3 .\" (C) 2003 Ximian, Inc.
4 .\" (C) 2004-2005 Novell, Inc.
6 .\" Miguel de Icaza (miguel@gnu.org)
10 mono \- Mono's ECMA-CLI native code generator (Just-in-Time and Ahead-of-Time)
13 .B mono [options] file [arguments...]
15 \fImono\fP is a runtime implementation of the ECMA Common Language
16 Infrastructure. This can be used to run ECMA and .NET applications.
18 The runtime contains a native code generator that transforms the
19 Common Intermediate Language into native code.
21 The code generator can operate in two modes: just in time compilation
22 (JIT) or ahead of time compilation (AOT). Since code can be
23 dynamically loaded, the runtime environment and the JIT are always
24 present, even if code is compiled ahead of time.
26 The runtime loads the specified
33 is an ECMA assembly. They typically have a .exe or .dll extension.
35 The runtime provides a number of configuration options for running
36 applications, for developing and debugging, and for testing and
37 debugging the runtime itself.
39 On Unix-based systems, Mono provides a mechanism to emulate the
40 Windows-style file access, this includes providing a case insensitive
41 view of the file system, directory separator mapping (from \\ to /) and
42 stripping the drive letters.
44 This functionality is enabled by setting the
46 environment variable to one of
51 See the description for
53 in the environment variables section for more details.
55 The following options are available:
57 \fB--aot\fR, \fB--aot[=options]\fR
58 This option is used to precompile the CIL code in the specified
59 assembly to native code. The generated code is stored in a file with
60 the extension .so. This file will be automatically picked up by the
61 runtime when the assembly is executed.
63 Ahead-of-Time compilation is most useful if you use it in combination
64 with the -O=all,-shared flag which enables all of the optimizations in
65 the code generator to be performed. Some of those optimizations are
66 not practical for Just-in-Time compilation since they might be very
69 Unlike the .NET Framework, Ahead-of-Time compilation will not generate
70 domain independent code: it generates the same code that the
71 Just-in-Time compiler would produce. Since most applications use a
72 single domain, this is fine. If you want to optimize the generated
73 code for use in multi-domain applications, consider using the
76 This pre-compiles the methods, but the original assembly is still
77 required to execute as this one contains the metadata and exception
78 information which is not available on the generated file. When
79 precompiling code, you might want to compile with all optimizations
80 (-O=all). Pre-compiled code is position independent code.
82 Pre compilation is just a mechanism to reduce startup time, increase
83 code sharing across multiple mono processes and avoid just-in-time
84 compilation program startup costs. The original assembly must still
85 be present, as the metadata is contained there.
87 AOT code typically can not be moved from one computer to another
88 (CPU-specific optimizations that are detected at runtime) so you
89 should not try to move the pre-generated assemblies or package the
90 pre-generated assemblies for deployment.
92 A few options are available as a parameter to the
94 command line option. The options are separated by commas, and more
95 than one can be specified:
99 .I bind-to-runtime-version
101 If specified, forces the generated AOT files to be bound to the
102 runtime version of the compiling Mono. This will prevent the AOT
103 files from being consumed by a different Mono runtime.
105 This is currently an experimental feature as it is not complete.
106 This instructs Mono to precompile code that has historically not been
107 precompiled with AOT.
110 Instructs the AOT compiler to emit debug symbol information.
113 Create an ELF object file (.o) which can be statically linked into an executable
114 when embedding the mono runtime. When this option is used, the object file needs to
115 be registered with the embedded runtime using the mono_aot_register_module function
116 which takes as its argument the mono_aot_module_<ASSEMBLY NAME>_info global symbol
117 from the object file:
120 extern void *mono_aot_module_hello_info;
122 mono_aot_register_module (mono_aot_module_hello_info);
127 For more information about AOT, see: http://www.mono-project.com/AOT
130 \fB--attach=[options]\fR
131 Currently the only option supported by this command line argument is
132 \fBdisable\fR which disables the attach functionality.
135 This is an experimental flag that instructs the Mono runtime to not
136 generate any code at runtime and depend exclusively on the code
137 generated from using mono --aot=full previously. This is useful for
138 platforms that do not permit dynamic code generation.
140 Notice that this feature will abort execution at runtime if a codepath
141 in your program, or Mono's class libraries attempts to generate code
142 dynamically. You should test your software upfront and make sure that
143 you do not use any dynamic features.
145 \fB--config filename\fR
146 Load the specified configuration file instead of the default one(s).
147 The default files are /etc/mono/config and ~/.mono/config or the file
148 specified in the MONO_CONFIG environment variable, if set. See the
149 mono-config(5) man page for details on the format of this file.
152 Configures the virtual machine to be better suited for desktop
153 applications. Currently this sets the GC system to avoid expanding
154 the heap as much as possible at the expense of slowing down garbage
157 \fB--help\fR, \fB-h\fR
158 Displays usage instructions.
160 \fB--optimize=MODE\fR, \fB-O=MODE\fR
161 MODE is a comma separated list of optimizations. They also allow
162 optimizations to be turned off by prefixing the optimization name with
165 In general, Mono has been tuned to use the default set of flags,
166 before using these flags for a deployment setting, you might want to
167 actually measure the benefits of using them.
169 The following optimizations are implemented:
171 all Turn on all optimizations
172 peephole Peephole postpass
173 branch Branch optimizations
174 inline Inline method calls
175 cfold Constant folding
176 consprop Constant propagation
177 copyprop Copy propagation
178 deadce Dead code elimination
179 linears Linear scan global reg allocation
180 cmov Conditional moves [arch-dependency]
181 shared Emit per-domain code
182 sched Instruction scheduling
183 intrins Intrinsic method implementations
184 tailc Tail recursion and tail calls
185 loop Loop related optimizations
186 fcmov Fast x86 FP compares [arch-dependency]
187 leaf Leaf procedures optimizations
188 aot Usage of Ahead Of Time compiled code
189 precomp Precompile all methods before executing Main
190 abcrem Array bound checks removal
191 ssapre SSA based Partial Redundancy Elimination
192 sse2 SSE2 instructions on x86 [arch-dependency]
193 gshared Enable generic code sharing.
196 For example, to enable all the optimization but dead code
197 elimination and inlining, you can use:
199 -O=all,-deadce,-inline
202 The flags that are flagged with [arch-dependency] indicate that the
203 given option if used in combination with Ahead of Time compilation
204 (--aot flag) would produce pre-compiled code that will depend on the
205 current CPU and might not be safely moved to another computer.
207 \fB--runtime=VERSION\fR
208 Mono supports different runtime versions. The version used depends on the program
209 that is being run or on its configuration file (named program.exe.config). This option
210 can be used to override such autodetection, by forcing a different runtime version
211 to be used. Note that this should only be used to select a later compatible runtime
212 version than the one the program was compiled against. A typical usage is for
213 running a 1.1 program on a 2.0 version:
215 mono --runtime=v2.0.50727 program.exe
218 \fB--security\fR, \fB--security=mode\fR
219 Activate the security manager, a currently experimental feature in
220 Mono and it is OFF by default. The new code verifier can be enabled
221 with this option as well.
225 Using security without parameters is equivalent as calling it with the
228 The following modes are supported:
231 This allows mono to support declarative security attributes,
232 e.g. execution of Code Access Security (CAS) or non-CAS demands.
235 Enables the core-clr security system, typically used for
236 Moonlight/Silverlight applications. It provides a much simpler
237 security system than CAS, see http://www.mono-project.com/Moonlight
238 for more details and links to the descriptions of this new system.
241 Enables the new verifier and performs basic verification for code
242 validity. In this mode, unsafe code and P/Invoke are allowed. This
243 mode provides a better safety guarantee but it is still possible
244 for managed code to crash Mono.
247 Enables the new verifier and performs full verification of the code
248 being executed. It only allows verifiable code to be executed.
249 Unsafe code is not allowed but P/Invoke is. This mode should
250 not allow managed code to crash mono. The verification is not as
251 strict as ECMA 335 standard in order to stay compatible with the MS
254 The security system acts on user code: code contained in mscorlib or
255 the global assembly cache is always trusted.
260 Configures the virtual machine to be better suited for server
261 operations (currently, a no-op).
264 Verifies mscorlib and assemblies in the global
265 assembly cache for valid IL, and all user code for IL
268 This is different from \fB--security\fR's verifiable
269 or validil in that these options only check user code and skip
270 mscorlib and assemblies located on the global assembly cache.
272 \fB-V\fR, \fB--version\fR
273 Prints JIT version information (system configuration, release number
274 and branch names if available).
277 .SH DEVELOPMENT OPTIONS
278 The following options are used to help when developing a JITed application.
280 \fB--debug\fR, \fB--debug=OPTIONS\fR
281 Turns on the debugging mode in the runtime. If an assembly was
282 compiled with debugging information, it will produce line number
283 information for stack traces.
287 The optional OPTIONS argument is a comma separated list of debugging
288 options. These options are turned off by default since they generate
289 much larger and slower code at runtime.
291 The following options are supported:
294 Produces a detailed error when throwing a InvalidCastException. This
295 option needs to be enabled as this generates more verbose code at
299 Disable some JIT optimizations which are usually only disabled when
300 running inside the debugger. This can be helpful if you want to attach
301 to the running process with mdb.
305 \fB--profile[=profiler[:profiler_args]]\fR
306 Turns on profiling. For more information about profiling applications
307 and code coverage see the sections "PROFILING" and "CODE COVERAGE"
310 \fB--trace[=expression]\fR
311 Shows method names as they are invoked. By default all methods are
314 The trace can be customized to include or exclude methods, classes or
315 assemblies. A trace expression is a comma separated list of targets,
316 each target can be prefixed with a minus sign to turn off a particular
317 target. The words `program', `all' and `disabled' have special
318 meaning. `program' refers to the main program being executed, and
319 `all' means all the method calls.
321 The `disabled' option is used to start up with tracing disabled. It
322 can be enabled at a later point in time in the program by sending the
323 SIGUSR2 signal to the runtime.
325 Assemblies are specified by their name, for example, to trace all
326 calls in the System assembly, use:
329 mono --trace=System app.exe
332 Classes are specified with the T: prefix. For example, to trace all
333 calls to the System.String class, use:
336 mono --trace=T:System.String app.exe
339 And individual methods are referenced with the M: prefix, and the
340 standard method notation:
343 mono --trace=M:System.Console:WriteLine app.exe
346 As previously noted, various rules can be specified at once:
349 mono --trace=T:System.String,T:System.Random app.exe
352 You can exclude pieces, the next example traces calls to
353 System.String except for the System.String:Concat method.
356 mono --trace=T:System.String,-M:System.String:Concat
359 Finally, namespaces can be specified using the N: prefix:
362 mono --trace=N:System.Xml
366 \fB--no-x86-stack-align\fR
367 Don't align stack frames on the x86 architecture. By default, Mono
368 aligns stack frames to 16 bytes on x86, so that local floating point
369 and SIMD variables can be properly aligned. This option turns off the
370 alignment, which usually saves one intruction per call, but might
371 result in significantly lower floating point and SIMD performance.
372 .SH JIT MAINTAINER OPTIONS
373 The maintainer options are only used by those developing the runtime
374 itself, and not typically of interest to runtime users or developers.
377 Inserts a breakpoint before the method whose name is `method'
378 (namespace.class:methodname). Use `Main' as method name to insert a
379 breakpoint on the application's main method.
382 Inserts a breakpoint on exceptions. This allows you to debug your
383 application with a native debugger when an exception is thrown.
386 This compiles a method (namespace.name:methodname), this is used for
387 testing the compiler performance or to examine the output of the code
391 Compiles all the methods in an assembly. This is used to test the
392 compiler performance or to examine the output of the code generator
394 \fB--graph=TYPE METHOD\fR
395 This generates a postscript file with a graph with the details about
396 the specified method (namespace.name:methodname). This requires `dot'
397 and ghostview to be installed (it expects Ghostview to be called
400 The following graphs are available:
402 cfg Control Flow Graph (CFG)
404 code CFG showing code
405 ssa CFG showing code after SSA translation
406 optcode CFG showing code after IR optimizations
409 Some graphs will only be available if certain optimizations are turned
413 Instruct the runtime on the number of times that the method specified
414 by --compile (or all the methods if --compileall is used) to be
415 compiled. This is used for testing the code generator performance.
418 Displays information about the work done by the runtime during the
419 execution of an application.
421 \fB--wapi=hps|semdel\fR
422 Perform maintenance of the process shared data.
424 semdel will delete the global semaphore.
426 hps will list the currently used handles.
428 \fB-v\fR, \fB--verbose\fR
429 Increases the verbosity level, each time it is listed, increases the
430 verbosity level to include more information (including, for example,
431 a disassembly of the native code produced, code selector info etc.).
433 The Mono runtime allows external processes to attach to a running
434 process and load assemblies into the running program. To attach to
435 the process, a special protocol is implemented in the Mono.Management
438 With this support it is possible to load assemblies that have an entry
439 point (they are created with -target:exe or -target:winexe) to be
440 loaded and executed in the Mono process.
442 The code is loaded into the root domain, and it starts execution on
443 the special runtime attach thread. The attached program should
444 create its own threads and return after invocation.
446 This support allows for example debugging applications by having the
447 csharp shell attach to running processes.
449 The mono runtime includes a profiler that can be used to explore
450 various performance related problems in your application. The
451 profiler is activated by passing the --profile command line argument
452 to the Mono runtime, the format is:
455 --profile[=profiler[:profiler_args]]
458 Mono has a built-in profiler called 'default' (and is also the default
459 if no arguments are specified), but developers can write custom
460 profilers, see the section "CUSTOM PROFILERS" for more details.
464 is not specified, the default profiler is used.
468 is a profiler-specific string of options for the profiler itself.
470 The default profiler accepts the following options 'alloc' to profile
471 memory consumption by the application; 'time' to profile the time
472 spent on each routine; 'jit' to collect time spent JIT-compiling methods
473 and 'stat' to perform sample statistical profiling.
474 If no options are provided the default is 'alloc,time,jit'.
477 profile data is printed to stdout: to change this, use the 'file=filename'
478 option to output the data to filename.
483 mono --profile program.exe
487 That will run the program with the default profiler and will do time
488 and allocation profiling.
492 mono --profile=default:stat,alloc,file=prof.out program.exe
495 Will do sample statistical profiling and allocation profiling on
496 program.exe. The profile data is put in prof.out.
498 Note that the statistical profiler has a very low overhead and should
499 be the preferred profiler to use (for better output use the full path
500 to the mono binary when running and make sure you have installed the
501 addr2line utility that comes from the binutils package).
506 will eventually replace the default profiler as it is more complete
507 and encompasses the functionality of all the other profilers for Mono.
508 It supports the following execution modes:
511 the program instruction pointer is periodically sampled (it works also with
512 unmanaged functions). If call chains are requested, for each sample the
513 profiler gets a partial stack trace (up to a desired depth) so that
514 caller-callee information is available.
517 each method enter and exit is logged with a timestamp; further processing of
518 the data can show the methods that took the longer to execute, with complete
519 accounting for callers and callees. However, this way of profiling is rather
520 intrusive and slows down the application significantly.
523 each allocation is logged.
525 .I Allocation summary:
526 shows, for each collection, a summary of the heap contents broken down by
527 class (for each class the number of allocated and released objects is
528 given, together with their aggregated size in bytes).
530 .I Heap snapshot mode:
531 dumps the whole heap contents at every collection (or at user specified
532 collections). It is also possible to request a collection and snapshot dump
535 Moreover, other events can be logged and analyzed, like jit time for each
536 method, load and unload for assemblies, modules and and individual classes,
537 and appdomain and thread creation and destruction.
539 Instead of reporting the collected
540 information at the end of the execution of the program, this profiler logs
541 all the events periodically into a file during program execution.
542 To minimize the performance impact with multi-threaded applications,
543 the logging uses per-thread buffers that are routinely saved to disk.
545 The output file contains compressed events, to process the data you should
546 use tools like the "Mono.Profiler" tool provided on the Mono SVN
549 This profiler is activated passing the \fB--profile=logging\fR option to
550 the mono runtime, and is controlled attaching further options, like
551 \fB--profile=logging:statistical\fR for doing statistical profiling (multiple
552 options are separated by commas).
554 As a quick primer, here are a few examples of the most common usage modes:
556 To write the resulting data to "mydata.mprof" (defaults to statistical
560 mono --profile=logging:output=mydata.mprof program.exe
563 To perform statistical profiling, inspecting call chains up to depth 8:
566 mono --profile=logging:statistical=8 program.exe
569 To profile allocations (by default the call stack will be analized for
570 each allocation, producing detailed caller method attribution infornation):
573 mono --profile=logging:allocations program.exe
576 To profile garbage collection activity at a high level (collection time and objects freed
577 at each collection for each class are reported, but heap snapshots are not saved to disk):
580 mono --profile=logging:allocations-summary program.exe
583 To perform heap profiling taking heap snapshots:
586 mono --profile=logging:heap=all program.exe
587 mono --profile=logging:heap=<signal> program.exe
590 If "all" is specified, a heap snapshot is taken at each collection.
591 If, instead, a signal name or number is given (one of SIGUSR1, SIGUSR2 and
592 SIGPROF, remembering that SIGPROF is not compatible with the statistical
593 profiler), a garbage collection is forced and a snapshot is taken every
594 time the signal is received.
595 Heap profiling also enables full allocation profiling (with call stacks),
596 and each allocation can be related to its corresponding object in the
597 snapshots, enabling investigations like "find all objects of a given class
598 allocated by a given method and still live at a given collection, and then
599 find all objects referencing them".
602 Then you would need to invoke the decoder \fImprof-decoder(1)\fR
603 on the output file to see the profiling results, or to examine heap
604 snapshots and allocations in detail \fImprof-heap-viewer(1)\fR.
607 The operating modes described above are the default ones, and are sufficient
610 To further customize the profiler behavior there are more options, described
612 These options can be individually enabled and disabled prefixing them with
613 an (optional) '+' character or a '-' character.
614 For instance, the "allocations" option by default records also the full call
615 stack at each allocation.
616 If only the caller is wanted, one should use "allocations,-save-allocation-stack",
617 or to disable call tracking completely (making the profiler less intrusive)
618 "allocations,-save-allocation-caller,-save-allocation-stack".
619 In practice the "allocation" option by default behaves like
620 "allocations,save-allocation-caller,save-allocation-stack", but the user can
621 tune this to his needs.
623 These are all the available options, organized by category:
625 \fBExecution profiling modes\fR
629 \fIstatistical\fR, \fIstat\fR or \fIs\fR
630 Performs statistical profiling. This is a lightweight profiling
631 mechanism and it has a much lower overhead than the \fIenter-leave\fR
632 profiling as it works by sampling where the program is spending its
633 time by using a timer.
634 If specified with \fIs=<number>\fR, also inspect call chains up to level
637 \fIenter-leave\fR, \fIcalls\fR or \fIc\fR
638 Measure the time spent inside each method call, this is done by
639 logging the time when a method enters and when the method leaves.
640 This can be a time consuming operation.
643 Collect information about time spent by the JIT engine compiling
648 \fBAllocation profiling modes\fR
652 \fIallocations\fR, \fIalloc\fR or \fIa\fR
653 Collect information about each allocation (object class and size).
654 By default this also implies "+save-allocation-caller" and
655 "+save-allocation-stack".
657 \fIsave-allocation-caller\fR, \fIsac\fR
658 Save the direct caller of each allocation. The profiler filters out wrapper
659 methods, and also recognizes if the allocation has been performed by the
660 runtime while jitting a method.
662 \fIsave-allocation-stack\fR, \fIsas\fR
663 Save the full managed execution stack at each allocation.
664 While the "sac" option saves the direct caller, this one records the whole
666 Note that in the call stack the wrapper methods are not filtered out.
667 Anyway the "sac" and "sas" options can be combined, and the decoder will
668 attribute the allocation to the correct method even if the wrapper is at the
669 top of the stack trace.
671 \fIallocations-summary\fR or \fIas\fR
672 At each collection dump a summary
673 of the heap contents (for each class, the number and collective size of all
674 live and freed heap objects). This very lightweight compared to full heap
677 \fIunreachable\fR, \fIfree\fR or \fIf\fR
678 Performs a lightweight profile of the garbage collector. On each
679 collection performed by the GC, the list of unreachable objects is
680 recorded, and for each object the class and size is provided. This
681 information can be used to compute the heap size broken down by class
682 (combined with "a" can give the same information of "as", but the log
683 file contains info about each individual object, while in "as" the
684 processing is done directly at runtime and the log file contains only
685 the summarized data broken down by class).
688 Measure the time spent in each collection, and also trace heap resizes.
690 \fIheap-shot\fR, \fIheap\fR or \fIh\fR
691 Performs full heap profiling. In this case on each
692 collection a full heap snapshot is recorded to disk.
693 Inside the snapshots, each object reference is still represented so
694 that it's possible to investigate who is responsible for keeping objects
697 The actual production of heap snapshots could produce large log files,
698 so it can be controlled in three ways:
700 \fIgc-dumps=N\fR, \fIgc-d=N\fR, \fIgcd=N\fR
701 states the number of snapshots that must be dumped (since the application
702 starts). Zero means no dumps at all, -1 means dump at all collections.
704 \fIgc-signal=<signal>\fR, \fIgc-s\fR or \fIgcs\fR
705 (where <signal> is one of "SIGUSR1", "SIGUSR2", or "SIGPROF")
706 specifies a signal that will immediately trigger a collection and a dump.
708 \fIgc-commands=FILE\fR, \fIgc-c=FILE\fR or \fIgcc=FILE\fR
709 specify a "command file". The file must contain an integer value in ASCII
710 form, and the profiler will stat it at every collection.
711 If it has been modified it will interpret its contents as a \fIgcd=N\fR
712 option value, and dump the required number of snapshots from that moment
714 If the file is present at application startup it takes precedence over an
715 eventual \fIgcd=N\fR option.
719 \fBProfiler activity control\fR
723 \fIoutput=FILE\fR, \fIout=FILE\fR or \fIo=FILE\fR
724 Use this option to provide the output file name for the profile log.
725 If this option is not specified, it will default to "<program-name>.mprof".
727 \fIoutput-suffix=SUFFIX\fR, \fIsuffix=SUFFIX\fR or \fIos=SUFFIX\fR: makes
728 the output file name equals to "<program-name>-SUFFIX.mprof".
730 \fIstart-enabled\fR or \fIse\fR: start with the profiler active
731 (which is the default).
733 \fIstart-disabled\fR or \fIsd\fR: start with the profiler inactive.
735 \fItoggle-signal=<SIGNAL>\fR or \fIts=<SIGNAL>\fR (where <SIGNAL>
736 is one of SIGUSR1, SIGUSR2 or SIGPROF): Choose a signal that will be used to
737 toggle the profiler activity on and off. This way you can decide to profile
738 only portions of the applicatopn lifetime (for instance, you can decide to
739 avoid profiling an initial setup phase using \fIsd\fR, and enable the
740 profiler later delivering the signal to the application).
742 \fIforce-accurate-timer\fR (or \fIfac\fR): the profiler by default uses
743 rtdsc to acquire timestamps for frequent events, but this can be imprecise;
744 using this option you force the use of "gettimeofday" at every event, which
745 is more accurate but much slower.
749 \fBInternal buffer sizes\fR
753 \fIper-thread-buffer-size=N\fR, \fItbs=N\fR
754 Use to specify the number of events that a thread buffer
755 can hold. When the thread buffer is full, a log block is
758 This defaults to tbs=10000.
760 \fIstatistical-thread-buffer-size=N\fR, \fIsbs=N\fR
761 The number of statistical samples that
762 are held in memory before they are dumped to disk (the system does
763 double-buffering and the statistical samples are written by a helper
764 thread, so the statistical profiler never stops and is able to profile
765 the profiler itself).
767 This defaults to sbs=10000.
769 \fIwrite-buffer-size\fR, \fIwbs\fR
770 Specifies the size in bytes of the internal write buffers.
772 This defaults to wbs=1024.
776 In its current state, this profiler can also perform heap analysis (like
777 heap-shot), and the decoder is already able to read the data, however
778 the user interface for this feature is experimental (the
779 \fImprof-heap-viewer\fR tool in the mono-tools module).
781 Another known issue is that if the timer is not strictly monotonic (like
782 rtdsc), differences between times can underflow (they are handled as
783 unsigned integers) and weird numbers can show up in the logs.
785 Finally, it can happen that when exceptions are thrown the profiler temporarily
786 loses track of the execution stack and misattributes the caller for a few
787 allocations (and method execution time).
789 More explanations are provided here: "http://www.mono-project.com/LoggingProfiler".
790 .SH EXTERNAL PROFILERS
791 There are a number of external profilers that have been developed for
792 Mono, we will update this section to contain the profilers.
794 The heap Shot profiler can track all live objects, and references to
795 these objects, and includes a GUI tool, this is our recommended
797 To install you must download the profiler
800 svn co svn://anonsvn.mono-project.com/source/trunk/heap-shot
807 See the included documentation for details on using it.
809 The Live Type profiler shows at every GC iteration all of the live
810 objects of a given type. To install you must download the profiler
813 svn co svn://anonsvn.mono-project.com/source/trunk/heap-prof
820 To use the profiler, execute:
822 mono --profile=desc-heap program.exe
825 The output of this profiler looks like this:
827 Checkpoint at 102 for heap-resize
828 System.MonoType : 708
829 System.Threading.Thread : 352
831 System.String[] : 104
832 Gnome.ModuleInfo : 112
833 System.Object[] : 160
834 System.Collections.Hashtable : 96
836 System.Collections.Hashtable+Slot[] : 296
837 System.Globalization.CultureInfo : 108
838 System.Globalization.NumberFormatInfo : 144
841 The first line describes the iteration number for the GC, in this case
844 Then on each line the type is displayed as well as the number of bytes
845 that are being consumed by live instances of this object.
847 The AOT profiler is used to feed back information to the AOT compiler
848 about how to order code based on the access patterns for pages. To
851 mono --profile=aot program.exe
853 The output of this profile can be fed back into Mono's AOT compiler to
854 order the functions on the disk to produce precompiled images that
855 have methods in sequential pages.
857 Mono provides a mechanism for loading other profiling modules which in
858 the form of shared libraries. These profiling modules can hook up to
859 various parts of the Mono runtime to gather information about the code
862 To use a third party profiler you must pass the name of the profiler
866 mono --profile=custom program.exe
870 In the above sample Mono will load the user defined profiler from the
871 shared library `mono-profiler-custom.so'. This profiler module must
872 be on your dynamic linker library path.
874 A list of other third party profilers is available from Mono's web
875 site (www.mono-project.com/Performance_Tips)
877 Custom profiles are written as shared libraries. The shared library
878 must be called `mono-profiler-NAME.so' where `NAME' is the name of
881 For a sample of how to write your own custom profiler look in the
882 Mono source tree for in the samples/profiler.c.
884 Mono ships with a code coverage module. This module is activated by
885 using the Mono --profile=cov option. The format is:
886 \fB--profile=cov[:assembly-name[/namespace]] test-suite.exe\fR
888 By default code coverage will default to all the assemblies loaded,
889 you can limit this by specifying the assembly name, for example to
890 perform code coverage in the routines of your program use, for example
891 the following command line limits the code coverage to routines in the
895 mono --profile=cov:demo demo.exe
901 does not include the extension.
903 You can further restrict the code coverage output by specifying a
907 mono --profile=cov:demo/My.Utilities demo.exe
911 Which will only perform code coverage in the given assembly and
914 Typical output looks like this:
917 Not covered: Class:.ctor ()
918 Not covered: Class:A ()
919 Not covered: Driver:.ctor ()
920 Not covered: Driver:method ()
921 Partial coverage: Driver:Main ()
926 The offsets displayed are IL offsets.
928 A more powerful coverage tool is available in the module `monocov'.
929 See the monocov(1) man page for details.
931 To debug managed applications, you can use the
933 command, a command line debugger.
935 It is possible to obtain a stack trace of all the active threads in
936 Mono by sending the QUIT signal to Mono, you can do this from the
937 command line, like this:
943 Where pid is the Process ID of the Mono process you want to examine.
944 The process will continue running afterwards, but its state is not
948 this is a last-resort mechanism for debugging applications and should
949 not be used to monitor or probe a production application. The
950 integrity of the runtime after sending this signal is not guaranteed
951 and the application might crash or terminate at any given point
954 The \fB--debug=casts\FR option can be used to get more detailed
955 information for Invalid Cast operations, it will provide information
956 about the types involved.
958 You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables
959 to get verbose debugging output about the execution of your
960 application within Mono.
964 environment variable if set, the logging level is changed to the set
965 value. Possible values are "error", "critical", "warning", "message",
966 "info", "debug". The default value is "error". Messages with a logging
967 level greater then or equal to the log level will be printed to
970 Use "info" to track the dynamic loading of assemblies.
975 environment variable to limit the extent of the messages you get:
976 If set, the log mask is changed to the set value. Possible values are
977 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
978 (garbage collector), "cfg" (config file loader), "aot" (precompiler) and "all".
979 The default value is "all". Changing the mask value allows you to display only
980 messages for a certain component. You can use multiple masks by comma
981 separating them. For example to see config file messages and assembly loader
982 messages set you mask to "asm,cfg".
984 The following is a common use to track down problems with P/Invoke:
987 $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
992 Mono's XML serialization engine by default will use a reflection-based
993 approach to serialize which might be slow for continuous processing
994 (web service applications). The serialization engine will determine
995 when a class must use a hand-tuned serializer based on a few
996 parameters and if needed it will produce a customized C# serializer
997 for your types at runtime. This customized serializer then gets
998 dynamically loaded into your application.
1000 You can control this with the MONO_XMLSERIALIZER_THS environment
1003 The possible values are
1005 to disable the use of a C# customized
1006 serializer, or an integer that is the minimum number of uses before
1007 the runtime will produce a custom serializer (0 will produce a
1008 custom serializer on the first access, 50 will produce a serializer on
1009 the 50th use). Mono will fallback to an interpreted serializer if the
1010 serializer generation somehow fails. This behavior can be disabled
1011 by setting the option
1013 (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
1014 .SH ENVIRONMENT VARIABLES
1017 Turns off the garbage collection in Mono. This should be only used
1018 for debugging purposes
1020 \fBMONO_AOT_CACHE\fR
1021 If set, this variable will instruct Mono to ahead-of-time compile new
1022 assemblies on demand and store the result into a cache in
1026 If set, this variable overrides the default system configuration directory
1027 ($PREFIX/etc). It's used to locate machine.config file.
1030 Sets the style of COM interop. If the value of this variable is "MS"
1031 Mono will use string marhsalling routines from the liboleaut32 for the
1032 BSTR type library, any other values will use the mono-builtin BSTR
1036 If set, this variable overrides the default runtime configuration file
1037 ($PREFIX/etc/mono/config). The --config command line options overrides the
1038 environment variable.
1041 If set, enables some features of the runtime useful for debugging.
1042 This variable should contain a comma separated list of debugging options.
1043 Currently, the following options are supported:
1047 \fBbreak-on-unverified\fR
1048 If this variable is set, when the Mono VM runs into a verification
1049 problem, instead of throwing an exception it will break into the
1050 debugger. This is useful when debugging verifier problems
1052 \fBcollect-pagefault-stats\fR
1053 Collects information about pagefaults. This is used internally to
1054 track the number of page faults produced to load metadata. To display
1055 this information you must use this option with "--stats" command line
1058 \fBdont-free-domains\fR
1059 This is an Optimization for multi-AppDomain applications (most
1060 commonly ASP.NET applications). Due to internal limitations Mono,
1061 Mono by default does not use typed allocations on multi-appDomain
1062 applications as they could leak memory when a domain is unloaded.
1064 Although this is a fine default, for applications that use more than
1065 on AppDomain heavily (for example, ASP.NET applications) it is worth
1066 trading off the small leaks for the increased performance
1067 (additionally, since ASP.NET applications are not likely going to
1068 unload the application domains on production systems, it is worth
1069 using this feature).
1072 Captures the interrupt signal (Control-C) and displays a stack trace
1073 when pressed. Useful to find out where the program is executing at a
1074 given point. This only displays the stack trace of a single thread.
1076 \fBkeep-delegates\fR
1077 This option will leak delegate trampolines that are no longer
1078 referenced as to present the user with more information about a
1079 delegate misuse. Basically a delegate instance might be created,
1080 passed to unmanaged code, and no references kept in managed code,
1081 which will garbage collect the code. With this option it is possible
1082 to track down the source of the problems.
1084 \fBno-gdb-backtrace\fR
1085 This option will disable the GDB backtrace emitted by the runtime
1086 after a SIGSEGV or SIGABRT in unmanaged code.
1088 \fBsuspend-on-sigsegv\fR
1090 This option will suspend the program when a native SIGSEGV is received.
1091 This is useful for debugging crashes which do not happen under gdb,
1092 since a live process contains more information than a core file.
1096 \fBMONO_DISABLE_AIO\fR
1097 If set, tells mono NOT to attempt using native asynchronous I/O services. In
1098 that case, a default select/poll implementation is used. Currently only epoll()
1101 \fBMONO_DISABLE_MANAGED_COLLATION\fR
1102 If this environment variable is `yes', the runtime uses unmanaged
1103 collation (which actually means no culture-sensitive collation). It
1104 internally disables managed collation functionality invoked via the
1105 members of System.Globalization.CompareInfo class. Collation is
1108 \fBMONO_EGD_SOCKET\fR
1109 For platforms that do not otherwise have a way of obtaining random bytes
1110 this can be set to the name of a file system socket on which an egd or
1111 prngd daemon is listening.
1113 \fBMONO_EVENTLOG_TYPE\fR
1114 Sets the type of event log provider to use (for System.Diagnostics.EventLog).
1116 Possible values are:
1121 Persists event logs and entries to the local file system.
1123 The directory in which to persist the event logs, event sources and entries
1124 can be specified as part of the value.
1126 If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog"
1127 on unix and "%APPDATA%\mono\eventlog" on Windows.
1132 Uses the native win32 API to write events and registers event logs and
1133 event sources in the registry. This is only available on Windows.
1135 On Unix, the directory permission for individual event log and event source
1136 directories is set to 777 (with +t bit) allowing everyone to read and write
1137 event log entries while only allowing entries to be deleted by the user(s)
1142 Silently discards any events.
1145 The default is "null" on Unix (and versions of Windows before NT), and
1146 "win32" on Windows NT (and higher).
1149 \fBMONO_EXTERNAL_ENCODINGS\fR
1150 If set, contains a colon-separated list of text encodings to try when
1151 turning externally-generated text (e.g. command-line arguments or
1152 filenames) into Unicode. The encoding names come from the list
1153 provided by iconv, and the special case "default_locale" which refers
1154 to the current locale's default encoding.
1156 When reading externally-generated text strings UTF-8 is tried first,
1157 and then this list is tried in order with the first successful
1158 conversion ending the search. When writing external text (e.g. new
1159 filenames or arguments to new processes) the first item in this list
1160 is used, or UTF-8 if the environment variable is not set.
1162 The problem with using MONO_EXTERNAL_ENCODINGS to process your
1163 files is that it results in a problem: although its possible to get
1164 the right file name it is not necessarily possible to open the file.
1165 In general if you have problems with encodings in your filenames you
1166 should use the "convmv" program.
1168 \fBMONO_GAC_PREFIX\fR
1169 Provides a prefix the runtime uses to look for Global Assembly Caches.
1170 Directories are separated by the platform path separator (colons on
1171 unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
1172 install. Or to the directory provided in the gacutil /gacdir command. Example:
1173 .B /home/username/.mono:/usr/local/mono/
1176 Enables some filename rewriting support to assist badly-written
1177 applications that hard-code Windows paths. Set to a colon-separated
1178 list of "drive" to strip drive letters, or "case" to do
1179 case-insensitive file matching in every directory in a path. "all"
1180 enables all rewriting methods. (Backslashes are always mapped to
1181 slashes if this variable is set to a valid option.)
1184 For example, this would work from the shell:
1187 MONO_IOMAP=drive:case
1191 If you are using mod_mono to host your web applications, you can use
1194 directive, like this:
1197 MonoSetEnv MONO_IOMAP=all
1201 \fBMONO_MANAGED_WATCHER\fR
1202 If set to "disabled", System.IO.FileSystemWatcher will use a file watcher
1203 implementation which silently ignores all the watching requests.
1204 If set to any other value, System.IO.FileSystemWatcher will use the default
1205 managed implementation (slow). If unset, mono will try to use inotify, FAM,
1206 Gamin, kevent under Unix systems and native API calls on Windows, falling
1207 back to the managed implementation on error.
1210 If set causes the mono process to be bound to a single processor. This may be
1211 useful when debugging or working around race conditions.
1214 Provides a search path to the runtime where to look for library
1215 files. This is a tool convenient for debugging applications, but
1216 should not be used by deployed applications as it breaks the assembly
1217 loader in subtle ways.
1219 Directories are separated by the platform path separator (colons on unix). Example:
1220 .B /home/username/lib:/usr/local/mono/lib
1222 Alternative solutions to MONO_PATH include: installing libraries into
1223 the Global Assembly Cache (see gacutil(1)) or having the dependent
1224 libraries side-by-side with the main executable.
1226 For a complete description of recommended practices for application
1228 http://www.mono-project.com/Guidelines:Application_Deployment page.
1231 Experimental RTC support in the statistical profiler: if the user has
1232 the permission, more accurate statistics are gathered. The MONO_RTC
1233 value must be restricted to what the Linux rtc allows: power of two
1234 from 64 to 8192 Hz. To enable higher frequencies like 4096 Hz, run as root:
1237 echo 4096 > /proc/sys/dev/rtc/max-user-freq
1244 MONO_RTC=4096 mono --profiler=default:stat program.exe
1249 Disable inlining of thread local accesses. Try setting this if you get a segfault
1250 early on in the execution of mono.
1252 \fBMONO_SHARED_DIR\fR
1253 If set its the directory where the ".wapi" handle state is stored.
1254 This is the directory where the Windows I/O Emulation layer stores its
1255 shared state data (files, events, mutexes, pipes). By default Mono
1256 will store the ".wapi" directory in the users's home directory.
1258 \fBMONO_SHARED_HOSTNAME\fR
1259 Uses the string value of this variable as a replacement for the host name when
1260 creating file names in the ".wapi" directory. This helps if the host name of
1261 your machine is likely to be changed when a mono application is running or if
1262 you have a .wapi directory shared among several different computers.
1264 Mono typically uses the hostname to create the files that are used to
1265 share state across multiple Mono processes. This is done to support
1266 home directories that might be shared over the network.
1268 \fBMONO_STRICT_IO_EMULATION\fR
1269 If set, extra checks are made during IO operations. Currently, this
1270 includes only advisory locks around file writes.
1272 \fBMONO_DISABLE_SHM\fR
1273 If set, disables the shared memory files used for cross-process
1274 handles: process have only private handles. This means that process
1275 and thread handles are not available to other processes, and named
1276 mutexes, named events and named semaphores are not visible between
1279 This is can also be enabled by default by passing the
1280 "--disable-shared-handles" option to configure.
1283 The name of the theme to be used by Windows.Forms. Available themes today
1284 include "clearlooks", "nice" and "win32".
1286 The default is "win32".
1288 \fBMONO_TLS_SESSION_CACHE_TIMEOUT\fR
1289 The time, in seconds, that the SSL/TLS session cache will keep it's entry to
1290 avoid a new negotiation between the client and a server. Negotiation are very
1291 CPU intensive so an application-specific custom value may prove useful for
1292 small embedded systems.
1294 The default is 180 seconds.
1296 \fBMONO_THREADS_PER_CPU\fR
1297 The maximum number of threads in the general threadpool will be
1298 20 + (MONO_THREADS_PER_CPU * number of CPUs). The default value for this
1301 \fBMONO_XMLSERIALIZER_THS\fR
1302 Controls the threshold for the XmlSerializer to produce a custom
1303 serializer for a given class instead of using the Reflection-based
1304 interpreter. The possible values are `no' to disable the use of a
1305 custom serializer or a number to indicate when the XmlSerializer
1306 should start serializing. The default value is 50, which means that
1307 the a custom serializer will be produced on the 50th use.
1309 \fBMONO_XMLSERIALIZER_DEBUG\fR
1310 Set this value to 1 to prevent the serializer from removing the
1311 temporary files that are created for fast serialization; This might
1312 be useful when debugging.
1314 \fBMONO_ASPNET_INHIBIT_SETTINGSMAP\fR
1315 Mono contains a feature which allows modifying settings in the .config files shipped
1316 with Mono by using config section mappers. The mappers and the mapping rules are
1317 defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the
1318 settings.map file found in the top-level directory of your ASP.NET application.
1319 Both files are read by System.Web on application startup, if they are found at the
1320 above locations. If you don't want the mapping to be performed you can set this
1321 variable in your environment before starting the application and no action will
1323 .SH ENVIRONMENT VARIABLES FOR DEBUGGING
1325 \fBMONO_ASPNET_NODELETE\fR
1326 If set to any value, temporary source files generated by ASP.NET support
1327 classes will not be removed. They will be kept in the user's temporary
1330 \fBMONO_LOG_LEVEL\fR
1331 The logging level, possible values are `error', `critical', `warning',
1332 `message', `info' and `debug'. See the DEBUGGING section for more
1336 Controls the domain of the Mono runtime that logging will apply to.
1337 If set, the log mask is changed to the set value. Possible values are
1338 "asm" (assembly loader), "type", "dll" (native library loader), "gc"
1339 (garbage collector), "cfg" (config file loader), "aot" (precompiler) and "all".
1340 The default value is "all". Changing the mask value allows you to display only
1341 messages for a certain component. You can use multiple masks by comma
1342 separating them. For example to see config file messages and assembly loader
1343 messages set you mask to "asm,cfg".
1346 Used for runtime tracing of method calls. The format of the comma separated
1355 disabled Trace output off upon start.
1358 You can toggle trace output on/off sending a SIGUSR2 signal to the program.
1360 \fBMONO_TRACE_LISTENER\fR
1361 If set, enables the System.Diagnostics.DefaultTraceListener, which will
1362 print the output of the System.Diagnostics Trace and Debug classes.
1363 It can be set to a filename, and to Console.Out or Console.Error to display
1364 output to standard output or standard error, respectively. If it's set to
1365 Console.Out or Console.Error you can append an optional prefix that will
1366 be used when writing messages like this: Console.Error:MyProgramName.
1367 See the System.Diagnostics.DefaultTraceListener documentation for more
1370 \fBMONO_XEXCEPTIONS\fR
1371 This throws an exception when a X11 error is encountered; by default a
1372 message is displayed but execution continues
1375 This is used in the System.Windows.Forms implementation when running
1376 with the X11 backend. This is used to debug problems in Windows.Forms
1377 as it forces all of the commands send to X11 server to be done
1378 synchronously. The default mode of operation is asynchronous which
1379 makes it hard to isolate the root of certain problems.
1381 \fBMONO_GENERIC_SHARING\fR
1382 This environment variable controls the kind of generic sharing used.
1383 This variable is used by internal JIT developers and should not be
1384 changed in production. Do not use it.
1386 The variable controls which classes will have generic code sharing
1389 Permissible values are:
1393 All generated code can be shared.
1396 Only the classes in System.Collections.Generic will have its code
1397 shared (this is the default value).
1400 Only code in corlib will have its code shared.
1403 No generic code sharing will be performed.
1406 Generic code sharing by default only applies to collections. The
1407 Mono JIT by default turns this on.
1410 When the the MONO_XDEBUG env var is set, debugging info for JITted
1411 code is emitted into a shared library, loadable into gdb. This enables,
1412 for example, to see managed frame names on gdb backtraces.
1414 \fBMONO_VERBOSE_METHOD\fR
1415 Enables the maximum JIT verbosity for the specified method. This is
1416 very helpfull to diagnose a miscompilation problems of a specific
1419 If you want to use Valgrind, you will find the file `mono.supp'
1420 useful, it contains the suppressions for the GC which trigger
1421 incorrect warnings. Use it like this:
1423 valgrind --suppressions=mono.supp mono ...
1426 On some platforms, Mono can expose a set of DTrace probes (also known
1427 as user-land statically defined, USDT Probes).
1429 They are defined in the file `mono.d'.
1431 .B ves-init-begin, ves-init-end
1433 Begin and end of runtime initialization.
1435 .B method-compile-begin, method-compile-end
1437 Begin and end of method compilation.
1438 The probe arguments are class name, method name and signature,
1439 and in case of method-compile-end success or failure of compilation.
1443 Begin and end of Garbage Collection.
1445 To verify the availability of the probes, run:
1447 dtrace -P mono'$target' -l -c mono
1450 On Unix assemblies are loaded from the installation lib directory. If you set
1451 `prefix' to /usr, the assemblies will be located in /usr/lib. On
1452 Windows, the assemblies are loaded from the directory where mono and
1455 .B ~/.mono/aot-cache
1457 The directory for the ahead-of-time compiler demand creation
1458 assemblies are located.
1460 .B /etc/mono/config, ~/.mono/config
1462 Mono runtime configuration file. See the mono-config(5) manual page
1463 for more information.
1465 .B ~/.config/.mono/certs, /usr/share/.mono/certs
1467 Contains Mono certificate stores for users / machine. See the certmgr(1)
1468 manual page for more information on managing certificate stores and
1469 the mozroots(1) page for information on how to import the Mozilla root
1470 certificates into the Mono certificate store.
1472 .B ~/.mono/assemblies/ASSEMBLY/ASSEMBLY.config
1474 Files in this directory allow a user to customize the configuration
1475 for a given system assembly, the format is the one described in the
1476 mono-config(5) page.
1478 .B ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
1480 Contains Mono cryptographic keypairs for users / machine. They can be
1481 accessed by using a CspParameters object with DSACryptoServiceProvider
1482 and RSACryptoServiceProvider classes.
1484 .B ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
1486 Contains Mono isolated storage for non-roaming users, roaming users and
1487 local machine. Isolated storage can be accessed using the classes from
1488 the System.IO.IsolatedStorage namespace.
1490 .B <assembly>.config
1492 Configuration information for individual assemblies is loaded by the
1493 runtime from side-by-side files with the .config files, see the
1494 http://www.mono-project.com/Config for more information.
1496 .B Web.config, web.config
1498 ASP.NET applications are configured through these files, the
1499 configuration is done on a per-directory basis. For more information
1500 on this subject see the http://www.mono-project.com/Config_system.web
1503 Mailing lists are listed at the
1504 http://www.mono-project.com/Mailing_Lists
1506 http://www.mono-project.com
1509 certmgr(1), csharp(1), mcs(1), mdb(1), monocov(1), monodis(1), mono-config(5), mozroots(1), xsp(1).
1511 For more information on AOT:
1512 http://www.mono-project.com/AOT
1514 For ASP.NET-related documentation, see the xsp(1) manual page