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.
129 When this option is specified, P/Invoke methods are invoked directly
130 instead of going through the operating system symbol lookup operation.
132 .I llvm-path=<PREFIX>
133 Same for the llvm tools 'opt' and 'llc'.
136 Use the GNU style target triple <TRIPLE> to determine some code generation options, i.e.
137 --mtriple=armv7-linux-gnueabi will generate code that targets ARMv7. This is currently
138 only supported by the ARM backend. In LLVM mode, this triple is passed on to the LLVM
141 .I nimt-trampolines=[number]
142 When compiling in full aot mode, the IMT trampolines must be precreated
143 in the AOT image. You can add additional method trampolines with this argument.
147 Instructs the AOT compiler to not output any debugging information.
150 This prevents the AOT compiler from generating a direct calls to a
151 method. The AOT compiler usually generates direct calls for certain
152 methods that do not require going through the PLT (for example,
153 methods that are known to not require a hook like a static
154 constructor) or call into simple internal calls.
157 Instructs the AOT compiler to emit DWARF debugging information. When
158 used together with the nodebug option, only DWARF debugging
159 information is emitted, but not the information that can be used at
162 .I nrgctx-trampolines=[number]
163 When compiling in full aot mode, the generic sharing trampolines must be precreated
164 in the AOT image. You can add additional method trampolines with this argument.
167 .I ntrampolines=[number]
168 When compiling in full aot mode, the method trampolines must be precreated
169 in the AOT image. You can add additional method trampolines with this argument.
172 .I outfile=[filename]
173 Instructs the AOT compiler to save the output to the specified file.
175 .I print-skipped-methods
176 If the AOT compiler cannot compile a method for any reason, enabling this flag
177 will output the skipped methods to the console.
179 .I readonly-value=namespace.typename.fieldname=type/value
180 Override the value of a static readonly field. Usually, during JIT
181 compilation, the static constructor is ran eagerly, so the value of
182 a static readonly field is known at compilation time and the compiler
183 can do a number of optimizations based on it. During AOT, instead, the static
184 constructor can't be ran, so this option can be used to set the value of such
185 a field and enable the same set of optimizations.
186 Type can be any of i1, i2, i4 for integers of the respective sizes (in bytes).
187 Note that signed/unsigned numbers do not matter here, just the storage size.
188 This option can be specified multiple times and it doesn't prevent the static
189 constructor for the type defining the field to execute with the usual rules
190 at runtime (hence possibly computing a different value for the field).
193 .I save-temps,keep-temps
194 Instructs the AOT compiler to keep temporary files.
197 This instructs the compiler to generate sequence point checks that
198 allow Mono's soft debugger to debug applications even on systems where
199 it is not possible to set breakpoints or to single step (certain
200 hardware configurations like the cell phones and video gaming
204 Create an ELF object file (.o) or .s file which can be statically linked into an
205 executable when embedding the mono runtime. When this option is used, the object file
206 needs to be registered with the embedded runtime using the mono_aot_register_module
207 function which takes as its argument the mono_aot_module_<ASSEMBLY NAME>_info global
208 symbol from the object file:
211 extern void *mono_aot_module_hello_info;
213 mono_aot_register_module (mono_aot_module_hello_info);
218 Print various stats collected during AOT compilation.
221 This is an experimental option for the AOT compiler to use multiple threads
222 when compiling the methods.
224 .I tool-prefix=<PREFIX>
225 Prepends <PREFIX> to the name of tools ran by the AOT compiler, i.e. 'as'/'ld'. For
226 example, --tool=prefix=arm-linux-gnueabi- will make the AOT compiler run
227 'arm-linux-gnueabi-as' instead of 'as'.
230 Instructs the AOT compiler to emit debug symbol information.
232 For more information about AOT, see: http://www.mono-project.com/docs/advanced/aot/
235 \fB--attach=[options]\fR
236 Currently the only option supported by this command line argument is
237 \fBdisable\fR which disables the attach functionality.
239 \fB--config filename\fR
240 Load the specified configuration file instead of the default one(s).
241 The default files are /etc/mono/config and ~/.mono/config or the file
242 specified in the MONO_CONFIG environment variable, if set. See the
243 mono-config(5) man page for details on the format of this file.
245 \fB--debugger-agent=[options]\fR
246 This instructs the Mono runtime to
247 start a debugging agent inside the Mono runtime and connect it to a
248 client user interface will control the Mono process.
249 This option is typically used by IDEs, like the MonoDevelop IDE.
251 The configuration is specified using one of more of the following options:
257 Use this option to specify the IP address where your debugger client is
262 Specifies the diagnostics log level for
266 Used to specify the file where the log will be stored, it defaults to
270 Defaults to no, with the default option Mono will actively connect to the
271 host/port configured with the \fBaddress\fR option. If you set it to 'y', it
272 instructs the Mono runtime to start debugging in server mode, where Mono
273 actively waits for the debugger front end to connect to the Mono process.
274 Mono will print out to stdout the IP address and port where it is listening.
277 If set to yes, Mono will call \fBsetpgid(0, 0)\fB on startup, if that function
278 is available on the system. This is useful for ensuring that signals delivered
279 to a process that is executing the debuggee are not propagated to the debuggee,
280 e.g. when Ctrl-C sends \fBSIGINT\fB to the \fBsdb\fB tool.
283 Defaults to yes, with the default option Mono will suspend the vm on startup
284 until it connects successfully to a debugger front end. If you set it to 'n', in
285 conjunction with \fBserver=y\fR, it instructs the Mono runtime to run as normal,
286 while caching metadata to send to the debugger front end on connection..
288 .I transport=transport_name
290 This is used to specify the transport that the debugger will use to
291 communicate. It must be specified and currently requires this to
297 Configures the virtual machine to be better suited for desktop
298 applications. Currently this sets the GC system to avoid expanding
299 the heap as much as possible at the expense of slowing down garbage
303 This is an experimental flag that instructs the Mono runtime to not
304 generate any code at runtime and depend exclusively on the code
305 generated from using mono --aot=full previously. This is useful for
306 platforms that do not permit dynamic code generation.
308 Notice that this feature will abort execution at runtime if a codepath
309 in your program, or Mono's class libraries attempts to generate code
310 dynamically. You should test your software upfront and make sure that
311 you do not use any dynamic features.
313 \fB--gc=boehm\fR, \fB--gc=sgen\fR
314 Selects the Garbage Collector engine for Mono to use, Boehm or SGen.
315 Currently this merely ensures that you are running either the
316 \fImono\fR or \fImono-sgen\fR commands. This flag can be set in the
317 \fBMONO_ENV_OPTIONS\fR environment variable to force all of your child
318 processes to use one particular kind of GC with the Mono runtime.
320 \fB--help\fR, \fB-h\fR
321 Displays usage instructions.
324 If the Mono runtime has been compiled with LLVM support (not available
325 in all configurations), Mono will use the LLVM optimization and code
326 generation engine to JIT or AOT compile.
328 For more information, consult: http://www.mono-project.com/docs/advanced/mono-llvm/
331 When using a Mono that has been compiled with LLVM support, it forces
332 Mono to fallback to its JIT engine and not use the LLVM backend.
334 \fB--optimize=MODE\fR, \fB-O=MODE\fR
335 MODE is a comma separated list of optimizations. They also allow
336 optimizations to be turned off by prefixing the optimization name with
339 In general, Mono has been tuned to use the default set of flags,
340 before using these flags for a deployment setting, you might want to
341 actually measure the benefits of using them.
343 The following optimization flags are implemented in the core engine:
345 abcrem Array bound checks removal
346 all Turn on all optimizations
347 aot Usage of Ahead Of Time compiled code
348 branch Branch optimizations
349 cfold Constant folding
350 cmov Conditional moves [arch-dependency]
351 deadce Dead code elimination
352 consprop Constant propagation
353 copyprop Copy propagation
354 fcmov Fast x86 FP compares [arch-dependency]
355 float32 Perform 32-bit float arithmetic using 32-bit operations
356 gshared Enable generic code sharing.
357 inline Inline method calls
358 intrins Intrinsic method implementations
359 linears Linear scan global reg allocation
360 leaf Leaf procedures optimizations
361 loop Loop related optimizations
362 peephole Peephole postpass
363 precomp Precompile all methods before executing Main
364 sched Instruction scheduling
365 shared Emit per-domain code
366 sse2 SSE2 instructions on x86 [arch-dependency]
367 tailc Tail recursion and tail calls
370 For example, to enable all the optimization but dead code
371 elimination and inlining, you can use:
373 -O=all,-deadce,-inline
376 The flags that are flagged with [arch-dependency] indicate that the
377 given option if used in combination with Ahead of Time compilation
378 (--aot flag) would produce pre-compiled code that will depend on the
379 current CPU and might not be safely moved to another computer.
383 The following optimizations are supported
386 Requests that the runtime performn 32-bit floating point operations
387 using only 32-bits. By default the Mono runtime tries to use the
388 highest precision available for floating point operations, but while
389 this might render better results, the code might run slower. This
390 options also affects the code generated by the LLVM backend.
393 Controls whether the runtime should attempt to inline (the default),
394 or not inline methods invocations
398 \fB--runtime=VERSION\fR
399 Mono supports different runtime versions. The version used depends on the program
400 that is being run or on its configuration file (named program.exe.config). This option
401 can be used to override such autodetection, by forcing a different runtime version
402 to be used. Note that this should only be used to select a later compatible runtime
403 version than the one the program was compiled against. A typical usage is for
404 running a 1.1 program on a 2.0 version:
406 mono --runtime=v2.0.50727 program.exe
409 \fB--security\fR, \fB--security=mode\fR
410 Activate the security manager, a currently experimental feature in
411 Mono and it is OFF by default. The new code verifier can be enabled
412 with this option as well.
416 Using security without parameters is equivalent as calling it with the
419 The following modes are supported:
422 Enables the core-clr security system, typically used for
423 Moonlight/Silverlight applications. It provides a much simpler
424 security system than CAS, see http://www.mono-project.com/docs/web/moonlight/
425 for more details and links to the descriptions of this new system.
428 Enables the new verifier and performs basic verification for code
429 validity. In this mode, unsafe code and P/Invoke are allowed. This
430 mode provides a better safety guarantee but it is still possible
431 for managed code to crash Mono.
434 Enables the new verifier and performs full verification of the code
435 being executed. It only allows verifiable code to be executed.
436 Unsafe code is not allowed but P/Invoke is. This mode should
437 not allow managed code to crash mono. The verification is not as
438 strict as ECMA 335 standard in order to stay compatible with the MS
441 The security system acts on user code: code contained in mscorlib or
442 the global assembly cache is always trusted.
447 Configures the virtual machine to be better suited for server
448 operations (currently, allows a heavier threadpool initialization).
451 Verifies mscorlib and assemblies in the global
452 assembly cache for valid IL, and all user code for IL
455 This is different from \fB--security\fR's verifiable
456 or validil in that these options only check user code and skip
457 mscorlib and assemblies located on the global assembly cache.
459 \fB-V\fR, \fB--version\fR
460 Prints JIT version information (system configuration, release number
461 and branch names if available).
464 .SH DEVELOPMENT OPTIONS
465 The following options are used to help when developing a JITed application.
467 \fB--debug\fR, \fB--debug=OPTIONS\fR
468 Turns on the debugging mode in the runtime. If an assembly was
469 compiled with debugging information, it will produce line number
470 information for stack traces.
474 The optional OPTIONS argument is a comma separated list of debugging
475 options. These options are turned off by default since they generate
476 much larger and slower code at runtime.
478 The following options are supported:
481 Produces a detailed error when throwing a InvalidCastException. This
482 option needs to be enabled as this generates more verbose code at
486 Disable some JIT optimizations which are usually only disabled when
487 running inside the debugger. This can be helpful if you want to attach
488 to the running process with mdb.
491 Generate and register debugging information with gdb. This is only supported on some
492 platforms, and only when using gdb 7.0 or later.
496 \fB--profile[=profiler[:profiler_args]]\fR
497 Turns on profiling. For more information about profiling applications
498 and code coverage see the sections "PROFILING" and "CODE COVERAGE"
501 This option can be used multiple times, each time will load an
502 additional profiler. This allows developers to use modules that
503 extend the JIT through the Mono profiling interface.
505 \fB--trace[=expression]\fR
506 Shows method names as they are invoked. By default all methods are
509 The trace can be customized to include or exclude methods, classes or
510 assemblies. A trace expression is a comma separated list of targets,
511 each target can be prefixed with a minus sign to turn off a particular
512 target. The words `program', `all' and `disabled' have special
513 meaning. `program' refers to the main program being executed, and
514 `all' means all the method calls.
516 The `disabled' option is used to start up with tracing disabled. It
517 can be enabled at a later point in time in the program by sending the
518 SIGUSR2 signal to the runtime.
520 Assemblies are specified by their name, for example, to trace all
521 calls in the System assembly, use:
524 mono --trace=System app.exe
527 Classes are specified with the T: prefix. For example, to trace all
528 calls to the System.String class, use:
531 mono --trace=T:System.String app.exe
534 And individual methods are referenced with the M: prefix, and the
535 standard method notation:
538 mono --trace=M:System.Console:WriteLine app.exe
541 Exceptions can also be traced, it will cause a stack trace to be
542 printed every time an exception of the specified type is thrown.
543 The exception type can be specified with or without the namespace,
544 and to trace all exceptions, specify 'all' as the type name.
547 mono --trace=E:System.Exception app.exe
550 As previously noted, various rules can be specified at once:
553 mono --trace=T:System.String,T:System.Random app.exe
556 You can exclude pieces, the next example traces calls to
557 System.String except for the System.String:Concat method.
560 mono --trace=T:System.String,-M:System.String:Concat
563 You can trace managed to unmanaged transitions using
564 the wrapper qualifier:
567 mono --trace=wrapper app.exe
570 Finally, namespaces can be specified using the N: prefix:
573 mono --trace=N:System.Xml
577 \fB--no-x86-stack-align\fR
578 Don't align stack frames on the x86 architecture. By default, Mono
579 aligns stack frames to 16 bytes on x86, so that local floating point
580 and SIMD variables can be properly aligned. This option turns off the
581 alignment, which usually saves one intruction per call, but might
582 result in significantly lower floating point and SIMD performance.
585 Generate a JIT method map in a /tmp/perf-PID.map file. This file is then
586 used, for example, by the perf tool included in recent Linux kernels.
587 Each line in the file has:
590 HEXADDR HEXSIZE methodname
593 Currently this option is only supported on Linux.
594 .SH JIT MAINTAINER OPTIONS
595 The maintainer options are only used by those developing the runtime
596 itself, and not typically of interest to runtime users or developers.
599 Inserts a breakpoint before the method whose name is `method'
600 (namespace.class:methodname). Use `Main' as method name to insert a
601 breakpoint on the application's main method. You can use it also with
602 generics, for example "System.Collections.Generic.Queue`1:Peek"
605 Inserts a breakpoint on exceptions. This allows you to debug your
606 application with a native debugger when an exception is thrown.
609 This compiles a method (namespace.name:methodname), this is used for
610 testing the compiler performance or to examine the output of the code
614 Compiles all the methods in an assembly. This is used to test the
615 compiler performance or to examine the output of the code generator
617 \fB--graph=TYPE METHOD\fR
618 This generates a postscript file with a graph with the details about
619 the specified method (namespace.name:methodname). This requires `dot'
620 and ghostview to be installed (it expects Ghostview to be called
623 The following graphs are available:
625 cfg Control Flow Graph (CFG)
627 code CFG showing code
628 ssa CFG showing code after SSA translation
629 optcode CFG showing code after IR optimizations
632 Some graphs will only be available if certain optimizations are turned
636 Instruct the runtime on the number of times that the method specified
637 by --compile (or all the methods if --compileall is used) to be
638 compiled. This is used for testing the code generator performance.
641 Displays information about the work done by the runtime during the
642 execution of an application.
644 \fB--wapi=hps|semdel\fR
645 Perform maintenance of the process shared data.
647 semdel will delete the global semaphore.
649 hps will list the currently used handles.
651 \fB-v\fR, \fB--verbose\fR
652 Increases the verbosity level, each time it is listed, increases the
653 verbosity level to include more information (including, for example,
654 a disassembly of the native code produced, code selector info etc.).
656 The Mono runtime allows external processes to attach to a running
657 process and load assemblies into the running program. To attach to
658 the process, a special protocol is implemented in the Mono.Management
661 With this support it is possible to load assemblies that have an entry
662 point (they are created with -target:exe or -target:winexe) to be
663 loaded and executed in the Mono process.
665 The code is loaded into the root domain, and it starts execution on
666 the special runtime attach thread. The attached program should
667 create its own threads and return after invocation.
669 This support allows for example debugging applications by having the
670 csharp shell attach to running processes.
672 The mono runtime includes a profiler that can be used to explore
673 various performance related problems in your application. The
674 profiler is activated by passing the --profile command line argument
675 to the Mono runtime, the format is:
678 --profile[=profiler[:profiler_args]]
681 Mono has a built-in profiler called 'default' (and is also the default
682 if no arguments are specified), but developers can write custom
683 profilers, see the section "CUSTOM PROFILERS" for more details.
687 is not specified, the default profiler is used.
691 is a profiler-specific string of options for the profiler itself.
693 The default profiler accepts the following options 'alloc' to profile
694 memory consumption by the application; 'time' to profile the time
695 spent on each routine; 'jit' to collect time spent JIT-compiling methods
696 and 'stat' to perform sample statistical profiling.
697 If no options are provided the default is 'alloc,time,jit'.
700 profile data is printed to stdout: to change this, use the 'file=filename'
701 option to output the data to filename.
706 mono --profile program.exe
710 That will run the program with the default profiler and will do time
711 and allocation profiling.
715 mono --profile=default:stat,alloc,file=prof.out program.exe
718 Will do sample statistical profiling and allocation profiling on
719 program.exe. The profile data is put in prof.out.
721 Note that the statistical profiler has a very low overhead and should
722 be the preferred profiler to use (for better output use the full path
723 to the mono binary when running and make sure you have installed the
724 addr2line utility that comes from the binutils package).
726 This is the most advanced profiler.
728 The Mono \f[I]log\f[] profiler can be used to collect a lot of
729 information about a program running in the Mono runtime.
730 This data can be used (both while the process is running and later)
731 to do analyses of the program behaviour, determine resource usage,
732 performance issues or even look for particular execution patterns.
734 This is accomplished by logging the events provided by the Mono
735 runtime through the profiling interface and periodically writing
736 them to a file which can be later inspected with the mprof-report(1)
739 More information about how to use the log profiler is available on the
740 mprof-report(1) page.
742 Mono provides a mechanism for loading other profiling modules which in
743 the form of shared libraries. These profiling modules can hook up to
744 various parts of the Mono runtime to gather information about the code
747 To use a third party profiler you must pass the name of the profiler
751 mono --profile=custom program.exe
755 In the above sample Mono will load the user defined profiler from the
756 shared library `mono-profiler-custom.so'. This profiler module must
757 be on your dynamic linker library path.
759 A list of other third party profilers is available from Mono's web
760 site (www.mono-project.com/docs/advanced/performance-tips/)
762 Custom profiles are written as shared libraries. The shared library
763 must be called `mono-profiler-NAME.so' where `NAME' is the name of
766 For a sample of how to write your own custom profiler look in the
767 Mono source tree for in the samples/profiler.c.
769 Mono ships with a code coverage module. This module is activated by
770 using the Mono --profile=cov option. The format is:
771 \fB--profile=cov[:assembly-name[/namespace]] test-suite.exe\fR
773 By default code coverage will default to all the assemblies loaded,
774 you can limit this by specifying the assembly name, for example to
775 perform code coverage in the routines of your program use, for example
776 the following command line limits the code coverage to routines in the
780 mono --profile=cov:demo demo.exe
786 does not include the extension.
788 You can further restrict the code coverage output by specifying a
792 mono --profile=cov:demo/My.Utilities demo.exe
796 Which will only perform code coverage in the given assembly and
799 Typical output looks like this:
802 Not covered: Class:.ctor ()
803 Not covered: Class:A ()
804 Not covered: Driver:.ctor ()
805 Not covered: Driver:method ()
806 Partial coverage: Driver:Main ()
811 The offsets displayed are IL offsets.
813 A more powerful coverage tool is available in the module `monocov'.
814 See the monocov(1) man page for details.
816 To debug managed applications, you can use the
818 command, a command line debugger.
820 It is possible to obtain a stack trace of all the active threads in
821 Mono by sending the QUIT signal to Mono, you can do this from the
822 command line, like this:
828 Where pid is the Process ID of the Mono process you want to examine.
829 The process will continue running afterwards, but its state is not
833 this is a last-resort mechanism for debugging applications and should
834 not be used to monitor or probe a production application. The
835 integrity of the runtime after sending this signal is not guaranteed
836 and the application might crash or terminate at any given point
839 The \fB--debug=casts\fR option can be used to get more detailed
840 information for Invalid Cast operations, it will provide information
841 about the types involved.
843 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
844 to get verbose debugging output about the execution of your
845 application within Mono.
849 environment variable if set, the logging level is changed to the set
850 value. Possible values are "error", "critical", "warning", "message",
851 "info", "debug". The default value is "error". Messages with a logging
852 level greater then or equal to the log level will be printed to
855 Use "info" to track the dynamic loading of assemblies.
860 environment variable to limit the extent of the messages you get:
861 If set, the log mask is changed to the set value. Possible values are
862 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
863 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
864 "security" (e.g. Moonlight CoreCLR support) and "all".
865 The default value is "all". Changing the mask value allows you to display only
866 messages for a certain component. You can use multiple masks by comma
867 separating them. For example to see config file messages and assembly loader
868 messages set you mask to "asm,cfg".
870 The following is a common use to track down problems with P/Invoke:
873 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
877 .SH DEBUGGING WITH LLDB
878 If you are using LLDB, you can use the
880 script to print some internal data structures with it. To use this,
885 command script import $PREFIX/lib/mono/lldb/mono.py
888 Where $PREFIX is the prefix value that you used when you configured
889 Mono (typically /usr).
891 Once this is done, then you can inspect some Mono Runtime data structures,
896 (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
899 Mono's XML serialization engine by default will use a reflection-based
900 approach to serialize which might be slow for continuous processing
901 (web service applications). The serialization engine will determine
902 when a class must use a hand-tuned serializer based on a few
903 parameters and if needed it will produce a customized C# serializer
904 for your types at runtime. This customized serializer then gets
905 dynamically loaded into your application.
907 You can control this with the MONO_XMLSERIALIZER_THS environment
910 The possible values are
912 to disable the use of a C# customized
913 serializer, or an integer that is the minimum number of uses before
914 the runtime will produce a custom serializer (0 will produce a
915 custom serializer on the first access, 50 will produce a serializer on
916 the 50th use). Mono will fallback to an interpreted serializer if the
917 serializer generation somehow fails. This behavior can be disabled
918 by setting the option
920 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
921 .SH ENVIRONMENT VARIABLES
924 Turns off the garbage collection in Mono. This should be only used
925 for debugging purposes
928 When Mono is compiled with LLVM support, this instructs the runtime to
929 stop using LLVM after the specified number of methods are JITed.
930 This is a tool used in diagnostics to help isolate problems in the
931 code generation backend. For example \fBLLVM_COUNT=10\fR would only
932 compile 10 methods with LLVM and then switch to the Mono JIT engine.
933 \fBLLVM_COUNT=0\fR would disable the LLVM engine altogether.
936 If set, this variable will instruct Mono to ahead-of-time compile new
937 assemblies on demand and store the result into a cache in
940 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
941 Mono contains a feature which allows modifying settings in the .config files shipped
942 with Mono by using config section mappers. The mappers and the mapping rules are
943 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
944 settings.map file found in the top-level directory of your ASP.NET application.
945 Both files are read by System.Web on application startup, if they are found at the
946 above locations. If you don't want the mapping to be performed you can set this
947 variable in your environment before starting the application and no action will
950 \fBMONO_ASPNET_WEBCONFIG_CACHESIZE\fR
951 Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager
952 queries. Its default size is 100 items, and when more items are needed, cache
953 evictions start happening. If evictions are too frequent this could impose
954 unnecessary overhead, which could be avoided by using this environment variable
955 to set up a higher cache size (or to lower memory requirements by decreasing it).
957 \fBMONO_CAIRO_DEBUG_DISPOSE\fR
958 If set, causes Mono.Cairo to collect stack traces when objects are allocated,
959 so that the finalization/Dispose warnings include information about the
963 If set, this variable overrides the default system configuration directory
964 ($PREFIX/etc). It's used to locate machine.config file.
967 Sets the style of COM interop. If the value of this variable is "MS"
968 Mono will use string marhsalling routines from the liboleaut32 for the
969 BSTR type library, any other values will use the mono-builtin BSTR
973 If set, this variable overrides the default runtime configuration file
974 ($PREFIX/etc/mono/config). The --config command line options overrides the
975 environment variable.
978 Override the automatic cpu detection mechanism. Currently used only on arm.
979 The format of the value is as follows:
985 where V is the architecture number 4, 5, 6, 7 and the options can be currently be
986 "thumb" or "thumb2". Example:
989 MONO_CPU_ARCH="armv4 thumb" mono ...
993 \fBMONO_ARM_FORCE_SOFT_FLOAT\fR
994 When Mono is built with a soft float fallback on ARM and this variable is set to
995 "1", Mono will always emit soft float code, even if a VFP unit is detected.
997 \fBMONO_DISABLE_AIO\fR
998 If set, tells mono NOT to attempt using native asynchronous I/O services. In
999 that case, a default select/poll implementation is used. Currently only epoll()
1002 \fBMONO_DISABLE_MANAGED_COLLATION\fR
1003 If this environment variable is `yes', the runtime uses unmanaged
1004 collation (which actually means no culture-sensitive collation). It
1005 internally disables managed collation functionality invoked via the
1006 members of System.Globalization.CompareInfo class. Collation is
1009 \fBMONO_DISABLE_SHM\fR
1010 Unix only: If set, disables the shared memory files used for
1011 cross-process handles: process have only private handles. This means
1012 that process and thread handles are not available to other processes,
1013 and named mutexes, named events and named semaphores are not visible
1016 This is can also be enabled by default by passing the
1017 "--disable-shared-handles" option to configure.
1019 This is the default from mono 2.8 onwards.
1021 \fBMONO_DISABLE_SHARED_AREA\fR
1022 Unix only: If set, disable usage of shared memory for exposing
1023 performance counters. This means it will not be possible to both
1024 externally read performance counters from this processes or read
1025 those of external processes.
1028 When set, enables the use of a fully managed DNS resolver instead of the
1029 regular libc functions. This resolver performs much better when multiple
1030 queries are run in parallel.
1032 Note that /etc/nsswitch.conf will be ignored.
1034 \fBMONO_EGD_SOCKET\fR
1035 For platforms that do not otherwise have a way of obtaining random bytes
1036 this can be set to the name of a file system socket on which an egd or
1037 prngd daemon is listening.
1039 \fBMONO_ENABLE_SHM\fR
1040 Unix only: Enable support for cross-process handles. Cross-process
1041 handles are used to expose process handles, thread handles, named
1042 mutexes, named events and named semaphores across Unix processes.
1044 \fBMONO_ENV_OPTIONS\fR
1045 This environment variable allows you to pass command line arguments to
1046 a Mono process through the environment. This is useful for example
1047 to force all of your Mono processes to use LLVM or SGEN without having
1048 to modify any launch scripts.
1050 \fBMONO_ENV_OPTIONS\fR
1051 Used to pass extra options to the debugger agent in the runtime, as they were passed
1052 using --debugger-agent=.
1054 \fBMONO_EVENTLOG_TYPE\fR
1055 Sets the type of event log provider to use (for System.Diagnostics.EventLog).
1057 Possible values are:
1062 Persists event logs and entries to the local file system.
1064 The directory in which to persist the event logs, event sources and entries
1065 can be specified as part of the value.
1067 If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog"
1068 on unix and "%APPDATA%\mono\eventlog" on Windows.
1073 Uses the native win32 API to write events and registers event logs and
1074 event sources in the registry. This is only available on Windows.
1076 On Unix, the directory permission for individual event log and event source
1077 directories is set to 777 (with +t bit) allowing everyone to read and write
1078 event log entries while only allowing entries to be deleted by the user(s)
1083 Silently discards any events.
1086 The default is "null" on Unix (and versions of Windows before NT), and
1087 "win32" on Windows NT (and higher).
1090 \fBMONO_EXTERNAL_ENCODINGS\fR
1091 If set, contains a colon-separated list of text encodings to try when
1092 turning externally-generated text (e.g. command-line arguments or
1093 filenames) into Unicode. The encoding names come from the list
1094 provided by iconv, and the special case "default_locale" which refers
1095 to the current locale's default encoding.
1097 When reading externally-generated text strings UTF-8 is tried first,
1098 and then this list is tried in order with the first successful
1099 conversion ending the search. When writing external text (e.g. new
1100 filenames or arguments to new processes) the first item in this list
1101 is used, or UTF-8 if the environment variable is not set.
1103 The problem with using MONO_EXTERNAL_ENCODINGS to process your
1104 files is that it results in a problem: although its possible to get
1105 the right file name it is not necessarily possible to open the file.
1106 In general if you have problems with encodings in your filenames you
1107 should use the "convmv" program.
1109 \fBMONO_GC_PARAMS\fR
1110 When using Mono with the SGen garbage collector this variable controls
1111 several parameters of the collector. The variable's value is a comma
1112 separated list of words.
1116 \fBnursery-size=\fIsize\fR
1117 Sets the size of the nursery. The size is specified in bytes and must
1118 be a power of two. The suffixes `k', `m' and `g' can be used to
1119 specify kilo-, mega- and gigabytes, respectively. The nursery is the
1120 first generation (of two). A larger nursery will usually speed up the
1121 program but will obviously use more memory. The default nursery size
1124 \fBmajor=\fIcollector\fR Specifies which major collector to use.
1125 Options are `marksweep' for the Mark&Sweep collector, and
1126 `marksweep-conc' for concurrent Mark&Sweep. The non-concurrent
1127 Mark&Sweep collector is the default.
1129 \fBsoft-heap-limit=\fIsize\fR
1130 Once the heap size gets larger than this size, ignore what the default
1131 major collection trigger metric says and only allow four nursery size's
1132 of major heap growth between major collections.
1134 \fBevacuation-threshold=\fIthreshold\fR
1135 Sets the evacuation threshold in percent. This option is only available
1136 on the Mark&Sweep major collectors. The value must be an
1137 integer in the range 0 to 100. The default is 66. If the sweep phase of
1138 the collection finds that the occupancy of a specific heap block type is
1139 less than this percentage, it will do a copying collection for that block
1140 type in the next major collection, thereby restoring occupancy to close
1141 to 100 percent. A value of 0 turns evacuation off.
1143 \fB(no-)lazy-sweep\fR
1144 Enables or disables lazy sweep for the Mark&Sweep collector. If
1145 enabled, the sweeping of individual major heap blocks is done
1146 piecemeal whenever the need arises, typically during nursery
1147 collections. Lazy sweeping is enabled by default.
1149 \fB(no-)concurrent-sweep\fR
1150 Enables or disables concurrent sweep for the Mark&Sweep collector. If
1151 enabled, the iteration of all major blocks to determine which ones can
1152 be freed and which ones have to be kept and swept, is done
1153 concurrently with the running program. Concurrent sweeping is enabled
1156 \fBstack-mark=\fImark-mode\fR
1157 Specifies how application threads should be scanned. Options are
1158 `precise` and `conservative`. Precise marking allow the collector
1159 to know what values on stack are references and what are not.
1160 Conservative marking threats all values as potentially references
1161 and leave them untouched. Precise marking reduces floating garbage
1162 and can speed up nursery collection and allocation rate, it has
1163 the downside of requiring a significant extra memory per compiled
1164 method. The right option, unfortunately, requires experimentation.
1166 \fBsave-target-ratio=\fIratio\fR
1167 Specifies the target save ratio for the major collector. The collector
1168 lets a given amount of memory to be promoted from the nursery due to
1169 minor collections before it triggers a major collection. This amount
1170 is based on how much memory it expects to free. It is represented as
1171 a ratio of the size of the heap after a major collection.
1172 Valid values are between 0.1 and 2.0. The default is 0.5.
1173 Smaller values will keep the major heap size smaller but will trigger
1174 more major collections. Likewise, bigger values will use more memory
1175 and result in less frequent major collections.
1176 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1178 \fBdefault-allowance-ratio=\fIratio\fR
1179 Specifies the default allocation allowance when the calculated size
1180 is too small. The allocation allowance is how much memory the collector
1181 let be promoted before triggered a major collection.
1182 It is a ratio of the nursery size.
1183 Valid values are between 1.0 and 10.0. The default is 4.0.
1184 Smaller values lead to smaller heaps and more frequent major collections.
1185 Likewise, bigger values will allow the heap to grow faster but use
1186 more memory when it reaches a stable size.
1187 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1189 \fBminor=\fIminor-collector\fR
1190 Specifies which minor collector to use. Options are 'simple' which
1191 promotes all objects from the nursery directly to the old generation
1192 and 'split' which lets object stay longer on the nursery before promoting.
1194 \fBalloc-ratio=\fIratio\fR
1195 Specifies the ratio of memory from the nursery to be use by the alloc space.
1196 This only can only be used with the split minor collector.
1197 Valid values are integers between 1 and 100. Default is 60.
1199 \fBpromotion-age=\fIage\fR
1200 Specifies the required age of an object must reach inside the nursery before
1201 been promoted to the old generation. This only can only be used with the
1202 split minor collector.
1203 Valid values are integers between 1 and 14. Default is 2.
1205 \fB(no-)cementing\fR
1206 Enables or disables cementing. This can dramatically shorten nursery
1207 collection times on some benchmarks where pinned objects are referred
1208 to from the major heap.
1213 When using Mono with the SGen garbage collector this environment
1214 variable can be used to turn on various debugging features of the
1215 collector. The value of this variable is a comma separated list of
1216 words. Do not use these options in production.
1221 Sets the debug level to the specified number.
1223 \fBprint-allowance\fR
1224 After each major collection prints memory consumption for before and
1225 after the collection and the allowance for the minor collector, i.e. how
1226 much the heap is allowed to grow from minor collections before the next
1227 major collection is triggered.
1230 Gathers statistics on the classes whose objects are pinned in the
1231 nursery and for which global remset entries are added. Prints those
1232 statistics when shutting down.
1234 \fBcollect-before-allocs\fR
1236 \fBcheck-at-minor-collections\fR
1237 This performs a consistency check on minor collections and also clears
1238 the nursery at collection time, instead of the default, when buffers
1239 are allocated (clear-at-gc). The consistency check ensures that
1240 there are no major to minor references that are not on the remembered
1243 \fBmod-union-consistency-check\fR
1244 Checks that the mod-union cardtable is consistent before each
1245 finishing major collection pause. This check is only applicable to
1246 concurrent major collectors.
1248 \fBcheck-mark-bits\fR
1249 Checks that mark bits in the major heap are consistent at the end of
1250 each major collection. Consistent mark bits mean that if an object is
1251 marked, all objects that it had references to must also be marked.
1253 \fBcheck-nursery-pinned\fR
1254 After nursery collections, and before starting concurrent collections,
1255 check whether all nursery objects are pinned, or not pinned -
1256 depending on context. Does nothing when the split nursery collector
1259 \fBxdomain-checks\fR
1260 Performs a check to make sure that no references are left to an
1263 \fBclear-at-tlab-creation\fR
1264 Clears the nursery incrementally when the thread local allocation
1265 buffers (TLAB) are created. The default setting clears the whole
1268 \fBdebug-clear-at-tlab-creation\fR
1269 Clears the nursery incrementally when the thread local allocation
1270 buffers (TLAB) are created, but at GC time fills it with the byte
1271 `0xff`, which should result in a crash more quickly if
1272 `clear-at-tlab-creation` doesn't work properly.
1275 This clears the nursery at GC time instead of doing it when the thread
1276 local allocation buffer (TLAB) is created. The default is to clear
1277 the nursery at TLAB creation time.
1280 Don't do minor collections. If the nursery is full, a major collection
1281 is triggered instead, unless it, too, is disabled.
1284 Don't do major collections.
1286 \fBconservative-stack-mark\fR
1287 Forces the GC to scan the stack conservatively, even if precise
1288 scanning is available.
1290 \fBno-managed-allocator\fR
1291 Disables the managed allocator.
1293 \fBcheck-scan-starts\fR
1294 If set, does a plausibility check on the scan_starts before and after each collection
1296 \fBverify-nursery-at-minor-gc\fR
1297 If set, does a complete object walk of the nursery at the start of each minor collection.
1299 \fBdump-nursery-at-minor-gc\fR
1300 If set, dumps the contents of the nursery at the start of each minor collection. Requires
1301 verify-nursery-at-minor-gc to be set.
1303 \fBheap-dump=\fIfile\fR
1304 Dumps the heap contents to the specified file. To visualize the
1305 information, use the mono-heapviz tool.
1307 \fBbinary-protocol=\fIfile\fR
1308 Outputs the debugging output to the specified file. For this to
1309 work, Mono needs to be compiled with the BINARY_PROTOCOL define on
1310 sgen-gc.c. You can then use this command to explore the output
1312 sgen-grep-binprot 0x1234 0x5678 < file
1315 \fBnursery-canaries\fR
1316 If set, objects allocated in the nursery are suffixed with a canary (guard)
1317 word, which is checked on each minor collection. Can be used to detect/debug
1318 heap corruption issues.
1321 \fBdo-not-finalize\fR
1322 If enabled, finalizers will not be run. Everything else will be
1323 unaffected: finalizable objects will still be put into the
1324 finalization queue where they survive until they're scheduled to
1325 finalize. Once they're not in the queue anymore they will be
1326 collected regularly.
1329 \fBlog-finalizers\fR
1330 Log verbosely around the finalization process to aid debugging.
1334 \fBMONO_GAC_PREFIX\fR
1335 Provides a prefix the runtime uses to look for Global Assembly Caches.
1336 Directories are separated by the platform path separator (colons on
1337 unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
1338 install. Or to the directory provided in the gacutil /gacdir command. Example:
1339 .B /home/username/.mono:/usr/local/mono/
1342 Enables some filename rewriting support to assist badly-written
1343 applications that hard-code Windows paths. Set to a colon-separated
1344 list of "drive" to strip drive letters, or "case" to do
1345 case-insensitive file matching in every directory in a path. "all"
1346 enables all rewriting methods. (Backslashes are always mapped to
1347 slashes if this variable is set to a valid option).
1350 For example, this would work from the shell:
1353 MONO_IOMAP=drive:case
1357 If you are using mod_mono to host your web applications, you can use
1360 directive instead, like this:
1363 MonoIOMAP <appalias> all
1366 See mod_mono(8) for more details.
1368 Additionally. Mono includes a profiler module which allows one to track what
1369 adjustements to file paths IOMAP code needs to do. The tracking code reports
1370 the managed location (full stack trace) from which the IOMAP-ed call was made and,
1371 on process exit, the locations where all the IOMAP-ed strings were created in
1372 managed code. The latter report is only approximate as it is not always possible
1373 to estimate the actual location where the string was created. The code uses simple
1374 heuristics - it analyzes stack trace leading back to the string allocation location
1375 and ignores all the managed code which lives in assemblies installed in GAC as well as in the
1376 class libraries shipped with Mono (since they are assumed to be free of case-sensitivity
1377 issues). It then reports the first location in the user's code - in most cases this will be
1378 the place where the string is allocated or very close to the location. The reporting code
1379 is implemented as a custom profiler module (see the "PROFILING" section) and can be loaded
1380 in the following way:
1385 mono --profile=iomap yourapplication.exe
1388 Note, however, that Mono currently supports only one profiler module
1392 When Mono is using the LLVM code generation backend you can use this
1393 environment variable to pass code generation options to the LLVM
1396 \fBMONO_MANAGED_WATCHER\fR
1397 If set to "disabled", System.IO.FileSystemWatcher will use a file watcher
1398 implementation which silently ignores all the watching requests.
1399 If set to any other value, System.IO.FileSystemWatcher will use the default
1400 managed implementation (slow). If unset, mono will try to use inotify, FAM,
1401 Gamin, kevent under Unix systems and native API calls on Windows, falling
1402 back to the managed implementation on error.
1404 \fBMONO_MESSAGING_PROVIDER\fR
1405 Mono supports a plugin model for its implementation of System.Messaging making
1406 it possible to support a variety of messaging implementations (e.g. AMQP, ActiveMQ).
1407 To specify which messaging implementation is to be used the evironement variable
1408 needs to be set to the full class name for the provider. E.g. to use the RabbitMQ based
1409 AMQP implementation the variable should be set to:
1412 Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
1415 If set causes the mono process to be bound to a single processor. This may be
1416 useful when debugging or working around race conditions.
1419 Disable inlining of thread local accesses. Try setting this if you get a segfault
1420 early on in the execution of mono.
1423 Provides a search path to the runtime where to look for library
1424 files. This is a tool convenient for debugging applications, but
1425 should not be used by deployed applications as it breaks the assembly
1426 loader in subtle ways.
1428 Directories are separated by the platform path separator (colons on unix). Example:
1429 .B /home/username/lib:/usr/local/mono/lib
1431 Relative paths are resolved based on the launch-time current directory.
1433 Alternative solutions to MONO_PATH include: installing libraries into
1434 the Global Assembly Cache (see gacutil(1)) or having the dependent
1435 libraries side-by-side with the main executable.
1437 For a complete description of recommended practices for application
1439 http://www.mono-project.com/docs/getting-started/application-deployment/
1442 Experimental RTC support in the statistical profiler: if the user has
1443 the permission, more accurate statistics are gathered. The MONO_RTC
1444 value must be restricted to what the Linux rtc allows: power of two
1445 from 64 to 8192 Hz. To enable higher frequencies like 4096 Hz, run as root:
1448 echo 4096 > /proc/sys/dev/rtc/max-user-freq
1455 MONO_RTC=4096 mono --profiler=default:stat program.exe
1459 \fBMONO_SHARED_DIR\fR
1460 If set its the directory where the ".wapi" handle state is stored.
1461 This is the directory where the Windows I/O Emulation layer stores its
1462 shared state data (files, events, mutexes, pipes). By default Mono
1463 will store the ".wapi" directory in the users's home directory.
1465 \fBMONO_SHARED_HOSTNAME\fR
1466 Uses the string value of this variable as a replacement for the host name when
1467 creating file names in the ".wapi" directory. This helps if the host name of
1468 your machine is likely to be changed when a mono application is running or if
1469 you have a .wapi directory shared among several different computers.
1471 Mono typically uses the hostname to create the files that are used to
1472 share state across multiple Mono processes. This is done to support
1473 home directories that might be shared over the network.
1475 \fBMONO_STRICT_IO_EMULATION\fR
1476 If set, extra checks are made during IO operations. Currently, this
1477 includes only advisory locks around file writes.
1480 The name of the theme to be used by Windows.Forms. Available themes today
1481 include "clearlooks", "nice" and "win32".
1483 The default is "win32".
1485 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1486 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1487 avoid a new negotiation between the client and a server. Negotiation are very
1488 CPU intensive so an application-specific custom value may prove useful for
1489 small embedded systems.
1491 The default is 180 seconds.
1493 \fBMONO_THREADS_PER_CPU\fR
1494 The minimum number of threads in the general threadpool will be
1495 MONO_THREADS_PER_CPU * number of CPUs. The default value for this
1498 \fBMONO_XMLSERIALIZER_THS\fR
1499 Controls the threshold for the XmlSerializer to produce a custom
1500 serializer for a given class instead of using the Reflection-based
1501 interpreter. The possible values are `no' to disable the use of a
1502 custom serializer or a number to indicate when the XmlSerializer
1503 should start serializing. The default value is 50, which means that
1504 the a custom serializer will be produced on the 50th use.
1506 \fBMONO_X509_REVOCATION_MODE\fR
1507 Sets the revocation mode used when validating a X509 certificate chain (https,
1508 ftps, smtps...). The default is 'nocheck', which performs no revocation check
1509 at all. The other possible values are 'offline', which performs CRL check (not
1510 implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
1511 status (not implemented yet).
1512 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1514 \fBMONO_ASPNET_NODELETE\fR
1515 If set to any value, temporary source files generated by ASP.NET support
1516 classes will not be removed. They will be kept in the user's temporary
1520 If set, enables some features of the runtime useful for debugging.
1521 This variable should contain a comma separated list of debugging options.
1522 Currently, the following options are supported:
1526 \fBalign-small-structs\fR
1527 Enables small structs alignment to 4/8 bytes.
1529 \fBarm-use-fallback-tls\fR
1530 When this option is set on ARM, a fallback TLS will be used instead
1531 of the default fast TLS.
1533 \fBbreak-on-unverified\fR
1534 If this variable is set, when the Mono VM runs into a verification
1535 problem, instead of throwing an exception it will break into the
1536 debugger. This is useful when debugging verifier problems
1539 This option can be used to get more detailed information from
1540 InvalidCast exceptions, it will provide information about the types
1543 \fBcheck-pinvoke-callconv\fR
1544 This option causes the runtime to check for calling convention
1545 mismatches when using pinvoke, i.e. mixing cdecl/stdcall. It only
1546 works on windows. If a mismatch is detected, an
1547 ExecutionEngineException is thrown.
1549 \fBcollect-pagefault-stats\fR
1550 Collects information about pagefaults. This is used internally to
1551 track the number of page faults produced to load metadata. To display
1552 this information you must use this option with "--stats" command line
1555 \fBdebug-domain-unload\fR
1556 When this option is set, the runtime will invalidate the domain memory
1557 pool instead of destroying it.
1559 \fBdont-free-domains\fR
1560 This is an Optimization for multi-AppDomain applications (most
1561 commonly ASP.NET applications). Due to internal limitations Mono,
1562 Mono by default does not use typed allocations on multi-appDomain
1563 applications as they could leak memory when a domain is unloaded.
1565 Although this is a fine default, for applications that use more than
1566 on AppDomain heavily (for example, ASP.NET applications) it is worth
1567 trading off the small leaks for the increased performance
1568 (additionally, since ASP.NET applications are not likely going to
1569 unload the application domains on production systems, it is worth
1570 using this feature).
1572 \fBdyn-runtime-invoke\fR
1573 Instructs the runtime to try to use a generic runtime-invoke wrapper
1574 instead of creating one invoke wrapper.
1576 \fBexplicit-null-checks\fR
1577 Makes the JIT generate an explicit NULL check on variable dereferences
1578 instead of depending on the operating system to raise a SIGSEGV or
1579 another form of trap event when an invalid memory location is
1583 Equivalent to setting the \fBMONO_XDEBUG\fR variable, this emits
1584 symbols into a shared library as the code is JITed that can be loaded
1585 into GDB to inspect symbols.
1587 \fBgen-seq-points\fR
1588 Automatically generates sequence points where the
1589 IL stack is empty. These are places where the debugger can set a
1592 \fBgen-compact-seq-points\fR
1593 This option generates sequence points data that maps native offsets to
1594 IL offsets. Sequence point data is used to display IL offset in
1595 stacktraces. Stacktraces with IL offsets can be symbolicated using
1596 mono-symbolicate tool.
1599 Captures the interrupt signal (Control-C) and displays a stack trace
1600 when pressed. Useful to find out where the program is executing at a
1601 given point. This only displays the stack trace of a single thread.
1604 Instructs the runtime to initialize the stack with
1605 some known values (0x2a on x86-64) at the start of a method to assist
1606 in debuggin the JIT engine.
1608 \fBkeep-delegates\fR
1609 This option will leak delegate trampolines that are no longer
1610 referenced as to present the user with more information about a
1611 delegate misuse. Basically a delegate instance might be created,
1612 passed to unmanaged code, and no references kept in managed code,
1613 which will garbage collect the code. With this option it is possible
1614 to track down the source of the problems.
1616 \fBno-gdb-backtrace\fR
1617 This option will disable the GDB backtrace emitted by the runtime
1618 after a SIGSEGV or SIGABRT in unmanaged code.
1620 \fBpartial-sharing\fR
1621 When this option is set, the runtime can share generated code between
1622 generic types effectively reducing the amount of code generated.
1624 \fBreverse-pinvoke-exceptions
1625 This option will cause mono to abort with a descriptive message when
1626 during stack unwinding after an exception it reaches a native stack
1627 frame. This happens when a managed delegate is passed to native code,
1628 and the managed delegate throws an exception. Mono will normally try
1629 to unwind the stack to the first (managed) exception handler, and it
1630 will skip any native stack frames in the process. This leads to
1631 undefined behaviour (since mono doesn't know how to process native
1632 frames), leaks, and possibly crashes too.
1634 \fBsingle-imm-size\fR
1635 This guarantees that each time managed code is compiled the same
1636 instructions and registers are used, regardless of the size of used
1639 \fBsoft-breakpoints\fR
1640 This option allows using single-steps and breakpoints in hardware
1641 where we cannot do it with signals.
1643 \fBsuspend-on-sigsegv\fR
1644 This option will suspend the program when a native SIGSEGV is received.
1645 This is useful for debugging crashes which do not happen under gdb,
1646 since a live process contains more information than a core file.
1648 \fBsuspend-on-exception\fR
1649 This option will suspend the program when an exception occurs.
1651 \fBsuspend-on-unhandled\fR
1652 This option will suspend the program when an unhadled exception occurs.
1656 \fBMONO_LOG_LEVEL\fR
1657 The logging level, possible values are `error', `critical', `warning',
1658 `message', `info' and `debug'. See the DEBUGGING section for more
1662 Controls the domain of the Mono runtime that logging will apply to.
1663 If set, the log mask is changed to the set value. Possible values are
1664 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1665 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
1666 "security" (e.g. Moonlight CoreCLR support) and "all".
1667 The default value is "all". Changing the mask value allows you to display only
1668 messages for a certain component. You can use multiple masks by comma
1669 separating them. For example to see config file messages and assembly loader
1670 messages set you mask to "asm,cfg".
1673 Used for runtime tracing of method calls. The format of the comma separated
1682 disabled Trace output off upon start.
1685 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1687 \fBMONO_TRACE_LISTENER\fR
1688 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1689 print the output of the System.Diagnostics Trace and Debug classes.
1690 It can be set to a filename, and to Console.Out or Console.Error to display
1691 output to standard output or standard error, respectively. If it's set to
1692 Console.Out or Console.Error you can append an optional prefix that will
1693 be used when writing messages like this: Console.Error:MyProgramName.
1694 See the System.Diagnostics.DefaultTraceListener documentation for more
1697 \fBMONO_WCF_TRACE\fR
1698 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.
1700 \fBMONO_XEXCEPTIONS\fR
1701 This throws an exception when a X11 error is encountered; by default a
1702 message is displayed but execution continues
1704 \fBMONO_XMLSERIALIZER_DEBUG\fR
1705 Set this value to 1 to prevent the serializer from removing the
1706 temporary files that are created for fast serialization; This might
1707 be useful when debugging.
1710 This is used in the System.Windows.Forms implementation when running
1711 with the X11 backend. This is used to debug problems in Windows.Forms
1712 as it forces all of the commands send to X11 server to be done
1713 synchronously. The default mode of operation is asynchronous which
1714 makes it hard to isolate the root of certain problems.
1716 \fBMONO_GENERIC_SHARING\fR
1717 This environment variable controls the kind of generic sharing used.
1718 This variable is used by internal JIT developers and should not be
1719 changed in production. Do not use it.
1721 The variable controls which classes will have generic code sharing
1724 Permissible values are:
1728 All generated code can be shared.
1731 Only the classes in System.Collections.Generic will have its code
1732 shared (this is the default value).
1735 Only code in corlib will have its code shared.
1738 No generic code sharing will be performed.
1741 Generic code sharing by default only applies to collections. The
1742 Mono JIT by default turns this on.
1745 When the the MONO_XDEBUG env var is set, debugging info for JITted
1746 code is emitted into a shared library, loadable into gdb. This enables,
1747 for example, to see managed frame names on gdb backtraces.
1749 \fBMONO_VERBOSE_METHOD\fR
1750 Enables the maximum JIT verbosity for the specified method. This is
1751 very helpfull to diagnose a miscompilation problems of a specific
1754 \fBMONO_VERBOSE_HWCAP\fR
1755 If set, makes the JIT output information about detected CPU features
1756 (such as SSE, CMOV, FCMOV, etc) to stdout.
1758 \fBMONO_CONSERVATIVE_HWCAP\fR
1759 If set, the JIT will not perform any hardware capability detection. This
1760 may be useful to pinpoint the cause of JIT issues. This is the default
1761 when Mono is built as an AOT cross compiler, so that the generated code
1762 will run on most hardware.
1764 If you want to use Valgrind, you will find the file `mono.supp'
1765 useful, it contains the suppressions for the GC which trigger
1766 incorrect warnings. Use it like this:
1768 valgrind --suppressions=mono.supp mono ...
1771 On some platforms, Mono can expose a set of DTrace probes (also known
1772 as user-land statically defined, USDT Probes).
1774 They are defined in the file `mono.d'.
1776 .B ves-init-begin, ves-init-end
1778 Begin and end of runtime initialization.
1780 .B method-compile-begin, method-compile-end
1782 Begin and end of method compilation.
1783 The probe arguments are class name, method name and signature,
1784 and in case of method-compile-end success or failure of compilation.
1788 Begin and end of Garbage Collection.
1790 To verify the availability of the probes, run:
1792 dtrace -P mono'$target' -l -c mono
1795 Mono's Ping implementation for detecting network reachability can
1796 create the ICMP packets itself without requiring the system ping
1797 command to do the work. If you want to enable this on Linux for
1798 non-root users, you need to give the Mono binary special permissions.
1800 As root, run this command:
1802 # setcap cap_net_raw=+ep /usr/bin/mono
1805 On Unix assemblies are loaded from the installation lib directory. If you set
1806 `prefix' to /usr, the assemblies will be located in /usr/lib. On
1807 Windows, the assemblies are loaded from the directory where mono and
1810 .B ~/.mono/aot-cache
1812 The directory for the ahead-of-time compiler demand creation
1813 assemblies are located.
1815 .B /etc/mono/config, ~/.mono/config
1817 Mono runtime configuration file. See the mono-config(5) manual page
1818 for more information.
1820 .B ~/.config/.mono/certs, /usr/share/.mono/certs
1822 Contains Mono certificate stores for users / machine. See the certmgr(1)
1823 manual page for more information on managing certificate stores and
1824 the mozroots(1) page for information on how to import the Mozilla root
1825 certificates into the Mono certificate store.
1827 .B ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
1829 Files in this directory allow a user to customize the configuration
1830 for a given system assembly, the format is the one described in the
1831 mono-config(5) page.
1833 .B ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
1835 Contains Mono cryptographic keypairs for users / machine. They can be
1836 accessed by using a CspParameters object with DSACryptoServiceProvider
1837 and RSACryptoServiceProvider classes.
1839 .B ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
1841 Contains Mono isolated storage for non-roaming users, roaming users and
1842 local machine. Isolated storage can be accessed using the classes from
1843 the System.IO.IsolatedStorage namespace.
1845 .B <assembly>.config
1847 Configuration information for individual assemblies is loaded by the
1848 runtime from side-by-side files with the .config files, see the
1849 http://www.mono-project.com/Config for more information.
1851 .B Web.config, web.config
1853 ASP.NET applications are configured through these files, the
1854 configuration is done on a per-directory basis. For more information
1855 on this subject see the http://www.mono-project.com/Config_system.web
1858 Mailing lists are listed at the
1859 http://www.mono-project.com/community/help/mailing-lists/
1861 http://www.mono-project.com
1864 certmgr(1), csharp(1), mcs(1), mdb(1), monocov(1), monodis(1),
1865 mono-config(5), mozroots(1), mprof-report(1), pdb2mdb(1), xsp(1), mod_mono(8).
1867 For more information on AOT:
1868 http://www.mono-project.com/docs/advanced/aot/
1870 For ASP.NET-related documentation, see the xsp(1) manual page
projects / mono.git / blob