diff options
Diffstat (limited to 'erts/doc/src/erlang.xml')
| -rw-r--r-- | erts/doc/src/erlang.xml | 176 |
1 files changed, 159 insertions, 17 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 3276bc34b0..bdaa6caa15 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -9034,16 +9034,16 @@ timestamp() -> <type name="trace_info_flag"/> <type name="trace_match_spec"/> <desc> - <p>Returns trace information about a port, process or function.</p> - <p>To get information about a port or process, - <c><anno>PidPortOrFunc</anno></c> is to + <p>Returns trace information about a port, process, function or event.</p> + <p><em>To get information about a port or process</em>, + <c><anno>PidPortFuncEvent</anno></c> is to be a process identifier (pid), port identifier or one of the atoms <c>new</c>, <c>new_processes</c>, <c>new_ports</c>. The atom <c>new</c> or <c>new_processes</c> means that the default trace state for processes to be created is returned. The atom <c>new_ports</c> means that the default trace state for ports to be created is returned. </p> - <p>The following <c>Item</c>s are valid:</p> + <p>The following <c>Item</c>s are valid for ports and processes:</p> <taglist> <tag><c>flags</c></tag> <item> @@ -9067,12 +9067,15 @@ timestamp() -> value is <c>[]</c>.</p> </item> </taglist> - <p>To get information about a function, <c><anno>PidPortOrFunc</anno></c> is to + <p><em>To get information about a function</em>, <c><anno>PidPortFuncEvent</anno></c> is to be the three-element tuple <c>{Module, Function, Arity}</c> or the atom <c>on_load</c>. No wild cards are allowed. Returns <c>undefined</c> if the function does not exist, or - <c>false</c> if the function is not traced.</p> - <p>The following <c>Item</c>s are valid::</p> + <c>false</c> if the function is not traced. If <c><anno>PidPortFuncEvent</anno></c> + is <c>on_load</c>, the information returned refers to + the default value for code that will be loaded.</p> + + <p>The following <c>Item</c>s are valid for functions:</p> <taglist> <tag><c>traced</c></tag> <item> @@ -9131,39 +9134,177 @@ timestamp() -> is active for this function.</p> </item> </taglist> + <p><em>To get information about an event</em>, <c><anno>PidPortFuncEvent</anno></c> is to + be one of the atoms <c>send</c> or <c>'receive'</c>.</p> + <p>The only valid <c>Item</c> for events is:</p> + <taglist> + <tag><c>match_spec</c></tag> + <item> + <p>Returns the match specification for this event, if it + has one, or <c>true</c> if no match specification has been + set.</p> + </item> + </taglist> <p>The return value is <c>{<anno>Item</anno>, Value}</c>, where <c>Value</c> is the requested information as described earlier. If a pid for a dead process was given, or the name of a non-existing function, <c>Value</c> is <c>undefined</c>.</p> - <p>If <c><anno>PidPortOrFunc</anno></c> is <c>on_load</c>, the information - returned refers to the default value for code that will be - loaded.</p> </desc> </func> <func> <name name="trace_pattern" arity="2" clause_i="1"/> - <fsummary>Sets trace patterns for global call tracing.</fsummary> + <fsummary>Sets trace patterns for call, send or 'receive' tracing.</fsummary> <type name="trace_pattern_mfa"/> <type name="trace_match_spec"/> <desc> <p>The same as - <seealso marker="#trace_pattern/3">erlang:trace_pattern(MFA, MatchSpec, [])</seealso>, + <seealso marker="#trace_pattern/3">erlang:trace_pattern(Event, MatchSpec, [])</seealso>, retained for backward compatibility.</p> </desc> </func> <func> - <name name="trace_pattern" arity="3"/> + <name name="trace_pattern" arity="3" clause_i="1"/> + <fsummary>Sets trace pattern for message sending.</fsummary> + <type name="trace_match_spec"/> + <desc> + <p>Sets trace pattern for <em>message sending</em>. + Must be combined with + <seealso marker="#trace/3">erlang:trace/3</seealso> + to set the <c>send</c> trace flag for one or more processes. + By default all messages, sent from <c>send</c> traced processes, + are traced. Use <c>erlang:trace_pattern/3</c> to limit + traced send events based on the message content, the sender + and/or the receiver.</p> + <p>Argument <c><anno>MatchSpec</anno></c> can take the + following forms:</p> + <taglist> + <tag><c><anno>MatchSpecList</anno></c></tag> + <item> + <p>A list of match specifications. The matching is done + on the list <c>[Receiver, Msg]</c>. <c>Receiver</c> + is the process or port identity of the receiver and + <c>Msg</c> is the message term. The pid of the sending + process can be accessed with the guard function + <c>self/0</c>. An empty list is the same as <c>true</c>. + See the users guide section + <seealso marker="erts:match_spec">Match Specifications in Erlang</seealso> + for more information.</p> + </item> + <tag><c>true</c></tag> + <item> + <p>Enables tracing for all sent messages (from <c>send</c> + traced processes). Any match specification is + removed. <em>This is the default</em>.</p> + </item> + <tag><c>false</c></tag> + <item> + <p>Disables tracing for all sent messages. + Any match specification is removed.</p> + </item> + </taglist> + <p>Argument <c><anno>FlagList</anno></c> must be <c>[]</c> + for send tracing.</p> + <p>The return value is always <c>1</c>.</p> + <p>Example; only trace messages to a specific process <c>Pid</c>:</p> + <pre> +> <input>erlang:trace_pattern(send, [{[Pid, '_'],[],[]}], []).</input> +1</pre> + <p>Only trace messages matching <c>{reply, _}</c>:</p> + <pre> +> <input>erlang:trace_pattern(send, [{['_', {reply,'_'}],[],[]}], []).</input> +1</pre> + <p>Only trace messages sent to the sender itself:</p> + <pre> +> <input>erlang:trace_pattern(send, [{['$1', '_'],[{'=:=','$1',{self}}],[]}], []).</input> +1</pre> + <p>Only trace messages sent to other nodes:</p> + <pre> +> <input>erlang:trace_pattern(send, [{['$1', '_'],[{'=/=',{node,'$1'},{node}}],[]}], []).</input> +1</pre> + <note><p>A match specification for <c>send</c> trace can use + all guard and body functions except <c>caller</c>.</p></note> + </desc> + </func> + + <func> + <name name="trace_pattern" arity="3" clause_i="2"/> + <fsummary>Sets trace pattern for tracing of message receiving.</fsummary> + <type name="trace_match_spec"/> + <desc> + <p></p> + <p>Sets trace pattern for <em>message receiving</em>. + Must be combined with + <seealso marker="#trace/3">erlang:trace/3</seealso> + to set the <c>'receive'</c> trace flag for one or more processes. + By default all messages, received by <c>'receive'</c> traced processes, + are traced. Use <c>erlang:trace_pattern/3</c> to limit + traced receive events based on the message content, the sender + and/or the receiver.</p> + <p>Argument <c><anno>MatchSpec</anno></c> can take the + following forms:</p> + <taglist> + <tag><c><anno>MatchSpecList</anno></c></tag> + <item> + <p>A list of match specifications. The matching is done + on the list <c>[Node, Sender, Msg]</c>. <c>Node</c> + is the node name of the sender. <c>Sender</c> is the + process or port identity of the sender, or the atom + <c>undefined</c> if the sender is not known (which may + be the case for remote senders). <c>Msg</c> is the + message term. The pid of the receiving process can be + accessed with the guard function <c>self/0</c>. An empty + list is the same as <c>true</c>. See the users guide section + <seealso marker="erts:match_spec">Match Specifications in Erlang</seealso> + for more information.</p> + </item> + <tag><c>true</c></tag> + <item> + <p>Enables tracing for all received messages (to <c>'receive'</c> + traced processes). Any match specification is + removed. <em>This is the default</em>.</p> + </item> + <tag><c>false</c></tag> + <item> + <p>Disables tracing for all received messages. + Any match specification is removed.</p> + </item> + </taglist> + <p>Argument <c><anno>FlagList</anno></c> must be <c>[]</c> + for receive tracing.</p> + <p>The return value is always <c>1</c>.</p> + <p>Example; only trace messages from a specific process <c>Pid</c>:</p> + <pre> +> <input>erlang:trace_pattern('receive', [{['_',Pid, '_'],[],[]}], []).</input> +1</pre> + <p>Only trace messages matching <c>{reply, _}</c>:</p> + <pre> +> <input>erlang:trace_pattern('receive', [{['_','_', {reply,'_'}],[],[]}], []).</input> +1</pre> + <p>Only trace messages from other nodes:</p> + <pre> +> <input>erlang:trace_pattern('receive', [{['$1', '_', '_'],[{'=/=','$1',{node}}],[]}], []).</input> +1</pre> + <note><p>A match specification for <c>'receive'</c> trace can + use all guard and body functions except <c>caller, + is_seq_trace, get_seq_token, set_seq_token, enable_trace, + disable_trace, trace, silent</c> and <c>process_dump</c>.</p></note> + </desc> + </func> + + <func> + <name name="trace_pattern" arity="3" clause_i="3"/> <fsummary>Sets trace patterns for tracing of function calls.</fsummary> <type name="trace_pattern_mfa"/> <type name="trace_match_spec"/> <type name="trace_pattern_flag"/> <desc> - <p>Enables or disables call tracing for - one or more functions. Must be combined with + <p>Enables or disables <em>call tracing</em> for one or more functions. + Must be combined with <seealso marker="#trace/3">erlang:trace/3</seealso> - to set the <c>call</c> trace flag for one or more processes.</p> + to set the <c>call</c> trace flag + for one or more processes.</p> <p>Conceptually, call tracing works as follows. Inside the Erlang Virtual Machine, a set of processes and a set of functions are to be traced. If a traced process @@ -9218,7 +9359,8 @@ timestamp() -> </item> <tag><c>true</c></tag> <item> - <p>Enables tracing for the matching functions.</p> + <p>Enables tracing for the matching functions. + Any match specification is removed.</p> </item> <tag><c><anno>MatchSpecList</anno></c></tag> <item> |