dtrace(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEMAPHORES | SEE ALSO | BUGS | COLOPHON

DTRACE(1)                General Commands Manual               DTRACE(1)

NAME         top

       dtrace - Dtrace compatible user application static probe
       generation tool.

SYNOPSIS         top

       dtrace -s file [OPTIONS]

DESCRIPTION         top

       The dtrace command converts probe descriptions defined in file.d
       into a probe header file via the -h option or a probe description
       file via the -G option.

OPTIONS         top

       -h     generate a systemtap header file.

       -G     generate a systemtap probe definition object file.

       -o file
              is the name of the output file.  If the -G option is given
              then the output file will be called file.o; if the -h
              option is given then the output file will be called
              file.h.

       -C     run the cpp preprocessor on the input file when the -h
              option is given.

       -I file
              give this include path to cpp when the -C option is given.

       -k     keep temporary files, for example the C language source
              for the -G option.

EXAMPLES         top

       Systemtap is source compatible with dtrace user application
       static probe support.  Given a file test.d containing:

              provider sdt_probes
              {
                probe test_0 (int type);
                probe test_1 (struct astruct node);
              };
              struct astruct {int a; int b;};

       Then the command "dtrace -s test.d -G" will create the probe
       definition file test.o and the command "dtrace -stest.d -h" will
       create the probe header file test.h Subsequently the application
       can use the generated macros this way:

              #include "test.h"
               ...
              struct astruct s;
               ...
              SDT_PROBES_TEST_0(value);
               ...
              if (SDT_PROBES_TEST_1_ENABLED())
                  SDT_PROBES_TEST_1(expensive_function(s));

SEMAPHORES         top

       Semaphores are flag variables used by probes as a way of
       bypassing potentially costly processing to prepare arguments for
       probes that may not even be active.  They are automatically
       set/cleared by systemtap when a relevant script is running, so
       the argument setup cost is only paid when necessary.  These
       semaphore variables are defined within the the "test.o" object
       file, which must therefore be linked into an application.

       Sometimes, semaphore variables are not necessary nor helpful.
       Skipping them can simplify the build process, by omitting the
       extra "test.o" file.  To skip dependence upon semaphore
       variables, include "<sys/sdt.h>" within the application before
       "test.h":

              #include <sys/sdt.h>
              #include "test.h"
               ...
              struct astruct s;
               ...
              SDT_PROBES_TEST_0(value);
               ...
              if (SDT_PROBES_TEST_1_ENABLED())
                 SDT_PROBES_TEST_1(cheap_function(s));

       In this mode, the ENABLED() test is fixed at 1.

SEE ALSO         top

       stap(1),
       stappaths(7)

BUGS         top

       Use the Bugzilla link of the project web page or our mailing
       list.  http://sourceware.org/systemtap/ ,
       <systemtap@sourceware.org>.

       error::reporting(7stap),
       https://sourceware.org/systemtap/wiki/HowToReportBugs 

COLOPHON         top

       This page is part of the systemtap (a tracing and live-system
       analysis tool) project.  Information about the project can be
       found at ⟨https://sourceware.org/systemtap/⟩.  If you have a bug
       report for this manual page, send it to systemtap@sourceware.org.
       This page was obtained from the project's upstream Git repository
       ⟨git://sourceware.org/git/systemtap.git⟩ on 2021-08-27.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-08-26.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

                                                               DTRACE(1)