diff options
| -rw-r--r-- | gdb/doc/ChangeLog | 8 | ||||
| -rw-r--r-- | gdb/doc/gdb.texinfo | 58 |
2 files changed, 47 insertions, 19 deletions
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 090442d..576a47b 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,5 +1,13 @@ 2015-02-17 Jose E. Marchesi <jose.marchesi@oracle.com> + * gdb.texinfo (Static Probe Points): Add cindex `static probe + point, DTrace'. + (Static Probe Points): Modified to cover DTrace probes in addition + to SystemTap probes. Also modified to cover the `enable probe' + and `disable probe' commands. + +2015-02-17 Jose E. Marchesi <jose.marchesi@oracle.com> + * gdb.texinfo (Static Probe Points): Cover the `enable probe' and `disable probe' commands. diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index b11c1bb..a9a8c66 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -4967,34 +4967,50 @@ that can no longer be recreated. @subsection Static Probe Points @cindex static probe point, SystemTap +@cindex static probe point, DTrace @value{GDBN} supports @dfn{SDT} probes in the code. @acronym{SDT} stands for Statically Defined Tracing, and the probes are designed to have a tiny -runtime code and data footprint, and no dynamic relocations. They are -usable from assembly, C and C@t{++} languages. See -@uref{http://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation} -for a good reference on how the @acronym{SDT} probes are implemented. +runtime code and data footprint, and no dynamic relocations. + +Currently, the following types of probes are supported on +ELF-compatible systems: + +@itemize @bullet -Currently, @code{SystemTap} (@uref{http://sourceware.org/systemtap/}) -@acronym{SDT} probes are supported on ELF-compatible systems. See +@item @code{SystemTap} (@uref{http://sourceware.org/systemtap/}) +@acronym{SDT} probes@footnote{See @uref{http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps} -for more information on how to add @code{SystemTap} @acronym{SDT} probes -in your applications. +for more information on how to add @code{SystemTap} @acronym{SDT} +probes in your applications.}. @code{SystemTap} probes are usable +from assembly, C and C@t{++} languages@footnote{See +@uref{http://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation} +for a good reference on how the @acronym{SDT} probes are implemented.}. + +@item @code{DTrace} (@uref{http://oss.oracle.com/projects/DTrace}) +@acronym{USDT} probes. @code{DTrace} probes are usable from C and +C@t{++} languages. +@end itemize @cindex semaphores on static probe points -Some probes have an associated semaphore variable; for instance, this -happens automatically if you defined your probe using a DTrace-style -@file{.d} file. If your probe has a semaphore, @value{GDBN} will -automatically enable it when you specify a breakpoint using the -@samp{-probe-stap} notation. But, if you put a breakpoint at a probe's -location by some other method (e.g., @code{break file:line}), then -@value{GDBN} will not automatically set the semaphore. +Some @code{SystemTap} probes have an associated semaphore variable; +for instance, this happens automatically if you defined your probe +using a DTrace-style @file{.d} file. If your probe has a semaphore, +@value{GDBN} will automatically enable it when you specify a +breakpoint using the @samp{-probe-stap} notation. But, if you put a +breakpoint at a probe's location by some other method (e.g., +@code{break file:line}), then @value{GDBN} will not automatically set +the semaphore. @code{DTrace} probes do not support semaphores. You can examine the available static static probes using @code{info probes}, with optional arguments: @table @code @kindex info probes -@item info probes stap @r{[}@var{provider} @r{[}@var{name} @r{[}@var{objfile}@r{]}@r{]}@r{]} +@item info probes @r{[}@var{type}@r{]} @r{[}@var{provider} @r{[}@var{name} @r{[}@var{objfile}@r{]}@r{]}@r{]} +If given, @var{type} is either @code{stap} for listing +@code{SystemTap} probes or @code{dtrace} for listing @code{DTrace} +probes. If omitted all probes are listed regardless of their types. + If given, @var{provider} is a regular expression used to match against provider names when selecting which probes to list. If omitted, probes by all probes from all providers are listed. @@ -5014,7 +5030,8 @@ List the available static probes, from all types. @cindex enabling and disabling probes Some probe points can be enabled and/or disabled. The effect of enabling or disabling a probe depends on the type of probe being -handled. @code{SystemTap} probes cannot be disabled. +handled. Some @code{DTrace} probes can be enabled or +disabled, but @code{SystemTap} probes cannot be disabled. You can enable (or disable) one or more probes using the following commands, with optional arguments: @@ -5045,8 +5062,11 @@ A probe may specify up to twelve arguments. These are available at the point at which the probe is defined---that is, when the current PC is at the probe's location. The arguments are available using the convenience variables (@pxref{Convenience Vars}) -@code{$_probe_arg0}@dots{}@code{$_probe_arg11}. Each probe argument is -an integer of the appropriate size; types are not preserved. The +@code{$_probe_arg0}@dots{}@code{$_probe_arg11}. In @code{SystemTap} +probes each probe argument is an integer of the appropriate size; +types are not preserved. In @code{DTrace} probes types are preserved +provided that they are recognized as such by @value{GDBN}; otherwise +the value of the probe argument will be a long integer. The convenience variable @code{$_probe_argc} holds the number of arguments at the current probe point. |