diff options
Diffstat (limited to 'erts/doc/src/erlang.xml')
| -rw-r--r-- | erts/doc/src/erlang.xml | 441 |
1 files changed, 341 insertions, 100 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index ef577c82bf..423ccdf98f 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -2613,6 +2613,48 @@ os_prompt% </pre> </func> <func> + <name name="match_spec_test" arity="3"/> + <fsummary>Test that a match specification works</fsummary> + <desc> + <p> + This function is a utility to test a match_spec used in calls to + <seealso marker="stdlib:ets#select/2">ets:select/2</seealso> and + <seealso marker="#trace_pattern/3">erlang:trace_pattern/3</seealso>. + The function both tests MatchSpec for "syntactic" correctness and + runs the match_spec against the object. If the match_spec contains + errors, the tuple {error, Errors} is returned where Errors is a list + of natural language descriptions of what was wrong with the match_spec. + </p> + <p> + If the <c><anno>Type</anno></c> is <c>table</c> the object to match + against should be a tuple. The function then returns + {ok,Result,[],Warnings} where Result is what would have been the + result in a real ets:select/2 call or false if the match_spec does + not match the object tuple. + </p> + + <p> + If <c><anno>Type</anno></c> is <c>trace</c> the object to match + against should be a list. The function returns + {ok, Result, Flags, Warnings} where Result is <c>true</c> if a trace + message should be emitted, <c>false</c> if a trace message should not + be emitted or the message term to be appended to the trace message. + Flags is a list containing all the trace flags that will be enabled, + at the moment this is only <c>return_trace</c>. + </p> + + <p> + This is a useful debugging and test tool, especially when writing complicated + match specifications. + </p> + <p> + See also + <seealso marker="stdlib:ets#test_ms/2">ets:test_ms/2</seealso>. + </p> + </desc> + </func> + + <func> <name name="max" arity="2"/> <fsummary>Returns the largest of two terms.</fsummary> <desc> @@ -8347,22 +8389,47 @@ timestamp() -> <c><anno>How</anno> == false</c>) the trace flags in <c><anno>FlagList</anno></c> for the process or processes represented by - <c><anno>PidSpec</anno></c>.</p> - <p><c><anno>PidSpec</anno></c> is either a process identifier - (pid) for a local process, or one of the following atoms:</p> + <c><anno>PidPortSpec</anno></c>.</p> + <p><c><anno>PidPortSpec</anno></c> is either a process identifier + (pid) for a local process, a port identifier, + or one of the following atoms:</p> <taglist> + <tag><c>all</c></tag> + <item> + <p>All currently existing processes and ports and all that + will be created in the future.</p> + </item> + <tag><c>processes</c></tag> + <item> + <p>All currently existing processes and all that will be created in the future.</p> + </item> + <tag><c>ports</c></tag> + <item> + <p>All currently existing ports and all that will be created in the future.</p> + </item> <tag><c>existing</c></tag> <item> + <p>All currently existing processes and ports.</p> + </item> + <tag><c>existing_processes</c></tag> + <item> <p>All currently existing processes.</p> </item> + <tag><c>existing_ports</c></tag> + <item> + <p>All currently existing ports.</p> + </item> <tag><c>new</c></tag> <item> - <p>All processes that are created in the future.</p> + <p>All processes and ports that will be created in the future.</p> </item> - <tag><c>all</c></tag> + <tag><c>new_processes</c></tag> + <item> + <p>All processes that will be created in the future.</p> + </item> + <tag><c>new_ports</c></tag> <item> - <p>All currently existing processes and all processes that - are created in the future.</p> + <p>All ports that will be created in the future.</p> </item> </taglist> <p><c><anno>FlagList</anno></c> can contain any number of the @@ -8371,35 +8438,28 @@ 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> <tag><c>send</c></tag> <item> <p>Traces sending of messages.</p> - <p>Message tags: <c>send</c> and - <c>send_to_non_existing_process</c>.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_send">send</seealso></c> and + <c><seealso marker="#trace_3_trace_messages_send_to_non_existing_process">send_to_non_existing_process</seealso></c>.</p> </item> <tag><c>'receive'</c></tag> <item> <p>Traces receiving of messages.</p> - <p>Message tags: <c>'receive'</c>.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_receive">'receive'</seealso></c>.</p> </item> - <tag><c>procs</c></tag> - <item> - <p>Traces process-related events.</p> - <p>Message tags: <c>spawn</c>, <c>exit</c>, - <c>register</c>, <c>unregister</c>, <c>link</c>, - <c>unlink</c>, <c>getting_linked</c>, and - <c>getting_unlinked</c>.</p> - </item> - <tag><c>call</c></tag> +<tag><c>call</c></tag> <item> <p>Traces certain function calls. Specify which function calls to trace by calling <seealso marker="#trace_pattern/3">erlang:trace_pattern/3</seealso>.</p> - <p>Message tags: <c>call</c> and <c>return_from</c>.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_call">call</seealso></c> and + <c><seealso marker="#trace_3_trace_messages_return_from">return_from</seealso></c>.</p> </item> <tag><c>silent</c></tag> <item> @@ -8417,8 +8477,9 @@ timestamp() -> specification function <c>{silent,Bool}</c>, giving a high degree of control of which functions with which arguments that trigger the trace.</p> - <p>Message tags: <c>call</c>, <c>return_from</c>, and - <c>return_to</c>. Or rather, the absence of.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_call">call</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_return_from">return_from</seealso></c>, and + <c><seealso marker="#trace_3_trace_messages_return_to">return_to</seealso></c>. Or rather, the absence of.</p> </item> <tag><c>return_to</c></tag> <item> @@ -8439,23 +8500,63 @@ timestamp() -> <p>To get trace messages containing return values from functions, use the <c>{return_trace}</c> match specification action instead.</p> - <p>Message tags: <c>return_to</c>.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_return_to">return_to</seealso></c>.</p> + </item> + <tag><c>procs</c></tag> + <item> + <p>Traces process-related events.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_spawn">spawn</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_spawned">spawned</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_exit">exit</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_register">register</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_unregister">unregister</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_link">link</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_unlink">unlink</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_getting_linked">getting_linked</seealso></c>, and + <c><seealso marker="#trace_3_trace_messages_getting_unlinked">getting_unlinked</seealso></c>.</p> + </item> + <tag><c>ports</c></tag> + <item> + <p>Traces port-related events.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_open">open</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_closed">closed</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_register">register</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_unregister">unregister</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_getting_linked">getting_linked</seealso></c>, and + <c><seealso marker="#trace_3_trace_messages_getting_unlinked">getting_unlinked</seealso></c>.</p> </item> <tag><c>running</c></tag> <item> <p>Traces scheduling of processes.</p> - <p>Message tags: <c>in</c> and <c>out</c>.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_in_proc">in</seealso></c> and + <c><seealso marker="#trace_3_trace_messages_out_proc">out</seealso></c>.</p> </item> <tag><c>exiting</c></tag> <item> <p>Traces scheduling of exiting processes.</p> - <p>Message tags: <c>in_exiting</c>, <c>out_exiting</c>, and - <c>out_exited</c>.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_in_exiting_proc">in_exiting</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_out_exiting_proc">out_exiting</seealso></c>, and + <c><seealso marker="#trace_3_trace_messages_out_exited_proc">out_exited</seealso></c>.</p> + </item> + <tag><c>running_procs</c></tag> + <item> + <p>Traces scheduling of processes just like <c>running</c>. + However this option also includes schedule events when the + process executes within the context of a port without + being scheduled out itself.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_in_proc">in</seealso></c> and + <c><seealso marker="#trace_3_trace_messages_out_proc">out</seealso></c>.</p> + </item> + <tag><c>running_ports</c></tag> + <item> + <p>Traces scheduling of ports.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_in_port">in</seealso></c> and + <c><seealso marker="#trace_3_trace_messages_out_port">out</seealso></c>.</p> </item> <tag><c>garbage_collection</c></tag> <item> <p>Traces garbage collections of processes.</p> - <p>Message tags: <c>gc_start</c> and <c>gc_end</c>.</p> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_gc_start">gc_start</seealso></c> and <c><seealso marker="#trace_3_trace_messages_gc_end">gc_end</seealso></c>.</p> </item> <tag><c>timestamp</c></tag> <item> @@ -8470,8 +8571,8 @@ timestamp() -> in CPU time, not wall clock time. That is, <c>cpu_timestamp</c> will not be used if <c>monotonic_timestamp</c>, or <c>strict_monotonic_timestamp</c> is enabled. - Only allowed with <c>PidSpec==all</c>. If the host - machine OS does not support high-resolution + Only allowed with <c><anno>PidPortSpec</anno>==all</c>. If the + host machine OS does not support high-resolution CPU time measurements, <c>trace/3</c> exits with <c>badarg</c>. Notice that most OS do not synchronize this value across cores, so be prepared @@ -8483,8 +8584,8 @@ timestamp() -> <seealso marker="time_correction#Erlang_Monotonic_Time">Erlang monotonic time</seealso> time-stamp in all trace messages. The time-stamp (Ts) has the same format and value as produced by - <c>erlang:monotonic_time(nano_seconds)</c>. This flag overrides - the <c>cpu_timestamp</c> flag.</p> + <c><seealso marker="#monotonic_time-1">erlang:monotonic_time(nano_seconds)</seealso></c>. + This flag overrides the <c>cpu_timestamp</c> flag.</p> </item> <tag><c>strict_monotonic_timestamp</c></tag> <item> @@ -8493,9 +8594,9 @@ timestamp() -> monotonic time</seealso> and a monotonically increasing integer in all trace messages. The time-stamp (Ts) has the same format and value as produced by - <c>{erlang:monotonic_time(nano_seconds), - erlang:unique_integer([monotonic])}</c>. This flag overrides - the <c>cpu_timestamp</c> flag.</p> + <c>{<seealso marker="#monotonic_time-1">erlang:monotonic_time(nano_seconds)</seealso>, + <seealso marker="#unique_integer-1">erlang:unique_integer([monotonic])</seealso>}</c>. + This flag overrides the <c>cpu_timestamp</c> flag.</p> </item> <tag><c>arity</c></tag> <item> @@ -8529,12 +8630,20 @@ 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 @@ -8555,21 +8664,36 @@ timestamp() -> the other one will become active.</p> <marker id="trace_3_trace_messages"></marker> <taglist> - <tag><c>{trace, Pid, 'receive', Msg}</c></tag> - <item> - <p>When <c>Pid</c> receives message <c>Msg</c>.</p> - </item> - <tag><c>{trace, Pid, send, Msg, To}</c></tag> + <tag> + <marker id="trace_3_trace_messages_send"></marker> + <c>{trace, PidPort, send, Msg, To}</c> + </tag> <item> - <p>When <c>Pid</c> sends message <c>Msg</c> to + <p>When <c>PidPort</c> sends message <c>Msg</c> to process <c>To</c>.</p> </item> - <tag><c>{trace, Pid, send_to_non_existing_process, Msg, To}</c></tag> + <tag> + <marker id="trace_3_trace_messages_send_to_non_existing_process"></marker> + <c>{trace, PidPort, send_to_non_existing_process, Msg, To}</c> + </tag> <item> - <p>When <c>Pid</c> sends message <c>Msg</c> to + <p>When <c>PidPort</c> sends message <c>Msg</c> to the non-existing process <c>To</c>.</p> </item> - <tag><c>{trace, Pid, call, {M, F, Args}}</c></tag> + <tag> + <marker id="trace_3_trace_messages_receive"></marker> + <c>{trace, PidPort, 'receive', Msg}</c> + </tag> + <item> + <p>When <c>PidPort</c> receives message <c>Msg</c>. + If <c>Msg</c> is set to timeout, then a receive + statement may have timedout, or the process received + a message with the payload <c>timeout</c>.</p> + </item> + <tag> + <marker id="trace_3_trace_messages_call"></marker> + <c>{trace, Pid, call, {M, F, Args}}</c> + </tag> <item> <p>When <c>Pid</c> calls a traced function. The return values of calls are never supplied, only the call and its @@ -8578,7 +8702,10 @@ timestamp() -> change the contents of this message, so that <c>Arity</c> is specified instead of <c>Args</c>.</p> </item> - <tag><c>{trace, Pid, return_to, {M, F, Arity}}</c></tag> + <tag> + <marker id="trace_3_trace_messages_return_to"></marker> + <c>{trace, Pid, return_to, {M, F, Arity}}</c> + </tag> <item> <p>When <c>Pid</c> returns <em>to</em> the specified function. This trace message is sent if both @@ -8590,73 +8717,172 @@ timestamp() -> (that is, the functions match specification matched, and <c>{message, false}</c> was not an action).</p> </item> - <tag><c>{trace, Pid, return_from, {M, F, Arity}, ReturnValue}</c></tag> + <tag> + <marker id="trace_3_trace_messages_return_from"></marker> + <c>{trace, Pid, return_from, {M, F, Arity}, ReturnValue}</c> + </tag> <item> <p>When <c>Pid</c> returns <em>from</em> the specified function. This trace message is sent if flag <c>call</c> is set, and the function has a match specification with a <c>return_trace</c> or <c>exception_trace</c> action.</p> </item> - <tag><c>{trace, Pid, exception_from, {M, F, Arity}, {Class, Value}}</c></tag> + <tag> + <marker id="trace_3_trace_messages_exception_from"></marker> + <c>{trace, Pid, exception_from, {M, F, Arity}, {Class, Value}}</c> + </tag> <item> <p>When <c>Pid</c> exits <em>from</em> the specified function because of an exception. This trace message is sent if flag <c>call</c> is set, and the function has a match specification with an <c>exception_trace</c> action.</p> </item> - <tag><c>{trace, Pid, spawn, Pid2, {M, F, Args}}</c></tag> + <tag> + <marker id="trace_3_trace_messages_spawn"></marker> + <c>{trace, Pid, spawn, Pid2, {M, F, Args}}</c> + </tag> <item> <p>When <c>Pid</c> spawns a new process <c>Pid2</c> with the specified function call as entry point.</p> <p><c>Args</c> is supposed to be the argument list, but can be any term if the spawn is erroneous.</p> </item> - <tag><c>{trace, Pid, exit, Reason}</c></tag> + <tag> + <marker id="trace_3_trace_messages_spawned"></marker> + <c>{trace, Pid, spawned, Pid2, {M, F, Args}}</c> + </tag> + <item> + <p>When <c>Pid</c> is spawned by process <c>Pid2</c> with + the specified function call as entry point.</p> + <p><c>Args</c> is supposed to be the argument list, + but can be any term if the spawn is erroneous.</p> + </item> + <tag> + <marker id="trace_3_trace_messages_exit"></marker> + <c>{trace, Pid, exit, Reason}</c> + </tag> <item> <p>When <c>Pid</c> exits with reason <c>Reason</c>.</p> </item> - <tag><c>{trace, Pid, link, Pid2}</c></tag> + <tag> + <marker id="trace_3_trace_messages_register"></marker> + <c>{trace, PidPort, register, RegName}</c> + </tag> + <item> + <p>When <c>PidPort</c> gets the name <c>RegName</c> registered.</p> + </item> + <tag> + <marker id="trace_3_trace_messages_unregister"></marker> + <c>{trace, PidPort, unregister, RegName}</c> + </tag> + <item> + <p>When <c>PidPort</c> gets the name <c>RegName</c> unregistered. + This is done automatically when a registered + process or port exits.</p> + </item> + <tag> + <marker id="trace_3_trace_messages_link"></marker> + <c>{trace, Pid, link, Pid2}</c> + </tag> <item> <p>When <c>Pid</c> links to a process <c>Pid2</c>.</p> </item> - <tag><c>{trace, Pid, unlink, Pid2}</c></tag> + <tag> + <marker id="trace_3_trace_messages_unlink"></marker> + <c>{trace, Pid, unlink, Pid2}</c> + </tag> <item> <p>When <c>Pid</c> removes the link from a process <c>Pid2</c>.</p> </item> - <tag><c>{trace, Pid, getting_linked, Pid2}</c></tag> + <tag> + <marker id="trace_3_trace_messages_getting_linked"></marker> + <c>{trace, PidPort, getting_linked, Pid2}</c> + </tag> <item> - <p>When <c>Pid</c> gets linked to a process <c>Pid2</c>.</p> + <p>When <c>PidPort</c> gets linked to a process <c>Pid2</c>.</p> </item> - <tag><c>{trace, Pid, getting_unlinked, Pid2}</c></tag> + <tag> + <marker id="trace_3_trace_messages_getting_unlinked"></marker> + <c>{trace, PidPort, getting_unlinked, Pid2}</c> + </tag> <item> - <p>When <c>Pid</c> gets unlinked from a process <c>Pid2</c>.</p> + <p>When <c>PidPort</c> gets unlinked from a process <c>Pid2</c>.</p> </item> - <tag><c>{trace, Pid, register, RegName}</c></tag> + <tag> + <marker id="trace_3_trace_messages_exit"></marker> + <c>{trace, Pid, exit, Reason}</c> + </tag> <item> - <p>When <c>Pid</c> gets the name <c>RegName</c> registered.</p> + <p>When <c>Pid</c> exits with reason <c>Reason</c>.</p> </item> - <tag><c>{trace, Pid, unregister, RegName}</c></tag> + <tag> + <marker id="trace_3_trace_messages_open"></marker> + <c>{trace, Port, open, Pid, Driver}</c> + </tag> <item> - <p>When <c>Pid</c> gets the name <c>RegName</c> unregistered. - This is done automatically when a registered - process exits.</p> + <p>When <c>Pid</c> opens a new port <c>Port</c> with + the running the <c>Driver</c>.</p> + <p><c>Driver</c> is the name of the driver as an atom.</p> + </item> + <tag> + <marker id="trace_3_trace_messages_closed"></marker> + <c>{trace, Port, closed, Reason}</c> + </tag> + <item> + <p>When <c>Port</c> closed with <c>Reason</c>.</p> </item> - <tag><c>{trace, Pid, in, {M, F, Arity} | 0}</c></tag> + <tag> + <marker id="trace_3_trace_messages_in_proc"></marker> + <marker id="trace_3_trace_messages_in_exiting_proc"></marker> + <c>{trace, Pid, in | in_exiting, {M, F, Arity} | 0}</c> + </tag> <item> <p>When <c>Pid</c> is scheduled to run. The process runs in function <c>{M, F, Arity}</c>. On some rare occasions, the current function cannot be determined, then the last element is <c>0</c>.</p> </item> - <tag><c>{trace, Pid, out, {M, F, Arity} | 0}</c></tag> + <tag> + <marker id="trace_3_trace_messages_out_proc"></marker> + <marker id="trace_3_trace_messages_out_exiting_proc"></marker> + <marker id="trace_3_trace_messages_out_exited_proc"></marker> + <c>{trace, Pid, out | out_exiting | out_exited, {M, F, Arity} | 0}</c> + </tag> <item> <p>When <c>Pid</c> is scheduled out. The process was running in function {M, F, Arity}. On some rare occasions, the current function cannot be determined, then the last element is <c>0</c>.</p> </item> - <tag><c>{trace, Pid, gc_start, Info}</c></tag> + <tag> + <marker id="trace_3_trace_messages_in_port"></marker> + <c>{trace, Port, in, Command | 0}</c> + </tag> + <item> + <p>When <c>Port</c> is scheduled to run. <c>Command</c> is the + first thing the port will execute, it may however run several + commands before being scheduled out. On some rare + occasions, the current function cannot be determined, + then the last element is <c>0</c>.</p> + <p>The possible commands are: <c>call | close | command | connect | control | flush | info | link | open | unlink</c></p> + </item> + <tag> + <marker id="trace_3_trace_messages_out_port"></marker> + <c>{trace, Port, out, Command | 0}</c> + </tag> + <item> + <p>When <c>Port</c> is scheduled out. The last command run + was <c>Command</c>. On some rare occasions, + the current function cannot be determined, then the last + element is <c>0</c>. <c>Command</c> can contain the same + commands as <c>in</c> + </p> + </item> + <tag> + <marker id="trace_3_trace_messages_gc_start"></marker> + <c>{trace, Pid, gc_start, Info}</c> + </tag> <item> <marker id="gc_start"></marker> <p>Sent when garbage collection is about to be started. @@ -8698,7 +8924,10 @@ timestamp() -> </taglist> <p>All sizes are in words.</p> </item> - <tag><c>{trace, Pid, gc_end, Info}</c></tag> + <tag> + <marker id="trace_3_trace_messages_gc_end"></marker> + <c>{trace, Pid, gc_end, Info}</c> + </tag> <item> <p>Sent when garbage collection is finished. <c>Info</c> contains the same kind of list as in message <c>gc_start</c>, @@ -8706,18 +8935,18 @@ 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>. - If <c><anno>PidSpec</anno></c> is a process + matched <c><anno>PidPortSpec</anno></c>. + If <c><anno>PidPortSpec</anno></c> is a process identifier, the return value is <c>1</c>. - If <c><anno>PidSpec</anno></c> + If <c><anno>PidPortSpec</anno></c> is <c>all</c> or <c>existing</c>, the return value is - the number of processes running, excluding tracer processes. - If <c><anno>PidSpec</anno></c> is <c>new</c>, the return value is + the number of processes running. + If <c><anno>PidPortSpec</anno></c> is <c>new</c>, the return value is <c>0</c>.</p> <p>Failure: <c>badarg</c> if the specified arguments are not supported. For example, <c>cpu_timestamp</c> is not @@ -8729,7 +8958,11 @@ timestamp() -> <name name="trace_delivered" arity="1"/> <fsummary>Notification when trace has been delivered.</fsummary> <desc> - <p>The delivery of trace messages is dislocated on the time-line + <p>The delivery of trace messages (generated by + <seealso marker="#trace/3"><c>erlang:trace/3</c></seealso>, + <seealso marker="kernel:seq_trace"><c>seq_trace</c></seealso> or + <seealso marker="#system_profile/2"><c>erlang:system_profile/2</c></seealso>) + is dislocated on the time-line compared to other events in the system. If you know that <c><anno>Tracee</anno></c> has passed some specific point in its execution, @@ -8750,13 +8983,16 @@ 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. The special <c><anno>Tracee</anno></c> atom <c>all</c> - denotes all processes - that currently are traced in the node.</p> + denotes all processes that currently are traced in the node.</p> + <p>When used together with an <seealso marker="#erl_tracer"> + Tracer Module</seealso> any message sent in the trace callback + is guaranteed to have reached it's recipient before the + <c>trace_delivered</c> message is sent.</p> <p>Example: Process <c>A</c> is <c><anno>Tracee</anno></c>, port <c>B</c> is tracer, and process <c>C</c> is the port owner of <c>B</c>. <c>C</c> wants to close <c>B</c> when @@ -8779,12 +9015,15 @@ timestamp() -> <type name="trace_info_flag"/> <type name="trace_match_spec"/> <desc> - <p>Returns trace information about a process or function.</p> - <p>To get information about a process, - <c><anno>PidOrFunc</anno></c> is to - be a process identifier (pid) or the atom <c>new</c>. - The atom <c>new</c> means that the default trace state for - processes to be created is returned.</p> + <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 + 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> <taglist> <tag><c>flags</c></tag> @@ -8794,19 +9033,22 @@ timestamp() -> traces are enabled, and one or more of the followings atoms if traces are enabled: <c>send</c>, <c>'receive'</c>, <c>set_on_spawn</c>, <c>call</c>, - <c>return_to</c>, <c>procs</c>, <c>set_on_first_spawn</c>, - <c>set_on_link</c>, <c>running</c>, + <c>return_to</c>, <c>procs</c>, <c>ports</c>, <c>set_on_first_spawn</c>, + <c>set_on_link</c>, <c>running</c>, <c>running_procs</c>, + <c>running_ports</c>, <c>silent</c>, <c>exiting</c> + <c>monotonic_timestamp</c>, <c>strict_monotonic_timestamp</c>, <c>garbage_collection</c>, <c>timestamp</c>, and <c>arity</c>. The order is arbitrary.</p> </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> </taglist> - <p>To get information about a function, <c>PidOrFunc</c> is to + <p>To get information about a function, <c><anno>PidPortOrFunc</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 @@ -8830,8 +9072,8 @@ 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> @@ -8874,7 +9116,7 @@ timestamp() -> <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>PidOrFunc</anno></c> is <c>on_load</c>, the information + <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> @@ -8999,13 +9241,12 @@ 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 +9254,7 @@ 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> |