produce a serializer on
979 the 50th use). Mono will fallback to an interpreted serializer if the
980 serializer generation somehow fails. This behavior can be disabled
981 by setting the option
983 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
984 .SH ENVIRONMENT VARIABLES
987 Turns off the garbage collection in Mono. This should be only used
988 for debugging purposes
991 (Also \fBhttp_proxy\fR) If set, web requests using the Mono
992 Class Library will be automatically proxied through the given URL.
993 Not supported on Windows, Mac OS, iOS or Android. See also \fBNO_PROXY\fR.
996 When Mono is compiled with LLVM support, this instructs the runtime to
997 stop using LLVM after the specified number of methods are JITed.
998 This is a tool used in diagnostics to help isolate problems in the
999 code generation backend. For example \fBLLVM_COUNT=10\fR would only
1000 compile 10 methods with LLVM and then switch to the Mono JIT engine.
1001 \fBLLVM_COUNT=0\fR would disable the LLVM engine altogether.
1003 \fBMONO_AOT_CACHE\fR
1004 If set, this variable will instruct Mono to ahead-of-time compile new
1005 assemblies on demand and store the result into a cache in
1008 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
1009 Mono contains a feature which allows modifying settings in the .config files shipped
1010 with Mono by using config section mappers. The mappers and the mapping rules are
1011 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
1012 settings.map file found in the top-level directory of your ASP.NET application.
1013 Both files are read by System.Web on application startup, if they are found at the
1014 above locations. If you don't want the mapping to be performed you can set this
1015 variable in your environment before starting the application and no action will
1018 \fBMONO_ASPNET_WEBCONFIG_CACHESIZE\fR
1019 Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager
1020 queries. Its default size is 100 items, and when more items are needed, cache
1021 evictions start happening. If evictions are too frequent this could impose
1022 unnecessary overhead, which could be avoided by using this environment variable
1023 to set up a higher cache size (or to lower memory requirements by decreasing it).
1025 \fBMONO_CAIRO_DEBUG_DISPOSE\fR
1026 If set, causes Mono.Cairo to collect stack traces when objects are allocated,
1027 so that the finalization/Dispose warnings include information about the
1031 If set, this variable overrides the default system configuration directory
1032 ($PREFIX/etc). It's used to locate machine.config file.
1035 Sets the style of COM interop. If the value of this variable is "MS"
1036 Mono will use string marhsalling routines from the liboleaut32 for the
1037 BSTR type library, any other values will use the mono-builtin BSTR
1041 If set, this variable overrides the default runtime configuration file
1042 ($PREFIX/etc/mono/config). The --config command line options overrides the
1043 environment variable.
1046 Override the automatic cpu detection mechanism. Currently used only on arm.
1047 The format of the value is as follows:
1053 where V is the architecture number 4, 5, 6, 7 and the options can be currently be
1054 "thumb" or "thumb2". Example:
1057 MONO_CPU_ARCH="armv4 thumb" mono ...
1061 \fBMONO_ARM_FORCE_SOFT_FLOAT\fR
1062 When Mono is built with a soft float fallback on ARM and this variable is set to
1063 "1", Mono will always emit soft float code, even if a VFP unit is
1066 \fBMONO_DARWIN_WATCHER_MAXFDS\fR
1067 This is a debugging aid used to force limits on the FileSystemWatcher
1068 implementation in Darwin. There is no limit by default.
1070 \fBMONO_DISABLE_AIO\fR
1071 If set, tells mono NOT to attempt using native asynchronous I/O services. In
1072 that case, a default select/poll implementation is used. Currently only epoll()
1075 \fBMONO_DISABLE_MANAGED_COLLATION\fR
1076 If this environment variable is `yes', the runtime uses unmanaged
1077 collation (which actually means no culture-sensitive collation). It
1078 internally disables managed collation functionality invoked via the
1079 members of System.Globalization.CompareInfo class. Collation is
1082 \fBMONO_DISABLE_SHM\fR
1083 Unix only: If set, disables the shared memory files used for
1084 cross-process handles: process have only private handles. This means
1085 that process and thread handles are not available to other processes,
1086 and named mutexes, named events and named semaphores are not visible
1089 This is can also be enabled by default by passing the
1090 "--disable-shared-handles" option to configure.
1092 This is the default from mono 2.8 onwards.
1094 \fBMONO_DISABLE_SHARED_AREA\fR
1095 Unix only: If set, disable usage of shared memory for exposing
1096 performance counters. This means it will not be possible to both
1097 externally read performance counters from this processes or read
1098 those of external processes.
1101 When set, enables the use of a fully managed DNS resolver instead of the
1102 regular libc functions. This resolver performs much better when multiple
1103 queries are run in parallel.
1105 Note that /etc/nsswitch.conf will be ignored.
1107 \fBMONO_EGD_SOCKET\fR
1108 For platforms that do not otherwise have a way of obtaining random bytes
1109 this can be set to the name of a file system socket on which an egd or
1110 prngd daemon is listening.
1112 \fBMONO_ENABLE_COOP\fR
1113 This makes the Mono runtime and the SGen garbage collector run in cooperative
1114 mode as opposed to run on preemptive mode. Preemptive mode is the mode
1115 that Mono has used historically, going back to the Boehm days, where the
1116 garbage collector would run at any point and suspend execution of all
1117 threads as required to perform a garbage collection. The cooperative mode
1118 on the other hand requires the cooperation of all threads to stop at a
1119 safe point. This makes for an easier to debug garbage collector. As
1120 of Mono 4.3.0 it is a work in progress, and while it works, it has not
1121 been used extensively. This option enabled the feature and allows us to
1122 find spots that need to be tuned for this mode of operation. Alternatively,
1123 this mode can be enabled at compile time by using the --with-cooperative-gc
1124 flag when calling configure.
1126 \fBMONO_ENV_OPTIONS\fR
1127 This environment variable allows you to pass command line arguments to
1128 a Mono process through the environment. This is useful for example
1129 to force all of your Mono processes to use LLVM or SGEN without having
1130 to modify any launch scripts.
1132 \fBMONO_SDB_ENV_OPTIONS\fR
1133 Used to pass extra options to the debugger agent in the runtime, as they were passed
1134 using --debugger-agent=.
1136 \fBMONO_EVENTLOG_TYPE\fR
1137 Sets the type of event log provider to use (for System.Diagnostics.EventLog).
1139 Possible values are:
1144 Persists event logs and entries to the local file system.
1146 The directory in which to persist the event logs, event sources and entries
1147 can be specified as part of the value.
1149 If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog"
1150 on unix and "%APPDATA%\mono\eventlog" on Windows.
1155 Uses the native win32 API to write events and registers event logs and
1156 event sources in the registry. This is only available on Windows.
1158 On Unix, the directory permission for individual event log and event source
1159 directories is set to 777 (with +t bit) allowing everyone to read and write
1160 event log entries while only allowing entries to be deleted by the user(s)
1165 Silently discards any events.
1168 The default is "null" on Unix (and versions of Windows before NT), and
1169 "win32" on Windows NT (and higher).
1172 \fBMONO_EXTERNAL_ENCODINGS\fR
1173 If set, contains a colon-separated list of text encodings to try when
1174 turning externally-generated text (e.g. command-line arguments or
1175 filenames) into Unicode. The encoding names come from the list
1176 provided by iconv, and the special case "default_locale" which refers
1177 to the current locale's default encoding.
1179 When reading externally-generated text strings UTF-8 is tried first,
1180 and then this list is tried in order with the first successful
1181 conversion ending the search. When writing external text (e.g. new
1182 filenames or arguments to new processes) the first item in this list
1183 is used, or UTF-8 if the environment variable is not set.
1185 The problem with using MONO_EXTERNAL_ENCODINGS to process your
1186 files is that it results in a problem: although its possible to get
1187 the right file name it is not necessarily possible to open the file.
1188 In general if you have problems with encodings in your filenames you
1189 should use the "convmv" program.
1191 \fBMONO_GC_PARAMS\fR
1192 When using Mono with the SGen garbage collector this variable controls
1193 several parameters of the collector. The variable's value is a comma
1194 separated list of words.
1198 \fBmax-heap-size=\fIsize\fR
1199 Sets the maximum size of the heap. The size is specified in bytes and must
1200 be a power of two. The suffixes `k', `m' and `g' can be used to
1201 specify kilo-, mega- and gigabytes, respectively. The limit is the sum
1202 of the nursery, major heap and large object heap. Once the limit is reached
1203 the application will receive OutOfMemoryExceptions when trying to allocate.
1204 Not the full extent of memory set in max-heap-size could be available to
1205 satisfy a single allocation due to internal fragmentation. By default heap
1206 limits is disabled and the GC will try to use all available memory.
1208 \fBnursery-size=\fIsize\fR
1209 Sets the size of the nursery. The size is specified in bytes and must
1210 be a power of two. The suffixes `k', `m' and `g' can be used to
1211 specify kilo-, mega- and gigabytes, respectively. The nursery is the
1212 first generation (of two). A larger nursery will usually speed up the
1213 program but will obviously use more memory. The default nursery size
1216 \fBmajor=\fIcollector\fR Specifies which major collector to use.
1217 Options are `marksweep' for the Mark&Sweep collector, and
1218 `marksweep-conc' for concurrent Mark&Sweep. The non-concurrent
1219 Mark&Sweep collector is the default.
1221 \fBsoft-heap-limit=\fIsize\fR
1222 Once the heap size gets larger than this size, ignore what the default
1223 major collection trigger metric says and only allow four nursery size's
1224 of major heap growth between major collections.
1226 \fBevacuation-threshold=\fIthreshold\fR
1227 Sets the evacuation threshold in percent. This option is only available
1228 on the Mark&Sweep major collectors. The value must be an
1229 integer in the range 0 to 100. The default is 66. If the sweep phase of
1230 the collection finds that the occupancy of a specific heap block type is
1231 less than this percentage, it will do a copying collection for that block
1232 type in the next major collection, thereby restoring occupancy to close
1233 to 100 percent. A value of 0 turns evacuation off.
1235 \fB(no-)lazy-sweep\fR
1236 Enables or disables lazy sweep for the Mark&Sweep collector. If
1237 enabled, the sweeping of individual major heap blocks is done
1238 piecemeal whenever the need arises, typically during nursery
1239 collections. Lazy sweeping is enabled by default.
1241 \fB(no-)concurrent-sweep\fR
1242 Enables or disables concurrent sweep for the Mark&Sweep collector. If
1243 enabled, the iteration of all major blocks to determine which ones can
1244 be freed and which ones have to be kept and swept, is done
1245 concurrently with the running program. Concurrent sweeping is enabled
1248 \fBstack-mark=\fImark-mode\fR
1249 Specifies how application threads should be scanned. Options are
1250 `precise` and `conservative`. Precise marking allow the collector
1251 to know what values on stack are references and what are not.
1252 Conservative marking threats all values as potentially references
1253 and leave them untouched. Precise marking reduces floating garbage
1254 and can speed up nursery collection and allocation rate, it has
1255 the downside of requiring a significant extra memory per compiled
1256 method. The right option, unfortunately, requires experimentation.
1258 \fBsave-target-ratio=\fIratio\fR
1259 Specifies the target save ratio for the major collector. The collector
1260 lets a given amount of memory to be promoted from the nursery due to
1261 minor collections before it triggers a major collection. This amount
1262 is based on how much memory it expects to free. It is represented as
1263 a ratio of the size of the heap after a major collection.
1264 Valid values are between 0.1 and 2.0. The default is 0.5.
1265 Smaller values will keep the major heap size smaller but will trigger
1266 more major collections. Likewise, bigger values will use more memory
1267 and result in less frequent major collections.
1268 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1270 \fBdefault-allowance-ratio=\fIratio\fR
1271 Specifies the default allocation allowance when the calculated size
1272 is too small. The allocation allowance is how much memory the collector
1273 let be promoted before triggered a major collection.
1274 It is a ratio of the nursery size.
1275 Valid values are between 1.0 and 10.0. The default is 4.0.
1276 Smaller values lead to smaller heaps and more frequent major collections.
1277 Likewise, bigger values will allow the heap to grow faster but use
1278 more memory when it reaches a stable size.
1279 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1281 \fBminor=\fIminor-collector\fR
1282 Specifies which minor collector to use. Options are 'simple' which
1283 promotes all objects from the nursery directly to the old generation
1284 and 'split' which lets object stay longer on the nursery before promoting.
1286 \fBalloc-ratio=\fIratio\fR
1287 Specifies the ratio of memory from the nursery to be use by the alloc space.
1288 This only can only be used with the split minor collector.
1289 Valid values are integers between 1 and 100. Default is 60.
1291 \fBpromotion-age=\fIage\fR
1292 Specifies the required age of an object must reach inside the nursery before
1293 been promoted to the old generation. This only can only be used with the
1294 split minor collector.
1295 Valid values are integers between 1 and 14. Default is 2.
1297 \fB(no-)cementing\fR
1298 Enables or disables cementing. This can dramatically shorten nursery
1299 collection times on some benchmarks where pinned objects are referred
1300 to from the major heap.
1302 \fBallow-synchronous-major\fR
1303 This forbids the major collector from performing synchronous major collections.
1304 The major collector might want to do a synchronous collection due to excessive
1305 fragmentation. Disabling this might trigger OutOfMemory error in situations that
1306 would otherwise not happen.
1311 When using Mono with the SGen garbage collector this environment
1312 variable can be used to turn on various debugging features of the
1313 collector. The value of this variable is a comma separated list of
1314 words. Do not use these options in production.
1319 Sets the debug level to the specified number.
1321 \fBprint-allowance\fR
1322 After each major collection prints memory consumption for before and
1323 after the collection and the allowance for the minor collector, i.e. how
1324 much the heap is allowed to grow from minor collections before the next
1325 major collection is triggered.
1328 Gathers statistics on the classes whose objects are pinned in the
1329 nursery and for which global remset entries are added. Prints those
1330 statistics when shutting down.
1332 \fBcollect-before-allocs\fR
1334 \fBcheck-remset-consistency\fR
1335 This performs a remset consistency check at various opportunities, and
1336 also clears the nursery at collection time, instead of the default,
1337 when buffers are allocated (clear-at-gc). The consistency check
1338 ensures that there are no major to minor references that are not on
1339 the remembered sets.
1341 \fBmod-union-consistency-check\fR
1342 Checks that the mod-union cardtable is consistent before each
1343 finishing major collection pause. This check is only applicable to
1344 concurrent major collectors.
1346 \fBcheck-mark-bits\fR
1347 Checks that mark bits in the major heap are consistent at the end of
1348 each major collection. Consistent mark bits mean that if an object is
1349 marked, all objects that it had references to must also be marked.
1351 \fBcheck-nursery-pinned\fR
1352 After nursery collections, and before starting concurrent collections,
1353 check whether all nursery objects are pinned, or not pinned -
1354 depending on context. Does nothing when the split nursery collector
1357 \fBxdomain-checks\fR
1358 Performs a check to make sure that no references are left to an
1361 \fBclear-at-tlab-creation\fR
1362 Clears the nursery incrementally when the thread local allocation
1363 buffers (TLAB) are created. The default setting clears the whole
1366 \fBdebug-clear-at-tlab-creation\fR
1367 Clears the nursery incrementally when the thread local allocation
1368 buffers (TLAB) are created, but at GC time fills it with the byte
1369 `0xff`, which should result in a crash more quickly if
1370 `clear-at-tlab-creation` doesn't work properly.
1373 This clears the nursery at GC time instead of doing it when the thread
1374 local allocation buffer (TLAB) is created. The default is to clear
1375 the nursery at TLAB creation time.
1378 Don't do minor collections. If the nursery is full, a major collection
1379 is triggered instead, unless it, too, is disabled.
1382 Don't do major collections.
1384 \fBconservative-stack-mark\fR
1385 Forces the GC to scan the stack conservatively, even if precise
1386 scanning is available.
1388 \fBno-managed-allocator\fR
1389 Disables the managed allocator.
1391 \fBcheck-scan-starts\fR
1392 If set, does a plausibility check on the scan_starts before and after each collection
1394 \fBverify-nursery-at-minor-gc\fR
1395 If set, does a complete object walk of the nursery at the start of each minor collection.
1397 \fBdump-nursery-at-minor-gc\fR
1398 If set, dumps the contents of the nursery at the start of each minor collection. Requires
1399 verify-nursery-at-minor-gc to be set.
1401 \fBheap-dump=\fIfile\fR
1402 Dumps the heap contents to the specified file. To visualize the
1403 information, use the mono-heapviz tool.
1405 \fBbinary-protocol=\fIfile\fR
1406 Outputs the debugging output to the specified file. For this to
1407 work, Mono needs to be compiled with the BINARY_PROTOCOL define on
1408 sgen-gc.c. You can then use this command to explore the output
1410 sgen-grep-binprot 0x1234 0x5678 < file
1413 \fBnursery-canaries\fR
1414 If set, objects allocated in the nursery are suffixed with a canary (guard)
1415 word, which is checked on each minor collection. Can be used to detect/debug
1416 heap corruption issues.
1419 \fBdo-not-finalize(=\fIclasses\fB)\fR
1420 If enabled, finalizers will not be run. Everything else will be
1421 unaffected: finalizable objects will still be put into the
1422 finalization queue where they survive until they're scheduled to
1423 finalize. Once they're not in the queue anymore they will be
1424 collected regularly. If a list of comma-separated class names is
1425 given, only objects from those classes will not be finalized.
1428 \fBlog-finalizers\fR
1429 Log verbosely around the finalization process to aid debugging.
1433 \fBMONO_GAC_PREFIX\fR
1434 Provides a prefix the runtime uses to look for Global Assembly Caches.
1435 Directories are separated by the platform path separator (colons on
1436 unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
1437 install. Or to the directory provided in the gacutil /gacdir command. Example:
1438 .B /home/username/.mono:/usr/local/mono/
1441 Enables some filename rewriting support to assist badly-written
1442 applications that hard-code Windows paths. Set to a colon-separated
1443 list of "drive" to strip drive letters, or "case" to do
1444 case-insensitive file matching in every directory in a path. "all"
1445 enables all rewriting methods. (Backslashes are always mapped to
1446 slashes if this variable is set to a valid option).
1449 For example, this would work from the shell:
1452 MONO_IOMAP=drive:case
1456 If you are using mod_mono to host your web applications, you can use
1459 directive instead, like this:
1462 MonoIOMAP <appalias> all
1465 See mod_mono(8) for more details.
1467 Additionally. Mono includes a profiler module which allows one to track what
1468 adjustements to file paths IOMAP code needs to do. The tracking code reports
1469 the managed location (full stack trace) from which the IOMAP-ed call was made and,
1470 on process exit, the locations where all the IOMAP-ed strings were created in
1471 managed code. The latter report is only approximate as it is not always possible
1472 to estimate the actual location where the string was created. The code uses simple
1473 heuristics - it analyzes stack trace leading back to the string allocation location
1474 and ignores all the managed code which lives in assemblies installed in GAC as well as in the
1475 class libraries shipped with Mono (since they are assumed to be free of case-sensitivity
1476 issues). It then reports the first location in the user's code - in most cases this will be
1477 the place where the string is allocated or very close to the location. The reporting code
1478 is implemented as a custom profiler module (see the "PROFILING" section) and can be loaded
1479 in the following way:
1484 mono --profile=iomap yourapplication.exe
1487 Note, however, that Mono currently supports only one profiler module
1491 When Mono is using the LLVM code generation backend you can use this
1492 environment variable to pass code generation options to the LLVM
1495 \fBMONO_MANAGED_WATCHER\fR
1496 If set to "disabled", System.IO.FileSystemWatcher will use a file watcher
1497 implementation which silently ignores all the watching requests.
1498 If set to any other value, System.IO.FileSystemWatcher will use the default
1499 managed implementation (slow). If unset, mono will try to use inotify, FAM,
1500 Gamin, kevent under Unix systems and native API calls on Windows, falling
1501 back to the managed implementation on error.
1503 \fBMONO_MESSAGING_PROVIDER\fR
1504 Mono supports a plugin model for its implementation of System.Messaging making
1505 it possible to support a variety of messaging implementations (e.g. AMQP, ActiveMQ).
1506 To specify which messaging implementation is to be used the evironement variable
1507 needs to be set to the full class name for the provider. E.g. to use the RabbitMQ based
1508 AMQP implementation the variable should be set to:
1511 Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
1514 If set causes the mono process to be bound to a single processor. This may be
1515 useful when debugging or working around race conditions.
1518 Disable inlining of thread local accesses. Try setting this if you get a segfault
1519 early on in the execution of mono.
1522 Provides a search path to the runtime where to look for library
1523 files. This is a tool convenient for debugging applications, but
1524 should not be used by deployed applications as it breaks the assembly
1525 loader in subtle ways.
1527 Directories are separated by the platform path separator (colons on unix). Example:
1528 .B /home/username/lib:/usr/local/mono/lib
1530 Relative paths are resolved based on the launch-time current directory.
1532 Alternative solutions to MONO_PATH include: installing libraries into
1533 the Global Assembly Cache (see gacutil(1)) or having the dependent
1534 libraries side-by-side with the main executable.
1536 For a complete description of recommended practices for application
1538 http://www.mono-project.com/docs/getting-started/application-deployment/
1540 \fBMONO_SHARED_DIR\fR
1541 If set its the directory where the ".wapi" handle state is stored.
1542 This is the directory where the Windows I/O Emulation layer stores its
1543 shared state data (files, events, mutexes, pipes). By default Mono
1544 will store the ".wapi" directory in the users's home directory.
1546 \fBMONO_SHARED_HOSTNAME\fR
1547 Uses the string value of this variable as a replacement for the host name when
1548 creating file names in the ".wapi" directory. This helps if the host name of
1549 your machine is likely to be changed when a mono application is running or if
1550 you have a .wapi directory shared among several different computers.
1552 Mono typically uses the hostname to create the files that are used to
1553 share state across multiple Mono processes. This is done to support
1554 home directories that might be shared over the network.
1556 \fBMONO_STRICT_IO_EMULATION\fR
1557 If set, extra checks are made during IO operations. Currently, this
1558 includes only advisory locks around file writes.
1561 The name of the theme to be used by Windows.Forms. Available themes today
1562 include "clearlooks", "nice" and "win32".
1564 The default is "win32".
1566 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1567 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1568 avoid a new negotiation between the client and a server. Negotiation are very
1569 CPU intensive so an application-specific custom value may prove useful for
1570 small embedded systems.
1572 The default is 180 seconds.
1574 \fBMONO_THREADS_PER_CPU\fR
1575 The minimum number of threads in the general threadpool will be
1576 MONO_THREADS_PER_CPU * number of CPUs. The default value for this
1579 \fBMONO_XMLSERIALIZER_THS\fR
1580 Controls the threshold for the XmlSerializer to produce a custom
1581 serializer for a given class instead of using the Reflection-based
1582 interpreter. The possible values are `no' to disable the use of a
1583 custom serializer or a number to indicate when the XmlSerializer
1584 should start serializing. The default value is 50, which means that
1585 the a custom serializer will be produced on the 50th use.
1587 \fBMONO_X509_REVOCATION_MODE\fR
1588 Sets the revocation mode used when validating a X509 certificate chain (https,
1589 ftps, smtps...). The default is 'nocheck', which performs no revocation check
1590 at all. The other possible values are 'offline', which performs CRL check (not
1591 implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
1592 status (not implemented yet).
1595 (Also \fBno_proxy\fR) If both \fBHTTP_PROXY\fR and \fBNO_PROXY\fR are
1596 set, \fBNO_PROXY\fR will be treated as a comma-separated list of "bypass" domains
1597 which will not be sent through the proxy. Domains in \fBNO_PROXY\fR may contain
1598 wildcards, as in "*.mono-project.com" or "build????.local". Not supported on
1599 Windows, Mac OS, iOS or Android.
1600 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1602 \fBMONO_ASPNET_NODELETE\fR
1603 If set to any value, temporary source files generated by ASP.NET support
1604 classes will not be removed. They will be kept in the user's temporary
1608 If set, enables some features of the runtime useful for debugging.
1609 This variable should contain a comma separated list of debugging options.
1610 Currently, the following options are supported:
1614 \fBalign-small-structs\fR
1615 Enables small structs alignment to 4/8 bytes.
1617 \fBarm-use-fallback-tls\fR
1618 When this option is set on ARM, a fallback TLS will be used instead
1619 of the default fast TLS.
1621 \fBbreak-on-unverified\fR
1622 If this variable is set, when the Mono VM runs into a verification
1623 problem, instead of throwing an exception it will break into the
1624 debugger. This is useful when debugging verifier problems
1627 This option can be used to get more detailed information from
1628 InvalidCast exceptions, it will provide information about the types
1631 \fBcheck-pinvoke-callconv\fR
1632 This option causes the runtime to check for calling convention
1633 mismatches when using pinvoke, i.e. mixing cdecl/stdcall. It only
1634 works on windows. If a mismatch is detected, an
1635 ExecutionEngineException is thrown.
1637 \fBcollect-pagefault-stats\fR
1638 Collects information about pagefaults. This is used internally to
1639 track the number of page faults produced to load metadata. To display
1640 this information you must use this option with "--stats" command line
1643 \fBdebug-domain-unload\fR
1644 When this option is set, the runtime will invalidate the domain memory
1645 pool instead of destroying it.
1647 \fBdisable_omit_fp\fR
1648 Disables a compiler optimization where the frame pointer is omitted
1649 from the stack. This optimization can interact badly with debuggers.
1651 \fBdont-free-domains\fR
1652 This is an Optimization for multi-AppDomain applications (most
1653 commonly ASP.NET applications). Due to internal limitations Mono,
1654 Mono by default does not use typed allocations on multi-appDomain
1655 applications as they could leak memory when a domain is unloaded.
1657 Although this is a fine default, for applications that use more than
1658 on AppDomain heavily (for example, ASP.NET applications) it is worth
1659 trading off the small leaks for the increased performance
1660 (additionally, since ASP.NET applications are not likely going to
1661 unload the application domains on production systems, it is worth
1662 using this feature).
1664 \fBdyn-runtime-invoke\fR
1665 Instructs the runtime to try to use a generic runtime-invoke wrapper
1666 instead of creating one invoke wrapper.
1668 \fBexplicit-null-checks\fR
1669 Makes the JIT generate an explicit NULL check on variable dereferences
1670 instead of depending on the operating system to raise a SIGSEGV or
1671 another form of trap event when an invalid memory location is
1675 Equivalent to setting the \fBMONO_XDEBUG\fR variable, this emits
1676 symbols into a shared library as the code is JITed that can be loaded
1677 into GDB to inspect symbols.
1679 \fBgen-seq-points\fR
1680 Automatically generates sequence points where the
1681 IL stack is empty. These are places where the debugger can set a
1684 \fBno-compact-seq-points\fR
1685 Unless the option is used, the runtime generates sequence points data that
1686 maps native offsets to IL offsets. Sequence point data is used to
1687 display IL offset in stacktraces. Stacktraces with IL offsets can be
1688 symbolicated using mono-symbolicate tool.
1691 Captures the interrupt signal (Control-C) and displays a stack trace
1692 when pressed. Useful to find out where the program is executing at a
1693 given point. This only displays the stack trace of a single thread.
1696 Instructs the runtime to initialize the stack with
1697 some known values (0x2a on x86-64) at the start of a method to assist
1698 in debuggin the JIT engine.
1700 \fBkeep-delegates\fR
1701 This option will leak delegate trampolines that are no longer
1702 referenced as to present the user with more information about a
1703 delegate misuse. Basically a delegate instance might be created,
1704 passed to unmanaged code, and no references kept in managed code,
1705 which will garbage collect the code. With this option it is possible
1706 to track down the source of the problems.
1708 \fBno-gdb-backtrace\fR
1709 This option will disable the GDB backtrace emitted by the runtime
1710 after a SIGSEGV or SIGABRT in unmanaged code.
1712 \fBpartial-sharing\fR
1713 When this option is set, the runtime can share generated code between
1714 generic types effectively reducing the amount of code generated.
1716 \fBreverse-pinvoke-exceptions
1717 This option will cause mono to abort with a descriptive message when
1718 during stack unwinding after an exception it reaches a native stack
1719 frame. This happens when a managed delegate is passed to native code,
1720 and the managed delegate throws an exception. Mono will normally try
1721 to unwind the stack to the first (managed) exception handler, and it
1722 will skip any native stack frames in the process. This leads to
1723 undefined behaviour (since mono doesn't know how to process native
1724 frames), leaks, and possibly crashes too.
1726 \fBsingle-imm-size\fR
1727 This guarantees that each time managed code is compiled the same
1728 instructions and registers are used, regardless of the size of used
1731 \fBsoft-breakpoints\fR
1732 This option allows using single-steps and breakpoints in hardware
1733 where we cannot do it with signals.
1735 \fBsuspend-on-native-crash\fR
1736 This option will suspend the program when a native crash occurs (SIGSEGV, SIGILL, ...).
1737 This is useful for debugging crashes which do not happen under gdb,
1738 since a live process contains more information than a core file.
1740 \fBsuspend-on-sigsegv\fR
1741 Same as \fBsuspend-on-native-crash\fR.
1743 \fBsuspend-on-exception\fR
1744 This option will suspend the program when an exception occurs.
1746 \fBsuspend-on-unhandled\fR
1747 This option will suspend the program when an unhandled exception occurs.
1751 \fBMONO_LOG_LEVEL\fR
1752 The logging level, possible values are `error', `critical', `warning',
1753 `message', `info' and `debug'. See the DEBUGGING section for more
1757 Controls the domain of the Mono runtime that logging will apply to.
1758 If set, the log mask is changed to the set value. Possible values are
1759 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1760 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
1761 "security" (e.g. Moonlight CoreCLR support) and "all".
1762 The default value is "all". Changing the mask value allows you to display only
1763 messages for a certain component. You can use multiple masks by comma
1764 separating them. For example to see config file messages and assembly loader
1765 messages set you mask to "asm,cfg".
1768 Controls where trace log messages are written. If not set then the messages go to stdout.
1769 If set, the string either specifies a path to a file that will have messages appended to
1770 it, or the string "syslog" in which case the messages will be written to the system log.
1771 Under Windows, this is simulated by writing to a file called "mono.log".
1772 \fBMONO_LOG_HEADER\fR
1773 Controls whether trace log messages not directed to syslog have the id, timestamp, and
1774 pid as the prefix to the log message. To enable a header this environment variable need
1778 Used for runtime tracing of method calls. The format of the comma separated
1787 disabled Trace output off upon start.
1790 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1792 \fBMONO_TRACE_LISTENER\fR
1793 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1794 print the output of the System.Diagnostics Trace and Debug classes.
1795 It can be set to a filename, and to Console.Out or Console.Error to display
1796 output to standard output or standard error, respectively. If it's set to
1797 Console.Out or Console.Error you can append an optional prefix that will
1798 be used when writing messages like this: Console.Error:MyProgramName.
1799 See the System.Diagnostics.DefaultTraceListener documentation for more
1802 \fBMONO_WCF_TRACE\fR
1803 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.
1805 \fBMONO_XEXCEPTIONS\fR
1806 This throws an exception when a X11 error is encountered; by default a
1807 message is displayed but execution continues
1809 \fBMONO_XMLSERIALIZER_DEBUG\fR
1810 Set this value to 1 to prevent the serializer from removing the
1811 temporary files that are created for fast serialization; This might
1812 be useful when debugging.
1815 This is used in the System.Windows.Forms implementation when running
1816 with the X11 backend. This is used to debug problems in Windows.Forms
1817 as it forces all of the commands send to X11 server to be done
1818 synchronously. The default mode of operation is asynchronous which
1819 makes it hard to isolate the root of certain problems.
1822 When the the MONO_XDEBUG env var is set, debugging info for JITted
1823 code is emitted into a shared library, loadable into gdb. This enables,
1824 for example, to see managed frame names on gdb backtraces.
1826 \fBMONO_VERBOSE_METHOD\fR
1827 Enables the maximum JIT verbosity for the specified method. This is
1828 very helpfull to diagnose a miscompilation problems of a specific
1831 \fBMONO_JIT_DUMP_METHOD\fR
1832 Enables sending of the JITs intermediate representation for a specified
1833 method to the IdealGraphVisualizer tool.
1835 \fBMONO_VERBOSE_HWCAP\fR
1836 If set, makes the JIT output information about detected CPU features
1837 (such as SSE, CMOV, FCMOV, etc) to stdout.
1839 \fBMONO_CONSERVATIVE_HWCAP\fR
1840 If set, the JIT will not perform any hardware capability detection. This
1841 may be useful to pinpoint the cause of JIT issues. This is the default
1842 when Mono is built as an AOT cross compiler, so that the generated code
1843 will run on most hardware.
1845 If you want to use Valgrind, you will find the file `mono.supp'
1846 useful, it contains the suppressions for the GC which trigger
1847 incorrect warnings. Use it like this:
1849 valgrind --suppressions=mono.supp mono ...
1852 On some platforms, Mono can expose a set of DTrace probes (also known
1853 as user-land statically defined, USDT Probes).
1855 They are defined in the file `mono.d'.
1857 .B ves-init-begin, ves-init-end
1859 Begin and end of runtime initialization.
1861 .B method-compile-begin, method-compile-end
1863 Begin and end of method compilation.
1864 The probe arguments are class name, method name and signature,
1865 and in case of method-compile-end success or failure of compilation.
1869 Begin and end of Garbage Collection.
1871 To verify the availability of the probes, run:
1873 dtrace -P mono'$target' -l -c mono
1876 Mono's Ping implementation for detecting network reachability can
1877 create the ICMP packets itself without requiring the system ping
1878 command to do the work. If you want to enable this on Linux for
1879 non-root users, you need to give the Mono binary special permissions.
1881 As root, run this command:
1883 # setcap cap_net_raw=+ep /usr/bin/mono
1886 On Unix assemblies are loaded from the installation lib directory. If you set
1887 `prefix' to /usr, the assemblies will be located in /usr/lib. On
1888 Windows, the assemblies are loaded from the directory where mono and
1891 .B ~/.mono/aot-cache
1893 The directory for the ahead-of-time compiler demand creation
1894 assemblies are located.
1896 .B /etc/mono/config, ~/.mono/config
1898 Mono runtime configuration file. See the mono-config(5) manual page
1899 for more information.
1901 .B ~/.config/.mono/certs, /usr/share/.mono/certs
1903 Contains Mono certificate stores for users / machine. See the certmgr(1)
1904 manual page for more information on managing certificate stores and
1905 the mozroots(1) page for information on how to import the Mozilla root
1906 certificates into the Mono certificate store.
1908 .B ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
1910 Files in this directory allow a user to customize the configuration
1911 for a given system assembly, the format is the one described in the
1912 mono-config(5) page.
1914 .B ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
1916 Contains Mono cryptographic keypairs for users / machine. They can be
1917 accessed by using a CspParameters object with DSACryptoServiceProvider
1918 and RSACryptoServiceProvider classes.
1920 .B ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
1922 Contains Mono isolated storage for non-roaming users, roaming users and
1923 local machine. Isolated storage can be accessed using the classes from
1924 the System.IO.IsolatedStorage namespace.
1926 .B <assembly>.config
1928 Configuration information for individual assemblies is loaded by the
1929 runtime from side-by-side files with the .config files, see the
1930 http://www.mono-project.com/Config for more information.
1932 .B Web.config, web.config
1934 ASP.NET applications are configured through these files, the
1935 configuration is done on a per-directory basis. For more information
1936 on this subject see the http://www.mono-project.com/Config_system.web
1939 Mailing lists are listed at the
1940 http://www.mono-project.com/community/help/mailing-lists/
1942 http://www.mono-project.com
1945 certmgr(1), csharp(1), mcs(1), mdb(1), monocov(1), monodis(1),
1946 mono-config(5), mozroots(1), mprof-report(1), pdb2mdb(1), xsp(1), mod_mono(8).
1948 For more information on AOT:
1949 http://www.mono-project.com/docs/advanced/aot/
1951 For ASP.NET-related documentation, see the xsp(1) manual page
projects / mono.git / blob