diff options
Diffstat (limited to 'erts/doc/src/erlang.xml')
| -rw-r--r-- | erts/doc/src/erlang.xml | 46 |
1 files changed, 27 insertions, 19 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index ef577c82bf..86bdb1dfe6 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -8371,7 +8371,7 @@ timestamp() -> <taglist> <tag><c>all</c></tag> <item> - <p>Sets all trace flags except <c>{tracer, Tracer}</c> and + <p>Sets all trace flags except <c>tracer</c> and <c>cpu_timestamp</c>, which are in their nature different than the others.</p> </item> @@ -8529,12 +8529,20 @@ timestamp() -> <item> <p>Specifies where to send the trace messages. <c>Tracer</c> must be the process identifier of a local process - or the port identifier - of a local port. If this flag is not given, trace - messages are sent to the process that called - <c>erlang:trace/3</c>.</p> + or the port identifier of a local port.</p> + </item> + <tag><c>{tracer, TracerModule, TracerState}</c></tag> + <item> + <p>Specifies that a tracer module should be called + instead of sending a trace message. The tracer module + can then ignore or change the trace message. For more details + on how to write a tracer module see <seealso marker="erl_tracer"> + erl_tracer</seealso> + </p> </item> </taglist> + <p>If no <c>tracer</c> is given, the calling process + will be receiving all of the trace messages</p> <p>The effect of combining <c>set_on_first_link</c> with <c>set_on_link</c> is the same as having <c>set_on_first_link</c> alone. Likewise for @@ -8706,9 +8714,9 @@ timestamp() -> garbage collection.</p> </item> </taglist> - <p>If the tracing process dies, the flags are silently - removed.</p> - <p>Only one process can trace a particular process. Therefore, + <p>If the tracing process/port dies or the tracer module returns + <c>remove</c>, the flags are silently removed.</p> + <p>Each process can only be traced by one tracer. Therefore, attempts to trace an already traced process fail.</p> <p>Returns: A number indicating the number of processes that matched <c><anno>PidSpec</anno></c>. @@ -8716,7 +8724,7 @@ timestamp() -> identifier, the return value is <c>1</c>. If <c><anno>PidSpec</anno></c> is <c>all</c> or <c>existing</c>, the return value is - the number of processes running, excluding tracer processes. + the number of processes running. If <c><anno>PidSpec</anno></c> is <c>new</c>, the return value is <c>0</c>.</p> <p>Failure: <c>badarg</c> if the specified arguments are @@ -8750,7 +8758,7 @@ timestamp() -> has not been traced by someone, but if this is the case, <em>no</em> trace messages have been delivered when the <c>trace_delivered</c> message arrives.</p> - <p>Notice that that <c><anno>Tracee</anno></c> must refer + <p>Notice that <c><anno>Tracee</anno></c> must refer to a process currently, or previously existing on the same node as the caller of <c>erlang:trace_delivered(<anno>Tracee</anno>)</c> resides on. @@ -8801,7 +8809,8 @@ timestamp() -> </item> <tag><c>tracer</c></tag> <item> - <p>Returns the identifier for process or port tracing this + <p>Returns the identifier for process, port or a tuple containing + the tracer module and tracer state tracing this process. If this process is not being traced, the return value is <c>[]</c>.</p> </item> @@ -8830,8 +8839,8 @@ timestamp() -> </item> <tag><c>meta</c></tag> <item> - <p>Returns the meta-trace tracer process or port for this - function, if it has one. If the function is not + <p>Returns the meta-trace tracer process, port or trace module + for this function, if it has one. If the function is not meta-traced, the returned value is <c>false</c>. If the function is meta-traced but has once detected that the tracer process is invalid, the returned value is [].</p> @@ -8999,13 +9008,12 @@ timestamp() -> the process, a <c>return_to</c> message is also sent when this function returns to its caller.</p> </item> - <tag><c>meta | {meta, <anno>Pid</anno>}</c></tag> + <tag><c>meta | {meta, <anno>Pid</anno>} | {meta, <anno>TracerModule</anno>, <anno>TracerState</anno>}</c> + </tag> <item> <p>Turns on or off meta-tracing for all types of function - calls. Trace messages are sent to the tracer process - or port <c><anno>Pid</anno></c> whenever any of the specified - functions are called, regardless of how they are called. - If no <c><anno>Pid</anno></c> is specified, + calls. Trace messages are sent to the tracer whenever any of + the specified functions are called. If no tracer is specified, <c>self()</c> is used as a default tracer process.</p> <p>Meta-tracing traces all processes and does not care about the process trace flags set by <c>trace/3</c>, @@ -9013,7 +9021,7 @@ timestamp() -> <c>[call, timestamp]</c>.</p> <p>The match specification function <c>{return_trace}</c> works with meta-trace and sends its trace message to the - same tracer process.</p> + same tracer.</p> </item> <tag><c>call_count</c></tag> <item> |