1DTRACE(1) General Commands Manual DTRACE(1)
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6 dtrace - Dtrace compatible user application static probe generation
7 tool.
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12 dtrace -s file [OPTIONS]
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16 The dtrace command converts probe descriptions defined in file.d into a
17 probe header file via the -h option or a probe description file via the
18 -G option.
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22 -h generate a systemtap header file.
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25 -G generate a systemtap probe definition object file.
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28 -o file
29 is the name of the output file. If the -G option is given then
30 the output file will be called file.o; if the -h option is given
31 then the output file will be called file.h.
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34 -C run the cpp preprocessor on the input file when the -h option is
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38 -I file
39 give this include path to cpp when the -C option is given.
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42 -k keep temporary files, for example the C language source for the
43 -G option.
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47 Systemtap is source compatible with dtrace user application static
48 probe support. Given a file test.d containing:
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50 provider sdt_probes
51 {
52 probe test_0 (int type);
53 probe test_1 (struct astruct node);
54 };
55 struct astruct {int a; int b;};
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57 Then the command "dtrace -s test.d -G" will create the probe definition
58 file test.o and the command "dtrace -stest.d -h" will create the probe
59 header file test.h Subsequently the application can use the generated
60 macros this way:
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62 #include "test.h"
63 ...
64 struct astruct s;
65 ...
66 SDT_PROBES_TEST_0(value);
67 ...
68 if (SDT_PROBES_TEST_1_ENABLED())
69 SDT_PROBES_TEST_1(expensive_function(s));
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74 Semaphores are flag variables used by probes as a way of bypassing po‐
75 tentially costly processing to prepare arguments for probes that may
76 not even be active. They are automatically set/cleared by systemtap
77 when a relevant script is running, so the argument setup cost is only
78 paid when necessary. These semaphore variables are defined within the
79 the "test.o" object file, which must therefore be linked into an appli‐
80 cation.
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82 Sometimes, semaphore variables are not necessary nor helpful. Skipping
83 them can simplify the build process, by omitting the extra "test.o"
84 file. To skip dependence upon semaphore variables, include
85 "<sys/sdt.h>" within the application before "test.h":
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87 #include <sys/sdt.h>
88 #include "test.h"
89 ...
90 struct astruct s;
91 ...
92 SDT_PROBES_TEST_0(value);
93 ...
94 if (SDT_PROBES_TEST_1_ENABLED())
95 SDT_PROBES_TEST_1(cheap_function(s));
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97 In this mode, the ENABLED() test is fixed at 1.
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101 stap(1),
102 stappaths(7)
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107 Use the Bugzilla link of the project web page or our mailing list.
108 http://sourceware.org/systemtap/, <systemtap@sourceware.org>.
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110 error::reporting(7stap),
111 https://sourceware.org/systemtap/wiki/HowToReportBugs
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115 DTRACE(1)