3 .\" Copyright 2003 Ximian, Inc.
4 .\" Copyright 2004-2011 Novell, Inc.
5 .\" Copyright 2011-2012 Xamarin Inc
6 .\" Copyright 2013 7digital Media Ltd.
8 .\" Miguel de Icaza (miguel@gnu.org)
12 mono \- Mono's ECMA-CLI native code generator (Just-in-Time and Ahead-of-Time)
15 .B mono [options] file [arguments...]
17 .B mono-sgen [options] file [arguments...]
19 \fImono\fP is a runtime implementation of the ECMA Common Language
20 Infrastructure. This can be used to run ECMA and .NET applications.
22 The runtime contains a native code generator that transforms the
23 Common Intermediate Language into native code.
25 The code generator can operate in two modes: just in time compilation
26 (JIT) or ahead of time compilation (AOT). Since code can be
27 dynamically loaded, the runtime environment and the JIT are always
28 present, even if code is compiled ahead of time.
30 The runtime loads the specified
37 is an ECMA assembly. They typically have a .exe or .dll extension.
39 The runtime provides a number of configuration options for running
40 applications, for developing and debugging, and for testing and
41 debugging the runtime itself.
43 The \fImono\fP command uses the Boehm conservative garbage collector
44 while the \fImono-sgen\fP command uses a moving and generational
47 On Unix-based systems, Mono provides a mechanism to emulate the
48 Windows-style file access, this includes providing a case insensitive
49 view of the file system, directory separator mapping (from \\ to /) and
50 stripping the drive letters.
52 This functionality is enabled by setting the
54 environment variable to one of
59 See the description for
61 in the environment variables section for more details.
63 The following options are available:
65 \fB--aot\fR, \fB--aot[=options]\fR
66 This option is used to precompile the CIL code in the specified
67 assembly to native code. The generated code is stored in a file with
68 the extension .so. This file will be automatically picked up by the
69 runtime when the assembly is executed.
71 Ahead-of-Time compilation is most useful if you use it in combination
72 with the -O=all,-shared flag which enables all of the optimizations in
73 the code generator to be performed. Some of those optimizations are
74 not practical for Just-in-Time compilation since they might be very
77 Unlike the .NET Framework, Ahead-of-Time compilation will not generate
78 domain independent code: it generates the same code that the
79 Just-in-Time compiler would produce. Since most applications use a
80 single domain, this is fine. If you want to optimize the generated
81 code for use in multi-domain applications, consider using the
84 This pre-compiles the methods, but the original assembly is still
85 required to execute as this one contains the metadata and exception
86 information which is not available on the generated file. When
87 precompiling code, you might want to compile with all optimizations
88 (-O=all). Pre-compiled code is position independent code.
90 Pre compilation is just a mechanism to reduce startup time, increase
91 code sharing across multiple mono processes and avoid just-in-time
92 compilation program startup costs. The original assembly must still
93 be present, as the metadata is contained there.
95 AOT code typically can not be moved from one computer to another
96 (CPU-specific optimizations that are detected at runtime) so you
97 should not try to move the pre-generated assemblies or package the
98 pre-generated assemblies for deployment.
100 A few options are available as a parameter to the
102 command line option. The options are separated by commas, and more
103 than one can be specified:
108 The AOT compiler will emit a (ELF only) library initializer to automatically
109 register the aot compiled module with the runtime. This is only useful in static
113 Instructs the AOT compiler to output assembly code instead of an
116 .I bind-to-runtime-version
118 If specified, forces the generated AOT files to be bound to the
119 runtime version of the compiling Mono. This will prevent the AOT
120 files from being consumed by a different Mono runtime.
123 This is currently an experimental feature as it is not complete.
124 This instructs Mono to precompile code that has historically not been
125 precompiled with AOT.
127 .I data-outfile=FILE.dll.aotdata
129 This instructs the AOT code generator to output certain data
130 constructs into a separate file. This can reduce the executable
131 images some five to twenty percent. Developers need to then ship the
132 resulting aotdata as a resource and register a hook to load the data
133 on demand by using the
134 .I mono_install_load_aot_data_hook
139 When this option is specified, P/Invoke methods are invoked directly
140 instead of going through the operating system symbol lookup operation.
142 .I llvm-path=<PREFIX>
143 Same for the llvm tools 'opt' and 'llc'.
146 Use the GNU style target triple <TRIPLE> to determine some code generation options, i.e.
147 --mtriple=armv7-linux-gnueabi will generate code that targets ARMv7. This is currently
148 only supported by the ARM backend. In LLVM mode, this triple is passed on to the LLVM
151 .I nimt-trampolines=[number]
152 When compiling in full aot mode, the IMT trampolines must be precreated
153 in the AOT image. You can add additional method trampolines with this argument.
157 Instructs the AOT compiler to not output any debugging information.
160 This prevents the AOT compiler from generating a direct calls to a
161 method. The AOT compiler usually generates direct calls for certain
162 methods that do not require going through the PLT (for example,
163 methods that are known to not require a hook like a static
164 constructor) or call into simple internal calls.
167 Instructs the AOT compiler to emit DWARF debugging information. When
168 used together with the nodebug option, only DWARF debugging
169 information is emitted, but not the information that can be used at
172 .I nrgctx-trampolines=[number]
173 When compiling in full aot mode, the generic sharing trampolines must be precreated
174 in the AOT image. You can add additional method trampolines with this argument.
177 .I ntrampolines=[number]
178 When compiling in full aot mode, the method trampolines must be precreated
179 in the AOT image. You can add additional method trampolines with this argument.
182 .I outfile=[filename]
183 Instructs the AOT compiler to save the output to the specified file.
185 .I print-skipped-methods
186 If the AOT compiler cannot compile a method for any reason, enabling this flag
187 will output the skipped methods to the console.
189 .I readonly-value=namespace.typename.fieldname=type/value
190 Override the value of a static readonly field. Usually, during JIT
191 compilation, the static constructor is ran eagerly, so the value of
192 a static readonly field is known at compilation time and the compiler
193 can do a number of optimizations based on it. During AOT, instead, the static
194 constructor can't be ran, so this option can be used to set the value of such
195 a field and enable the same set of optimizations.
196 Type can be any of i1, i2, i4 for integers of the respective sizes (in bytes).
197 Note that signed/unsigned numbers do not matter here, just the storage size.
198 This option can be specified multiple times and it doesn't prevent the static
199 constructor for the type defining the field to execute with the usual rules
200 at runtime (hence possibly computing a different value for the field).
203 .I save-temps,keep-temps
204 Instructs the AOT compiler to keep temporary files.
207 This instructs the compiler to generate sequence point checks that
208 allow Mono's soft debugger to debug applications even on systems where
209 it is not possible to set breakpoints or to single step (certain
210 hardware configurations like the cell phones and video gaming
214 Create an ELF object file (.o) or .s file which can be statically linked into an
215 executable when embedding the mono runtime. When this option is used, the object file
216 needs to be registered with the embedded runtime using the mono_aot_register_module
217 function which takes as its argument the mono_aot_module_<ASSEMBLY NAME>_info global
218 symbol from the object file:
221 extern void *mono_aot_module_hello_info;
223 mono_aot_register_module (mono_aot_module_hello_info);
228 Print various stats collected during AOT compilation.
231 This is an experimental option for the AOT compiler to use multiple threads
232 when compiling the methods.
234 .I tool-prefix=<PREFIX>
235 Prepends <PREFIX> to the name of tools ran by the AOT compiler, i.e. 'as'/'ld'. For
236 example, --tool=prefix=arm-linux-gnueabi- will make the AOT compiler run
237 'arm-linux-gnueabi-as' instead of 'as'.
240 Instructs the AOT compiler to emit debug symbol information.
242 For more information about AOT, see: http://www.mono-project.com/docs/advanced/aot/
245 \fB--attach=[options]\fR
246 Currently the only option supported by this command line argument is
247 \fBdisable\fR which disables the attach functionality.
249 \fB--config filename\fR
250 Load the specified configuration file instead of the default one(s).
251 The default files are /etc/mono/config and ~/.mono/config or the file
252 specified in the MONO_CONFIG environment variable, if set. See the
253 mono-config(5) man page for details on the format of this file.
255 \fB--debugger-agent=[options]\fR
256 This instructs the Mono runtime to
257 start a debugging agent inside the Mono runtime and connect it to a
258 client user interface will control the Mono process.
259 This option is typically used by IDEs, like the MonoDevelop IDE.
261 The configuration is specified using one of more of the following options:
267 Use this option to specify the IP address where your debugger client is
272 Specifies the diagnostics log level for
276 Used to specify the file where the log will be stored, it defaults to
280 Defaults to no, with the default option Mono will actively connect to the
281 host/port configured with the \fBaddress\fR option. If you set it to 'y', it
282 instructs the Mono runtime to start debugging in server mode, where Mono
283 actively waits for the debugger front end to connect to the Mono process.
284 Mono will print out to stdout the IP address and port where it is listening.
287 If set to yes, Mono will call \fBsetpgid(0, 0)\fB on startup, if that function
288 is available on the system. This is useful for ensuring that signals delivered
289 to a process that is executing the debuggee are not propagated to the debuggee,
290 e.g. when Ctrl-C sends \fBSIGINT\fB to the \fBsdb\fB tool.
293 Defaults to yes, with the default option Mono will suspend the vm on startup
294 until it connects successfully to a debugger front end. If you set it to 'n', in
295 conjunction with \fBserver=y\fR, it instructs the Mono runtime to run as normal,
296 while caching metadata to send to the debugger front end on connection..
298 .I transport=transport_name
300 This is used to specify the transport that the debugger will use to
301 communicate. It must be specified and currently requires this to
307 Configures the virtual machine to be better suited for desktop
308 applications. Currently this sets the GC system to avoid expanding
309 the heap as much as possible at the expense of slowing down garbage
313 This is an experimental flag that instructs the Mono runtime to not
314 generate any code at runtime and depend exclusively on the code
315 generated from using mono --aot=full previously. This is useful for
316 platforms that do not permit dynamic code generation.
318 Notice that this feature will abort execution at runtime if a codepath
319 in your program, or Mono's class libraries attempts to generate code
320 dynamically. You should test your software upfront and make sure that
321 you do not use any dynamic features.
323 \fB--gc=boehm\fR, \fB--gc=sgen\fR
324 Selects the Garbage Collector engine for Mono to use, Boehm or SGen.
325 Currently this merely ensures that you are running either the
326 \fImono\fR or \fImono-sgen\fR commands. This flag can be set in the
327 \fBMONO_ENV_OPTIONS\fR environment variable to force all of your child
328 processes to use one particular kind of GC with the Mono runtime.
330 \fB--arch=32\fR, \fB--arch=64\fR
331 (Mac OS X only): Selects the bitness of the Mono binary used, if
332 available. If the binary used is already for the selected bitness, nothing
333 changes. If not, the execution switches to a binary with the selected
334 bitness suffix installed side by side (for example, '/bin/mono --arch=64'
335 will switch to '/bin/mono64' iff '/bin/mono' is a 32-bit build).
337 \fB--help\fR, \fB-h\fR
338 Displays usage instructions.
341 If the Mono runtime has been compiled with LLVM support (not available
342 in all configurations), Mono will use the LLVM optimization and code
343 generation engine to JIT or AOT compile.
345 For more information, consult: http://www.mono-project.com/docs/advanced/mono-llvm/
348 When using a Mono that has been compiled with LLVM support, it forces
349 Mono to fallback to its JIT engine and not use the LLVM backend.
351 \fB--optimize=MODE\fR, \fB-O=MODE\fR
352 MODE is a comma separated list of optimizations. They also allow
353 optimizations to be turned off by prefixing the optimization name with
356 In general, Mono has been tuned to use the default set of flags,
357 before using these flags for a deployment setting, you might want to
358 actually measure the benefits of using them.
360 The following optimization flags are implemented in the core engine:
362 abcrem Array bound checks removal
363 all Turn on all optimizations
364 aot Usage of Ahead Of Time compiled code
365 branch Branch optimizations
366 cfold Constant folding
367 cmov Conditional moves [arch-dependency]
368 deadce Dead code elimination
369 consprop Constant propagation
370 copyprop Copy propagation
371 fcmov Fast x86 FP compares [arch-dependency]
372 float32 Perform 32-bit float arithmetic using 32-bit operations
373 gshared Enable generic code sharing.
374 inline Inline method calls
375 intrins Intrinsic method implementations
376 linears Linear scan global reg allocation
377 leaf Leaf procedures optimizations
378 loop Loop related optimizations
379 peephole Peephole postpass
380 precomp Precompile all methods before executing Main
381 sched Instruction scheduling
382 shared Emit per-domain code
383 sse2 SSE2 instructions on x86 [arch-dependency]
384 tailc Tail recursion and tail calls
387 For example, to enable all the optimization but dead code
388 elimination and inlining, you can use:
390 -O=all,-deadce,-inline
393 The flags that are flagged with [arch-dependency] indicate that the
394 given option if used in combination with Ahead of Time compilation
395 (--aot flag) would produce pre-compiled code that will depend on the
396 current CPU and might not be safely moved to another computer.
400 The following optimizations are supported
403 Requests that the runtime performn 32-bit floating point operations
404 using only 32-bits. By default the Mono runtime tries to use the
405 highest precision available for floating point operations, but while
406 this might render better results, the code might run slower. This
407 options also affects the code generated by the LLVM backend.
410 Controls whether the runtime should attempt to inline (the default),
411 or not inline methods invocations
415 \fB--runtime=VERSION\fR
416 Mono supports different runtime versions. The version used depends on the program
417 that is being run or on its configuration file (named program.exe.config). This option
418 can be used to override such autodetection, by forcing a different runtime version
419 to be used. Note that this should only be used to select a later compatible runtime
420 version than the one the program was compiled against. A typical usage is for
421 running a 1.1 program on a 2.0 version:
423 mono --runtime=v2.0.50727 program.exe
426 \fB--security\fR, \fB--security=mode\fR
427 Activate the security manager, a currently experimental feature in
428 Mono and it is OFF by default. The new code verifier can be enabled
429 with this option as well.
433 Using security without parameters is equivalent as calling it with the
436 The following modes are supported:
439 Enables the core-clr security system, typically used for
440 Moonlight/Silverlight applications. It provides a much simpler
441 security system than CAS, see http://www.mono-project.com/docs/web/moonlight/
442 for more details and links to the descriptions of this new system.
445 Enables the new verifier and performs basic verification for code
446 validity. In this mode, unsafe code and P/Invoke are allowed. This
447 mode provides a better safety guarantee but it is still possible
448 for managed code to crash Mono.
451 Enables the new verifier and performs full verification of the code
452 being executed. It only allows verifiable code to be executed.
453 Unsafe code is not allowed but P/Invoke is. This mode should
454 not allow managed code to crash mono. The verification is not as
455 strict as ECMA 335 standard in order to stay compatible with the MS
458 The security system acts on user code: code contained in mscorlib or
459 the global assembly cache is always trusted.
464 Configures the virtual machine to be better suited for server
465 operations (currently, allows a heavier threadpool initialization).
468 Verifies mscorlib and assemblies in the global
469 assembly cache for valid IL, and all user code for IL
472 This is different from \fB--security\fR's verifiable
473 or validil in that these options only check user code and skip
474 mscorlib and assemblies located on the global assembly cache.
476 \fB-V\fR, \fB--version\fR
477 Prints JIT version information (system configuration, release number
478 and branch names if available).
481 .SH DEVELOPMENT OPTIONS
482 The following options are used to help when developing a JITed application.
484 \fB--debug\fR, \fB--debug=OPTIONS\fR
485 Turns on the debugging mode in the runtime. If an assembly was
486 compiled with debugging information, it will produce line number
487 information for stack traces.
491 The optional OPTIONS argument is a comma separated list of debugging
492 options. These options are turned off by default since they generate
493 much larger and slower code at runtime.
495 The following options are supported:
498 Produces a detailed error when throwing a InvalidCastException. This
499 option needs to be enabled as this generates more verbose code at
503 Disable some JIT optimizations which are usually only disabled when
504 running inside the debugger. This can be helpful if you want to attach
505 to the running process with mdb.
508 Generate and register debugging information with gdb. This is only supported on some
509 platforms, and only when using gdb 7.0 or later.
513 \fB--profile[=profiler[:profiler_args]]\fR
514 Turns on profiling. For more information about profiling applications
515 and code coverage see the sections "PROFILING" and "CODE COVERAGE"
518 This option can be used multiple times, each time will load an
519 additional profiler. This allows developers to use modules that
520 extend the JIT through the Mono profiling interface.
522 \fB--trace[=expression]\fR
523 Shows method names as they are invoked. By default all methods are
526 The trace can be customized to include or exclude methods, classes or
527 assemblies. A trace expression is a comma separated list of targets,
528 each target can be prefixed with a minus sign to turn off a particular
529 target. The words `program', `all' and `disabled' have special
530 meaning. `program' refers to the main program being executed, and
531 `all' means all the method calls.
533 The `disabled' option is used to start up with tracing disabled. It
534 can be enabled at a later point in time in the program by sending the
535 SIGUSR2 signal to the runtime.
537 Assemblies are specified by their name, for example, to trace all
538 calls in the System assembly, use:
541 mono --trace=System app.exe
544 Classes are specified with the T: prefix. For example, to trace all
545 calls to the System.String class, use:
548 mono --trace=T:System.String app.exe
551 And individual methods are referenced with the M: prefix, and the
552 standard method notation:
555 mono --trace=M:System.Console:WriteLine app.exe
558 Exceptions can also be traced, it will cause a stack trace to be
559 printed every time an exception of the specified type is thrown.
560 The exception type can be specified with or without the namespace,
561 and to trace all exceptions, specify 'all' as the type name.
564 mono --trace=E:System.Exception app.exe
567 As previously noted, various rules can be specified at once:
570 mono --trace=T:System.String,T:System.Random app.exe
573 You can exclude pieces, the next example traces calls to
574 System.String except for the System.String:Concat method.
577 mono --trace=T:System.String,-M:System.String:Concat
580 You can trace managed to unmanaged transitions using
581 the wrapper qualifier:
584 mono --trace=wrapper app.exe
587 Finally, namespaces can be specified using the N: prefix:
590 mono --trace=N:System.Xml
594 \fB--no-x86-stack-align\fR
595 Don't align stack frames on the x86 architecture. By default, Mono
596 aligns stack frames to 16 bytes on x86, so that local floating point
597 and SIMD variables can be properly aligned. This option turns off the
598 alignment, which usually saves one intruction per call, but might
599 result in significantly lower floating point and SIMD performance.
602 Generate a JIT method map in a /tmp/perf-PID.map file. This file is then
603 used, for example, by the perf tool included in recent Linux kernels.
604 Each line in the file has:
607 HEXADDR HEXSIZE methodname
610 Currently this option is only supported on Linux.
611 .SH JIT MAINTAINER OPTIONS
612 The maintainer options are only used by those developing the runtime
613 itself, and not typically of interest to runtime users or developers.
615 \fB--bisect=optimization:filename\fR
616 This flag is used by the automatic optimization bug bisector. It
617 takes an optimization flag and a filename of a file containing a list
618 of full method names, one per line. When it compiles one of the
619 methods in the file it will use the optimization given, in addition to
620 the optimizations that are otherwise enabled. Note that if the
621 optimization is enabled by default, you should disable it with `-O`,
622 otherwise it will just apply to every method, whether it's in the file
626 Inserts a breakpoint before the method whose name is `method'
627 (namespace.class:methodname). Use `Main' as method name to insert a
628 breakpoint on the application's main method. You can use it also with
629 generics, for example "System.Collections.Generic.Queue`1:Peek"
632 Inserts a breakpoint on exceptions. This allows you to debug your
633 application with a native debugger when an exception is thrown.
636 This compiles a method (namespace.name:methodname), this is used for
637 testing the compiler performance or to examine the output of the code
641 Compiles all the methods in an assembly. This is used to test the
642 compiler performance or to examine the output of the code generator
644 \fB--graph=TYPE METHOD\fR
645 This generates a postscript file with a graph with the details about
646 the specified method (namespace.name:methodname). This requires `dot'
647 and ghostview to be installed (it expects Ghostview to be called
650 The following graphs are available:
652 cfg Control Flow Graph (CFG)
654 code CFG showing code
655 ssa CFG showing code after SSA translation
656 optcode CFG showing code after IR optimizations
659 Some graphs will only be available if certain optimizations are turned
663 Instruct the runtime on the number of times that the method specified
664 by --compile (or all the methods if --compileall is used) to be
665 compiled. This is used for testing the code generator performance.
668 Displays information about the work done by the runtime during the
669 execution of an application.
671 \fB--wapi=hps|semdel\fR
672 Perform maintenance of the process shared data.
674 semdel will delete the global semaphore.
676 hps will list the currently used handles.
678 \fB-v\fR, \fB--verbose\fR
679 Increases the verbosity level, each time it is listed, increases the
680 verbosity level to include more information (including, for example,
681 a disassembly of the native code produced, code selector info etc.).
683 The Mono runtime allows external processes to attach to a running
684 process and load assemblies into the running program. To attach to
685 the process, a special protocol is implemented in the Mono.Management
688 With this support it is possible to load assemblies that have an entry
689 point (they are created with -target:exe or -target:winexe) to be
690 loaded and executed in the Mono process.
692 The code is loaded into the root domain, and it starts execution on
693 the special runtime attach thread. The attached program should
694 create its own threads and return after invocation.
696 This support allows for example debugging applications by having the
697 csharp shell attach to running processes.
699 The mono runtime includes a profiler that can be used to explore
700 various performance related problems in your application. The
701 profiler is activated by passing the --profile command line argument
702 to the Mono runtime, the format is:
705 --profile[=profiler[:profiler_args]]
708 Mono has a built-in profiler called 'default' (and is also the default
709 if no arguments are specified), but developers can write custom
710 profilers, see the section "CUSTOM PROFILERS" for more details.
714 is not specified, the default profiler is used.
718 is a profiler-specific string of options for the profiler itself.
720 The default profiler accepts the following options 'alloc' to profile
721 memory consumption by the application; 'time' to profile the time
722 spent on each routine; 'jit' to collect time spent JIT-compiling methods
723 and 'stat' to perform sample statistical profiling.
724 If no options are provided the default is 'alloc,time,jit'.
727 profile data is printed to stdout: to change this, use the 'file=filename'
728 option to output the data to filename.
733 mono --profile program.exe
737 That will run the program with the default profiler and will do time
738 and allocation profiling.
742 mono --profile=default:stat,alloc,file=prof.out program.exe
745 Will do sample statistical profiling and allocation profiling on
746 program.exe. The profile data is put in prof.out.
748 Note that the statistical profiler has a very low overhead and should
749 be the preferred profiler to use (for better output use the full path
750 to the mono binary when running and make sure you have installed the
751 addr2line utility that comes from the binutils package).
753 This is the most advanced profiler.
755 The Mono \f[I]log\f[] profiler can be used to collect a lot of
756 information about a program running in the Mono runtime.
757 This data can be used (both while the process is running and later)
758 to do analyses of the program behaviour, determine resource usage,
759 performance issues or even look for particular execution patterns.
761 This is accomplished by logging the events provided by the Mono
762 runtime through the profiling interface and periodically writing
763 them to a file which can be later inspected with the mprof-report(1)
766 More information about how to use the log profiler is available on the
767 mprof-report(1) page.
769 Mono provides a mechanism for loading other profiling modules which in
770 the form of shared libraries. These profiling modules can hook up to
771 various parts of the Mono runtime to gather information about the code
774 To use a third party profiler you must pass the name of the profiler
778 mono --profile=custom program.exe
782 In the above sample Mono will load the user defined profiler from the
783 shared library `mono-profiler-custom.so'. This profiler module must
784 be on your dynamic linker library path.
786 A list of other third party profilers is available from Mono's web
787 site (www.mono-project.com/docs/advanced/performance-tips/)
789 Custom profiles are written as shared libraries. The shared library
790 must be called `mono-profiler-NAME.so' where `NAME' is the name of
793 For a sample of how to write your own custom profiler look in the
794 Mono source tree for in the samples/profiler.c.
796 Mono ships with a code coverage module. This module is activated by
797 using the Mono --profile=cov option. The format is:
798 \fB--profile=cov[:assembly-name[/namespace]] test-suite.exe\fR
800 By default code coverage will default to all the assemblies loaded,
801 you can limit this by specifying the assembly name, for example to
802 perform code coverage in the routines of your program use, for example
803 the following command line limits the code coverage to routines in the
807 mono --profile=cov:demo demo.exe
813 does not include the extension.
815 You can further restrict the code coverage output by specifying a
819 mono --profile=cov:demo/My.Utilities demo.exe
823 Which will only perform code coverage in the given assembly and
826 Typical output looks like this:
829 Not covered: Class:.ctor ()
830 Not covered: Class:A ()
831 Not covered: Driver:.ctor ()
832 Not covered: Driver:method ()
833 Partial coverage: Driver:Main ()
838 The offsets displayed are IL offsets.
840 A more powerful coverage tool is available in the module `monocov'.
841 See the monocov(1) man page for details.
843 To debug managed applications, you can use the
845 command, a command line debugger.
847 It is possible to obtain a stack trace of all the active threads in
848 Mono by sending the QUIT signal to Mono, you can do this from the
849 command line, like this:
855 Where pid is the Process ID of the Mono process you want to examine.
856 The process will continue running afterwards, but its state is not
860 this is a last-resort mechanism for debugging applications and should
861 not be used to monitor or probe a production application. The
862 integrity of the runtime after sending this signal is not guaranteed
863 and the application might crash or terminate at any given point
866 The \fB--debug=casts\fR option can be used to get more detailed
867 information for Invalid Cast operations, it will provide information
868 about the types involved.
870 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
871 to get verbose debugging output about the execution of your
872 application within Mono.
876 environment variable if set, the logging level is changed to the set
877 value. Possible values are "error", "critical", "warning", "message",
878 "info", "debug". The default value is "error". Messages with a logging
879 level greater then or equal to the log level will be printed to
882 Use "info" to track the dynamic loading of assemblies.
887 environment variable to limit the extent of the messages you get:
888 If set, the log mask is changed to the set value. Possible values are
889 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
890 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
891 "security" (e.g. Moonlight CoreCLR support), "threadpool" (thread pool generic),
892 "io-threadpool" (thread pool I/O), "io-layer" (I/O layer - sockets, handles, shared memory etc)
894 The default value is "all". Changing the mask value allows you to display only
895 messages for a certain component. You can use multiple masks by comma
896 separating them. For example to see config file messages and assembly loader
897 messages set you mask to "asm,cfg".
899 The following is a common use to track down problems with P/Invoke:
902 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
906 .SH DEBUGGING WITH LLDB
907 If you are using LLDB, you can use the
909 script to print some internal data structures with it. To use this,
914 command script import $PREFIX/lib/mono/lldb/mono.py
917 Where $PREFIX is the prefix value that you used when you configured
918 Mono (typically /usr).
920 Once this is done, then you can inspect some Mono Runtime data structures,
925 (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
928 Mono's XML serialization engine by default will use a reflection-based
929 approach to serialize which might be slow for continuous processing
930 (web service applications). The serialization engine will determine
931 when a class must use a hand-tuned serializer based on a few
932 parameters and if needed it will produce a customized C# serializer
933 for your types at runtime. This customized serializer then gets
934 dynamically loaded into your application.
936 You can control this with the MONO_XMLSERIALIZER_THS environment
939 The possible values are
941 to disable the use of a C# customized
942 serializer, or an integer that is the minimum number of uses before
943 the runtime will produce a custom serializer (0 will produce a
944 custom serializer on the first access, 50 will produce a serializer on
945 the 50th use). Mono will fallback to an interpreted serializer if the
946 serializer generation somehow fails. This behavior can be disabled
947 by setting the option
949 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
950 .SH ENVIRONMENT VARIABLES
953 Turns off the garbage collection in Mono. This should be only used
954 for debugging purposes
957 (Also \fBhttp_proxy\fR) If set, web requests using the Mono
958 Class Library will be automatically proxied through the given URL.
959 Not supported on Windows, Mac OS, iOS or Android. See also \fBNO_PROXY\fR.
962 When Mono is compiled with LLVM support, this instructs the runtime to
963 stop using LLVM after the specified number of methods are JITed.
964 This is a tool used in diagnostics to help isolate problems in the
965 code generation backend. For example \fBLLVM_COUNT=10\fR would only
966 compile 10 methods with LLVM and then switch to the Mono JIT engine.
967 \fBLLVM_COUNT=0\fR would disable the LLVM engine altogether.
970 If set, this variable will instruct Mono to ahead-of-time compile new
971 assemblies on demand and store the result into a cache in
974 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
975 Mono contains a feature which allows modifying settings in the .config files shipped
976 with Mono by using config section mappers. The mappers and the mapping rules are
977 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
978 settings.map file found in the top-level directory of your ASP.NET application.
979 Both files are read by System.Web on application startup, if they are found at the
980 above locations. If you don't want the mapping to be performed you can set this
981 variable in your environment before starting the application and no action will
984 \fBMONO_ASPNET_WEBCONFIG_CACHESIZE\fR
985 Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager
986 queries. Its default size is 100 items, and when more items are needed, cache
987 evictions start happening. If evictions are too frequent this could impose
988 unnecessary overhead, which could be avoided by using this environment variable
989 to set up a higher cache size (or to lower memory requirements by decreasing it).
991 \fBMONO_CAIRO_DEBUG_DISPOSE\fR
992 If set, causes Mono.Cairo to collect stack traces when objects are allocated,
993 so that the finalization/Dispose warnings include information about the
997 If set, this variable overrides the default system configuration directory
998 ($PREFIX/etc). It's used to locate machine.config file.
1001 Sets the style of COM interop. If the value of this variable is "MS"
1002 Mono will use string marhsalling routines from the liboleaut32 for the
1003 BSTR type library, any other values will use the mono-builtin BSTR
1007 If set, this variable overrides the default runtime configuration file
1008 ($PREFIX/etc/mono/config). The --config command line options overrides the
1009 environment variable.
1012 Override the automatic cpu detection mechanism. Currently used only on arm.
1013 The format of the value is as follows:
1019 where V is the architecture number 4, 5, 6, 7 and the options can be currently be
1020 "thumb" or "thumb2". Example:
1023 MONO_CPU_ARCH="armv4 thumb" mono ...
1027 \fBMONO_ARM_FORCE_SOFT_FLOAT\fR
1028 When Mono is built with a soft float fallback on ARM and this variable is set to
1029 "1", Mono will always emit soft float code, even if a VFP unit is
1032 \fBMONO_DARWIN_WATCHER_MAXFDS\fR
1033 This is a debugging aid used to force limits on the FileSystemWatcher
1034 implementation in Darwin. There is no limit by default.
1036 \fBMONO_DISABLE_AIO\fR
1037 If set, tells mono NOT to attempt using native asynchronous I/O services. In
1038 that case, a default select/poll implementation is used. Currently only epoll()
1041 \fBMONO_DISABLE_MANAGED_COLLATION\fR
1042 If this environment variable is `yes', the runtime uses unmanaged
1043 collation (which actually means no culture-sensitive collation). It
1044 internally disables managed collation functionality invoked via the
1045 members of System.Globalization.CompareInfo class. Collation is
1048 \fBMONO_DISABLE_SHM\fR
1049 Unix only: If set, disables the shared memory files used for
1050 cross-process handles: process have only private handles. This means
1051 that process and thread handles are not available to other processes,
1052 and named mutexes, named events and named semaphores are not visible
1055 This is can also be enabled by default by passing the
1056 "--disable-shared-handles" option to configure.
1058 This is the default from mono 2.8 onwards.
1060 \fBMONO_DISABLE_SHARED_AREA\fR
1061 Unix only: If set, disable usage of shared memory for exposing
1062 performance counters. This means it will not be possible to both
1063 externally read performance counters from this processes or read
1064 those of external processes.
1067 When set, enables the use of a fully managed DNS resolver instead of the
1068 regular libc functions. This resolver performs much better when multiple
1069 queries are run in parallel.
1071 Note that /etc/nsswitch.conf will be ignored.
1073 \fBMONO_EGD_SOCKET\fR
1074 For platforms that do not otherwise have a way of obtaining random bytes
1075 this can be set to the name of a file system socket on which an egd or
1076 prngd daemon is listening.
1078 \fBMONO_ENABLE_COOP\fR
1079 This makes the Mono runtime and the SGen garbage collector run in cooperative
1080 mode as opposed to run on preemptive mode. Preemptive mode is the mode
1081 that Mono has used historically, going back to the Boehm days, where the
1082 garbage collector would run at any point and suspend execution of all
1083 threads as required to perform a garbage collection. The cooperative mode
1084 on the other hand requires the cooperation of all threads to stop at a
1085 safe point. This makes for an easier to debug garbage collector. As
1086 of Mono 4.3.0 it is a work in progress, and while it works, it has not
1087 been used extensively. This option enabled the feature and allows us to
1088 find spots that need to be tuned for this mode of operation. Alternatively,
1089 this mode can be enabled at compile time by using the --with-cooperative-gc
1090 flag when calling configure.
1092 \fBMONO_ENABLE_SHM\fR
1093 Unix only: Enable support for cross-process handles. Cross-process
1094 handles are used to expose process handles, thread handles, named
1095 mutexes, named events and named semaphores across Unix processes.
1097 \fBMONO_ENV_OPTIONS\fR
1098 This environment variable allows you to pass command line arguments to
1099 a Mono process through the environment. This is useful for example
1100 to force all of your Mono processes to use LLVM or SGEN without having
1101 to modify any launch scripts.
1103 \fBMONO_ENV_OPTIONS\fR
1104 Used to pass extra options to the debugger agent in the runtime, as they were passed
1105 using --debugger-agent=.
1107 \fBMONO_EVENTLOG_TYPE\fR
1108 Sets the type of event log provider to use (for System.Diagnostics.EventLog).
1110 Possible values are:
1115 Persists event logs and entries to the local file system.
1117 The directory in which to persist the event logs, event sources and entries
1118 can be specified as part of the value.
1120 If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog"
1121 on unix and "%APPDATA%\mono\eventlog" on Windows.
1126 Uses the native win32 API to write events and registers event logs and
1127 event sources in the registry. This is only available on Windows.
1129 On Unix, the directory permission for individual event log and event source
1130 directories is set to 777 (with +t bit) allowing everyone to read and write
1131 event log entries while only allowing entries to be deleted by the user(s)
1136 Silently discards any events.
1139 The default is "null" on Unix (and versions of Windows before NT), and
1140 "win32" on Windows NT (and higher).
1143 \fBMONO_EXTERNAL_ENCODINGS\fR
1144 If set, contains a colon-separated list of text encodings to try when
1145 turning externally-generated text (e.g. command-line arguments or
1146 filenames) into Unicode. The encoding names come from the list
1147 provided by iconv, and the special case "default_locale" which refers
1148 to the current locale's default encoding.
1150 When reading externally-generated text strings UTF-8 is tried first,
1151 and then this list is tried in order with the first successful
1152 conversion ending the search. When writing external text (e.g. new
1153 filenames or arguments to new processes) the first item in this list
1154 is used, or UTF-8 if the environment variable is not set.
1156 The problem with using MONO_EXTERNAL_ENCODINGS to process your
1157 files is that it results in a problem: although its possible to get
1158 the right file name it is not necessarily possible to open the file.
1159 In general if you have problems with encodings in your filenames you
1160 should use the "convmv" program.
1162 \fBMONO_GC_PARAMS\fR
1163 When using Mono with the SGen garbage collector this variable controls
1164 several parameters of the collector. The variable's value is a comma
1165 separated list of words.
1169 \fBmax-heap-size=\fIsize\fR
1170 Sets the maximum size of the heap. The size is specified in bytes and must
1171 be a power of two. The suffixes `k', `m' and `g' can be used to
1172 specify kilo-, mega- and gigabytes, respectively. The limit is the sum
1173 of the nursery, major heap and large object heap. Once the limit is reached
1174 the application will receive OutOfMemoryExceptions when trying to allocate.
1175 Not the full extent of memory set in max-heap-size could be available to
1176 satisfy a single allocation due to internal fragmentation. By default heap
1177 limits is disabled and the GC will try to use all available memory.
1179 \fBnursery-size=\fIsize\fR
1180 Sets the size of the nursery. The size is specified in bytes and must
1181 be a power of two. The suffixes `k', `m' and `g' can be used to
1182 specify kilo-, mega- and gigabytes, respectively. The nursery is the
1183 first generation (of two). A larger nursery will usually speed up the
1184 program but will obviously use more memory. The default nursery size
1187 \fBmajor=\fIcollector\fR Specifies which major collector to use.
1188 Options are `marksweep' for the Mark&Sweep collector, and
1189 `marksweep-conc' for concurrent Mark&Sweep. The non-concurrent
1190 Mark&Sweep collector is the default.
1192 \fBsoft-heap-limit=\fIsize\fR
1193 Once the heap size gets larger than this size, ignore what the default
1194 major collection trigger metric says and only allow four nursery size's
1195 of major heap growth between major collections.
1197 \fBevacuation-threshold=\fIthreshold\fR
1198 Sets the evacuation threshold in percent. This option is only available
1199 on the Mark&Sweep major collectors. The value must be an
1200 integer in the range 0 to 100. The default is 66. If the sweep phase of
1201 the collection finds that the occupancy of a specific heap block type is
1202 less than this percentage, it will do a copying collection for that block
1203 type in the next major collection, thereby restoring occupancy to close
1204 to 100 percent. A value of 0 turns evacuation off.
1206 \fB(no-)lazy-sweep\fR
1207 Enables or disables lazy sweep for the Mark&Sweep collector. If
1208 enabled, the sweeping of individual major heap blocks is done
1209 piecemeal whenever the need arises, typically during nursery
1210 collections. Lazy sweeping is enabled by default.
1212 \fB(no-)concurrent-sweep\fR
1213 Enables or disables concurrent sweep for the Mark&Sweep collector. If
1214 enabled, the iteration of all major blocks to determine which ones can
1215 be freed and which ones have to be kept and swept, is done
1216 concurrently with the running program. Concurrent sweeping is enabled
1219 \fBstack-mark=\fImark-mode\fR
1220 Specifies how application threads should be scanned. Options are
1221 `precise` and `conservative`. Precise marking allow the collector
1222 to know what values on stack are references and what are not.
1223 Conservative marking threats all values as potentially references
1224 and leave them untouched. Precise marking reduces floating garbage
1225 and can speed up nursery collection and allocation rate, it has
1226 the downside of requiring a significant extra memory per compiled
1227 method. The right option, unfortunately, requires experimentation.
1229 \fBsave-target-ratio=\fIratio\fR
1230 Specifies the target save ratio for the major collector. The collector
1231 lets a given amount of memory to be promoted from the nursery due to
1232 minor collections before it triggers a major collection. This amount
1233 is based on how much memory it expects to free. It is represented as
1234 a ratio of the size of the heap after a major collection.
1235 Valid values are between 0.1 and 2.0. The default is 0.5.
1236 Smaller values will keep the major heap size smaller but will trigger
1237 more major collections. Likewise, bigger values will use more memory
1238 and result in less frequent major collections.
1239 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1241 \fBdefault-allowance-ratio=\fIratio\fR
1242 Specifies the default allocation allowance when the calculated size
1243 is too small. The allocation allowance is how much memory the collector
1244 let be promoted before triggered a major collection.
1245 It is a ratio of the nursery size.
1246 Valid values are between 1.0 and 10.0. The default is 4.0.
1247 Smaller values lead to smaller heaps and more frequent major collections.
1248 Likewise, bigger values will allow the heap to grow faster but use
1249 more memory when it reaches a stable size.
1250 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1252 \fBminor=\fIminor-collector\fR
1253 Specifies which minor collector to use. Options are 'simple' which
1254 promotes all objects from the nursery directly to the old generation
1255 and 'split' which lets object stay longer on the nursery before promoting.
1257 \fBalloc-ratio=\fIratio\fR
1258 Specifies the ratio of memory from the nursery to be use by the alloc space.
1259 This only can only be used with the split minor collector.
1260 Valid values are integers between 1 and 100. Default is 60.
1262 \fBpromotion-age=\fIage\fR
1263 Specifies the required age of an object must reach inside the nursery before
1264 been promoted to the old generation. This only can only be used with the
1265 split minor collector.
1266 Valid values are integers between 1 and 14. Default is 2.
1268 \fB(no-)cementing\fR
1269 Enables or disables cementing. This can dramatically shorten nursery
1270 collection times on some benchmarks where pinned objects are referred
1271 to from the major heap.
1273 \fBallow-synchronous-major\fR
1274 This forbids the major collector from performing synchronous major collections.
1275 The major collector might want to do a synchronous collection due to excessive
1276 fragmentation. Disabling this might trigger OutOfMemory error in situations that
1277 would otherwise not happen.
1282 When using Mono with the SGen garbage collector this environment
1283 variable can be used to turn on various debugging features of the
1284 collector. The value of this variable is a comma separated list of
1285 words. Do not use these options in production.
1290 Sets the debug level to the specified number.
1292 \fBprint-allowance\fR
1293 After each major collection prints memory consumption for before and
1294 after the collection and the allowance for the minor collector, i.e. how
1295 much the heap is allowed to grow from minor collections before the next
1296 major collection is triggered.
1299 Gathers statistics on the classes whose objects are pinned in the
1300 nursery and for which global remset entries are added. Prints those
1301 statistics when shutting down.
1303 \fBcollect-before-allocs\fR
1305 \fBcheck-at-minor-collections\fR
1306 This performs a consistency check on minor collections and also clears
1307 the nursery at collection time, instead of the default, when buffers
1308 are allocated (clear-at-gc). The consistency check ensures that
1309 there are no major to minor references that are not on the remembered
1312 \fBmod-union-consistency-check\fR
1313 Checks that the mod-union cardtable is consistent before each
1314 finishing major collection pause. This check is only applicable to
1315 concurrent major collectors.
1317 \fBcheck-mark-bits\fR
1318 Checks that mark bits in the major heap are consistent at the end of
1319 each major collection. Consistent mark bits mean that if an object is
1320 marked, all objects that it had references to must also be marked.
1322 \fBcheck-nursery-pinned\fR
1323 After nursery collections, and before starting concurrent collections,
1324 check whether all nursery objects are pinned, or not pinned -
1325 depending on context. Does nothing when the split nursery collector
1328 \fBxdomain-checks\fR
1329 Performs a check to make sure that no references are left to an
1332 \fBclear-at-tlab-creation\fR
1333 Clears the nursery incrementally when the thread local allocation
1334 buffers (TLAB) are created. The default setting clears the whole
1337 \fBdebug-clear-at-tlab-creation\fR
1338 Clears the nursery incrementally when the thread local allocation
1339 buffers (TLAB) are created, but at GC time fills it with the byte
1340 `0xff`, which should result in a crash more quickly if
1341 `clear-at-tlab-creation` doesn't work properly.
1344 This clears the nursery at GC time instead of doing it when the thread
1345 local allocation buffer (TLAB) is created. The default is to clear
1346 the nursery at TLAB creation time.
1349 Don't do minor collections. If the nursery is full, a major collection
1350 is triggered instead, unless it, too, is disabled.
1353 Don't do major collections.
1355 \fBconservative-stack-mark\fR
1356 Forces the GC to scan the stack conservatively, even if precise
1357 scanning is available.
1359 \fBno-managed-allocator\fR
1360 Disables the managed allocator.
1362 \fBcheck-scan-starts\fR
1363 If set, does a plausibility check on the scan_starts before and after each collection
1365 \fBverify-nursery-at-minor-gc\fR
1366 If set, does a complete object walk of the nursery at the start of each minor collection.
1368 \fBdump-nursery-at-minor-gc\fR
1369 If set, dumps the contents of the nursery at the start of each minor collection. Requires
1370 verify-nursery-at-minor-gc to be set.
1372 \fBheap-dump=\fIfile\fR
1373 Dumps the heap contents to the specified file. To visualize the
1374 information, use the mono-heapviz tool.
1376 \fBbinary-protocol=\fIfile\fR
1377 Outputs the debugging output to the specified file. For this to
1378 work, Mono needs to be compiled with the BINARY_PROTOCOL define on
1379 sgen-gc.c. You can then use this command to explore the output
1381 sgen-grep-binprot 0x1234 0x5678 < file
1384 \fBnursery-canaries\fR
1385 If set, objects allocated in the nursery are suffixed with a canary (guard)
1386 word, which is checked on each minor collection. Can be used to detect/debug
1387 heap corruption issues.
1390 \fBdo-not-finalize(=\fIclasses\fB)\fR
1391 If enabled, finalizers will not be run. Everything else will be
1392 unaffected: finalizable objects will still be put into the
1393 finalization queue where they survive until they're scheduled to
1394 finalize. Once they're not in the queue anymore they will be
1395 collected regularly. If a list of comma-separated class names is
1396 given, only objects from those classes will not be finalized.
1399 \fBlog-finalizers\fR
1400 Log verbosely around the finalization process to aid debugging.
1404 \fBMONO_GAC_PREFIX\fR
1405 Provides a prefix the runtime uses to look for Global Assembly Caches.
1406 Directories are separated by the platform path separator (colons on
1407 unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
1408 install. Or to the directory provided in the gacutil /gacdir command. Example:
1409 .B /home/username/.mono:/usr/local/mono/
1412 Enables some filename rewriting support to assist badly-written
1413 applications that hard-code Windows paths. Set to a colon-separated
1414 list of "drive" to strip drive letters, or "case" to do
1415 case-insensitive file matching in every directory in a path. "all"
1416 enables all rewriting methods. (Backslashes are always mapped to
1417 slashes if this variable is set to a valid option).
1420 For example, this would work from the shell:
1423 MONO_IOMAP=drive:case
1427 If you are using mod_mono to host your web applications, you can use
1430 directive instead, like this:
1433 MonoIOMAP <appalias> all
1436 See mod_mono(8) for more details.
1438 Additionally. Mono includes a profiler module which allows one to track what
1439 adjustements to file paths IOMAP code needs to do. The tracking code reports
1440 the managed location (full stack trace) from which the IOMAP-ed call was made and,
1441 on process exit, the locations where all the IOMAP-ed strings were created in
1442 managed code. The latter report is only approximate as it is not always possible
1443 to estimate the actual location where the string was created. The code uses simple
1444 heuristics - it analyzes stack trace leading back to the string allocation location
1445 and ignores all the managed code which lives in assemblies installed in GAC as well as in the
1446 class libraries shipped with Mono (since they are assumed to be free of case-sensitivity
1447 issues). It then reports the first location in the user's code - in most cases this will be
1448 the place where the string is allocated or very close to the location. The reporting code
1449 is implemented as a custom profiler module (see the "PROFILING" section) and can be loaded
1450 in the following way:
1455 mono --profile=iomap yourapplication.exe
1458 Note, however, that Mono currently supports only one profiler module
1462 When Mono is using the LLVM code generation backend you can use this
1463 environment variable to pass code generation options to the LLVM
1466 \fBMONO_MANAGED_WATCHER\fR
1467 If set to "disabled", System.IO.FileSystemWatcher will use a file watcher
1468 implementation which silently ignores all the watching requests.
1469 If set to any other value, System.IO.FileSystemWatcher will use the default
1470 managed implementation (slow). If unset, mono will try to use inotify, FAM,
1471 Gamin, kevent under Unix systems and native API calls on Windows, falling
1472 back to the managed implementation on error.
1474 \fBMONO_MESSAGING_PROVIDER\fR
1475 Mono supports a plugin model for its implementation of System.Messaging making
1476 it possible to support a variety of messaging implementations (e.g. AMQP, ActiveMQ).
1477 To specify which messaging implementation is to be used the evironement variable
1478 needs to be set to the full class name for the provider. E.g. to use the RabbitMQ based
1479 AMQP implementation the variable should be set to:
1482 Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
1485 If set causes the mono process to be bound to a single processor. This may be
1486 useful when debugging or working around race conditions.
1489 Disable inlining of thread local accesses. Try setting this if you get a segfault
1490 early on in the execution of mono.
1493 Provides a search path to the runtime where to look for library
1494 files. This is a tool convenient for debugging applications, but
1495 should not be used by deployed applications as it breaks the assembly
1496 loader in subtle ways.
1498 Directories are separated by the platform path separator (colons on unix). Example:
1499 .B /home/username/lib:/usr/local/mono/lib
1501 Relative paths are resolved based on the launch-time current directory.
1503 Alternative solutions to MONO_PATH include: installing libraries into
1504 the Global Assembly Cache (see gacutil(1)) or having the dependent
1505 libraries side-by-side with the main executable.
1507 For a complete description of recommended practices for application
1509 http://www.mono-project.com/docs/getting-started/application-deployment/
1512 Experimental RTC support in the statistical profiler: if the user has
1513 the permission, more accurate statistics are gathered. The MONO_RTC
1514 value must be restricted to what the Linux rtc allows: power of two
1515 from 64 to 8192 Hz. To enable higher frequencies like 4096 Hz, run as root:
1518 echo 4096 > /proc/sys/dev/rtc/max-user-freq
1525 MONO_RTC=4096 mono --profiler=default:stat program.exe
1529 \fBMONO_SHARED_DIR\fR
1530 If set its the directory where the ".wapi" handle state is stored.
1531 This is the directory where the Windows I/O Emulation layer stores its
1532 shared state data (files, events, mutexes, pipes). By default Mono
1533 will store the ".wapi" directory in the users's home directory.
1535 \fBMONO_SHARED_HOSTNAME\fR
1536 Uses the string value of this variable as a replacement for the host name when
1537 creating file names in the ".wapi" directory. This helps if the host name of
1538 your machine is likely to be changed when a mono application is running or if
1539 you have a .wapi directory shared among several different computers.
1541 Mono typically uses the hostname to create the files that are used to
1542 share state across multiple Mono processes. This is done to support
1543 home directories that might be shared over the network.
1545 \fBMONO_STRICT_IO_EMULATION\fR
1546 If set, extra checks are made during IO operations. Currently, this
1547 includes only advisory locks around file writes.
1550 The name of the theme to be used by Windows.Forms. Available themes today
1551 include "clearlooks", "nice" and "win32".
1553 The default is "win32".
1555 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1556 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1557 avoid a new negotiation between the client and a server. Negotiation are very
1558 CPU intensive so an application-specific custom value may prove useful for
1559 small embedded systems.
1561 The default is 180 seconds.
1563 \fBMONO_THREADS_PER_CPU\fR
1564 The minimum number of threads in the general threadpool will be
1565 MONO_THREADS_PER_CPU * number of CPUs. The default value for this
1568 \fBMONO_XMLSERIALIZER_THS\fR
1569 Controls the threshold for the XmlSerializer to produce a custom
1570 serializer for a given class instead of using the Reflection-based
1571 interpreter. The possible values are `no' to disable the use of a
1572 custom serializer or a number to indicate when the XmlSerializer
1573 should start serializing. The default value is 50, which means that
1574 the a custom serializer will be produced on the 50th use.
1576 \fBMONO_X509_REVOCATION_MODE\fR
1577 Sets the revocation mode used when validating a X509 certificate chain (https,
1578 ftps, smtps...). The default is 'nocheck', which performs no revocation check
1579 at all. The other possible values are 'offline', which performs CRL check (not
1580 implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
1581 status (not implemented yet).
1584 (Also \fBno_proxy\fR) If both \fBHTTP_PROXY\fR and \fBNO_PROXY\fR are
1585 set, \fBNO_PROXY\fR will be treated as a comma-separated list of "bypass" domains
1586 which will not be sent through the proxy. Domains in \fBNO_PROXY\fR may contain
1587 wildcards, as in "*.mono-project.com" or "build????.local". Not supported on
1588 Windows, Mac OS, iOS or Android.
1589 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1591 \fBMONO_ASPNET_NODELETE\fR
1592 If set to any value, temporary source files generated by ASP.NET support
1593 classes will not be removed. They will be kept in the user's temporary
1597 If set, enables some features of the runtime useful for debugging.
1598 This variable should contain a comma separated list of debugging options.
1599 Currently, the following options are supported:
1603 \fBalign-small-structs\fR
1604 Enables small structs alignment to 4/8 bytes.
1606 \fBarm-use-fallback-tls\fR
1607 When this option is set on ARM, a fallback TLS will be used instead
1608 of the default fast TLS.
1610 \fBbreak-on-unverified\fR
1611 If this variable is set, when the Mono VM runs into a verification
1612 problem, instead of throwing an exception it will break into the
1613 debugger. This is useful when debugging verifier problems
1616 This option can be used to get more detailed information from
1617 InvalidCast exceptions, it will provide information about the types
1620 \fBcheck-pinvoke-callconv\fR
1621 This option causes the runtime to check for calling convention
1622 mismatches when using pinvoke, i.e. mixing cdecl/stdcall. It only
1623 works on windows. If a mismatch is detected, an
1624 ExecutionEngineException is thrown.
1626 \fBcollect-pagefault-stats\fR
1627 Collects information about pagefaults. This is used internally to
1628 track the number of page faults produced to load metadata. To display
1629 this information you must use this option with "--stats" command line
1632 \fBdebug-domain-unload\fR
1633 When this option is set, the runtime will invalidate the domain memory
1634 pool instead of destroying it.
1636 \fBdont-free-domains\fR
1637 This is an Optimization for multi-AppDomain applications (most
1638 commonly ASP.NET applications). Due to internal limitations Mono,
1639 Mono by default does not use typed allocations on multi-appDomain
1640 applications as they could leak memory when a domain is unloaded.
1642 Although this is a fine default, for applications that use more than
1643 on AppDomain heavily (for example, ASP.NET applications) it is worth
1644 trading off the small leaks for the increased performance
1645 (additionally, since ASP.NET applications are not likely going to
1646 unload the application domains on production systems, it is worth
1647 using this feature).
1649 \fBdyn-runtime-invoke\fR
1650 Instructs the runtime to try to use a generic runtime-invoke wrapper
1651 instead of creating one invoke wrapper.
1653 \fBexplicit-null-checks\fR
1654 Makes the JIT generate an explicit NULL check on variable dereferences
1655 instead of depending on the operating system to raise a SIGSEGV or
1656 another form of trap event when an invalid memory location is
1660 Equivalent to setting the \fBMONO_XDEBUG\fR variable, this emits
1661 symbols into a shared library as the code is JITed that can be loaded
1662 into GDB to inspect symbols.
1664 \fBgen-seq-points\fR
1665 Automatically generates sequence points where the
1666 IL stack is empty. These are places where the debugger can set a
1669 \fBgen-compact-seq-points\fR
1670 This option generates sequence points data that maps native offsets to
1671 IL offsets. Sequence point data is used to display IL offset in
1672 stacktraces. Stacktraces with IL offsets can be symbolicated using
1673 mono-symbolicate tool.
1676 Captures the interrupt signal (Control-C) and displays a stack trace
1677 when pressed. Useful to find out where the program is executing at a
1678 given point. This only displays the stack trace of a single thread.
1681 Instructs the runtime to initialize the stack with
1682 some known values (0x2a on x86-64) at the start of a method to assist
1683 in debuggin the JIT engine.
1685 \fBkeep-delegates\fR
1686 This option will leak delegate trampolines that are no longer
1687 referenced as to present the user with more information about a
1688 delegate misuse. Basically a delegate instance might be created,
1689 passed to unmanaged code, and no references kept in managed code,
1690 which will garbage collect the code. With this option it is possible
1691 to track down the source of the problems.
1693 \fBno-gdb-backtrace\fR
1694 This option will disable the GDB backtrace emitted by the runtime
1695 after a SIGSEGV or SIGABRT in unmanaged code.
1697 \fBpartial-sharing\fR
1698 When this option is set, the runtime can share generated code between
1699 generic types effectively reducing the amount of code generated.
1701 \fBreverse-pinvoke-exceptions
1702 This option will cause mono to abort with a descriptive message when
1703 during stack unwinding after an exception it reaches a native stack
1704 frame. This happens when a managed delegate is passed to native code,
1705 and the managed delegate throws an exception. Mono will normally try
1706 to unwind the stack to the first (managed) exception handler, and it
1707 will skip any native stack frames in the process. This leads to
1708 undefined behaviour (since mono doesn't know how to process native
1709 frames), leaks, and possibly crashes too.
1711 \fBsingle-imm-size\fR
1712 This guarantees that each time managed code is compiled the same
1713 instructions and registers are used, regardless of the size of used
1716 \fBsoft-breakpoints\fR
1717 This option allows using single-steps and breakpoints in hardware
1718 where we cannot do it with signals.
1720 \fBsuspend-on-sigsegv\fR
1721 This option will suspend the program when a native SIGSEGV is received.
1722 This is useful for debugging crashes which do not happen under gdb,
1723 since a live process contains more information than a core file.
1725 \fBsuspend-on-exception\fR
1726 This option will suspend the program when an exception occurs.
1728 \fBsuspend-on-unhandled\fR
1729 This option will suspend the program when an unhandled exception occurs.
1733 \fBMONO_LOG_LEVEL\fR
1734 The logging level, possible values are `error', `critical', `warning',
1735 `message', `info' and `debug'. See the DEBUGGING section for more
1739 Controls the domain of the Mono runtime that logging will apply to.
1740 If set, the log mask is changed to the set value. Possible values are
1741 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1742 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
1743 "security" (e.g. Moonlight CoreCLR support) and "all".
1744 The default value is "all". Changing the mask value allows you to display only
1745 messages for a certain component. You can use multiple masks by comma
1746 separating them. For example to see config file messages and assembly loader
1747 messages set you mask to "asm,cfg".
1750 Used for runtime tracing of method calls. The format of the comma separated
1759 disabled Trace output off upon start.
1762 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1764 \fBMONO_TRACE_LISTENER\fR
1765 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1766 print the output of the System.Diagnostics Trace and Debug classes.
1767 It can be set to a filename, and to Console.Out or Console.Error to display
1768 output to standard output or standard error, respectively. If it's set to
1769 Console.Out or Console.Error you can append an optional prefix that will
1770 be used when writing messages like this: Console.Error:MyProgramName.
1771 See the System.Diagnostics.DefaultTraceListener documentation for more
1774 \fBMONO_WCF_TRACE\fR
1775 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.
1777 \fBMONO_XEXCEPTIONS\fR
1778 This throws an exception when a X11 error is encountered; by default a
1779 message is displayed but execution continues
1781 \fBMONO_XMLSERIALIZER_DEBUG\fR
1782 Set this value to 1 to prevent the serializer from removing the
1783 temporary files that are created for fast serialization; This might
1784 be useful when debugging.
1787 This is used in the System.Windows.Forms implementation when running
1788 with the X11 backend. This is used to debug problems in Windows.Forms
1789 as it forces all of the commands send to X11 server to be done
1790 synchronously. The default mode of operation is asynchronous which
1791 makes it hard to isolate the root of certain problems.
1794 When the the MONO_XDEBUG env var is set, debugging info for JITted
1795 code is emitted into a shared library, loadable into gdb. This enables,
1796 for example, to see managed frame names on gdb backtraces.
1798 \fBMONO_VERBOSE_METHOD\fR
1799 Enables the maximum JIT verbosity for the specified method. This is
1800 very helpfull to diagnose a miscompilation problems of a specific
1803 \fBMONO_VERBOSE_HWCAP\fR
1804 If set, makes the JIT output information about detected CPU features
1805 (such as SSE, CMOV, FCMOV, etc) to stdout.
1807 \fBMONO_CONSERVATIVE_HWCAP\fR
1808 If set, the JIT will not perform any hardware capability detection. This
1809 may be useful to pinpoint the cause of JIT issues. This is the default
1810 when Mono is built as an AOT cross compiler, so that the generated code
1811 will run on most hardware.
1813 If you want to use Valgrind, you will find the file `mono.supp'
1814 useful, it contains the suppressions for the GC which trigger
1815 incorrect warnings. Use it like this:
1817 valgrind --suppressions=mono.supp mono ...
1820 On some platforms, Mono can expose a set of DTrace probes (also known
1821 as user-land statically defined, USDT Probes).
1823 They are defined in the file `mono.d'.
1825 .B ves-init-begin, ves-init-end
1827 Begin and end of runtime initialization.
1829 .B method-compile-begin, method-compile-end
1831 Begin and end of method compilation.
1832 The probe arguments are class name, method name and signature,
1833 and in case of method-compile-end success or failure of compilation.
1837 Begin and end of Garbage Collection.
1839 To verify the availability of the probes, run:
1841 dtrace -P mono'$target' -l -c mono
1844 Mono's Ping implementation for detecting network reachability can
1845 create the ICMP packets itself without requiring the system ping
1846 command to do the work. If you want to enable this on Linux for
1847 non-root users, you need to give the Mono binary special permissions.
1849 As root, run this command:
1851 # setcap cap_net_raw=+ep /usr/bin/mono
1854 On Unix assemblies are loaded from the installation lib directory. If you set
1855 `prefix' to /usr, the assemblies will be located in /usr/lib. On
1856 Windows, the assemblies are loaded from the directory where mono and
1859 .B ~/.mono/aot-cache
1861 The directory for the ahead-of-time compiler demand creation
1862 assemblies are located.
1864 .B /etc/mono/config, ~/.mono/config
1866 Mono runtime configuration file. See the mono-config(5) manual page
1867 for more information.
1869 .B ~/.config/.mono/certs, /usr/share/.mono/certs
1871 Contains Mono certificate stores for users / machine. See the certmgr(1)
1872 manual page for more information on managing certificate stores and
1873 the mozroots(1) page for information on how to import the Mozilla root
1874 certificates into the Mono certificate store.
1876 .B ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
1878 Files in this directory allow a user to customize the configuration
1879 for a given system assembly, the format is the one described in the
1880 mono-config(5) page.
1882 .B ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
1884 Contains Mono cryptographic keypairs for users / machine. They can be
1885 accessed by using a CspParameters object with DSACryptoServiceProvider
1886 and RSACryptoServiceProvider classes.
1888 .B ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
1890 Contains Mono isolated storage for non-roaming users, roaming users and
1891 local machine. Isolated storage can be accessed using the classes from
1892 the System.IO.IsolatedStorage namespace.
1894 .B <assembly>.config
1896 Configuration information for individual assemblies is loaded by the
1897 runtime from side-by-side files with the .config files, see the
1898 http://www.mono-project.com/Config for more information.
1900 .B Web.config, web.config
1902 ASP.NET applications are configured through these files, the
1903 configuration is done on a per-directory basis. For more information
1904 on this subject see the http://www.mono-project.com/Config_system.web
1907 Mailing lists are listed at the
1908 http://www.mono-project.com/community/help/mailing-lists/
1910 http://www.mono-project.com
1913 certmgr(1), csharp(1), mcs(1), mdb(1), monocov(1), monodis(1),
1914 mono-config(5), mozroots(1), mprof-report(1), pdb2mdb(1), xsp(1), mod_mono(8).
1916 For more information on AOT:
1917 http://www.mono-project.com/docs/advanced/aot/
1919 For ASP.NET-related documentation, see the xsp(1) manual page
projects / mono.git / blob