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--debugger-agent=[options]\fR
261 This instructs the Mono runtime to
262 start a debugging agent inside the Mono runtime and connect it to a
263 client user interface will control the Mono process.
264 This option is typically used by IDEs, like the MonoDevelop IDE.
266 The configuration is specified using one of more of the following options:
272 Use this option to specify the IP address where your debugger client is
277 Specifies the diagnostics log level for
281 Used to specify the file where the log will be stored, it defaults to
285 Defaults to no, with the default option Mono will actively connect to the
286 host/port configured with the \fBaddress\fR option. If you set it to 'y', it
287 instructs the Mono runtime to start debugging in server mode, where Mono
288 actively waits for the debugger front end to connect to the Mono process.
289 Mono will print out to stdout the IP address and port where it is listening.
292 If set to yes, Mono will call \fBsetpgid(0, 0)\fB on startup, if that function
293 is available on the system. This is useful for ensuring that signals delivered
294 to a process that is executing the debuggee are not propagated to the debuggee,
295 e.g. when Ctrl-C sends \fBSIGINT\fB to the \fBsdb\fB tool.
298 Defaults to yes, with the default option Mono will suspend the vm on startup
299 until it connects successfully to a debugger front end. If you set it to 'n', in
300 conjunction with \fBserver=y\fR, it instructs the Mono runtime to run as normal,
301 while caching metadata to send to the debugger front end on connection..
303 .I transport=transport_name
305 This is used to specify the transport that the debugger will use to
306 communicate. It must be specified and currently requires this to
312 Configures the virtual machine to be better suited for desktop
313 applications. Currently this sets the GC system to avoid expanding
314 the heap as much as possible at the expense of slowing down garbage
318 This is an experimental flag that instructs the Mono runtime to not
319 generate any code at runtime and depend exclusively on the code
320 generated from using mono --aot=full previously. This is useful for
321 platforms that do not permit dynamic code generation.
323 Notice that this feature will abort execution at runtime if a codepath
324 in your program, or Mono's class libraries attempts to generate code
325 dynamically. You should test your software upfront and make sure that
326 you do not use any dynamic features.
328 \fB--gc=boehm\fR, \fB--gc=sgen\fR
329 Selects the Garbage Collector engine for Mono to use, Boehm or SGen.
330 Currently this merely ensures that you are running either the
331 \fImono\fR or \fImono-sgen\fR commands. This flag can be set in the
332 \fBMONO_ENV_OPTIONS\fR environment variable to force all of your child
333 processes to use one particular kind of GC with the Mono runtime.
335 \fB--gc-debug=[options]\fR
336 Command line equivalent of the \fBMONO_GC_DEBUG\fR environment variable.
338 \fB--gc-params=[options]\fR
339 Command line equivalent of the \fBMONO_GC_PARAMS\fR environment variable.
341 \fB--arch=32\fR, \fB--arch=64\fR
342 (Mac OS X only): Selects the bitness of the Mono binary used, if
343 available. If the binary used is already for the selected bitness, nothing
344 changes. If not, the execution switches to a binary with the selected
345 bitness suffix installed side by side (for example, '/bin/mono --arch=64'
346 will switch to '/bin/mono64' iff '/bin/mono' is a 32-bit build).
348 \fB--help\fR, \fB-h\fR
349 Displays usage instructions.
352 If the Mono runtime has been compiled with LLVM support (not available
353 in all configurations), Mono will use the LLVM optimization and code
354 generation engine to JIT or AOT compile.
356 For more information, consult: http://www.mono-project.com/docs/advanced/mono-llvm/
359 When using a Mono that has been compiled with LLVM support, it forces
360 Mono to fallback to its JIT engine and not use the LLVM backend.
362 \fB--optimize=MODE\fR, \fB-O=MODE\fR
363 MODE is a comma separated list of optimizations. They also allow
364 optimizations to be turned off by prefixing the optimization name with
367 In general, Mono has been tuned to use the default set of flags,
368 before using these flags for a deployment setting, you might want to
369 actually measure the benefits of using them.
371 The following optimization flags are implemented in the core engine:
373 abcrem Array bound checks removal
374 all Turn on all optimizations
375 aot Usage of Ahead Of Time compiled code
376 branch Branch optimizations
377 cfold Constant folding
378 cmov Conditional moves [arch-dependency]
379 deadce Dead code elimination
380 consprop Constant propagation
381 copyprop Copy propagation
382 fcmov Fast x86 FP compares [arch-dependency]
383 float32 Perform 32-bit float arithmetic using 32-bit operations
384 gshared Enable generic code sharing.
385 inline Inline method calls
386 intrins Intrinsic method implementations
387 linears Linear scan global reg allocation
388 leaf Leaf procedures optimizations
389 loop Loop related optimizations
390 peephole Peephole postpass
391 precomp Precompile all methods before executing Main
392 sched Instruction scheduling
393 shared Emit per-domain code
394 sse2 SSE2 instructions on x86 [arch-dependency]
395 tailc Tail recursion and tail calls
398 For example, to enable all the optimization but dead code
399 elimination and inlining, you can use:
401 -O=all,-deadce,-inline
404 The flags that are flagged with [arch-dependency] indicate that the
405 given option if used in combination with Ahead of Time compilation
406 (--aot flag) would produce pre-compiled code that will depend on the
407 current CPU and might not be safely moved to another computer.
411 The following optimizations are supported
414 Requests that the runtime performn 32-bit floating point operations
415 using only 32-bits. By default the Mono runtime tries to use the
416 highest precision available for floating point operations, but while
417 this might render better results, the code might run slower. This
418 options also affects the code generated by the LLVM backend.
421 Controls whether the runtime should attempt to inline (the default),
422 or not inline methods invocations
426 \fB--runtime=VERSION\fR
427 Mono supports different runtime versions. The version used depends on the program
428 that is being run or on its configuration file (named program.exe.config). This option
429 can be used to override such autodetection, by forcing a different runtime version
430 to be used. Note that this should only be used to select a later compatible runtime
431 version than the one the program was compiled against. A typical usage is for
432 running a 1.1 program on a 2.0 version:
434 mono --runtime=v2.0.50727 program.exe
437 \fB--security\fR, \fB--security=mode\fR
438 Activate the security manager, a currently experimental feature in
439 Mono and it is OFF by default. The new code verifier can be enabled
440 with this option as well.
444 Using security without parameters is equivalent as calling it with the
447 The following modes are supported:
450 Enables the core-clr security system, typically used for
451 Moonlight/Silverlight applications. It provides a much simpler
452 security system than CAS, see http://www.mono-project.com/docs/web/moonlight/
453 for more details and links to the descriptions of this new system.
456 Enables the new verifier and performs basic verification for code
457 validity. In this mode, unsafe code and P/Invoke are allowed. This
458 mode provides a better safety guarantee but it is still possible
459 for managed code to crash Mono.
462 Enables the new verifier and performs full verification of the code
463 being executed. It only allows verifiable code to be executed.
464 Unsafe code is not allowed but P/Invoke is. This mode should
465 not allow managed code to crash mono. The verification is not as
466 strict as ECMA 335 standard in order to stay compatible with the MS
469 The security system acts on user code: code contained in mscorlib or
470 the global assembly cache is always trusted.
475 Configures the virtual machine to be better suited for server
476 operations (currently, allows a heavier threadpool initialization).
479 Verifies mscorlib and assemblies in the global
480 assembly cache for valid IL, and all user code for IL
483 This is different from \fB--security\fR's verifiable
484 or validil in that these options only check user code and skip
485 mscorlib and assemblies located on the global assembly cache.
487 \fB-V\fR, \fB--version\fR
488 Prints JIT version information (system configuration, release number
489 and branch names if available).
492 .SH DEVELOPMENT OPTIONS
493 The following options are used to help when developing a JITed application.
495 \fB--debug\fR, \fB--debug=OPTIONS\fR
496 Turns on the debugging mode in the runtime. If an assembly was
497 compiled with debugging information, it will produce line number
498 information for stack traces.
502 The optional OPTIONS argument is a comma separated list of debugging
503 options. These options are turned off by default since they generate
504 much larger and slower code at runtime.
506 The following options are supported:
509 Produces a detailed error when throwing a InvalidCastException. This
510 option needs to be enabled as this generates more verbose code at
514 Disable some JIT optimizations which are usually only disabled when
515 running inside the debugger. This can be helpful if you want to attach
516 to the running process with mdb.
519 Generate and register debugging information with gdb. This is only supported on some
520 platforms, and only when using gdb 7.0 or later.
524 \fB--profile[=profiler[:profiler_args]]\fR
525 Turns on profiling. For more information about profiling applications
526 and code coverage see the sections "PROFILING" and "CODE COVERAGE"
529 This option can be used multiple times, each time will load an
530 additional profiler. This allows developers to use modules that
531 extend the JIT through the Mono profiling interface.
533 \fB--trace[=expression]\fR
534 Shows method names as they are invoked. By default all methods are
537 The trace can be customized to include or exclude methods, classes or
538 assemblies. A trace expression is a comma separated list of targets,
539 each target can be prefixed with a minus sign to turn off a particular
540 target. The words `program', `all' and `disabled' have special
541 meaning. `program' refers to the main program being executed, and
542 `all' means all the method calls.
544 The `disabled' option is used to start up with tracing disabled. It
545 can be enabled at a later point in time in the program by sending the
546 SIGUSR2 signal to the runtime.
548 Assemblies are specified by their name, for example, to trace all
549 calls in the System assembly, use:
552 mono --trace=System app.exe
555 Classes are specified with the T: prefix. For example, to trace all
556 calls to the System.String class, use:
559 mono --trace=T:System.String app.exe
562 And individual methods are referenced with the M: prefix, and the
563 standard method notation:
566 mono --trace=M:System.Console:WriteLine app.exe
569 Exceptions can also be traced, it will cause a stack trace to be
570 printed every time an exception of the specified type is thrown.
571 The exception type can be specified with or without the namespace,
572 and to trace all exceptions, specify 'all' as the type name.
575 mono --trace=E:System.Exception app.exe
578 As previously noted, various rules can be specified at once:
581 mono --trace=T:System.String,T:System.Random app.exe
584 You can exclude pieces, the next example traces calls to
585 System.String except for the System.String:Concat method.
588 mono --trace=T:System.String,-M:System.String:Concat
591 You can trace managed to unmanaged transitions using
592 the wrapper qualifier:
595 mono --trace=wrapper app.exe
598 Finally, namespaces can be specified using the N: prefix:
601 mono --trace=N:System.Xml
605 \fB--no-x86-stack-align\fR
606 Don't align stack frames on the x86 architecture. By default, Mono
607 aligns stack frames to 16 bytes on x86, so that local floating point
608 and SIMD variables can be properly aligned. This option turns off the
609 alignment, which usually saves one intruction per call, but might
610 result in significantly lower floating point and SIMD performance.
613 Generate a JIT method map in a /tmp/perf-PID.map file. This file is then
614 used, for example, by the perf tool included in recent Linux kernels.
615 Each line in the file has:
618 HEXADDR HEXSIZE methodname
621 Currently this option is only supported on Linux.
622 .SH JIT MAINTAINER OPTIONS
623 The maintainer options are only used by those developing the runtime
624 itself, and not typically of interest to runtime users or developers.
626 \fB--bisect=optimization:filename\fR
627 This flag is used by the automatic optimization bug bisector. It
628 takes an optimization flag and a filename of a file containing a list
629 of full method names, one per line. When it compiles one of the
630 methods in the file it will use the optimization given, in addition to
631 the optimizations that are otherwise enabled. Note that if the
632 optimization is enabled by default, you should disable it with `-O`,
633 otherwise it will just apply to every method, whether it's in the file
637 Inserts a breakpoint before the method whose name is `method'
638 (namespace.class:methodname). Use `Main' as method name to insert a
639 breakpoint on the application's main method. You can use it also with
640 generics, for example "System.Collections.Generic.Queue`1:Peek"
643 Inserts a breakpoint on exceptions. This allows you to debug your
644 application with a native debugger when an exception is thrown.
647 This compiles a method (namespace.name:methodname), this is used for
648 testing the compiler performance or to examine the output of the code
652 Compiles all the methods in an assembly. This is used to test the
653 compiler performance or to examine the output of the code generator
655 \fB--graph=TYPE METHOD\fR
656 This generates a postscript file with a graph with the details about
657 the specified method (namespace.name:methodname). This requires `dot'
658 and ghostview to be installed (it expects Ghostview to be called
661 The following graphs are available:
663 cfg Control Flow Graph (CFG)
665 code CFG showing code
666 ssa CFG showing code after SSA translation
667 optcode CFG showing code after IR optimizations
670 Some graphs will only be available if certain optimizations are turned
674 Instruct the runtime on the number of times that the method specified
675 by --compile (or all the methods if --compileall is used) to be
676 compiled. This is used for testing the code generator performance.
679 Displays information about the work done by the runtime during the
680 execution of an application.
682 \fB--wapi=hps|semdel\fR
683 Perform maintenance of the process shared data.
685 semdel will delete the global semaphore.
687 hps will list the currently used handles.
689 \fB-v\fR, \fB--verbose\fR
690 Increases the verbosity level, each time it is listed, increases the
691 verbosity level to include more information (including, for example,
692 a disassembly of the native code produced, code selector info etc.).
694 The Mono runtime allows external processes to attach to a running
695 process and load assemblies into the running program. To attach to
696 the process, a special protocol is implemented in the Mono.Management
699 With this support it is possible to load assemblies that have an entry
700 point (they are created with -target:exe or -target:winexe) to be
701 loaded and executed in the Mono process.
703 The code is loaded into the root domain, and it starts execution on
704 the special runtime attach thread. The attached program should
705 create its own threads and return after invocation.
707 This support allows for example debugging applications by having the
708 csharp shell attach to running processes.
710 The mono runtime includes a profiler that can be used to explore
711 various performance related problems in your application. The
712 profiler is activated by passing the --profile command line argument
713 to the Mono runtime, the format is:
716 --profile[=profiler[:profiler_args]]
719 Mono has a built-in profiler called 'default' (and is also the default
720 if no arguments are specified), but developers can write custom
721 profilers, see the section "CUSTOM PROFILERS" for more details.
725 is not specified, the default profiler is used.
729 is a profiler-specific string of options for the profiler itself.
731 The default profiler accepts the following options 'alloc' to profile
732 memory consumption by the application; 'time' to profile the time
733 spent on each routine; 'jit' to collect time spent JIT-compiling methods
734 and 'stat' to perform sample statistical profiling.
735 If no options are provided the default is 'alloc,time,jit'.
738 profile data is printed to stdout: to change this, use the 'file=filename'
739 option to output the data to filename.
744 mono --profile program.exe
748 That will run the program with the default profiler and will do time
749 and allocation profiling.
753 mono --profile=default:stat,alloc,file=prof.out program.exe
756 Will do sample statistical profiling and allocation profiling on
757 program.exe. The profile data is put in prof.out.
759 Note that the statistical profiler has a very low overhead and should
760 be the preferred profiler to use (for better output use the full path
761 to the mono binary when running and make sure you have installed the
762 addr2line utility that comes from the binutils package).
764 This is the most advanced profiler.
766 The Mono \f[I]log\f[] profiler can be used to collect a lot of
767 information about a program running in the Mono runtime.
768 This data can be used (both while the process is running and later)
769 to do analyses of the program behaviour, determine resource usage,
770 performance issues or even look for particular execution patterns.
772 This is accomplished by logging the events provided by the Mono
773 runtime through the profiling interface and periodically writing
774 them to a file which can be later inspected with the mprof-report(1)
777 More information about how to use the log profiler is available on the
778 mprof-report(1) page.
780 Mono provides a mechanism for loading other profiling modules which in
781 the form of shared libraries. These profiling modules can hook up to
782 various parts of the Mono runtime to gather information about the code
785 To use a third party profiler you must pass the name of the profiler
789 mono --profile=custom program.exe
793 In the above sample Mono will load the user defined profiler from the
794 shared library `mono-profiler-custom.so'. This profiler module must
795 be on your dynamic linker library path.
797 A list of other third party profilers is available from Mono's web
798 site (www.mono-project.com/docs/advanced/performance-tips/)
800 Custom profiles are written as shared libraries. The shared library
801 must be called `mono-profiler-NAME.so' where `NAME' is the name of
804 For a sample of how to write your own custom profiler look in the
805 Mono source tree for in the samples/profiler.c.
807 Mono ships with a code coverage module. This module is activated by
808 using the Mono --profile=cov option. The format is:
809 \fB--profile=cov[:assembly-name[/namespace]] test-suite.exe\fR
811 By default code coverage will default to all the assemblies loaded,
812 you can limit this by specifying the assembly name, for example to
813 perform code coverage in the routines of your program use, for example
814 the following command line limits the code coverage to routines in the
818 mono --profile=cov:demo demo.exe
824 does not include the extension.
826 You can further restrict the code coverage output by specifying a
830 mono --profile=cov:demo/My.Utilities demo.exe
834 Which will only perform code coverage in the given assembly and
837 Typical output looks like this:
840 Not covered: Class:.ctor ()
841 Not covered: Class:A ()
842 Not covered: Driver:.ctor ()
843 Not covered: Driver:method ()
844 Partial coverage: Driver:Main ()
849 The offsets displayed are IL offsets.
851 A more powerful coverage tool is available in the module `monocov'.
852 See the monocov(1) man page for details.
854 To debug managed applications, you can use the
856 command, a command line debugger.
858 It is possible to obtain a stack trace of all the active threads in
859 Mono by sending the QUIT signal to Mono, you can do this from the
860 command line, like this:
866 Where pid is the Process ID of the Mono process you want to examine.
867 The process will continue running afterwards, but its state is not
871 this is a last-resort mechanism for debugging applications and should
872 not be used to monitor or probe a production application. The
873 integrity of the runtime after sending this signal is not guaranteed
874 and the application might crash or terminate at any given point
877 The \fB--debug=casts\fR option can be used to get more detailed
878 information for Invalid Cast operations, it will provide information
879 about the types involved.
881 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
882 to get verbose debugging output about the execution of your
883 application within Mono.
887 environment variable if set, the logging level is changed to the set
888 value. Possible values are "error", "critical", "warning", "message",
889 "info", "debug". The default value is "error". Messages with a logging
890 level greater then or equal to the log level will be printed to
893 Use "info" to track the dynamic loading of assemblies.
898 environment variable to limit the extent of the messages you get:
899 If set, the log mask is changed to the set value. Possible values are
900 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
901 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
902 "security" (e.g. Moonlight CoreCLR support), "threadpool" (thread pool generic),
903 "io-threadpool" (thread pool I/O), "io-layer" (I/O layer - sockets, handles, shared memory etc)
905 The default value is "all". Changing the mask value allows you to display only
906 messages for a certain component. You can use multiple masks by comma
907 separating them. For example to see config file messages and assembly loader
908 messages set you mask to "asm,cfg".
910 The following is a common use to track down problems with P/Invoke:
913 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
917 .SH DEBUGGING WITH LLDB
918 If you are using LLDB, you can use the
920 script to print some internal data structures with it. To use this,
925 command script import $PREFIX/lib/mono/lldb/mono.py
928 Where $PREFIX is the prefix value that you used when you configured
929 Mono (typically /usr).
931 Once this is done, then you can inspect some Mono Runtime data structures,
936 (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
939 Mono's XML serialization engine by default will use a reflection-based
940 approach to serialize which might be slow for continuous processing
941 (web service applications). The serialization engine will determine
942 when a class must use a hand-tuned serializer based on a few
943 parameters and if needed it will produce a customized C# serializer
944 for your types at runtime. This customized serializer then gets
945 dynamically loaded into your application.
947 You can control this with the MONO_XMLSERIALIZER_THS environment
950 The possible values are
952 to disable the use of a C# customized
953 serializer, or an integer that is the minimum number of uses before
954 the runtime will produce a custom serializer (0 will produce a
955 custom serializer on the first access, 50 will produce a serializer on
956 the 50th use). Mono will fallback to an interpreted serializer if the
957 serializer generation somehow fails. This behavior can be disabled
958 by setting the option
960 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
961 .SH ENVIRONMENT VARIABLES
964 Turns off the garbage collection in Mono. This should be only used
965 for debugging purposes
968 (Also \fBhttp_proxy\fR) If set, web requests using the Mono
969 Class Library will be automatically proxied through the given URL.
970 Not supported on Windows, Mac OS, iOS or Android. See also \fBNO_PROXY\fR.
973 When Mono is compiled with LLVM support, this instructs the runtime to
974 stop using LLVM after the specified number of methods are JITed.
975 This is a tool used in diagnostics to help isolate problems in the
976 code generation backend. For example \fBLLVM_COUNT=10\fR would only
977 compile 10 methods with LLVM and then switch to the Mono JIT engine.
978 \fBLLVM_COUNT=0\fR would disable the LLVM engine altogether.
981 If set, this variable will instruct Mono to ahead-of-time compile new
982 assemblies on demand and store the result into a cache in
985 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
986 Mono contains a feature which allows modifying settings in the .config files shipped
987 with Mono by using config section mappers. The mappers and the mapping rules are
988 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
989 settings.map file found in the top-level directory of your ASP.NET application.
990 Both files are read by System.Web on application startup, if they are found at the
991 above locations. If you don't want the mapping to be performed you can set this
992 variable in your environment before starting the application and no action will
995 \fBMONO_ASPNET_WEBCONFIG_CACHESIZE\fR
996 Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager
997 queries. Its default size is 100 items, and when more items are needed, cache
998 evictions start happening. If evictions are too frequent this could impose
999 unnecessary overhead, which could be avoided by using this environment variable
1000 to set up a higher cache size (or to lower memory requirements by decreasing it).
1002 \fBMONO_CAIRO_DEBUG_DISPOSE\fR
1003 If set, causes Mono.Cairo to collect stack traces when objects are allocated,
1004 so that the finalization/Dispose warnings include information about the
1008 If set, this variable overrides the default system configuration directory
1009 ($PREFIX/etc). It's used to locate machine.config file.
1012 Sets the style of COM interop. If the value of this variable is "MS"
1013 Mono will use string marhsalling routines from the liboleaut32 for the
1014 BSTR type library, any other values will use the mono-builtin BSTR
1018 If set, this variable overrides the default runtime configuration file
1019 ($PREFIX/etc/mono/config). The --config command line options overrides the
1020 environment variable.
1023 Override the automatic cpu detection mechanism. Currently used only on arm.
1024 The format of the value is as follows:
1030 where V is the architecture number 4, 5, 6, 7 and the options can be currently be
1031 "thumb" or "thumb2". Example:
1034 MONO_CPU_ARCH="armv4 thumb" mono ...
1038 \fBMONO_ARM_FORCE_SOFT_FLOAT\fR
1039 When Mono is built with a soft float fallback on ARM and this variable is set to
1040 "1", Mono will always emit soft float code, even if a VFP unit is
1043 \fBMONO_DARWIN_WATCHER_MAXFDS\fR
1044 This is a debugging aid used to force limits on the FileSystemWatcher
1045 implementation in Darwin. There is no limit by default.
1047 \fBMONO_DISABLE_AIO\fR
1048 If set, tells mono NOT to attempt using native asynchronous I/O services. In
1049 that case, a default select/poll implementation is used. Currently only epoll()
1052 \fBMONO_DISABLE_MANAGED_COLLATION\fR
1053 If this environment variable is `yes', the runtime uses unmanaged
1054 collation (which actually means no culture-sensitive collation). It
1055 internally disables managed collation functionality invoked via the
1056 members of System.Globalization.CompareInfo class. Collation is
1059 \fBMONO_DISABLE_SHM\fR
1060 Unix only: If set, disables the shared memory files used for
1061 cross-process handles: process have only private handles. This means
1062 that process and thread handles are not available to other processes,
1063 and named mutexes, named events and named semaphores are not visible
1066 This is can also be enabled by default by passing the
1067 "--disable-shared-handles" option to configure.
1069 This is the default from mono 2.8 onwards.
1071 \fBMONO_DISABLE_SHARED_AREA\fR
1072 Unix only: If set, disable usage of shared memory for exposing
1073 performance counters. This means it will not be possible to both
1074 externally read performance counters from this processes or read
1075 those of external processes.
1078 When set, enables the use of a fully managed DNS resolver instead of the
1079 regular libc functions. This resolver performs much better when multiple
1080 queries are run in parallel.
1082 Note that /etc/nsswitch.conf will be ignored.
1084 \fBMONO_EGD_SOCKET\fR
1085 For platforms that do not otherwise have a way of obtaining random bytes
1086 this can be set to the name of a file system socket on which an egd or
1087 prngd daemon is listening.
1089 \fBMONO_ENABLE_COOP\fR
1090 This makes the Mono runtime and the SGen garbage collector run in cooperative
1091 mode as opposed to run on preemptive mode. Preemptive mode is the mode
1092 that Mono has used historically, going back to the Boehm days, where the
1093 garbage collector would run at any point and suspend execution of all
1094 threads as required to perform a garbage collection. The cooperative mode
1095 on the other hand requires the cooperation of all threads to stop at a
1096 safe point. This makes for an easier to debug garbage collector. As
1097 of Mono 4.3.0 it is a work in progress, and while it works, it has not
1098 been used extensively. This option enabled the feature and allows us to
1099 find spots that need to be tuned for this mode of operation. Alternatively,
1100 this mode can be enabled at compile time by using the --with-cooperative-gc
1101 flag when calling configure.
1103 \fBMONO_ENV_OPTIONS\fR
1104 This environment variable allows you to pass command line arguments to
1105 a Mono process through the environment. This is useful for example
1106 to force all of your Mono processes to use LLVM or SGEN without having
1107 to modify any launch scripts.
1109 \fBMONO_SDB_ENV_OPTIONS\fR
1110 Used to pass extra options to the debugger agent in the runtime, as they were passed
1111 using --debugger-agent=.
1113 \fBMONO_EVENTLOG_TYPE\fR
1114 Sets the type of event log provider to use (for System.Diagnostics.EventLog).
1116 Possible values are:
1121 Persists event logs and entries to the local file system.
1123 The directory in which to persist the event logs, event sources and entries
1124 can be specified as part of the value.
1126 If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog"
1127 on unix and "%APPDATA%\mono\eventlog" on Windows.
1132 Uses the native win32 API to write events and registers event logs and
1133 event sources in the registry. This is only available on Windows.
1135 On Unix, the directory permission for individual event log and event source
1136 directories is set to 777 (with +t bit) allowing everyone to read and write
1137 event log entries while only allowing entries to be deleted by the user(s)
1142 Silently discards any events.
1145 The default is "null" on Unix (and versions of Windows before NT), and
1146 "win32" on Windows NT (and higher).
1149 \fBMONO_EXTERNAL_ENCODINGS\fR
1150 If set, contains a colon-separated list of text encodings to try when
1151 turning externally-generated text (e.g. command-line arguments or
1152 filenames) into Unicode. The encoding names come from the list
1153 provided by iconv, and the special case "default_locale" which refers
1154 to the current locale's default encoding.
1156 When reading externally-generated text strings UTF-8 is tried first,
1157 and then this list is tried in order with the first successful
1158 conversion ending the search. When writing external text (e.g. new
1159 filenames or arguments to new processes) the first item in this list
1160 is used, or UTF-8 if the environment variable is not set.
1162 The problem with using MONO_EXTERNAL_ENCODINGS to process your
1163 files is that it results in a problem: although its possible to get
1164 the right file name it is not necessarily possible to open the file.
1165 In general if you have problems with encodings in your filenames you
1166 should use the "convmv" program.
1168 \fBMONO_GC_PARAMS\fR
1169 When using Mono with the SGen garbage collector this variable controls
1170 several parameters of the collector. The variable's value is a comma
1171 separated list of words.
1175 \fBmax-heap-size=\fIsize\fR
1176 Sets the maximum size of the heap. The size is specified in bytes and must
1177 be a power of two. The suffixes `k', `m' and `g' can be used to
1178 specify kilo-, mega- and gigabytes, respectively. The limit is the sum
1179 of the nursery, major heap and large object heap. Once the limit is reached
1180 the application will receive OutOfMemoryExceptions when trying to allocate.
1181 Not the full extent of memory set in max-heap-size could be available to
1182 satisfy a single allocation due to internal fragmentation. By default heap
1183 limits is disabled and the GC will try to use all available memory.
1185 \fBnursery-size=\fIsize\fR
1186 Sets the size of the nursery. The size is specified in bytes and must
1187 be a power of two. The suffixes `k', `m' and `g' can be used to
1188 specify kilo-, mega- and gigabytes, respectively. The nursery is the
1189 first generation (of two). A larger nursery will usually speed up the
1190 program but will obviously use more memory. The default nursery size
1193 \fBmajor=\fIcollector\fR Specifies which major collector to use.
1194 Options are `marksweep' for the Mark&Sweep collector, and
1195 `marksweep-conc' for concurrent Mark&Sweep. The non-concurrent
1196 Mark&Sweep collector is the default.
1198 \fBsoft-heap-limit=\fIsize\fR
1199 Once the heap size gets larger than this size, ignore what the default
1200 major collection trigger metric says and only allow four nursery size's
1201 of major heap growth between major collections.
1203 \fBevacuation-threshold=\fIthreshold\fR
1204 Sets the evacuation threshold in percent. This option is only available
1205 on the Mark&Sweep major collectors. The value must be an
1206 integer in the range 0 to 100. The default is 66. If the sweep phase of
1207 the collection finds that the occupancy of a specific heap block type is
1208 less than this percentage, it will do a copying collection for that block
1209 type in the next major collection, thereby restoring occupancy to close
1210 to 100 percent. A value of 0 turns evacuation off.
1212 \fB(no-)lazy-sweep\fR
1213 Enables or disables lazy sweep for the Mark&Sweep collector. If
1214 enabled, the sweeping of individual major heap blocks is done
1215 piecemeal whenever the need arises, typically during nursery
1216 collections. Lazy sweeping is enabled by default.
1218 \fB(no-)concurrent-sweep\fR
1219 Enables or disables concurrent sweep for the Mark&Sweep collector. If
1220 enabled, the iteration of all major blocks to determine which ones can
1221 be freed and which ones have to be kept and swept, is done
1222 concurrently with the running program. Concurrent sweeping is enabled
1225 \fBstack-mark=\fImark-mode\fR
1226 Specifies how application threads should be scanned. Options are
1227 `precise` and `conservative`. Precise marking allow the collector
1228 to know what values on stack are references and what are not.
1229 Conservative marking threats all values as potentially references
1230 and leave them untouched. Precise marking reduces floating garbage
1231 and can speed up nursery collection and allocation rate, it has
1232 the downside of requiring a significant extra memory per compiled
1233 method. The right option, unfortunately, requires experimentation.
1235 \fBsave-target-ratio=\fIratio\fR
1236 Specifies the target save ratio for the major collector. The collector
1237 lets a given amount of memory to be promoted from the nursery due to
1238 minor collections before it triggers a major collection. This amount
1239 is based on how much memory it expects to free. It is represented as
1240 a ratio of the size of the heap after a major collection.
1241 Valid values are between 0.1 and 2.0. The default is 0.5.
1242 Smaller values will keep the major heap size smaller but will trigger
1243 more major collections. Likewise, bigger values will use more memory
1244 and result in less frequent major collections.
1245 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1247 \fBdefault-allowance-ratio=\fIratio\fR
1248 Specifies the default allocation allowance when the calculated size
1249 is too small. The allocation allowance is how much memory the collector
1250 let be promoted before triggered a major collection.
1251 It is a ratio of the nursery size.
1252 Valid values are between 1.0 and 10.0. The default is 4.0.
1253 Smaller values lead to smaller heaps and more frequent major collections.
1254 Likewise, bigger values will allow the heap to grow faster but use
1255 more memory when it reaches a stable size.
1256 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1258 \fBminor=\fIminor-collector\fR
1259 Specifies which minor collector to use. Options are 'simple' which
1260 promotes all objects from the nursery directly to the old generation
1261 and 'split' which lets object stay longer on the nursery before promoting.
1263 \fBalloc-ratio=\fIratio\fR
1264 Specifies the ratio of memory from the nursery to be use by the alloc space.
1265 This only can only be used with the split minor collector.
1266 Valid values are integers between 1 and 100. Default is 60.
1268 \fBpromotion-age=\fIage\fR
1269 Specifies the required age of an object must reach inside the nursery before
1270 been promoted to the old generation. This only can only be used with the
1271 split minor collector.
1272 Valid values are integers between 1 and 14. Default is 2.
1274 \fB(no-)cementing\fR
1275 Enables or disables cementing. This can dramatically shorten nursery
1276 collection times on some benchmarks where pinned objects are referred
1277 to from the major heap.
1279 \fBallow-synchronous-major\fR
1280 This forbids the major collector from performing synchronous major collections.
1281 The major collector might want to do a synchronous collection due to excessive
1282 fragmentation. Disabling this might trigger OutOfMemory error in situations that
1283 would otherwise not happen.
1288 When using Mono with the SGen garbage collector this environment
1289 variable can be used to turn on various debugging features of the
1290 collector. The value of this variable is a comma separated list of
1291 words. Do not use these options in production.
1296 Sets the debug level to the specified number.
1298 \fBprint-allowance\fR
1299 After each major collection prints memory consumption for before and
1300 after the collection and the allowance for the minor collector, i.e. how
1301 much the heap is allowed to grow from minor collections before the next
1302 major collection is triggered.
1305 Gathers statistics on the classes whose objects are pinned in the
1306 nursery and for which global remset entries are added. Prints those
1307 statistics when shutting down.
1309 \fBcollect-before-allocs\fR
1311 \fBcheck-remset-consistency\fR
1312 This performs a remset consistency check at various opportunities, and
1313 also clears the nursery at collection time, instead of the default,
1314 when buffers are allocated (clear-at-gc). The consistency check
1315 ensures that there are no major to minor references that are not on
1316 the remembered sets.
1318 \fBmod-union-consistency-check\fR
1319 Checks that the mod-union cardtable is consistent before each
1320 finishing major collection pause. This check is only applicable to
1321 concurrent major collectors.
1323 \fBcheck-mark-bits\fR
1324 Checks that mark bits in the major heap are consistent at the end of
1325 each major collection. Consistent mark bits mean that if an object is
1326 marked, all objects that it had references to must also be marked.
1328 \fBcheck-nursery-pinned\fR
1329 After nursery collections, and before starting concurrent collections,
1330 check whether all nursery objects are pinned, or not pinned -
1331 depending on context. Does nothing when the split nursery collector
1334 \fBxdomain-checks\fR
1335 Performs a check to make sure that no references are left to an
1338 \fBclear-at-tlab-creation\fR
1339 Clears the nursery incrementally when the thread local allocation
1340 buffers (TLAB) are created. The default setting clears the whole
1343 \fBdebug-clear-at-tlab-creation\fR
1344 Clears the nursery incrementally when the thread local allocation
1345 buffers (TLAB) are created, but at GC time fills it with the byte
1346 `0xff`, which should result in a crash more quickly if
1347 `clear-at-tlab-creation` doesn't work properly.
1350 This clears the nursery at GC time instead of doing it when the thread
1351 local allocation buffer (TLAB) is created. The default is to clear
1352 the nursery at TLAB creation time.
1355 Don't do minor collections. If the nursery is full, a major collection
1356 is triggered instead, unless it, too, is disabled.
1359 Don't do major collections.
1361 \fBconservative-stack-mark\fR
1362 Forces the GC to scan the stack conservatively, even if precise
1363 scanning is available.
1365 \fBno-managed-allocator\fR
1366 Disables the managed allocator.
1368 \fBcheck-scan-starts\fR
1369 If set, does a plausibility check on the scan_starts before and after each collection
1371 \fBverify-nursery-at-minor-gc\fR
1372 If set, does a complete object walk of the nursery at the start of each minor collection.
1374 \fBdump-nursery-at-minor-gc\fR
1375 If set, dumps the contents of the nursery at the start of each minor collection. Requires
1376 verify-nursery-at-minor-gc to be set.
1378 \fBheap-dump=\fIfile\fR
1379 Dumps the heap contents to the specified file. To visualize the
1380 information, use the mono-heapviz tool.
1382 \fBbinary-protocol=\fIfile\fR
1383 Outputs the debugging output to the specified file. For this to
1384 work, Mono needs to be compiled with the BINARY_PROTOCOL define on
1385 sgen-gc.c. You can then use this command to explore the output
1387 sgen-grep-binprot 0x1234 0x5678 < file
1390 \fBnursery-canaries\fR
1391 If set, objects allocated in the nursery are suffixed with a canary (guard)
1392 word, which is checked on each minor collection. Can be used to detect/debug
1393 heap corruption issues.
1396 \fBdo-not-finalize(=\fIclasses\fB)\fR
1397 If enabled, finalizers will not be run. Everything else will be
1398 unaffected: finalizable objects will still be put into the
1399 finalization queue where they survive until they're scheduled to
1400 finalize. Once they're not in the queue anymore they will be
1401 collected regularly. If a list of comma-separated class names is
1402 given, only objects from those classes will not be finalized.
1405 \fBlog-finalizers\fR
1406 Log verbosely around the finalization process to aid debugging.
1410 \fBMONO_GAC_PREFIX\fR
1411 Provides a prefix the runtime uses to look for Global Assembly Caches.
1412 Directories are separated by the platform path separator (colons on
1413 unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
1414 install. Or to the directory provided in the gacutil /gacdir command. Example:
1415 .B /home/username/.mono:/usr/local/mono/
1418 Enables some filename rewriting support to assist badly-written
1419 applications that hard-code Windows paths. Set to a colon-separated
1420 list of "drive" to strip drive letters, or "case" to do
1421 case-insensitive file matching in every directory in a path. "all"
1422 enables all rewriting methods. (Backslashes are always mapped to
1423 slashes if this variable is set to a valid option).
1426 For example, this would work from the shell:
1429 MONO_IOMAP=drive:case
1433 If you are using mod_mono to host your web applications, you can use
1436 directive instead, like this:
1439 MonoIOMAP <appalias> all
1442 See mod_mono(8) for more details.
1444 Additionally. Mono includes a profiler module which allows one to track what
1445 adjustements to file paths IOMAP code needs to do. The tracking code reports
1446 the managed location (full stack trace) from which the IOMAP-ed call was made and,
1447 on process exit, the locations where all the IOMAP-ed strings were created in
1448 managed code. The latter report is only approximate as it is not always possible
1449 to estimate the actual location where the string was created. The code uses simple
1450 heuristics - it analyzes stack trace leading back to the string allocation location
1451 and ignores all the managed code which lives in assemblies installed in GAC as well as in the
1452 class libraries shipped with Mono (since they are assumed to be free of case-sensitivity
1453 issues). It then reports the first location in the user's code - in most cases this will be
1454 the place where the string is allocated or very close to the location. The reporting code
1455 is implemented as a custom profiler module (see the "PROFILING" section) and can be loaded
1456 in the following way:
1461 mono --profile=iomap yourapplication.exe
1464 Note, however, that Mono currently supports only one profiler module
1468 When Mono is using the LLVM code generation backend you can use this
1469 environment variable to pass code generation options to the LLVM
1472 \fBMONO_MANAGED_WATCHER\fR
1473 If set to "disabled", System.IO.FileSystemWatcher will use a file watcher
1474 implementation which silently ignores all the watching requests.
1475 If set to any other value, System.IO.FileSystemWatcher will use the default
1476 managed implementation (slow). If unset, mono will try to use inotify, FAM,
1477 Gamin, kevent under Unix systems and native API calls on Windows, falling
1478 back to the managed implementation on error.
1480 \fBMONO_MESSAGING_PROVIDER\fR
1481 Mono supports a plugin model for its implementation of System.Messaging making
1482 it possible to support a variety of messaging implementations (e.g. AMQP, ActiveMQ).
1483 To specify which messaging implementation is to be used the evironement variable
1484 needs to be set to the full class name for the provider. E.g. to use the RabbitMQ based
1485 AMQP implementation the variable should be set to:
1488 Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
1491 If set causes the mono process to be bound to a single processor. This may be
1492 useful when debugging or working around race conditions.
1495 Disable inlining of thread local accesses. Try setting this if you get a segfault
1496 early on in the execution of mono.
1499 Provides a search path to the runtime where to look for library
1500 files. This is a tool convenient for debugging applications, but
1501 should not be used by deployed applications as it breaks the assembly
1502 loader in subtle ways.
1504 Directories are separated by the platform path separator (colons on unix). Example:
1505 .B /home/username/lib:/usr/local/mono/lib
1507 Relative paths are resolved based on the launch-time current directory.
1509 Alternative solutions to MONO_PATH include: installing libraries into
1510 the Global Assembly Cache (see gacutil(1)) or having the dependent
1511 libraries side-by-side with the main executable.
1513 For a complete description of recommended practices for application
1515 http://www.mono-project.com/docs/getting-started/application-deployment/
1517 \fBMONO_SHARED_DIR\fR
1518 If set its the directory where the ".wapi" handle state is stored.
1519 This is the directory where the Windows I/O Emulation layer stores its
1520 shared state data (files, events, mutexes, pipes). By default Mono
1521 will store the ".wapi" directory in the users's home directory.
1523 \fBMONO_SHARED_HOSTNAME\fR
1524 Uses the string value of this variable as a replacement for the host name when
1525 creating file names in the ".wapi" directory. This helps if the host name of
1526 your machine is likely to be changed when a mono application is running or if
1527 you have a .wapi directory shared among several different computers.
1529 Mono typically uses the hostname to create the files that are used to
1530 share state across multiple Mono processes. This is done to support
1531 home directories that might be shared over the network.
1533 \fBMONO_STRICT_IO_EMULATION\fR
1534 If set, extra checks are made during IO operations. Currently, this
1535 includes only advisory locks around file writes.
1538 The name of the theme to be used by Windows.Forms. Available themes today
1539 include "clearlooks", "nice" and "win32".
1541 The default is "win32".
1543 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1544 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1545 avoid a new negotiation between the client and a server. Negotiation are very
1546 CPU intensive so an application-specific custom value may prove useful for
1547 small embedded systems.
1549 The default is 180 seconds.
1551 \fBMONO_THREADS_PER_CPU\fR
1552 The minimum number of threads in the general threadpool will be
1553 MONO_THREADS_PER_CPU * number of CPUs. The default value for this
1556 \fBMONO_XMLSERIALIZER_THS\fR
1557 Controls the threshold for the XmlSerializer to produce a custom
1558 serializer for a given class instead of using the Reflection-based
1559 interpreter. The possible values are `no' to disable the use of a
1560 custom serializer or a number to indicate when the XmlSerializer
1561 should start serializing. The default value is 50, which means that
1562 the a custom serializer will be produced on the 50th use.
1564 \fBMONO_X509_REVOCATION_MODE\fR
1565 Sets the revocation mode used when validating a X509 certificate chain (https,
1566 ftps, smtps...). The default is 'nocheck', which performs no revocation check
1567 at all. The other possible values are 'offline', which performs CRL check (not
1568 implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
1569 status (not implemented yet).
1572 (Also \fBno_proxy\fR) If both \fBHTTP_PROXY\fR and \fBNO_PROXY\fR are
1573 set, \fBNO_PROXY\fR will be treated as a comma-separated list of "bypass" domains
1574 which will not be sent through the proxy. Domains in \fBNO_PROXY\fR may contain
1575 wildcards, as in "*.mono-project.com" or "build????.local". Not supported on
1576 Windows, Mac OS, iOS or Android.
1577 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1579 \fBMONO_ASPNET_NODELETE\fR
1580 If set to any value, temporary source files generated by ASP.NET support
1581 classes will not be removed. They will be kept in the user's temporary
1585 If set, enables some features of the runtime useful for debugging.
1586 This variable should contain a comma separated list of debugging options.
1587 Currently, the following options are supported:
1591 \fBalign-small-structs\fR
1592 Enables small structs alignment to 4/8 bytes.
1594 \fBarm-use-fallback-tls\fR
1595 When this option is set on ARM, a fallback TLS will be used instead
1596 of the default fast TLS.
1598 \fBbreak-on-unverified\fR
1599 If this variable is set, when the Mono VM runs into a verification
1600 problem, instead of throwing an exception it will break into the
1601 debugger. This is useful when debugging verifier problems
1604 This option can be used to get more detailed information from
1605 InvalidCast exceptions, it will provide information about the types
1608 \fBcheck-pinvoke-callconv\fR
1609 This option causes the runtime to check for calling convention
1610 mismatches when using pinvoke, i.e. mixing cdecl/stdcall. It only
1611 works on windows. If a mismatch is detected, an
1612 ExecutionEngineException is thrown.
1614 \fBcollect-pagefault-stats\fR
1615 Collects information about pagefaults. This is used internally to
1616 track the number of page faults produced to load metadata. To display
1617 this information you must use this option with "--stats" command line
1620 \fBdebug-domain-unload\fR
1621 When this option is set, the runtime will invalidate the domain memory
1622 pool instead of destroying it.
1624 \fBdisable_omit_fp\fR
1625 Disables a compiler optimization where the frame pointer is omitted
1626 from the stack. This optimization can interact badly with debuggers.
1628 \fBdont-free-domains\fR
1629 This is an Optimization for multi-AppDomain applications (most
1630 commonly ASP.NET applications). Due to internal limitations Mono,
1631 Mono by default does not use typed allocations on multi-appDomain
1632 applications as they could leak memory when a domain is unloaded.
1634 Although this is a fine default, for applications that use more than
1635 on AppDomain heavily (for example, ASP.NET applications) it is worth
1636 trading off the small leaks for the increased performance
1637 (additionally, since ASP.NET applications are not likely going to
1638 unload the application domains on production systems, it is worth
1639 using this feature).
1641 \fBdyn-runtime-invoke\fR
1642 Instructs the runtime to try to use a generic runtime-invoke wrapper
1643 instead of creating one invoke wrapper.
1645 \fBexplicit-null-checks\fR
1646 Makes the JIT generate an explicit NULL check on variable dereferences
1647 instead of depending on the operating system to raise a SIGSEGV or
1648 another form of trap event when an invalid memory location is
1652 Equivalent to setting the \fBMONO_XDEBUG\fR variable, this emits
1653 symbols into a shared library as the code is JITed that can be loaded
1654 into GDB to inspect symbols.
1656 \fBgen-seq-points\fR
1657 Automatically generates sequence points where the
1658 IL stack is empty. These are places where the debugger can set a
1661 \fBno-compact-seq-points\fR
1662 Unless the option is used, the runtime generates sequence points data that
1663 maps native offsets to IL offsets. Sequence point data is used to
1664 display IL offset in stacktraces. Stacktraces with IL offsets can be
1665 symbolicated using mono-symbolicate tool.
1668 Captures the interrupt signal (Control-C) and displays a stack trace
1669 when pressed. Useful to find out where the program is executing at a
1670 given point. This only displays the stack trace of a single thread.
1673 Instructs the runtime to initialize the stack with
1674 some known values (0x2a on x86-64) at the start of a method to assist
1675 in debuggin the JIT engine.
1677 \fBkeep-delegates\fR
1678 This option will leak delegate trampolines that are no longer
1679 referenced as to present the user with more information about a
1680 delegate misuse. Basically a delegate instance might be created,
1681 passed to unmanaged code, and no references kept in managed code,
1682 which will garbage collect the code. With this option it is possible
1683 to track down the source of the problems.
1685 \fBno-gdb-backtrace\fR
1686 This option will disable the GDB backtrace emitted by the runtime
1687 after a SIGSEGV or SIGABRT in unmanaged code.
1689 \fBpartial-sharing\fR
1690 When this option is set, the runtime can share generated code between
1691 generic types effectively reducing the amount of code generated.
1693 \fBreverse-pinvoke-exceptions
1694 This option will cause mono to abort with a descriptive message when
1695 during stack unwinding after an exception it reaches a native stack
1696 frame. This happens when a managed delegate is passed to native code,
1697 and the managed delegate throws an exception. Mono will normally try
1698 to unwind the stack to the first (managed) exception handler, and it
1699 will skip any native stack frames in the process. This leads to
1700 undefined behaviour (since mono doesn't know how to process native
1701 frames), leaks, and possibly crashes too.
1703 \fBsingle-imm-size\fR
1704 This guarantees that each time managed code is compiled the same
1705 instructions and registers are used, regardless of the size of used
1708 \fBsoft-breakpoints\fR
1709 This option allows using single-steps and breakpoints in hardware
1710 where we cannot do it with signals.
1712 \fBsuspend-on-sigsegv\fR
1713 This option will suspend the program when a native SIGSEGV is received.
1714 This is useful for debugging crashes which do not happen under gdb,
1715 since a live process contains more information than a core file.
1717 \fBsuspend-on-exception\fR
1718 This option will suspend the program when an exception occurs.
1720 \fBsuspend-on-unhandled\fR
1721 This option will suspend the program when an unhandled exception occurs.
1725 \fBMONO_LOG_LEVEL\fR
1726 The logging level, possible values are `error', `critical', `warning',
1727 `message', `info' and `debug'. See the DEBUGGING section for more
1731 Controls the domain of the Mono runtime that logging will apply to.
1732 If set, the log mask is changed to the set value. Possible values are
1733 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1734 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
1735 "security" (e.g. Moonlight CoreCLR support) and "all".
1736 The default value is "all". Changing the mask value allows you to display only
1737 messages for a certain component. You can use multiple masks by comma
1738 separating them. For example to see config file messages and assembly loader
1739 messages set you mask to "asm,cfg".
1742 Controls where trace log messages are written. If not set then the messages go to stdout.
1743 If set, the string either specifies a path to a file that will have messages appended to
1744 it, or the string "syslog" in which case the messages will be written to the system log.
1745 Under Windows, this is simulated by writing to a file called "mono.log".
1746 \fBMONO_LOG_HEADER\fR
1747 Controls whether trace log messages not directed to syslog have the id, timestamp, and
1748 pid as the prefix to the log message. To enable a header this environment variable need
1752 Used for runtime tracing of method calls. The format of the comma separated
1761 disabled Trace output off upon start.
1764 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1766 \fBMONO_TRACE_LISTENER\fR
1767 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1768 print the output of the System.Diagnostics Trace and Debug classes.
1769 It can be set to a filename, and to Console.Out or Console.Error to display
1770 output to standard output or standard error, respectively. If it's set to
1771 Console.Out or Console.Error you can append an optional prefix that will
1772 be used when writing messages like this: Console.Error:MyProgramName.
1773 See the System.Diagnostics.DefaultTraceListener documentation for more
1776 \fBMONO_WCF_TRACE\fR
1777 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.
1779 \fBMONO_XEXCEPTIONS\fR
1780 This throws an exception when a X11 error is encountered; by default a
1781 message is displayed but execution continues
1783 \fBMONO_XMLSERIALIZER_DEBUG\fR
1784 Set this value to 1 to prevent the serializer from removing the
1785 temporary files that are created for fast serialization; This might
1786 be useful when debugging.
1789 This is used in the System.Windows.Forms implementation when running
1790 with the X11 backend. This is used to debug problems in Windows.Forms
1791 as it forces all of the commands send to X11 server to be done
1792 synchronously. The default mode of operation is asynchronous which
1793 makes it hard to isolate the root of certain problems.
1796 When the the MONO_XDEBUG env var is set, debugging info for JITted
1797 code is emitted into a shared library, loadable into gdb. This enables,
1798 for example, to see managed frame names on gdb backtraces.
1800 \fBMONO_VERBOSE_METHOD\fR
1801 Enables the maximum JIT verbosity for the specified method. This is
1802 very helpfull to diagnose a miscompilation problems of a specific
1805 \fBMONO_JIT_DUMP_METHOD\fR
1806 Enables sending of the JITs intermediate representation for a specified
1807 method to the IdealGraphVisualizer tool.
1809 \fBMONO_VERBOSE_HWCAP\fR
1810 If set, makes the JIT output information about detected CPU features
1811 (such as SSE, CMOV, FCMOV, etc) to stdout.
1813 \fBMONO_CONSERVATIVE_HWCAP\fR
1814 If set, the JIT will not perform any hardware capability detection. This
1815 may be useful to pinpoint the cause of JIT issues. This is the default
1816 when Mono is built as an AOT cross compiler, so that the generated code
1817 will run on most hardware.
1819 If you want to use Valgrind, you will find the file `mono.supp'
1820 useful, it contains the suppressions for the GC which trigger
1821 incorrect warnings. Use it like this:
1823 valgrind --suppressions=mono.supp mono ...
1826 On some platforms, Mono can expose a set of DTrace probes (also known
1827 as user-land statically defined, USDT Probes).
1829 They are defined in the file `mono.d'.
1831 .B ves-init-begin, ves-init-end
1833 Begin and end of runtime initialization.
1835 .B method-compile-begin, method-compile-end
1837 Begin and end of method compilation.
1838 The probe arguments are class name, method name and signature,
1839 and in case of method-compile-end success or failure of compilation.
1843 Begin and end of Garbage Collection.
1845 To verify the availability of the probes, run:
1847 dtrace -P mono'$target' -l -c mono
1850 Mono's Ping implementation for detecting network reachability can
1851 create the ICMP packets itself without requiring the system ping
1852 command to do the work. If you want to enable this on Linux for
1853 non-root users, you need to give the Mono binary special permissions.
1855 As root, run this command:
1857 # setcap cap_net_raw=+ep /usr/bin/mono
1860 On Unix assemblies are loaded from the installation lib directory. If you set
1861 `prefix' to /usr, the assemblies will be located in /usr/lib. On
1862 Windows, the assemblies are loaded from the directory where mono and
1865 .B ~/.mono/aot-cache
1867 The directory for the ahead-of-time compiler demand creation
1868 assemblies are located.
1870 .B /etc/mono/config, ~/.mono/config
1872 Mono runtime configuration file. See the mono-config(5) manual page
1873 for more information.
1875 .B ~/.config/.mono/certs, /usr/share/.mono/certs
1877 Contains Mono certificate stores for users / machine. See the certmgr(1)
1878 manual page for more information on managing certificate stores and
1879 the mozroots(1) page for information on how to import the Mozilla root
1880 certificates into the Mono certificate store.
1882 .B ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
1884 Files in this directory allow a user to customize the configuration
1885 for a given system assembly, the format is the one described in the
1886 mono-config(5) page.
1888 .B ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
1890 Contains Mono cryptographic keypairs for users / machine. They can be
1891 accessed by using a CspParameters object with DSACryptoServiceProvider
1892 and RSACryptoServiceProvider classes.
1894 .B ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
1896 Contains Mono isolated storage for non-roaming users, roaming users and
1897 local machine. Isolated storage can be accessed using the classes from
1898 the System.IO.IsolatedStorage namespace.
1900 .B <assembly>.config
1902 Configuration information for individual assemblies is loaded by the
1903 runtime from side-by-side files with the .config files, see the
1904 http://www.mono-project.com/Config for more information.
1906 .B Web.config, web.config
1908 ASP.NET applications are configured through these files, the
1909 configuration is done on a per-directory basis. For more information
1910 on this subject see the http://www.mono-project.com/Config_system.web
1913 Mailing lists are listed at the
1914 http://www.mono-project.com/community/help/mailing-lists/
1916 http://www.mono-project.com
1919 certmgr(1), csharp(1), mcs(1), mdb(1), monocov(1), monodis(1),
1920 mono-config(5), mozroots(1), mprof-report(1), pdb2mdb(1), xsp(1), mod_mono(8).
1922 For more information on AOT:
1923 http://www.mono-project.com/docs/advanced/aot/
1925 For ASP.NET-related documentation, see the xsp(1) manual page
projects / mono.git / blob