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'.
145 .I gen-seq-points-file=FILE.msym
146 Instructs the AOT compiler to generate offline sequence points .msym files.
147 The path is optional, if none is passed then a .msym file will be generated
148 next to the input assembly.
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--arch=32\fR, \fB--arch=64\fR
336 (Mac OS X only): Selects the bitness of the Mono binary used, if
337 available. If the binary used is already for the selected bitness, nothing
338 changes. If not, the execution switches to a binary with the selected
339 bitness suffix installed side by side (for example, '/bin/mono --arch=64'
340 will switch to '/bin/mono64' iff '/bin/mono' is a 32-bit build).
342 \fB--help\fR, \fB-h\fR
343 Displays usage instructions.
346 If the Mono runtime has been compiled with LLVM support (not available
347 in all configurations), Mono will use the LLVM optimization and code
348 generation engine to JIT or AOT compile.
350 For more information, consult: http://www.mono-project.com/docs/advanced/mono-llvm/
353 When using a Mono that has been compiled with LLVM support, it forces
354 Mono to fallback to its JIT engine and not use the LLVM backend.
356 \fB--optimize=MODE\fR, \fB-O=MODE\fR
357 MODE is a comma separated list of optimizations. They also allow
358 optimizations to be turned off by prefixing the optimization name with
361 In general, Mono has been tuned to use the default set of flags,
362 before using these flags for a deployment setting, you might want to
363 actually measure the benefits of using them.
365 The following optimization flags are implemented in the core engine:
367 abcrem Array bound checks removal
368 all Turn on all optimizations
369 aot Usage of Ahead Of Time compiled code
370 branch Branch optimizations
371 cfold Constant folding
372 cmov Conditional moves [arch-dependency]
373 deadce Dead code elimination
374 consprop Constant propagation
375 copyprop Copy propagation
376 fcmov Fast x86 FP compares [arch-dependency]
377 float32 Perform 32-bit float arithmetic using 32-bit operations
378 gshared Enable generic code sharing.
379 inline Inline method calls
380 intrins Intrinsic method implementations
381 linears Linear scan global reg allocation
382 leaf Leaf procedures optimizations
383 loop Loop related optimizations
384 peephole Peephole postpass
385 precomp Precompile all methods before executing Main
386 sched Instruction scheduling
387 shared Emit per-domain code
388 sse2 SSE2 instructions on x86 [arch-dependency]
389 tailc Tail recursion and tail calls
392 For example, to enable all the optimization but dead code
393 elimination and inlining, you can use:
395 -O=all,-deadce,-inline
398 The flags that are flagged with [arch-dependency] indicate that the
399 given option if used in combination with Ahead of Time compilation
400 (--aot flag) would produce pre-compiled code that will depend on the
401 current CPU and might not be safely moved to another computer.
405 The following optimizations are supported
408 Requests that the runtime performn 32-bit floating point operations
409 using only 32-bits. By default the Mono runtime tries to use the
410 highest precision available for floating point operations, but while
411 this might render better results, the code might run slower. This
412 options also affects the code generated by the LLVM backend.
415 Controls whether the runtime should attempt to inline (the default),
416 or not inline methods invocations
420 \fB--runtime=VERSION\fR
421 Mono supports different runtime versions. The version used depends on the program
422 that is being run or on its configuration file (named program.exe.config). This option
423 can be used to override such autodetection, by forcing a different runtime version
424 to be used. Note that this should only be used to select a later compatible runtime
425 version than the one the program was compiled against. A typical usage is for
426 running a 1.1 program on a 2.0 version:
428 mono --runtime=v2.0.50727 program.exe
431 \fB--security\fR, \fB--security=mode\fR
432 Activate the security manager, a currently experimental feature in
433 Mono and it is OFF by default. The new code verifier can be enabled
434 with this option as well.
438 Using security without parameters is equivalent as calling it with the
441 The following modes are supported:
444 Enables the core-clr security system, typically used for
445 Moonlight/Silverlight applications. It provides a much simpler
446 security system than CAS, see http://www.mono-project.com/docs/web/moonlight/
447 for more details and links to the descriptions of this new system.
450 Enables the new verifier and performs basic verification for code
451 validity. In this mode, unsafe code and P/Invoke are allowed. This
452 mode provides a better safety guarantee but it is still possible
453 for managed code to crash Mono.
456 Enables the new verifier and performs full verification of the code
457 being executed. It only allows verifiable code to be executed.
458 Unsafe code is not allowed but P/Invoke is. This mode should
459 not allow managed code to crash mono. The verification is not as
460 strict as ECMA 335 standard in order to stay compatible with the MS
463 The security system acts on user code: code contained in mscorlib or
464 the global assembly cache is always trusted.
469 Configures the virtual machine to be better suited for server
470 operations (currently, allows a heavier threadpool initialization).
473 Verifies mscorlib and assemblies in the global
474 assembly cache for valid IL, and all user code for IL
477 This is different from \fB--security\fR's verifiable
478 or validil in that these options only check user code and skip
479 mscorlib and assemblies located on the global assembly cache.
481 \fB-V\fR, \fB--version\fR
482 Prints JIT version information (system configuration, release number
483 and branch names if available).
486 .SH DEVELOPMENT OPTIONS
487 The following options are used to help when developing a JITed application.
489 \fB--debug\fR, \fB--debug=OPTIONS\fR
490 Turns on the debugging mode in the runtime. If an assembly was
491 compiled with debugging information, it will produce line number
492 information for stack traces.
496 The optional OPTIONS argument is a comma separated list of debugging
497 options. These options are turned off by default since they generate
498 much larger and slower code at runtime.
500 The following options are supported:
503 Produces a detailed error when throwing a InvalidCastException. This
504 option needs to be enabled as this generates more verbose code at
508 Disable some JIT optimizations which are usually only disabled when
509 running inside the debugger. This can be helpful if you want to attach
510 to the running process with mdb.
513 Generate and register debugging information with gdb. This is only supported on some
514 platforms, and only when using gdb 7.0 or later.
518 \fB--profile[=profiler[:profiler_args]]\fR
519 Turns on profiling. For more information about profiling applications
520 and code coverage see the sections "PROFILING" and "CODE COVERAGE"
523 This option can be used multiple times, each time will load an
524 additional profiler. This allows developers to use modules that
525 extend the JIT through the Mono profiling interface.
527 \fB--trace[=expression]\fR
528 Shows method names as they are invoked. By default all methods are
531 The trace can be customized to include or exclude methods, classes or
532 assemblies. A trace expression is a comma separated list of targets,
533 each target can be prefixed with a minus sign to turn off a particular
534 target. The words `program', `all' and `disabled' have special
535 meaning. `program' refers to the main program being executed, and
536 `all' means all the method calls.
538 The `disabled' option is used to start up with tracing disabled. It
539 can be enabled at a later point in time in the program by sending the
540 SIGUSR2 signal to the runtime.
542 Assemblies are specified by their name, for example, to trace all
543 calls in the System assembly, use:
546 mono --trace=System app.exe
549 Classes are specified with the T: prefix. For example, to trace all
550 calls to the System.String class, use:
553 mono --trace=T:System.String app.exe
556 And individual methods are referenced with the M: prefix, and the
557 standard method notation:
560 mono --trace=M:System.Console:WriteLine app.exe
563 Exceptions can also be traced, it will cause a stack trace to be
564 printed every time an exception of the specified type is thrown.
565 The exception type can be specified with or without the namespace,
566 and to trace all exceptions, specify 'all' as the type name.
569 mono --trace=E:System.Exception app.exe
572 As previously noted, various rules can be specified at once:
575 mono --trace=T:System.String,T:System.Random app.exe
578 You can exclude pieces, the next example traces calls to
579 System.String except for the System.String:Concat method.
582 mono --trace=T:System.String,-M:System.String:Concat
585 You can trace managed to unmanaged transitions using
586 the wrapper qualifier:
589 mono --trace=wrapper app.exe
592 Finally, namespaces can be specified using the N: prefix:
595 mono --trace=N:System.Xml
599 \fB--no-x86-stack-align\fR
600 Don't align stack frames on the x86 architecture. By default, Mono
601 aligns stack frames to 16 bytes on x86, so that local floating point
602 and SIMD variables can be properly aligned. This option turns off the
603 alignment, which usually saves one intruction per call, but might
604 result in significantly lower floating point and SIMD performance.
607 Generate a JIT method map in a /tmp/perf-PID.map file. This file is then
608 used, for example, by the perf tool included in recent Linux kernels.
609 Each line in the file has:
612 HEXADDR HEXSIZE methodname
615 Currently this option is only supported on Linux.
616 .SH JIT MAINTAINER OPTIONS
617 The maintainer options are only used by those developing the runtime
618 itself, and not typically of interest to runtime users or developers.
620 \fB--bisect=optimization:filename\fR
621 This flag is used by the automatic optimization bug bisector. It
622 takes an optimization flag and a filename of a file containing a list
623 of full method names, one per line. When it compiles one of the
624 methods in the file it will use the optimization given, in addition to
625 the optimizations that are otherwise enabled. Note that if the
626 optimization is enabled by default, you should disable it with `-O`,
627 otherwise it will just apply to every method, whether it's in the file
631 Inserts a breakpoint before the method whose name is `method'
632 (namespace.class:methodname). Use `Main' as method name to insert a
633 breakpoint on the application's main method. You can use it also with
634 generics, for example "System.Collections.Generic.Queue`1:Peek"
637 Inserts a breakpoint on exceptions. This allows you to debug your
638 application with a native debugger when an exception is thrown.
641 This compiles a method (namespace.name:methodname), this is used for
642 testing the compiler performance or to examine the output of the code
646 Compiles all the methods in an assembly. This is used to test the
647 compiler performance or to examine the output of the code generator
649 \fB--graph=TYPE METHOD\fR
650 This generates a postscript file with a graph with the details about
651 the specified method (namespace.name:methodname). This requires `dot'
652 and ghostview to be installed (it expects Ghostview to be called
655 The following graphs are available:
657 cfg Control Flow Graph (CFG)
659 code CFG showing code
660 ssa CFG showing code after SSA translation
661 optcode CFG showing code after IR optimizations
664 Some graphs will only be available if certain optimizations are turned
668 Instruct the runtime on the number of times that the method specified
669 by --compile (or all the methods if --compileall is used) to be
670 compiled. This is used for testing the code generator performance.
673 Displays information about the work done by the runtime during the
674 execution of an application.
676 \fB--wapi=hps|semdel\fR
677 Perform maintenance of the process shared data.
679 semdel will delete the global semaphore.
681 hps will list the currently used handles.
683 \fB-v\fR, \fB--verbose\fR
684 Increases the verbosity level, each time it is listed, increases the
685 verbosity level to include more information (including, for example,
686 a disassembly of the native code produced, code selector info etc.).
688 The Mono runtime allows external processes to attach to a running
689 process and load assemblies into the running program. To attach to
690 the process, a special protocol is implemented in the Mono.Management
693 With this support it is possible to load assemblies that have an entry
694 point (they are created with -target:exe or -target:winexe) to be
695 loaded and executed in the Mono process.
697 The code is loaded into the root domain, and it starts execution on
698 the special runtime attach thread. The attached program should
699 create its own threads and return after invocation.
701 This support allows for example debugging applications by having the
702 csharp shell attach to running processes.
704 The mono runtime includes a profiler that can be used to explore
705 various performance related problems in your application. The
706 profiler is activated by passing the --profile command line argument
707 to the Mono runtime, the format is:
710 --profile[=profiler[:profiler_args]]
713 Mono has a built-in profiler called 'default' (and is also the default
714 if no arguments are specified), but developers can write custom
715 profilers, see the section "CUSTOM PROFILERS" for more details.
719 is not specified, the default profiler is used.
723 is a profiler-specific string of options for the profiler itself.
725 The default profiler accepts the following options 'alloc' to profile
726 memory consumption by the application; 'time' to profile the time
727 spent on each routine; 'jit' to collect time spent JIT-compiling methods
728 and 'stat' to perform sample statistical profiling.
729 If no options are provided the default is 'alloc,time,jit'.
732 profile data is printed to stdout: to change this, use the 'file=filename'
733 option to output the data to filename.
738 mono --profile program.exe
742 That will run the program with the default profiler and will do time
743 and allocation profiling.
747 mono --profile=default:stat,alloc,file=prof.out program.exe
750 Will do sample statistical profiling and allocation profiling on
751 program.exe. The profile data is put in prof.out.
753 Note that the statistical profiler has a very low overhead and should
754 be the preferred profiler to use (for better output use the full path
755 to the mono binary when running and make sure you have installed the
756 addr2line utility that comes from the binutils package).
758 This is the most advanced profiler.
760 The Mono \f[I]log\f[] profiler can be used to collect a lot of
761 information about a program running in the Mono runtime.
762 This data can be used (both while the process is running and later)
763 to do analyses of the program behaviour, determine resource usage,
764 performance issues or even look for particular execution patterns.
766 This is accomplished by logging the events provided by the Mono
767 runtime through the profiling interface and periodically writing
768 them to a file which can be later inspected with the mprof-report(1)
771 More information about how to use the log profiler is available on the
772 mprof-report(1) page.
774 Mono provides a mechanism for loading other profiling modules which in
775 the form of shared libraries. These profiling modules can hook up to
776 various parts of the Mono runtime to gather information about the code
779 To use a third party profiler you must pass the name of the profiler
783 mono --profile=custom program.exe
787 In the above sample Mono will load the user defined profiler from the
788 shared library `mono-profiler-custom.so'. This profiler module must
789 be on your dynamic linker library path.
791 A list of other third party profilers is available from Mono's web
792 site (www.mono-project.com/docs/advanced/performance-tips/)
794 Custom profiles are written as shared libraries. The shared library
795 must be called `mono-profiler-NAME.so' where `NAME' is the name of
798 For a sample of how to write your own custom profiler look in the
799 Mono source tree for in the samples/profiler.c.
801 Mono ships with a code coverage module. This module is activated by
802 using the Mono --profile=cov option. The format is:
803 \fB--profile=cov[:assembly-name[/namespace]] test-suite.exe\fR
805 By default code coverage will default to all the assemblies loaded,
806 you can limit this by specifying the assembly name, for example to
807 perform code coverage in the routines of your program use, for example
808 the following command line limits the code coverage to routines in the
812 mono --profile=cov:demo demo.exe
818 does not include the extension.
820 You can further restrict the code coverage output by specifying a
824 mono --profile=cov:demo/My.Utilities demo.exe
828 Which will only perform code coverage in the given assembly and
831 Typical output looks like this:
834 Not covered: Class:.ctor ()
835 Not covered: Class:A ()
836 Not covered: Driver:.ctor ()
837 Not covered: Driver:method ()
838 Partial coverage: Driver:Main ()
843 The offsets displayed are IL offsets.
845 A more powerful coverage tool is available in the module `monocov'.
846 See the monocov(1) man page for details.
848 To debug managed applications, you can use the
850 command, a command line debugger.
852 It is possible to obtain a stack trace of all the active threads in
853 Mono by sending the QUIT signal to Mono, you can do this from the
854 command line, like this:
860 Where pid is the Process ID of the Mono process you want to examine.
861 The process will continue running afterwards, but its state is not
865 this is a last-resort mechanism for debugging applications and should
866 not be used to monitor or probe a production application. The
867 integrity of the runtime after sending this signal is not guaranteed
868 and the application might crash or terminate at any given point
871 The \fB--debug=casts\fR option can be used to get more detailed
872 information for Invalid Cast operations, it will provide information
873 about the types involved.
875 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
876 to get verbose debugging output about the execution of your
877 application within Mono.
881 environment variable if set, the logging level is changed to the set
882 value. Possible values are "error", "critical", "warning", "message",
883 "info", "debug". The default value is "error". Messages with a logging
884 level greater then or equal to the log level will be printed to
887 Use "info" to track the dynamic loading of assemblies.
892 environment variable to limit the extent of the messages you get:
893 If set, the log mask is changed to the set value. Possible values are
894 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
895 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
896 "security" (e.g. Moonlight CoreCLR support), "threadpool" (thread pool generic),
897 "io-threadpool" (thread pool I/O), "io-layer" (I/O layer - sockets, handles, shared memory etc)
899 The default value is "all". Changing the mask value allows you to display only
900 messages for a certain component. You can use multiple masks by comma
901 separating them. For example to see config file messages and assembly loader
902 messages set you mask to "asm,cfg".
904 The following is a common use to track down problems with P/Invoke:
907 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
911 .SH DEBUGGING WITH LLDB
912 If you are using LLDB, you can use the
914 script to print some internal data structures with it. To use this,
919 command script import $PREFIX/lib/mono/lldb/mono.py
922 Where $PREFIX is the prefix value that you used when you configured
923 Mono (typically /usr).
925 Once this is done, then you can inspect some Mono Runtime data structures,
930 (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
933 Mono's XML serialization engine by default will use a reflection-based
934 approach to serialize which might be slow for continuous processing
935 (web service applications). The serialization engine will determine
936 when a class must use a hand-tuned serializer based on a few
937 parameters and if needed it will produce a customized C# serializer
938 for your types at runtime. This customized serializer then gets
939 dynamically loaded into your application.
941 You can control this with the MONO_XMLSERIALIZER_THS environment
944 The possible values are
946 to disable the use of a C# customized
947 serializer, or an integer that is the minimum number of uses before
948 the runtime will produce a custom serializer (0 will produce a
949 custom serializer on the first access, 50 will produce a serializer on
950 the 50th use). Mono will fallback to an interpreted serializer if the
951 serializer generation somehow fails. This behavior can be disabled
952 by setting the option
954 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
955 .SH ENVIRONMENT VARIABLES
958 Turns off the garbage collection in Mono. This should be only used
959 for debugging purposes
962 (Also \fBhttp_proxy\fR) If set, web requests using the Mono
963 Class Library will be automatically proxied through the given URL.
964 Not supported on Windows, Mac OS, iOS or Android. See also \fBNO_PROXY\fR.
967 When Mono is compiled with LLVM support, this instructs the runtime to
968 stop using LLVM after the specified number of methods are JITed.
969 This is a tool used in diagnostics to help isolate problems in the
970 code generation backend. For example \fBLLVM_COUNT=10\fR would only
971 compile 10 methods with LLVM and then switch to the Mono JIT engine.
972 \fBLLVM_COUNT=0\fR would disable the LLVM engine altogether.
975 If set, this variable will instruct Mono to ahead-of-time compile new
976 assemblies on demand and store the result into a cache in
979 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
980 Mono contains a feature which allows modifying settings in the .config files shipped
981 with Mono by using config section mappers. The mappers and the mapping rules are
982 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
983 settings.map file found in the top-level directory of your ASP.NET application.
984 Both files are read by System.Web on application startup, if they are found at the
985 above locations. If you don't want the mapping to be performed you can set this
986 variable in your environment before starting the application and no action will
989 \fBMONO_ASPNET_WEBCONFIG_CACHESIZE\fR
990 Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager
991 queries. Its default size is 100 items, and when more items are needed, cache
992 evictions start happening. If evictions are too frequent this could impose
993 unnecessary overhead, which could be avoided by using this environment variable
994 to set up a higher cache size (or to lower memory requirements by decreasing it).
996 \fBMONO_CAIRO_DEBUG_DISPOSE\fR
997 If set, causes Mono.Cairo to collect stack traces when objects are allocated,
998 so that the finalization/Dispose warnings include information about the
1002 If set, this variable overrides the default system configuration directory
1003 ($PREFIX/etc). It's used to locate machine.config file.
1006 Sets the style of COM interop. If the value of this variable is "MS"
1007 Mono will use string marhsalling routines from the liboleaut32 for the
1008 BSTR type library, any other values will use the mono-builtin BSTR
1012 If set, this variable overrides the default runtime configuration file
1013 ($PREFIX/etc/mono/config). The --config command line options overrides the
1014 environment variable.
1017 Override the automatic cpu detection mechanism. Currently used only on arm.
1018 The format of the value is as follows:
1024 where V is the architecture number 4, 5, 6, 7 and the options can be currently be
1025 "thumb" or "thumb2". Example:
1028 MONO_CPU_ARCH="armv4 thumb" mono ...
1032 \fBMONO_ARM_FORCE_SOFT_FLOAT\fR
1033 When Mono is built with a soft float fallback on ARM and this variable is set to
1034 "1", Mono will always emit soft float code, even if a VFP unit is
1037 \fBMONO_DARWIN_WATCHER_MAXFDS\fR
1038 This is a debugging aid used to force limits on the FileSystemWatcher
1039 implementation in Darwin. There is no limit by default.
1041 \fBMONO_DISABLE_AIO\fR
1042 If set, tells mono NOT to attempt using native asynchronous I/O services. In
1043 that case, a default select/poll implementation is used. Currently only epoll()
1046 \fBMONO_DISABLE_MANAGED_COLLATION\fR
1047 If this environment variable is `yes', the runtime uses unmanaged
1048 collation (which actually means no culture-sensitive collation). It
1049 internally disables managed collation functionality invoked via the
1050 members of System.Globalization.CompareInfo class. Collation is
1053 \fBMONO_DISABLE_SHM\fR
1054 Unix only: If set, disables the shared memory files used for
1055 cross-process handles: process have only private handles. This means
1056 that process and thread handles are not available to other processes,
1057 and named mutexes, named events and named semaphores are not visible
1060 This is can also be enabled by default by passing the
1061 "--disable-shared-handles" option to configure.
1063 This is the default from mono 2.8 onwards.
1065 \fBMONO_DISABLE_SHARED_AREA\fR
1066 Unix only: If set, disable usage of shared memory for exposing
1067 performance counters. This means it will not be possible to both
1068 externally read performance counters from this processes or read
1069 those of external processes.
1072 When set, enables the use of a fully managed DNS resolver instead of the
1073 regular libc functions. This resolver performs much better when multiple
1074 queries are run in parallel.
1076 Note that /etc/nsswitch.conf will be ignored.
1078 \fBMONO_EGD_SOCKET\fR
1079 For platforms that do not otherwise have a way of obtaining random bytes
1080 this can be set to the name of a file system socket on which an egd or
1081 prngd daemon is listening.
1083 \fBMONO_ENABLE_COOP\fR
1084 This makes the Mono runtime and the SGen garbage collector run in cooperative
1085 mode as opposed to run on preemptive mode. Preemptive mode is the mode
1086 that Mono has used historically, going back to the Boehm days, where the
1087 garbage collector would run at any point and suspend execution of all
1088 threads as required to perform a garbage collection. The cooperative mode
1089 on the other hand requires the cooperation of all threads to stop at a
1090 safe point. This makes for an easier to debug garbage collector. As
1091 of Mono 4.3.0 it is a work in progress, and while it works, it has not
1092 been used extensively. This option enabled the feature and allows us to
1093 find spots that need to be tuned for this mode of operation. Alternatively,
1094 this mode can be enabled at compile time by using the --with-cooperative-gc
1095 flag when calling configure.
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/
1511 \fBMONO_SHARED_DIR\fR
1512 If set its the directory where the ".wapi" handle state is stored.
1513 This is the directory where the Windows I/O Emulation layer stores its
1514 shared state data (files, events, mutexes, pipes). By default Mono
1515 will store the ".wapi" directory in the users's home directory.
1517 \fBMONO_SHARED_HOSTNAME\fR
1518 Uses the string value of this variable as a replacement for the host name when
1519 creating file names in the ".wapi" directory. This helps if the host name of
1520 your machine is likely to be changed when a mono application is running or if
1521 you have a .wapi directory shared among several different computers.
1523 Mono typically uses the hostname to create the files that are used to
1524 share state across multiple Mono processes. This is done to support
1525 home directories that might be shared over the network.
1527 \fBMONO_STRICT_IO_EMULATION\fR
1528 If set, extra checks are made during IO operations. Currently, this
1529 includes only advisory locks around file writes.
1532 The name of the theme to be used by Windows.Forms. Available themes today
1533 include "clearlooks", "nice" and "win32".
1535 The default is "win32".
1537 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1538 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1539 avoid a new negotiation between the client and a server. Negotiation are very
1540 CPU intensive so an application-specific custom value may prove useful for
1541 small embedded systems.
1543 The default is 180 seconds.
1545 \fBMONO_THREADS_PER_CPU\fR
1546 The minimum number of threads in the general threadpool will be
1547 MONO_THREADS_PER_CPU * number of CPUs. The default value for this
1550 \fBMONO_XMLSERIALIZER_THS\fR
1551 Controls the threshold for the XmlSerializer to produce a custom
1552 serializer for a given class instead of using the Reflection-based
1553 interpreter. The possible values are `no' to disable the use of a
1554 custom serializer or a number to indicate when the XmlSerializer
1555 should start serializing. The default value is 50, which means that
1556 the a custom serializer will be produced on the 50th use.
1558 \fBMONO_X509_REVOCATION_MODE\fR
1559 Sets the revocation mode used when validating a X509 certificate chain (https,
1560 ftps, smtps...). The default is 'nocheck', which performs no revocation check
1561 at all. The other possible values are 'offline', which performs CRL check (not
1562 implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
1563 status (not implemented yet).
1566 (Also \fBno_proxy\fR) If both \fBHTTP_PROXY\fR and \fBNO_PROXY\fR are
1567 set, \fBNO_PROXY\fR will be treated as a comma-separated list of "bypass" domains
1568 which will not be sent through the proxy. Domains in \fBNO_PROXY\fR may contain
1569 wildcards, as in "*.mono-project.com" or "build????.local". Not supported on
1570 Windows, Mac OS, iOS or Android.
1571 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1573 \fBMONO_ASPNET_NODELETE\fR
1574 If set to any value, temporary source files generated by ASP.NET support
1575 classes will not be removed. They will be kept in the user's temporary
1579 If set, enables some features of the runtime useful for debugging.
1580 This variable should contain a comma separated list of debugging options.
1581 Currently, the following options are supported:
1585 \fBalign-small-structs\fR
1586 Enables small structs alignment to 4/8 bytes.
1588 \fBarm-use-fallback-tls\fR
1589 When this option is set on ARM, a fallback TLS will be used instead
1590 of the default fast TLS.
1592 \fBbreak-on-unverified\fR
1593 If this variable is set, when the Mono VM runs into a verification
1594 problem, instead of throwing an exception it will break into the
1595 debugger. This is useful when debugging verifier problems
1598 This option can be used to get more detailed information from
1599 InvalidCast exceptions, it will provide information about the types
1602 \fBcheck-pinvoke-callconv\fR
1603 This option causes the runtime to check for calling convention
1604 mismatches when using pinvoke, i.e. mixing cdecl/stdcall. It only
1605 works on windows. If a mismatch is detected, an
1606 ExecutionEngineException is thrown.
1608 \fBcollect-pagefault-stats\fR
1609 Collects information about pagefaults. This is used internally to
1610 track the number of page faults produced to load metadata. To display
1611 this information you must use this option with "--stats" command line
1614 \fBdebug-domain-unload\fR
1615 When this option is set, the runtime will invalidate the domain memory
1616 pool instead of destroying it.
1618 \fBdisable_omit_fp\fR
1619 Disables a compiler optimization where the frame pointer is omitted
1620 from the stack. This optimization can interact badly with debuggers.
1622 \fBdont-free-domains\fR
1623 This is an Optimization for multi-AppDomain applications (most
1624 commonly ASP.NET applications). Due to internal limitations Mono,
1625 Mono by default does not use typed allocations on multi-appDomain
1626 applications as they could leak memory when a domain is unloaded.
1628 Although this is a fine default, for applications that use more than
1629 on AppDomain heavily (for example, ASP.NET applications) it is worth
1630 trading off the small leaks for the increased performance
1631 (additionally, since ASP.NET applications are not likely going to
1632 unload the application domains on production systems, it is worth
1633 using this feature).
1635 \fBdyn-runtime-invoke\fR
1636 Instructs the runtime to try to use a generic runtime-invoke wrapper
1637 instead of creating one invoke wrapper.
1639 \fBexplicit-null-checks\fR
1640 Makes the JIT generate an explicit NULL check on variable dereferences
1641 instead of depending on the operating system to raise a SIGSEGV or
1642 another form of trap event when an invalid memory location is
1646 Equivalent to setting the \fBMONO_XDEBUG\fR variable, this emits
1647 symbols into a shared library as the code is JITed that can be loaded
1648 into GDB to inspect symbols.
1650 \fBgen-seq-points\fR
1651 Automatically generates sequence points where the
1652 IL stack is empty. These are places where the debugger can set a
1655 \fBgen-compact-seq-points\fR
1656 This option generates sequence points data that maps native offsets to
1657 IL offsets. Sequence point data is used to display IL offset in
1658 stacktraces. Stacktraces with IL offsets can be symbolicated using
1659 mono-symbolicate tool.
1662 Captures the interrupt signal (Control-C) and displays a stack trace
1663 when pressed. Useful to find out where the program is executing at a
1664 given point. This only displays the stack trace of a single thread.
1667 Instructs the runtime to initialize the stack with
1668 some known values (0x2a on x86-64) at the start of a method to assist
1669 in debuggin the JIT engine.
1671 \fBkeep-delegates\fR
1672 This option will leak delegate trampolines that are no longer
1673 referenced as to present the user with more information about a
1674 delegate misuse. Basically a delegate instance might be created,
1675 passed to unmanaged code, and no references kept in managed code,
1676 which will garbage collect the code. With this option it is possible
1677 to track down the source of the problems.
1679 \fBno-gdb-backtrace\fR
1680 This option will disable the GDB backtrace emitted by the runtime
1681 after a SIGSEGV or SIGABRT in unmanaged code.
1683 \fBpartial-sharing\fR
1684 When this option is set, the runtime can share generated code between
1685 generic types effectively reducing the amount of code generated.
1687 \fBreverse-pinvoke-exceptions
1688 This option will cause mono to abort with a descriptive message when
1689 during stack unwinding after an exception it reaches a native stack
1690 frame. This happens when a managed delegate is passed to native code,
1691 and the managed delegate throws an exception. Mono will normally try
1692 to unwind the stack to the first (managed) exception handler, and it
1693 will skip any native stack frames in the process. This leads to
1694 undefined behaviour (since mono doesn't know how to process native
1695 frames), leaks, and possibly crashes too.
1697 \fBsingle-imm-size\fR
1698 This guarantees that each time managed code is compiled the same
1699 instructions and registers are used, regardless of the size of used
1702 \fBsoft-breakpoints\fR
1703 This option allows using single-steps and breakpoints in hardware
1704 where we cannot do it with signals.
1706 \fBsuspend-on-sigsegv\fR
1707 This option will suspend the program when a native SIGSEGV is received.
1708 This is useful for debugging crashes which do not happen under gdb,
1709 since a live process contains more information than a core file.
1711 \fBsuspend-on-exception\fR
1712 This option will suspend the program when an exception occurs.
1714 \fBsuspend-on-unhandled\fR
1715 This option will suspend the program when an unhandled exception occurs.
1719 \fBMONO_LOG_LEVEL\fR
1720 The logging level, possible values are `error', `critical', `warning',
1721 `message', `info' and `debug'. See the DEBUGGING section for more
1725 Controls the domain of the Mono runtime that logging will apply to.
1726 If set, the log mask is changed to the set value. Possible values are
1727 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1728 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
1729 "security" (e.g. Moonlight CoreCLR support) and "all".
1730 The default value is "all". Changing the mask value allows you to display only
1731 messages for a certain component. You can use multiple masks by comma
1732 separating them. For example to see config file messages and assembly loader
1733 messages set you mask to "asm,cfg".
1736 Controls where trace log messages are written. If not set then the messages go to stdout.
1737 If set, the string either specifies a path to a file that will have messages appended to
1738 it, or the string "syslog" in which case the messages will be written to the system log.
1739 Under Windows, this is simulated by writing to a file called "mono.log".
1740 \fBMONO_LOG_HEADER\fR
1741 Controls whether trace log messages not directed to syslog have the id, timestamp, and
1742 pid as the prefix to the log message. To enable a header this environment variable need
1746 Used for runtime tracing of method calls. The format of the comma separated
1755 disabled Trace output off upon start.
1758 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1760 \fBMONO_TRACE_LISTENER\fR
1761 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1762 print the output of the System.Diagnostics Trace and Debug classes.
1763 It can be set to a filename, and to Console.Out or Console.Error to display
1764 output to standard output or standard error, respectively. If it's set to
1765 Console.Out or Console.Error you can append an optional prefix that will
1766 be used when writing messages like this: Console.Error:MyProgramName.
1767 See the System.Diagnostics.DefaultTraceListener documentation for more
1770 \fBMONO_WCF_TRACE\fR
1771 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.
1773 \fBMONO_XEXCEPTIONS\fR
1774 This throws an exception when a X11 error is encountered; by default a
1775 message is displayed but execution continues
1777 \fBMONO_XMLSERIALIZER_DEBUG\fR
1778 Set this value to 1 to prevent the serializer from removing the
1779 temporary files that are created for fast serialization; This might
1780 be useful when debugging.
1783 This is used in the System.Windows.Forms implementation when running
1784 with the X11 backend. This is used to debug problems in Windows.Forms
1785 as it forces all of the commands send to X11 server to be done
1786 synchronously. The default mode of operation is asynchronous which
1787 makes it hard to isolate the root of certain problems.
1790 When the the MONO_XDEBUG env var is set, debugging info for JITted
1791 code is emitted into a shared library, loadable into gdb. This enables,
1792 for example, to see managed frame names on gdb backtraces.
1794 \fBMONO_VERBOSE_METHOD\fR
1795 Enables the maximum JIT verbosity for the specified method. This is
1796 very helpfull to diagnose a miscompilation problems of a specific
1799 \fBMONO_JIT_DUMP_METHOD\fR
1800 Enables sending of the JITs intermediate representation for a specified
1801 method to the IdealGraphVisualizer tool.
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