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 loads the specified
29 is an ECMA assembly. They typically have a .exe or .dll extension.
31 These executables can reference additionaly functionality in the form
32 of assembly references. By default those assembly references are
33 resolved as follows: the \fBmscorlib.dll\fR is resolved from the
34 system profile that is configured by Mono, and other assemblies are
35 loaded from the Global Assembly Cache (GAC).
37 The runtime contains a native code generator that transforms the
38 Common Intermediate Language into native code.
40 The code generator can operate in two modes: just in time compilation
41 (JIT) or ahead of time compilation (AOT). Since code can be
42 dynamically loaded, the runtime environment and the JIT are always
43 present, even if code is compiled ahead of time.
45 The runtime provides a number of configuration options for running
46 applications, for developing and debugging, and for testing and
47 debugging the runtime itself.
49 The \fImono\fP command uses the moving and generational SGen garbage collector
50 while the \fImono-boehm\fP command uses the conservative Boehm
53 On Unix-based systems, Mono provides a mechanism to emulate the
54 Windows-style file access, this includes providing a case insensitive
55 view of the file system, directory separator mapping (from \\ to /) and
56 stripping the drive letters.
58 This functionality is enabled by setting the
60 environment variable to one of
65 See the description for
67 in the environment variables section for more details.
68 .SH METHOD DESCRIPTIONS
69 A number of diagnostic command line options take as argument a method
70 description. A method description is a textual representation that
71 can be used to uniquely identify a method. The syntax is as follows:
73 [namespace]classname:methodname[(arguments)]
76 The values in brackets are optional, like the namespace and the
77 arguments. The arguments themselves are either empty, or a
78 comma-separated list of arguments. Both the
82 can be set to the special value '*' to match any values (Unix shell
83 users should escape the argument to avoid the shell interpreting
86 The arguments, if present should be a comma separated list of types
87 either a full typename, or for built-in types it should use the
88 low-level ILAsm type names for the built-in types,
89 like 'void', 'char', 'bool', 'byte', 'sbyte', 'uint16', 'int16', 'uint',
90 'int', 'ulong', 'long', 'uintptr', 'intptr', 'single', 'double', 'string', 'object'.
92 Pointer types should be the name of the type, followed by a '*',
93 arrays should be the typename followed by '[' one or more commas (to
94 indicate the rank of the array), and ']'.
96 Generic values should use '<', one or more type names, separated by
97 both a comma and a space and '>'.
99 By-reference arguments should include a "&" after the typename.
103 *:ctor(int) // All constructors that take an int as an argument
104 *:Main // Methods named Main in any class
105 *:Main(string[]) // Methods named Main that take a string array in any class
108 The following options are available:
110 \fB--aot\fR, \fB--aot[=options]\fR
111 This option is used to precompile the CIL code in the specified
112 assembly to native code. The generated code is stored in a file with
113 the extension .so. This file will be automatically picked up by the
114 runtime when the assembly is executed.
116 Ahead-of-Time compilation is most useful if you use it in combination
117 with the -O=all,-shared flag which enables all of the optimizations in
118 the code generator to be performed. Some of those optimizations are
119 not practical for Just-in-Time compilation since they might be very
122 Unlike the .NET Framework, Ahead-of-Time compilation will not generate
123 domain independent code: it generates the same code that the
124 Just-in-Time compiler would produce. Since most applications use a
125 single domain, this is fine. If you want to optimize the generated
126 code for use in multi-domain applications, consider using the
129 This pre-compiles the methods, but the original assembly is still
130 required to execute as this one contains the metadata and exception
131 information which is not available on the generated file. When
132 precompiling code, you might want to compile with all optimizations
133 (-O=all). Pre-compiled code is position independent code.
135 Precompilation is just a mechanism to reduce startup time, increase
136 code sharing across multiple mono processes and avoid just-in-time
137 compilation program startup costs. The original assembly must still
138 be present, as the metadata is contained there.
140 AOT code typically can not be moved from one computer to another
141 (CPU-specific optimizations that are detected at runtime) so you
142 should not try to move the pre-generated assemblies or package the
143 pre-generated assemblies for deployment.
145 A few options are available as a parameter to the
147 command line option. The options are separated by commas, and more
148 than one can be specified:
153 Instructs the AOT compiler to output assembly code instead of an
156 .I bind-to-runtime-version
158 If specified, forces the generated AOT files to be bound to the
159 runtime version of the compiling Mono. This will prevent the AOT
160 files from being consumed by a different Mono runtime.
162 .I data-outfile=FILE.dll.aotdata
164 This instructs the AOT code generator to output certain data
165 constructs into a separate file. This can reduce the executable
166 images some five to twenty percent. Developers need to then ship the
167 resulting aotdata as a resource and register a hook to load the data
168 on demand by using the
169 .I mono_install_load_aot_data_hook
174 When this option is specified, icalls (internal calls made from the
175 standard library into the mono runtime code) are invoked directly
176 instead of going through the operating system symbol lookup operation.
177 This requires use of the
183 When this option is specified, P/Invoke methods are invoked directly
184 instead of going through the operating system symbol lookup operation.
185 This requires use of the
190 Instructs the AOT compiler to emit DWARF debugging information. When
191 used together with the nodebug option, only DWARF debugging
192 information is emitted, but not the information that can be used at
197 This creates binaries which can be used with the --full-aot option.
201 This creates binaries which can be used with the --hybrid-aot option.
204 AOT will be performed with the LLVM backend instead of the Mono backend where possible. This will be slower to compile but most likely result in a performance improvement.
207 AOT will be performed with the LLVM backend exclusively and the Mono backend will not be used. The only output in this mode will be the bitcode file normally specified with the
211 automatically enables the
215 options. This feature is experimental.
217 .I llvm-outfile=[filename]
218 Gives the path for the temporary LLVM bitcode file created during AOT.
220 Each AOT module will typically contain the code for inflated methods and wrappers that
221 are called by code in that module. In dedup mode, we identify and skip compiling all of those
222 methods. When using this mode with fullaot, dedup-include is required or these methods will
225 .I dedup-include=[filename]
226 In dedup-include mode, we are in the pass of compilation where we compile the methods
227 that we had previously skipped. All of them are emitted into the assembly that is passed
228 as this option. We consolidate the many duplicate skipped copies of the same method into one.
232 Print the architecture the AOT in this copy of Mono targets and quit.
235 Generates all required wrappers, so that it is possible to run --interpreter without
236 any code generation at runtime. This option only makes sense with \fBmscorlib.dll\fR.
240 mono_jit_set_aot_mode (MONO_AOT_MODE_INTERP);
245 Additional flags to pass to the C linker (if the current AOT mode calls for invoking it).
247 .I llvm-path=<PREFIX>
248 Same for the llvm tools 'opt' and 'llc'.
251 Instructs the AOT compiler to generate offline sequence points .msym files.
252 The generated .msym files will be stored into a subfolder of <PATH> named as the
256 Use the GNU style target triple <TRIPLE> to determine some code generation options, i.e.
257 --mtriple=armv7-linux-gnueabi will generate code that targets ARMv7. This is currently
258 only supported by the ARM backend. In LLVM mode, this triple is passed on to the LLVM
261 .I nimt-trampolines=[number]
262 When compiling in full aot mode, the IMT trampolines must be precreated
263 in the AOT image. You can add additional method trampolines with this argument.
266 .I ngsharedvt-trampolines=[number]
267 When compiling in full aot mode, the value type generic sharing trampolines must be precreated
268 in the AOT image. You can add additional method trampolines with this argument.
272 Instructs the AOT compiler to not output any debugging information.
275 This prevents the AOT compiler from generating a direct calls to a
276 method. The AOT compiler usually generates direct calls for certain
277 methods that do not require going through the PLT (for example,
278 methods that are known to not require a hook like a static
279 constructor) or call into simple internal calls.
281 .I nrgctx-trampolines=[number]
282 When compiling in full aot mode, the generic sharing trampolines must be precreated
283 in the AOT image. You can add additional method trampolines with this argument.
286 .I nrgctx-fetch-trampolines=[number]
287 When compiling in full aot mode, the generic sharing fetch trampolines must be precreated
288 in the AOT image. You can add additional method trampolines with this argument.
291 .I ntrampolines=[number]
292 When compiling in full aot mode, the method trampolines must be precreated
293 in the AOT image. You can add additional method trampolines with this argument.
296 .I outfile=[filename]
297 Instructs the AOT compiler to save the output to the specified file.
299 .I print-skipped-methods
300 If the AOT compiler cannot compile a method for any reason, enabling this flag
301 will output the skipped methods to the console.
304 Specify a file to use for profile-guided optimization. See the \fBAOT profiler\fR sub-section. To specify multiple files, include the
306 option multiple times.
309 AOT *only* the methods described in the files specified with the
311 option. See the \fBAOT profiler\fR sub-section.
313 .I readonly-value=namespace.typename.fieldname=type/value
314 Override the value of a static readonly field. Usually, during JIT
315 compilation, the static constructor is ran eagerly, so the value of
316 a static readonly field is known at compilation time and the compiler
317 can do a number of optimizations based on it. During AOT, instead, the static
318 constructor can't be ran, so this option can be used to set the value of such
319 a field and enable the same set of optimizations.
320 Type can be any of i1, i2, i4 for integers of the respective sizes (in bytes).
321 Note that signed/unsigned numbers do not matter here, just the storage size.
322 This option can be specified multiple times and it doesn't prevent the static
323 constructor for the type defining the field to execute with the usual rules
324 at runtime (hence possibly computing a different value for the field).
326 .I save-temps,keep-temps
327 Instructs the AOT compiler to keep temporary files.
330 This instructs the compiler to generate sequence point checks that
331 allow Mono's soft debugger to debug applications even on systems where
332 it is not possible to set breakpoints or to single step (certain
333 hardware configurations like the cell phones and video gaming
337 Create an ELF object file (.o) or .s file which can be statically linked into an
338 executable when embedding the mono runtime. When this option is used, the object file
339 needs to be registered with the embedded runtime using the mono_aot_register_module
340 function which takes as its argument the mono_aot_module_<ASSEMBLY NAME>_info global
341 symbol from the object file:
344 extern void *mono_aot_module_hello_info;
346 mono_aot_register_module (mono_aot_module_hello_info);
351 Print various stats collected during AOT compilation.
354 Explicitly specify path to store temporary files created during AOT compilation.
357 This is an experimental option for the AOT compiler to use multiple threads
358 when compiling the methods.
360 .I tool-prefix=<PREFIX>
361 Prepends <PREFIX> to the name of tools ran by the AOT compiler, i.e. 'as'/'ld'. For
362 example, --tool=prefix=arm-linux-gnueabi- will make the AOT compiler run
363 'arm-linux-gnueabi-as' instead of 'as'.
366 Prints additional information about type loading failures.
368 .I write-symbols,no-write-symbols
369 Instructs the AOT compiler to emit (or not emit) debug symbol information.
371 For more information about AOT, see: http://www.mono-project.com/docs/advanced/aot/
374 \fB--aot-path=PATH\fR
375 List of additional directories to search for AOT images.
377 \fB--apply-bindings=FILE\fR
378 Apply the assembly bindings from the specified configuration file when running
379 the AOT compiler. This is useful when compiling an auxiliary assembly that is
380 referenced by a main assembly that provides a configuration file. For example,
381 if app.exe uses lib.dll then in order to make the assembly bindings from
382 app.exe.config available when compiling lib.dll ahead of time, use:
384 mono --apply-bindings=app.exe.config --aot lib.dll
387 \fB--assembly-loader=MODE\fR
388 If mode is \fBstrict\fR, Mono will check that the public key token, culture and version
389 of a candidate assembly matches the requested strong name. If mode is \fBlegacy\fR, as
390 long as the name matches, the candidate will be allowed. \fBstrict\fR is the behavior
391 consistent with .NET Framework but may break some existing mono-based applications.
392 The default is \fBlegacy\fR.
394 \fB--attach=[options]\fR
395 Currently the only option supported by this command line argument is
396 \fBdisable\fR which disables the attach functionality.
398 \fB--config filename\fR
399 Load the specified configuration file instead of the default one(s).
400 The default files are /etc/mono/config and ~/.mono/config or the file
401 specified in the MONO_CONFIG environment variable, if set. See the
402 mono-config(5) man page for details on the format of this file.
404 \fB--debugger-agent=[options]\fR
405 This instructs the Mono runtime to
406 start a debugging agent inside the Mono runtime and connect it to a
407 client user interface will control the Mono process.
408 This option is typically used by IDEs, like the MonoDevelop or Visual Studio IDEs.
410 The configuration is specified using one of more of the following options:
416 Use this option to specify the IP address where your debugger client is
421 Specifies the diagnostics log level for
425 Used to specify the file where the log will be stored, it defaults to
429 Defaults to no, with the default option Mono will actively connect to the
430 host/port configured with the \fBaddress\fR option. If you set it to 'y', it
431 instructs the Mono runtime to start debugging in server mode, where Mono
432 actively waits for the debugger front end to connect to the Mono process.
433 Mono will print out to stdout the IP address and port where it is listening.
436 If set to yes, Mono will call \fBsetpgid(0, 0)\fR on startup, if that function
437 is available on the system. This is useful for ensuring that signals delivered
438 to a process that is executing the debuggee are not propagated to the debuggee,
439 e.g. when Ctrl-C sends \fBSIGINT\fR to the \fBsdb\fR tool.
442 Defaults to yes, with the default option Mono will suspend the vm on startup
443 until it connects successfully to a debugger front end. If you set it to 'n', in
444 conjunction with \fBserver=y\fR, it instructs the Mono runtime to run as normal,
445 while caching metadata to send to the debugger front end on connection..
447 .I transport=transport_name
449 This is used to specify the transport that the debugger will use to
450 communicate. It must be specified and currently requires this to
456 Configures the virtual machine to be better suited for desktop
457 applications. Currently this sets the GC system to avoid expanding
458 the heap as much as possible at the expense of slowing down garbage
462 This flag instructs the Mono runtime to not
463 generate any code at runtime and depend exclusively on the code
464 generated from using mono --aot=full previously. This is useful for
465 platforms that do not permit dynamic code generation, or if you need
466 to run assemblies that have been stripped of IL (for example using
469 Notice that this feature will abort execution at runtime if a codepath
470 in your program, or Mono's class libraries attempts to generate code
471 dynamically. You should test your software upfront and make sure that
472 you do not use any dynamic features.
474 \fB--gc=boehm\fR, \fB--gc=sgen\fR
475 Selects the Garbage Collector engine for Mono to use, Boehm or SGen.
476 Currently this merely ensures that you are running either the
477 \fImono\fR or \fImono-sgen\fR commands. This flag can be set in the
478 \fBMONO_ENV_OPTIONS\fR environment variable to force all of your child
479 processes to use one particular kind of GC with the Mono runtime.
481 \fB--gc-debug=[options]\fR
482 Command line equivalent of the \fBMONO_GC_DEBUG\fR environment variable.
484 \fB--gc-params=[options]\fR
485 Command line equivalent of the \fBMONO_GC_PARAMS\fR environment variable.
487 \fB--arch=32\fR, \fB--arch=64\fR
488 (Mac OS X only): Selects the bitness of the Mono binary used, if
489 available. If the binary used is already for the selected bitness, nothing
490 changes. If not, the execution switches to a binary with the selected
491 bitness suffix installed side by side (for example, '/bin/mono --arch=64'
492 will switch to '/bin/mono64' iff '/bin/mono' is a 32-bit build).
494 \fB--help\fR, \fB-h\fR
495 Displays usage instructions.
498 The Mono runtime will use its interpreter to execute a given assembly.
499 The interpreter is usually slower than the JIT, but it can be useful on
500 platforms where code generation at runtime is not allowed.
503 This flag allows the Mono runtime to run assemblies
504 that have been stripped of IL, for example using mono-cil-strip. For this to
505 work, the assembly must have been AOT compiled with --aot=hybrid.
507 This flag is similar to --full-aot, but it does not disable the JIT. This means
508 you can use dynamic features such as System.Reflection.Emit.
511 If the Mono runtime has been compiled with LLVM support (not available
512 in all configurations), Mono will use the LLVM optimization and code
513 generation engine to JIT or AOT compile.
515 For more information, consult: http://www.mono-project.com/docs/advanced/mono-llvm/
518 When using a Mono that has been compiled with LLVM support, it forces
519 Mono to fallback to its JIT engine and not use the LLVM backend.
521 \fB--optimize=MODE\fR, \fB-O=MODE\fR
522 MODE is a comma separated list of optimizations. They also allow
523 optimizations to be turned off by prefixing the optimization name with
526 In general, Mono has been tuned to use the default set of flags,
527 before using these flags for a deployment setting, you might want to
528 actually measure the benefits of using them.
530 The following optimization flags are implemented in the core engine:
532 abcrem Array bound checks removal
533 all Turn on all optimizations
534 aot Usage of Ahead Of Time compiled code
535 branch Branch optimizations
536 cfold Constant folding
537 cmov Conditional moves [arch-dependency]
538 deadce Dead code elimination
539 consprop Constant propagation
540 copyprop Copy propagation
541 fcmov Fast x86 FP compares [arch-dependency]
542 float32 Perform 32-bit float arithmetic using 32-bit operations
543 gshared Enable generic code sharing.
544 inline Inline method calls
545 intrins Intrinsic method implementations
546 linears Linear scan global reg allocation
547 leaf Leaf procedures optimizations
548 loop Loop related optimizations
549 peephole Peephole postpass
550 precomp Precompile all methods before executing Main
551 sched Instruction scheduling
552 shared Emit per-domain code
553 sse2 SSE2 instructions on x86 [arch-dependency]
554 tailc Tail recursion and tail calls
557 For example, to enable all the optimization but dead code
558 elimination and inlining, you can use:
560 -O=all,-deadce,-inline
563 The flags that are flagged with [arch-dependency] indicate that the
564 given option if used in combination with Ahead of Time compilation
565 (--aot flag) would produce pre-compiled code that will depend on the
566 current CPU and might not be safely moved to another computer.
570 The following optimizations are supported
573 Requests that the runtime performn 32-bit floating point operations
574 using only 32-bits. By default the Mono runtime tries to use the
575 highest precision available for floating point operations, but while
576 this might render better results, the code might run slower. This
577 options also affects the code generated by the LLVM backend.
580 Controls whether the runtime should attempt to inline (the default),
581 or not inline methods invocations
585 \fB--runtime=VERSION\fR
586 Mono supports different runtime versions. The version used depends on the program
587 that is being run or on its configuration file (named program.exe.config). This option
588 can be used to override such autodetection, by forcing a different runtime version
589 to be used. Note that this should only be used to select a later compatible runtime
590 version than the one the program was compiled against. A typical usage is for
591 running a 1.1 program on a 2.0 version:
593 mono --runtime=v2.0.50727 program.exe
596 \fB--security\fR, \fB--security=mode\fR
597 Activate the security manager, a currently experimental feature in
598 Mono and it is OFF by default. The new code verifier can be enabled
599 with this option as well.
603 Using security without parameters is equivalent as calling it with the
606 The following modes are supported:
609 Enables the core-clr security system, typically used for
610 Moonlight/Silverlight applications. It provides a much simpler
611 security system than CAS, see http://www.mono-project.com/docs/web/moonlight/
612 for more details and links to the descriptions of this new system.
615 Enables the new verifier and performs basic verification for code
616 validity. In this mode, unsafe code and P/Invoke are allowed. This
617 mode provides a better safety guarantee but it is still possible
618 for managed code to crash Mono.
621 Enables the new verifier and performs full verification of the code
622 being executed. It only allows verifiable code to be executed.
623 Unsafe code is not allowed but P/Invoke is. This mode should
624 not allow managed code to crash mono. The verification is not as
625 strict as ECMA 335 standard in order to stay compatible with the MS
628 The security system acts on user code: code contained in mscorlib or
629 the global assembly cache is always trusted.
634 Configures the virtual machine to be better suited for server
635 operations (currently, allows a heavier threadpool initialization).
638 Verifies mscorlib and assemblies in the global
639 assembly cache for valid IL, and all user code for IL
642 This is different from \fB--security\fR's verifiable
643 or validil in that these options only check user code and skip
644 mscorlib and assemblies located on the global assembly cache.
646 \fB-V\fR, \fB--version\fR
647 Prints JIT version information (system configuration, release number
648 and branch names if available).
651 .SH DEVELOPMENT OPTIONS
652 The following options are used to help when developing a JITed application.
654 \fB--debug\fR, \fB--debug=OPTIONS\fR
655 Turns on the debugging mode in the runtime. If an assembly was
656 compiled with debugging information, it will produce line number
657 information for stack traces.
661 The optional OPTIONS argument is a comma separated list of debugging
662 options. These options are turned off by default since they generate
663 much larger and slower code at runtime.
665 The following options are supported:
668 Produces a detailed error when throwing a InvalidCastException. This
669 option needs to be enabled as this generates more verbose code at
673 Disable some JIT optimizations which are usually only disabled when
674 running inside the debugger. This can be helpful if you want to attach
675 to the running process with mdb.
678 Generate and register debugging information with gdb. This is only supported on some
679 platforms, and only when using gdb 7.0 or later.
683 \fB\-\-profile\fR[=\fIprofiler\fR[:\fIprofiler_args\fR]]\fR
684 Loads a profiler module with the given arguments. For more information,
685 see the \fBPROFILING\fR section.
687 This option can be used multiple times; each time will load an additional
690 \fB--trace[=expression]\fR
691 Shows method names as they are invoked. By default all methods are
694 The trace can be customized to include or exclude methods, classes or
695 assemblies. A trace expression is a comma separated list of targets,
696 each target can be prefixed with a minus sign to turn off a particular
697 target. The words `program', `all' and `disabled' have special
698 meaning. `program' refers to the main program being executed, and
699 `all' means all the method calls.
701 The `disabled' option is used to start up with tracing disabled. It
702 can be enabled at a later point in time in the program by sending the
703 SIGUSR2 signal to the runtime.
705 Assemblies are specified by their name, for example, to trace all
706 calls in the System assembly, use:
709 mono --trace=System app.exe
712 Classes are specified with the T: prefix. For example, to trace all
713 calls to the System.String class, use:
716 mono --trace=T:System.String app.exe
719 And individual methods are referenced with the M: prefix, and the
720 standard method notation:
723 mono --trace=M:System.Console:WriteLine app.exe
726 Exceptions can also be traced, it will cause a stack trace to be
727 printed every time an exception of the specified type is thrown.
728 The exception type can be specified with or without the namespace,
729 and to trace all exceptions, specify 'all' as the type name.
732 mono --trace=E:System.Exception app.exe
735 As previously noted, various rules can be specified at once:
738 mono --trace=T:System.String,T:System.Random app.exe
741 You can exclude pieces, the next example traces calls to
742 System.String except for the System.String:Concat method.
745 mono --trace=T:System.String,-M:System.String:Concat
748 You can trace managed to unmanaged transitions using
749 the wrapper qualifier:
752 mono --trace=wrapper app.exe
755 Finally, namespaces can be specified using the N: prefix:
758 mono --trace=N:System.Xml
762 \fB--no-x86-stack-align\fR
763 Don't align stack frames on the x86 architecture. By default, Mono
764 aligns stack frames to 16 bytes on x86, so that local floating point
765 and SIMD variables can be properly aligned. This option turns off the
766 alignment, which usually saves one instruction per call, but might
767 result in significantly lower floating point and SIMD performance.
770 Generate a JIT method map in a /tmp/perf-PID.map file. This file is then
771 used, for example, by the perf tool included in recent Linux kernels.
772 Each line in the file has:
775 HEXADDR HEXSIZE methodname
778 Currently this option is only supported on Linux.
779 .SH JIT MAINTAINER OPTIONS
780 The maintainer options are only used by those developing the runtime
781 itself, and not typically of interest to runtime users or developers.
783 \fB--bisect=optimization:filename\fR
784 This flag is used by the automatic optimization bug bisector. It
785 takes an optimization flag and a filename of a file containing a list
786 of full method names, one per line. When it compiles one of the
787 methods in the file it will use the optimization given, in addition to
788 the optimizations that are otherwise enabled. Note that if the
789 optimization is enabled by default, you should disable it with `-O`,
790 otherwise it will just apply to every method, whether it's in the file
794 Inserts a breakpoint before the method whose name is `method'
795 (namespace.class:methodname). Use `Main' as method name to insert a
796 breakpoint on the application's main method. You can use it also with
797 generics, for example "System.Collections.Generic.Queue`1:Peek"
800 Inserts a breakpoint on exceptions. This allows you to debug your
801 application with a native debugger when an exception is thrown.
804 This compiles a method (namespace.name:methodname), this is used for
805 testing the compiler performance or to examine the output of the code
809 Compiles all the methods in an assembly. This is used to test the
810 compiler performance or to examine the output of the code generator
812 \fB--graph=TYPE METHOD\fR
813 This generates a postscript file with a graph with the details about
814 the specified method (namespace.name:methodname). This requires `dot'
815 and ghostview to be installed (it expects Ghostview to be called
818 The following graphs are available:
820 cfg Control Flow Graph (CFG)
822 code CFG showing code
823 ssa CFG showing code after SSA translation
824 optcode CFG showing code after IR optimizations
827 Some graphs will only be available if certain optimizations are turned
831 Instruct the runtime on the number of times that the method specified
832 by --compile (or all the methods if --compileall is used) to be
833 compiled. This is used for testing the code generator performance.
836 Displays information about the work done by the runtime during the
837 execution of an application.
839 \fB--wapi=hps|semdel\fR
840 Perform maintenance of the process shared data.
842 semdel will delete the global semaphore.
844 hps will list the currently used handles.
846 \fB-v\fR, \fB--verbose\fR
847 Increases the verbosity level, each time it is listed, increases the
848 verbosity level to include more information (including, for example,
849 a disassembly of the native code produced, code selector info etc.).
851 The Mono runtime allows external processes to attach to a running
852 process and load assemblies into the running program. To attach to
853 the process, a special protocol is implemented in the Mono.Management
856 With this support it is possible to load assemblies that have an entry
857 point (they are created with -target:exe or -target:winexe) to be
858 loaded and executed in the Mono process.
860 The code is loaded into the root domain, and it starts execution on
861 the special runtime attach thread. The attached program should
862 create its own threads and return after invocation.
864 This support allows for example debugging applications by having the
865 csharp shell attach to running processes.
867 The Mono runtime includes a profiler API that dynamically loaded
868 profiler modules and embedders can use to collect performance-related
869 data about an application. Profiler modules are loaded by passing the
870 \fB\-\-profile\fR command line argument to the Mono runtime.
872 Mono ships with a few profiler modules, of which the \fBlog\fR profiler
873 is the most feature-rich. It is also the default profiler if the
874 \fIprofiler\fR argument is not given, or if \fBdefault\fR is given.
875 It is possible to write your own profiler modules; see the
876 \fBCustom profilers\fR sub-section.
878 The log profiler can be used to collect a lot of information about
879 a program running in the Mono runtime. This data can be used (both
880 while the process is running and later) to do analyses of the
881 program behavior, determine resource usage, performance issues or
882 even look for particular execution patterns.
884 This is accomplished by logging the events provided by the Mono
885 runtime through the profiler API and periodically writing them to a
886 file which can later be inspected with the \fBmprof\-report\fR(1)
889 More information about how to use the log profiler is available on
890 the \fBmono\-profilers\fR(1) page, under the \fBLOG PROFILER\fR
891 section, as well as the \fBmprof\-report\fR(1) page.
892 .SS Coverage profiler
893 The code coverage profiler can instrument a program to help determine
894 which classes, methods, code paths, etc are actually executed. This
895 is most useful when running a test suite to determine whether the
896 tests actually cover the code they're expected to.
898 More information about how to use the coverage profiler is available
899 on the \fBmono\-profilers\fR(1) page, under the \fBCOVERAGE
902 The AOT profiler can help improve startup performance by logging
903 which generic instantiations are used by a program, which the AOT
904 compiler can then use to compile those instantiations ahead of time
905 so that they won't have to be JIT compiled at startup.
907 More information about how to use the AOT profiler is available on
908 the \fBmono\-profilers\fR(1) page, under the \fBAOT PROFILER\fR
911 Custom profiler modules can be loaded in exactly the same way as the
912 standard modules that ship with Mono. They can also access the same
913 profiler API to gather all kinds of information about the code being
916 For example, to use a third-party profiler called \fBcustom\fR, you
917 would load it like this:
921 mono --profile=custom program.exe
925 You could also pass arguments to it:
929 mono --profile=custom:arg1,arg2=arg3 program.exe
933 In the above example, Mono will load the profiler from the shared
934 library called \fIlibmono\-profiler\-custom.so\fR (name varies based
935 on platform, e.g., \fIlibmono\-profiler\-custom.dylib\fR on OS X).
936 This profiler module must be on your dynamic linker library path
937 (\fBLD_LIBRARY_PATH\fR on most systems, \fBDYLD_LIBRARY_PATH\fR on
940 For a sample of how to write your own custom profiler, look at the
941 \fIsamples/profiler/sample.c\fR file in the Mono source tree.
943 To debug managed applications, you can use the
945 command, a command line debugger.
947 It is possible to obtain a stack trace of all the active threads in
948 Mono by sending the QUIT signal to Mono, you can do this from the
949 command line, like this:
955 Where pid is the Process ID of the Mono process you want to examine.
956 The process will continue running afterwards, but its state is not
960 this is a last-resort mechanism for debugging applications and should
961 not be used to monitor or probe a production application. The
962 integrity of the runtime after sending this signal is not guaranteed
963 and the application might crash or terminate at any given point
966 The \fB--debug=casts\fR option can be used to get more detailed
967 information for Invalid Cast operations, it will provide information
968 about the types involved.
970 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
971 to get verbose debugging output about the execution of your
972 application within Mono.
976 environment variable if set, the logging level is changed to the set
977 value. Possible values are "error", "critical", "warning", "message",
978 "info", "debug". The default value is "error". Messages with a logging
979 level greater then or equal to the log level will be printed to
982 Use "info" to track the dynamic loading of assemblies.
987 environment variable to limit the extent of the messages you get:
988 If set, the log mask is changed to the set value. Possible values are
989 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
990 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
991 "security" (e.g. Moonlight CoreCLR support), "threadpool" (thread pool generic),
992 "io-selector" (async socket operations), "io-layer" (I/O layer - processes, files,
993 sockets, events, semaphores, mutexes and handles), "io-layer-process",
994 "io-layer-file", "io-layer-socket", "io-layer-event", "io-layer-semaphore",
995 "io-layer-mutex", "io-layer-handle" and "all".
996 The default value is "all". Changing the mask value allows you to display only
997 messages for a certain component. You can use multiple masks by comma
998 separating them. For example to see config file messages and assembly loader
999 messages set you mask to "asm,cfg".
1001 The following is a common use to track down problems with P/Invoke:
1004 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
1008 .SH DEBUGGING WITH LLDB
1009 If you are using LLDB, you can use the
1011 script to print some internal data structures with it. To use this,
1016 command script import $PREFIX/lib/mono/lldb/mono.py
1019 Where $PREFIX is the prefix value that you used when you configured
1020 Mono (typically /usr).
1022 Once this is done, then you can inspect some Mono Runtime data structures,
1027 (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
1030 Mono's XML serialization engine by default will use a reflection-based
1031 approach to serialize which might be slow for continuous processing
1032 (web service applications). The serialization engine will determine
1033 when a class must use a hand-tuned serializer based on a few
1034 parameters and if needed it will produce a customized C# serializer
1035 for your types at runtime. This customized serializer then gets
1036 dynamically loaded into your application.
1038 You can control this with the MONO_XMLSERIALIZER_THS environment
1041 The possible values are
1043 to disable the use of a C# customized
1044 serializer, or an integer that is the minimum number of uses before
1045 the runtime will produce a custom serializer (0 will produce a
1046 custom serializer on the first access, 50 will produce a serializer on
1047 the 50th use). Mono will fallback to an interpreted serializer if the
1048 serializer generation somehow fails. This behavior can be disabled
1049 by setting the option
1051 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
1052 .SH ENVIRONMENT VARIABLES
1055 Turns off the garbage collection in Mono. This should be only used
1056 for debugging purposes
1059 (Also \fBhttp_proxy\fR) If set, web requests using the Mono
1060 Class Library will be automatically proxied through the given URL.
1061 Not supported on Windows, Mac OS, iOS or Android. See also \fBNO_PROXY\fR.
1064 When Mono is compiled with LLVM support, this instructs the runtime to
1065 stop using LLVM after the specified number of methods are JITed.
1066 This is a tool used in diagnostics to help isolate problems in the
1067 code generation backend. For example \fBLLVM_COUNT=10\fR would only
1068 compile 10 methods with LLVM and then switch to the Mono JIT engine.
1069 \fBLLVM_COUNT=0\fR would disable the LLVM engine altogether.
1071 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
1072 Mono contains a feature which allows modifying settings in the .config files shipped
1073 with Mono by using config section mappers. The mappers and the mapping rules are
1074 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
1075 settings.map file found in the top-level directory of your ASP.NET application.
1076 Both files are read by System.Web on application startup, if they are found at the
1077 above locations. If you don't want the mapping to be performed you can set this
1078 variable in your environment before starting the application and no action will
1081 \fBMONO_ASPNET_WEBCONFIG_CACHESIZE\fR
1082 Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager
1083 queries. Its default size is 100 items, and when more items are needed, cache
1084 evictions start happening. If evictions are too frequent this could impose
1085 unnecessary overhead, which could be avoided by using this environment variable
1086 to set up a higher cache size (or to lower memory requirements by decreasing it).
1088 \fBMONO_CAIRO_DEBUG_DISPOSE\fR
1089 If set, causes Mono.Cairo to collect stack traces when objects are allocated,
1090 so that the finalization/Dispose warnings include information about the
1094 If set, this variable overrides the default system configuration directory
1095 ($PREFIX/etc). It's used to locate machine.config file.
1098 Sets the style of COM interop. If the value of this variable is "MS"
1099 Mono will use string marhsalling routines from the liboleaut32 for the
1100 BSTR type library, any other values will use the mono-builtin BSTR
1104 If set, this variable overrides the default runtime configuration file
1105 ($PREFIX/etc/mono/config). The --config command line options overrides the
1106 environment variable.
1109 Override the automatic cpu detection mechanism. Currently used only on arm.
1110 The format of the value is as follows:
1116 where V is the architecture number 4, 5, 6, 7 and the options can be currently be
1117 "thumb" or "thumb2". Example:
1120 MONO_CPU_ARCH="armv4 thumb" mono ...
1124 \fBMONO_ARM_FORCE_SOFT_FLOAT\fR
1125 When Mono is built with a soft float fallback on ARM and this variable is set to
1126 "1", Mono will always emit soft float code, even if a VFP unit is
1129 \fBMONO_DARWIN_USE_KQUEUE_FSW\fR
1130 Fall back on the kqueue FileSystemWatcher implementation in Darwin. The default is the FSEvent implementation.
1132 \fBMONO_DARWIN_WATCHER_MAXFDS\fR
1133 This is a debugging aid used to force limits on the kqueue FileSystemWatcher
1134 implementation in Darwin. There is no limit by default.
1136 \fBMONO_DISABLE_MANAGED_COLLATION\fR
1137 If this environment variable is `yes', the runtime uses unmanaged
1138 collation (which actually means no culture-sensitive collation). It
1139 internally disables managed collation functionality invoked via the
1140 members of System.Globalization.CompareInfo class. Collation is
1143 \fBMONO_DISABLE_SHARED_AREA\fR
1144 Unix only: If set, disable usage of shared memory for exposing
1145 performance counters. This means it will not be possible to both
1146 externally read performance counters from this processes or read
1147 those of external processes.
1150 When set, enables the use of a fully managed DNS resolver instead of the
1151 regular libc functions. This resolver performs much better when multiple
1152 queries are run in parallel.
1154 Note that /etc/nsswitch.conf will be ignored.
1156 \fBMONO_EGD_SOCKET\fR
1157 For platforms that do not otherwise have a way of obtaining random bytes
1158 this can be set to the name of a file system socket on which an egd or
1159 prngd daemon is listening.
1161 \fBMONO_ENABLE_AIO\fR
1162 If set, tells mono to attempt using native asynchronous I/O services. If not
1163 set, a default select/poll implementation is used. Currently epoll and kqueue
1166 \fBMONO_ENABLE_COOP\fR
1167 This makes the Mono runtime and the SGen garbage collector run in cooperative
1168 mode as opposed to run on preemptive mode. Preemptive mode is the mode
1169 that Mono has used historically, going back to the Boehm days, where the
1170 garbage collector would run at any point and suspend execution of all
1171 threads as required to perform a garbage collection. The cooperative mode
1172 on the other hand requires the cooperation of all threads to stop at a
1173 safe point. This makes for an easier to debug garbage collector. As
1174 of Mono 4.3.0 it is a work in progress, and while it works, it has not
1175 been used extensively. This option enabled the feature and allows us to
1176 find spots that need to be tuned for this mode of operation. Alternatively,
1177 this mode can be enabled at compile time by using the --with-cooperative-gc
1178 flag when calling configure.
1180 \fBMONO_ENV_OPTIONS\fR
1181 This environment variable allows you to pass command line arguments to
1182 a Mono process through the environment. This is useful for example
1183 to force all of your Mono processes to use LLVM or SGEN without having
1184 to modify any launch scripts.
1186 \fBMONO_SDB_ENV_OPTIONS\fR
1187 Used to pass extra options to the debugger agent in the runtime, as they were passed
1188 using --debugger-agent=.
1190 \fBMONO_EVENTLOG_TYPE\fR
1191 Sets the type of event log provider to use (for System.Diagnostics.EventLog).
1193 Possible values are:
1198 Persists event logs and entries to the local file system.
1200 The directory in which to persist the event logs, event sources and entries
1201 can be specified as part of the value.
1203 If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog"
1204 on unix and "%APPDATA%\mono\eventlog" on Windows.
1209 Uses the native win32 API to write events and registers event logs and
1210 event sources in the registry. This is only available on Windows.
1212 On Unix, the directory permission for individual event log and event source
1213 directories is set to 777 (with +t bit) allowing everyone to read and write
1214 event log entries while only allowing entries to be deleted by the user(s)
1219 Silently discards any events.
1222 The default is "null" on Unix (and versions of Windows before NT), and
1223 "win32" on Windows NT (and higher).
1226 \fBMONO_EXTERNAL_ENCODINGS\fR
1227 If set, contains a colon-separated list of text encodings to try when
1228 turning externally-generated text (e.g. command-line arguments or
1229 filenames) into Unicode. The encoding names come from the list
1230 provided by iconv, and the special case "default_locale" which refers
1231 to the current locale's default encoding.
1233 When reading externally-generated text strings UTF-8 is tried first,
1234 and then this list is tried in order with the first successful
1235 conversion ending the search. When writing external text (e.g. new
1236 filenames or arguments to new processes) the first item in this list
1237 is used, or UTF-8 if the environment variable is not set.
1239 The problem with using MONO_EXTERNAL_ENCODINGS to process your
1240 files is that it results in a problem: although its possible to get
1241 the right file name it is not necessarily possible to open the file.
1242 In general if you have problems with encodings in your filenames you
1243 should use the "convmv" program.
1245 \fBMONO_GC_PARAMS\fR
1246 When using Mono with the SGen garbage collector this variable controls
1247 several parameters of the collector. The variable's value is a comma
1248 separated list of words.
1252 \fBmax-heap-size=\fIsize\fR
1253 Sets the maximum size of the heap. The size is specified in bytes and must
1254 be a power of two. The suffixes `k', `m' and `g' can be used to
1255 specify kilo-, mega- and gigabytes, respectively. The limit is the sum
1256 of the nursery, major heap and large object heap. Once the limit is reached
1257 the application will receive OutOfMemoryExceptions when trying to allocate.
1258 Not the full extent of memory set in max-heap-size could be available to
1259 satisfy a single allocation due to internal fragmentation. By default heap
1260 limits is disabled and the GC will try to use all available memory.
1262 \fBnursery-size=\fIsize\fR
1263 Sets the size of the nursery. The size is specified in bytes and must
1264 be a power of two. The suffixes `k', `m' and `g' can be used to
1265 specify kilo-, mega- and gigabytes, respectively. The nursery is the
1266 first generation (of two). A larger nursery will usually speed up the
1267 program but will obviously use more memory. The default nursery size
1270 \fBmajor=\fIcollector\fR
1271 Specifies which major collector to use.
1272 Options are `marksweep' for the Mark&Sweep collector, `marksweep-conc'
1273 for concurrent Mark&Sweep and `marksweep-conc-par' for parallel and
1274 concurrent Mark&Sweep. The concurrent Mark&Sweep collector is the default.
1276 \fBmode=balanced|throughput|pause\fR[:\fImax-pause\fR]
1277 Specifies what should be the garbage collector's target. The `throughput'
1278 mode aims to reduce time spent in the garbage collector and improve
1279 application speed, the `pause' mode aims to keep pause times to a minimum
1280 and it receives the argument \fImax-pause\fR which specifies the maximum
1281 pause time in milliseconds that is acceptable and the `balanced' mode
1282 which is a general purpose optimal mode.
1284 \fBsoft-heap-limit=\fIsize\fR
1285 Once the heap size gets larger than this size, ignore what the default
1286 major collection trigger metric says and only allow four nursery size's
1287 of major heap growth between major collections.
1289 \fBevacuation-threshold=\fIthreshold\fR
1290 Sets the evacuation threshold in percent. This option is only available
1291 on the Mark&Sweep major collectors. The value must be an
1292 integer in the range 0 to 100. The default is 66. If the sweep phase of
1293 the collection finds that the occupancy of a specific heap block type is
1294 less than this percentage, it will do a copying collection for that block
1295 type in the next major collection, thereby restoring occupancy to close
1296 to 100 percent. A value of 0 turns evacuation off.
1298 \fB(no-)lazy-sweep\fR
1299 Enables or disables lazy sweep for the Mark&Sweep collector. If
1300 enabled, the sweeping of individual major heap blocks is done
1301 piecemeal whenever the need arises, typically during nursery
1302 collections. Lazy sweeping is enabled by default.
1304 \fB(no-)concurrent-sweep\fR
1305 Enables or disables concurrent sweep for the Mark&Sweep collector. If
1306 enabled, the iteration of all major blocks to determine which ones can
1307 be freed and which ones have to be kept and swept, is done
1308 concurrently with the running program. Concurrent sweeping is enabled
1311 \fBstack-mark=\fImark-mode\fR
1312 Specifies how application threads should be scanned. Options are
1313 `precise` and `conservative`. Precise marking allow the collector
1314 to know what values on stack are references and what are not.
1315 Conservative marking threats all values as potentially references
1316 and leave them untouched. Precise marking reduces floating garbage
1317 and can speed up nursery collection and allocation rate, it has
1318 the downside of requiring a significant extra memory per compiled
1319 method. The right option, unfortunately, requires experimentation.
1321 \fBsave-target-ratio=\fIratio\fR
1322 Specifies the target save ratio for the major collector. The collector
1323 lets a given amount of memory to be promoted from the nursery due to
1324 minor collections before it triggers a major collection. This amount
1325 is based on how much memory it expects to free. It is represented as
1326 a ratio of the size of the heap after a major collection.
1327 Valid values are between 0.1 and 2.0. The default is 0.5.
1328 Smaller values will keep the major heap size smaller but will trigger
1329 more major collections. Likewise, bigger values will use more memory
1330 and result in less frequent major collections.
1331 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1333 \fBdefault-allowance-ratio=\fIratio\fR
1334 Specifies the default allocation allowance when the calculated size
1335 is too small. The allocation allowance is how much memory the collector
1336 let be promoted before triggered a major collection.
1337 It is a ratio of the nursery size.
1338 Valid values are between 1.0 and 10.0. The default is 4.0.
1339 Smaller values lead to smaller heaps and more frequent major collections.
1340 Likewise, bigger values will allow the heap to grow faster but use
1341 more memory when it reaches a stable size.
1342 This option is EXPERIMENTAL, so it might disappear in later versions of mono.
1344 \fBminor=\fIminor-collector\fR
1345 Specifies which minor collector to use. Options are `simple' which
1346 promotes all objects from the nursery directly to the old generation,
1347 `simple-par' which has same promotion behavior as `simple' but using
1348 multiple workers and `split' which lets objects stay longer on the nursery
1351 \fBalloc-ratio=\fIratio\fR
1352 Specifies the ratio of memory from the nursery to be use by the alloc space.
1353 This only can only be used with the split minor collector.
1354 Valid values are integers between 1 and 100. Default is 60.
1356 \fBpromotion-age=\fIage\fR
1357 Specifies the required age of an object must reach inside the nursery before
1358 been promoted to the old generation. This only can only be used with the
1359 split minor collector.
1360 Valid values are integers between 1 and 14. Default is 2.
1362 \fB(no-)cementing\fR
1363 Enables or disables cementing. This can dramatically shorten nursery
1364 collection times on some benchmarks where pinned objects are referred
1365 to from the major heap.
1367 \fBallow-synchronous-major\fR
1368 This forbids the major collector from performing synchronous major collections.
1369 The major collector might want to do a synchronous collection due to excessive
1370 fragmentation. Disabling this might trigger OutOfMemory error in situations that
1371 would otherwise not happen.
1376 When using Mono with the SGen garbage collector this environment
1377 variable can be used to turn on various debugging features of the
1378 collector. The value of this variable is a comma separated list of
1379 words. Do not use these options in production.
1384 Sets the debug level to the specified number.
1386 \fBprint-allowance\fR
1387 After each major collection prints memory consumption for before and
1388 after the collection and the allowance for the minor collector, i.e. how
1389 much the heap is allowed to grow from minor collections before the next
1390 major collection is triggered.
1393 Gathers statistics on the classes whose objects are pinned in the
1394 nursery and for which global remset entries are added. Prints those
1395 statistics when shutting down.
1397 \fBcollect-before-allocs\fR
1399 \fBcheck-remset-consistency\fR
1400 This performs a remset consistency check at various opportunities, and
1401 also clears the nursery at collection time, instead of the default,
1402 when buffers are allocated (clear-at-gc). The consistency check
1403 ensures that there are no major to minor references that are not on
1404 the remembered sets.
1406 \fBmod-union-consistency-check\fR
1407 Checks that the mod-union cardtable is consistent before each
1408 finishing major collection pause. This check is only applicable to
1409 concurrent major collectors.
1411 \fBcheck-mark-bits\fR
1412 Checks that mark bits in the major heap are consistent at the end of
1413 each major collection. Consistent mark bits mean that if an object is
1414 marked, all objects that it had references to must also be marked.
1416 \fBcheck-nursery-pinned\fR
1417 After nursery collections, and before starting concurrent collections,
1418 check whether all nursery objects are pinned, or not pinned -
1419 depending on context. Does nothing when the split nursery collector
1422 \fBxdomain-checks\fR
1423 Performs a check to make sure that no references are left to an
1426 \fBclear-at-tlab-creation\fR
1427 Clears the nursery incrementally when the thread local allocation
1428 buffers (TLAB) are created. The default setting clears the whole
1431 \fBdebug-clear-at-tlab-creation\fR
1432 Clears the nursery incrementally when the thread local allocation
1433 buffers (TLAB) are created, but at GC time fills it with the byte
1434 `0xff`, which should result in a crash more quickly if
1435 `clear-at-tlab-creation` doesn't work properly.
1438 This clears the nursery at GC time instead of doing it when the thread
1439 local allocation buffer (TLAB) is created. The default is to clear
1440 the nursery at TLAB creation time.
1443 Don't do minor collections. If the nursery is full, a major collection
1444 is triggered instead, unless it, too, is disabled.
1447 Don't do major collections.
1449 \fBconservative-stack-mark\fR
1450 Forces the GC to scan the stack conservatively, even if precise
1451 scanning is available.
1453 \fBno-managed-allocator\fR
1454 Disables the managed allocator.
1456 \fBcheck-scan-starts\fR
1457 If set, does a plausibility check on the scan_starts before and after each collection
1459 \fBverify-nursery-at-minor-gc\fR
1460 If set, does a complete object walk of the nursery at the start of each minor collection.
1462 \fBdump-nursery-at-minor-gc\fR
1463 If set, dumps the contents of the nursery at the start of each minor collection. Requires
1464 verify-nursery-at-minor-gc to be set.
1466 \fBheap-dump=\fIfile\fR
1467 Dumps the heap contents to the specified file. To visualize the
1468 information, use the mono-heapviz tool.
1470 \fBbinary-protocol=\fIfile\fR
1471 Outputs the debugging output to the specified file. For this to
1472 work, Mono needs to be compiled with the BINARY_PROTOCOL define on
1473 sgen-gc.c. You can then use this command to explore the output
1475 sgen-grep-binprot 0x1234 0x5678 < file
1478 \fBnursery-canaries\fR
1479 If set, objects allocated in the nursery are suffixed with a canary (guard)
1480 word, which is checked on each minor collection. Can be used to detect/debug
1481 heap corruption issues.
1484 \fBdo-not-finalize(=\fIclasses\fB)\fR
1485 If enabled, finalizers will not be run. Everything else will be
1486 unaffected: finalizable objects will still be put into the
1487 finalization queue where they survive until they're scheduled to
1488 finalize. Once they're not in the queue anymore they will be
1489 collected regularly. If a list of comma-separated class names is
1490 given, only objects from those classes will not be finalized.
1493 \fBlog-finalizers\fR
1494 Log verbosely around the finalization process to aid debugging.
1498 \fBMONO_GAC_PREFIX\fR
1499 Provides a prefix the runtime uses to look for Global Assembly Caches.
1500 Directories are separated by the platform path separator (colons on
1501 unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
1502 install. Or to the directory provided in the gacutil /gacdir command. Example:
1503 .B /home/username/.mono:/usr/local/mono/
1506 Enables some filename rewriting support to assist badly-written
1507 applications that hard-code Windows paths. Set to a colon-separated
1508 list of "drive" to strip drive letters, or "case" to do
1509 case-insensitive file matching in every directory in a path. "all"
1510 enables all rewriting methods. (Backslashes are always mapped to
1511 slashes if this variable is set to a valid option).
1514 For example, this would work from the shell:
1517 MONO_IOMAP=drive:case
1521 If you are using mod_mono to host your web applications, you can use
1524 directive instead, like this:
1527 MonoIOMAP <appalias> all
1530 See mod_mono(8) for more details.
1533 When Mono is using the LLVM code generation backend you can use this
1534 environment variable to pass code generation options to the LLVM
1537 \fBMONO_MANAGED_WATCHER\fR
1538 If set to "disabled", System.IO.FileSystemWatcher will use a file watcher
1539 implementation which silently ignores all the watching requests.
1540 If set to any other value, System.IO.FileSystemWatcher will use the default
1541 managed implementation (slow). If unset, mono will try to use inotify, FAM,
1542 Gamin, kevent under Unix systems and native API calls on Windows, falling
1543 back to the managed implementation on error.
1545 \fBMONO_MESSAGING_PROVIDER\fR
1546 Mono supports a plugin model for its implementation of System.Messaging making
1547 it possible to support a variety of messaging implementations (e.g. AMQP, ActiveMQ).
1548 To specify which messaging implementation is to be used the evironement variable
1549 needs to be set to the full class name for the provider. E.g. to use the RabbitMQ based
1550 AMQP implementation the variable should be set to:
1553 Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
1556 If set causes the mono process to be bound to a single processor. This may be
1557 useful when debugging or working around race conditions.
1560 Disable inlining of thread local accesses. Try setting this if you get a segfault
1561 early on in the execution of mono.
1564 Provides a search path to the runtime where to look for library
1565 files. This is a tool convenient for debugging applications, but
1566 should not be used by deployed applications as it breaks the assembly
1567 loader in subtle ways.
1569 Directories are separated by the platform path separator (colons on unix). Example:
1570 .B /home/username/lib:/usr/local/mono/lib
1572 Relative paths are resolved based on the launch-time current directory.
1574 Alternative solutions to MONO_PATH include: installing libraries into
1575 the Global Assembly Cache (see gacutil(1)) or having the dependent
1576 libraries side-by-side with the main executable.
1578 For a complete description of recommended practices for application
1580 http://www.mono-project.com/docs/getting-started/application-deployment/
1582 \fBMONO_SHARED_DIR\fR
1583 If set its the directory where the ".wapi" handle state is stored.
1584 This is the directory where the Windows I/O Emulation layer stores its
1585 shared state data (files, events, mutexes, pipes). By default Mono
1586 will store the ".wapi" directory in the users's home directory.
1588 \fBMONO_SHARED_HOSTNAME\fR
1589 Uses the string value of this variable as a replacement for the host name when
1590 creating file names in the ".wapi" directory. This helps if the host name of
1591 your machine is likely to be changed when a mono application is running or if
1592 you have a .wapi directory shared among several different computers.
1594 Mono typically uses the hostname to create the files that are used to
1595 share state across multiple Mono processes. This is done to support
1596 home directories that might be shared over the network.
1598 \fBMONO_STRICT_IO_EMULATION\fR
1599 If set, extra checks are made during IO operations. Currently, this
1600 includes only advisory locks around file writes.
1602 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1603 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1604 avoid a new negotiation between the client and a server. Negotiation are very
1605 CPU intensive so an application-specific custom value may prove useful for
1606 small embedded systems.
1608 The default is 180 seconds.
1610 \fBMONO_THREADS_PER_CPU\fR
1611 The minimum number of threads in the general threadpool will be
1612 MONO_THREADS_PER_CPU * number of CPUs. The default value for this
1615 \fBMONO_XMLSERIALIZER_THS\fR
1616 Controls the threshold for the XmlSerializer to produce a custom
1617 serializer for a given class instead of using the Reflection-based
1618 interpreter. The possible values are `no' to disable the use of a
1619 custom serializer or a number to indicate when the XmlSerializer
1620 should start serializing. The default value is 50, which means that
1621 the a custom serializer will be produced on the 50th use.
1623 \fBMONO_X509_REVOCATION_MODE\fR
1624 Sets the revocation mode used when validating a X509 certificate chain (https,
1625 ftps, smtps...). The default is 'nocheck', which performs no revocation check
1626 at all. The other possible values are 'offline', which performs CRL check (not
1627 implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
1628 status (not implemented yet).
1631 (Also \fBno_proxy\fR) If both \fBHTTP_PROXY\fR and \fBNO_PROXY\fR are
1632 set, \fBNO_PROXY\fR will be treated as a comma-separated list of "bypass" domains
1633 which will not be sent through the proxy. Domains in \fBNO_PROXY\fR may contain
1634 wildcards, as in "*.mono-project.com" or "build????.local". Not supported on
1635 Windows, Mac OS, iOS or Android.
1636 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1638 \fBMONO_ASPNET_NODELETE\fR
1639 If set to any value, temporary source files generated by ASP.NET support
1640 classes will not be removed. They will be kept in the user's temporary
1644 If set, enables some features of the runtime useful for debugging.
1645 This variable should contain a comma separated list of debugging options.
1646 Currently, the following options are supported:
1650 \fBalign-small-structs\fR
1651 Enables small structs alignment to 4/8 bytes.
1653 \fBarm-use-fallback-tls\fR
1654 When this option is set on ARM, a fallback TLS will be used instead
1655 of the default fast TLS.
1657 \fBbreak-on-unverified\fR
1658 If this variable is set, when the Mono VM runs into a verification
1659 problem, instead of throwing an exception it will break into the
1660 debugger. This is useful when debugging verifier problems
1663 This option can be used to get more detailed information from
1664 InvalidCast exceptions, it will provide information about the types
1667 \fBcheck-pinvoke-callconv\fR
1668 This option causes the runtime to check for calling convention
1669 mismatches when using pinvoke, i.e. mixing cdecl/stdcall. It only
1670 works on windows. If a mismatch is detected, an
1671 ExecutionEngineException is thrown.
1673 \fBcollect-pagefault-stats\fR
1674 Collects information about pagefaults. This is used internally to
1675 track the number of page faults produced to load metadata. To display
1676 this information you must use this option with "--stats" command line
1679 \fBdebug-domain-unload\fR
1680 When this option is set, the runtime will invalidate the domain memory
1681 pool instead of destroying it.
1683 \fBdisable_omit_fp\fR
1684 Disables a compiler optimization where the frame pointer is omitted
1685 from the stack. This optimization can interact badly with debuggers.
1687 \fBdont-free-domains\fR
1688 This is an Optimization for multi-AppDomain applications (most
1689 commonly ASP.NET applications). Due to internal limitations Mono,
1690 Mono by default does not use typed allocations on multi-appDomain
1691 applications as they could leak memory when a domain is unloaded.
1693 Although this is a fine default, for applications that use more than
1694 on AppDomain heavily (for example, ASP.NET applications) it is worth
1695 trading off the small leaks for the increased performance
1696 (additionally, since ASP.NET applications are not likely going to
1697 unload the application domains on production systems, it is worth
1698 using this feature).
1700 \fBdyn-runtime-invoke\fR
1701 Instructs the runtime to try to use a generic runtime-invoke wrapper
1702 instead of creating one invoke wrapper.
1704 \fBexplicit-null-checks\fR
1705 Makes the JIT generate an explicit NULL check on variable dereferences
1706 instead of depending on the operating system to raise a SIGSEGV or
1707 another form of trap event when an invalid memory location is
1711 Equivalent to setting the \fBMONO_XDEBUG\fR variable, this emits
1712 symbols into a shared library as the code is JITed that can be loaded
1713 into GDB to inspect symbols.
1715 \fBgen-seq-points\fR
1716 Automatically generates sequence points where the
1717 IL stack is empty. These are places where the debugger can set a
1720 \fBno-compact-seq-points\fR
1721 Unless the option is used, the runtime generates sequence points data that
1722 maps native offsets to IL offsets. Sequence point data is used to
1723 display IL offset in stacktraces. Stacktraces with IL offsets can be
1724 symbolicated using mono-symbolicate tool.
1727 Captures the interrupt signal (Control-C) and displays a stack trace
1728 when pressed. Useful to find out where the program is executing at a
1729 given point. This only displays the stack trace of a single thread.
1732 Instructs the runtime to initialize the stack with
1733 some known values (0x2a on x86-64) at the start of a method to assist
1734 in debuggin the JIT engine.
1736 \fBkeep-delegates\fR
1737 This option will leak delegate trampolines that are no longer
1738 referenced as to present the user with more information about a
1739 delegate misuse. Basically a delegate instance might be created,
1740 passed to unmanaged code, and no references kept in managed code,
1741 which will garbage collect the code. With this option it is possible
1742 to track down the source of the problems.
1744 \fBno-gdb-backtrace\fR
1745 This option will disable the GDB backtrace emitted by the runtime
1746 after a SIGSEGV or SIGABRT in unmanaged code.
1748 \fBpartial-sharing\fR
1749 When this option is set, the runtime can share generated code between
1750 generic types effectively reducing the amount of code generated.
1752 \fBreverse-pinvoke-exceptions
1753 This option will cause mono to abort with a descriptive message when
1754 during stack unwinding after an exception it reaches a native stack
1755 frame. This happens when a managed delegate is passed to native code,
1756 and the managed delegate throws an exception. Mono will normally try
1757 to unwind the stack to the first (managed) exception handler, and it
1758 will skip any native stack frames in the process. This leads to
1759 undefined behaviour (since mono doesn't know how to process native
1760 frames), leaks, and possibly crashes too.
1762 \fBsingle-imm-size\fR
1763 This guarantees that each time managed code is compiled the same
1764 instructions and registers are used, regardless of the size of used
1767 \fBsoft-breakpoints\fR
1768 This option allows using single-steps and breakpoints in hardware
1769 where we cannot do it with signals.
1771 \fBsuspend-on-native-crash\fR
1772 This option will suspend the program when a native crash occurs (SIGSEGV, SIGILL, ...).
1773 This is useful for debugging crashes which do not happen under gdb,
1774 since a live process contains more information than a core file.
1776 \fBsuspend-on-sigsegv\fR
1777 Same as \fBsuspend-on-native-crash\fR.
1779 \fBsuspend-on-exception\fR
1780 This option will suspend the program when an exception occurs.
1782 \fBsuspend-on-unhandled\fR
1783 This option will suspend the program when an unhandled exception occurs.
1787 \fBMONO_LOG_LEVEL\fR
1788 The logging level, possible values are `error', `critical', `warning',
1789 `message', `info' and `debug'. See the DEBUGGING section for more
1793 Controls the domain of the Mono runtime that logging will apply to.
1794 If set, the log mask is changed to the set value. Possible values are
1795 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1796 (garbage collector), "cfg" (config file loader), "aot" (precompiler),
1797 "security" (e.g. Moonlight CoreCLR support) and "all".
1798 The default value is "all". Changing the mask value allows you to display only
1799 messages for a certain component. You can use multiple masks by comma
1800 separating them. For example to see config file messages and assembly loader
1801 messages set you mask to "asm,cfg".
1804 Controls where trace log messages are written. If not set then the messages go to stdout.
1805 If set, the string either specifies a path to a file that will have messages appended to
1806 it, or the string "syslog" in which case the messages will be written to the system log.
1807 Under Windows, this is simulated by writing to a file called "mono.log".
1808 \fBMONO_LOG_HEADER\fR
1809 Controls whether trace log messages not directed to syslog have the id, timestamp, and
1810 pid as the prefix to the log message. To enable a header this environment variable need
1814 Used for runtime tracing of method calls. The format of the comma separated
1823 disabled Trace output off upon start.
1826 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1828 \fBMONO_TRACE_LISTENER\fR
1829 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1830 print the output of the System.Diagnostics Trace and Debug classes.
1831 It can be set to a filename, and to Console.Out or Console.Error to display
1832 output to standard output or standard error, respectively. If it's set to
1833 Console.Out or Console.Error you can append an optional prefix that will
1834 be used when writing messages like this: Console.Error:MyProgramName.
1835 See the System.Diagnostics.DefaultTraceListener documentation for more
1838 \fBMONO_WCF_TRACE\fR
1839 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.
1841 \fBMONO_XEXCEPTIONS\fR
1842 This throws an exception when a X11 error is encountered; by default a
1843 message is displayed but execution continues
1845 \fBMONO_XMLSERIALIZER_DEBUG\fR
1846 Set this value to 1 to prevent the serializer from removing the
1847 temporary files that are created for fast serialization; This might
1848 be useful when debugging.
1851 This is used in the System.Windows.Forms implementation when running
1852 with the X11 backend. This is used to debug problems in Windows.Forms
1853 as it forces all of the commands send to X11 server to be done
1854 synchronously. The default mode of operation is asynchronous which
1855 makes it hard to isolate the root of certain problems.
1858 When the the MONO_XDEBUG env var is set, debugging info for JITted
1859 code is emitted into a shared library, loadable into gdb. This enables,
1860 for example, to see managed frame names on gdb backtraces.
1862 \fBMONO_VERBOSE_METHOD\fR
1863 Enables the maximum JIT verbosity for the specified method. This is
1864 very helpfull to diagnose a miscompilation problems of a specific
1865 method. This can be a comma-separated list of method names to
1866 match. If the name is simple, this applies to any method with that
1867 name, otherwise you can use a mono method description (see the section
1868 METHOD DESCRIPTIONS).
1870 \fBMONO_JIT_DUMP_METHOD\fR
1871 Enables sending of the JITs intermediate representation for a specified
1872 method to the IdealGraphVisualizer tool.
1874 \fBMONO_VERBOSE_HWCAP\fR
1875 If set, makes the JIT output information about detected CPU features
1876 (such as SSE, CMOV, FCMOV, etc) to stdout.
1878 \fBMONO_CONSERVATIVE_HWCAP\fR
1879 If set, the JIT will not perform any hardware capability detection. This
1880 may be useful to pinpoint the cause of JIT issues. This is the default
1881 when Mono is built as an AOT cross compiler, so that the generated code
1882 will run on most hardware.
1884 If you want to use Valgrind, you will find the file `mono.supp'
1885 useful, it contains the suppressions for the GC which trigger
1886 incorrect warnings. Use it like this:
1888 valgrind --suppressions=mono.supp mono ...
1891 On some platforms, Mono can expose a set of DTrace probes (also known
1892 as user-land statically defined, USDT Probes).
1894 They are defined in the file `mono.d'.
1896 .B ves-init-begin, ves-init-end
1898 Begin and end of runtime initialization.
1900 .B method-compile-begin, method-compile-end
1902 Begin and end of method compilation.
1903 The probe arguments are class name, method name and signature,
1904 and in case of method-compile-end success or failure of compilation.
1908 Begin and end of Garbage Collection.
1910 To verify the availability of the probes, run:
1912 dtrace -P mono'$target' -l -c mono
1915 Mono's Ping implementation for detecting network reachability can
1916 create the ICMP packets itself without requiring the system ping
1917 command to do the work. If you want to enable this on Linux for
1918 non-root users, you need to give the Mono binary special permissions.
1920 As root, run this command:
1922 # setcap cap_net_raw=+ep /usr/bin/mono
1925 On Unix assemblies are loaded from the installation lib directory. If you set
1926 `prefix' to /usr, the assemblies will be located in /usr/lib. On
1927 Windows, the assemblies are loaded from the directory where mono and
1930 .B ~/.mono/aot-cache
1932 The directory for the ahead-of-time compiler demand creation
1933 assemblies are located.
1935 .B /etc/mono/config, ~/.mono/config
1937 Mono runtime configuration file. See the mono-config(5) manual page
1938 for more information.
1940 .B ~/.config/.mono/certs, /usr/share/.mono/certs
1942 Contains Mono certificate stores for users / machine. See the certmgr(1)
1943 manual page for more information on managing certificate stores and
1944 the mozroots(1) page for information on how to import the Mozilla root
1945 certificates into the Mono certificate store.
1947 .B ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
1949 Files in this directory allow a user to customize the configuration
1950 for a given system assembly, the format is the one described in the
1951 mono-config(5) page.
1953 .B ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
1955 Contains Mono cryptographic keypairs for users / machine. They can be
1956 accessed by using a CspParameters object with DSACryptoServiceProvider
1957 and RSACryptoServiceProvider classes.
1959 .B ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
1961 Contains Mono isolated storage for non-roaming users, roaming users and
1962 local machine. Isolated storage can be accessed using the classes from
1963 the System.IO.IsolatedStorage namespace.
1965 .B <assembly>.config
1967 Configuration information for individual assemblies is loaded by the
1968 runtime from side-by-side files with the .config files, see the
1969 http://www.mono-project.com/Config for more information.
1971 .B Web.config, web.config
1973 ASP.NET applications are configured through these files, the
1974 configuration is done on a per-directory basis. For more information
1975 on this subject see the http://www.mono-project.com/Config_system.web
1978 Mailing lists are listed at the
1979 http://www.mono-project.com/community/help/mailing-lists/
1981 http://www.mono-project.com
1984 \fBcertmgr\fR(1), \fBcert-sync\fR(1), \fBcsharp\fR(1),
1985 \fBgacutil\fR(1), \fBmcs\fR(1), \fBmonodis\fR(1),
1986 \fBmono-config\fR(5), \fBmono\-profilers\fR(1),
1987 \fBmprof\-report\fR(1), \fBpdb2mdb\fR(1), \fBxsp\fR(1),
1990 For more information on AOT:
1991 http://www.mono-project.com/docs/advanced/aot/
1993 For ASP.NET-related documentation, see the xsp(1) manual page