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Diffstat (limited to 'lib/runtime_tools/doc/src/dbg.xml')
| -rw-r--r-- | lib/runtime_tools/doc/src/dbg.xml | 281 |
1 files changed, 165 insertions, 116 deletions
diff --git a/lib/runtime_tools/doc/src/dbg.xml b/lib/runtime_tools/doc/src/dbg.xml index 0232cc0453..ccb3bca50e 100644 --- a/lib/runtime_tools/doc/src/dbg.xml +++ b/lib/runtime_tools/doc/src/dbg.xml @@ -36,14 +36,30 @@ <modulesummary>The Text Based Trace Facility</modulesummary> <description> <p>This module implements a text based interface to the - <c>trace/3</c> and the <c>trace_pattern/2</c> BIFs. It makes it - possible to trace functions, processes and messages on text based - terminals. It can be used instead of, or as complement to, the - <c>pman</c> module. - </p> - <p>For some examples of how to use <c>dbg</c> from the Erlang + <c><seealso marker="erts:erlang#trace-3">trace/3</seealso></c> and the + <c><seealso marker="erts:erlang#trace_pattern-2">trace_pattern/2</seealso></c> BIFs. It makes it + possible to trace functions, processes, ports and messages. + </p> + <p> + To quickly get started on tracing function calls you can use the following + code in the Erlang shell: + </p> + <pre> +1> dbg:tracer(). %% Start the default trace message receiver +{ok,<0.36.0>} +2> dbg:p(all, c). %% Setup call (c) tracing on all processes +{ok,[{matched,nonode@nohost,26}]} +3> dbg:tp(lists, seq, x). %% Setup an exception return trace (x) on lists:seq +{ok,[{matched,nonode@nohost,2},{saved,x}]} +4> lists:seq(1,10). +(<0.34.0>) call lists:seq(1,10) +(<0.34.0>) returned from lists:seq/2 -> [1,2,3,4,5,6,7,8,9,10] +[1,2,3,4,5,6,7,8,9,10] + </pre> + <p> + For more examples of how to use <c>dbg</c> from the Erlang shell, see the <seealso marker="#simple_example">simple example</seealso> section. - </p> + </p> <p>The utilities are also suitable to use in system testing on large systems, where other tools have too much impact on the system performance. Some primitive support for sequential tracing @@ -164,53 +180,66 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <desc> <p>Traces <c>Item</c> in accordance to the value specified by <c>Flags</c>. The variation of <c>Item</c> is listed below:</p> - <list type="bulleted"> - <item>If the <c>Item</c> is a <c>pid()</c>, the corresponding - process is traced. The process may be a remote process - (on another Erlang node). The node must be in the list of - traced nodes (see <seealso marker="#n"><c>n/1</c></seealso> and - <c>tracer/0/2/3</c>).</item> - <item>If the <c>Item</c> is the atom <c>all</c>, all processes in the - system as well as all processes created hereafter are - to be traced. This also affects all nodes added with the - <c>n/1</c> or <c>tracer/0/2/3</c> function.</item> - <item>If the <c>Item</c> is the atom <c>new</c>, no currently existing - processes are affected, but every process created after the - call is.This also affects all nodes added with the - <c>n/1</c> or <c>tracer/0/2/3</c> function.</item> - <item>If the <c>Item</c> is the atom <c>existing</c>, all - existing processes are traced, but new processes will not - be affected.This also affects all nodes added with the - <c>n/1</c> or <c>tracer/0/2/3</c> function.</item> - <item>If the <c>Item</c> is an atom other than <c>all</c>, - <c>new</c> or <c>existing</c>, the process with the - corresponding registered name is traced.The process may be a - remote process (on another Erlang node). The node must be added - with the <c>n/1</c> or <c>tracer/0/2/3</c> function.</item> - <item>If the <c>Item</c> is an integer, the process <c><![CDATA[<0.Item.0>]]></c> is - traced.</item> - <item>If the <c>Item</c> is a tuple <c>{X, Y, Z}</c>, the - process <c><![CDATA[<X.Y.Z>]]></c> is - traced. </item> + <taglist> + <tag><c>pid()</c> or <c>port()</c></tag> + <item>The corresponding process or port is traced. The process or port may + be a remote process or port (on another Erlang node). The node must + be in the list of traced nodes (see <seealso marker="#n-1"><c>n/1</c></seealso> + and <c><seealso marker="#tracer-3">tracer/3</seealso></c>).</item> + <tag><c>all</c></tag> + <item>All processes and ports in the system as well as all processes and ports + created hereafter are to be traced.</item> + <tag><c>all_processes</c></tag> + <item>All processes in the system as well as all processes created hereafter are to be traced.</item> + <tag><c>all_ports</c></tag> + <item>All ports in the system as well as all ports created hereafter are to be traced.</item> + <tag><c>new</c></tag> + <item>All processes and ports created after the call is are to be traced.</item> + <tag><c>new_processes</c></tag> + <item>All processes created after the call is are to be traced.</item> + <tag><c>new_ports</c></tag> + <item>All ports created after the call is are to be traced.</item> + <tag><c>existing</c></tag> + <item>All existing processes and ports are traced.</item> + <tag><c>existing_processes</c></tag> + <item>All existing processes are traced.</item> + <tag><c>existing_ports</c></tag> + <item>All existing ports are traced.</item> + <tag><c>atom()</c></tag> + <item>The process or port with the corresponding registered name is traced. The process or + port may be a remote process (on another Erlang node). The node must be + added with the <c><seealso marker="#n-1">n/1</seealso></c> or + <c><seealso marker="#tracer-3">tracer/3</seealso></c> function.</item> + <tag><c>integer()</c></tag> + <item>The process <c><![CDATA[<0.Item.0>]]></c> is traced.</item> + <tag><c>{X, Y, Z}</c></tag> + <item>The process <c><![CDATA[<X.Y.Z>]]></c> is traced. </item> + <tag><c>string()</c></tag> <item>If the <c>Item</c> is a string <![CDATA["<X.Y.Z>"]]> - as returned from <c>pid_to_list/1</c>, the process + as returned from <c><seealso marker="erts:erlang#pid_to_list-1">pid_to_list/1</seealso></c>, the process <c><![CDATA[<X.Y.Z>]]></c> is traced. </item> - </list> + </taglist> + + <p>When enabling an <c>Item</c> that represents a group of processes, + the <c>Item</c> is enabled on all nodes added with the + <c><seealso marker="#n-1">n/1</seealso></c> or + <c><seealso marker="#tracer-3">tracer/3</seealso></c> function.</p> + <p><c>Flags</c> can be a single atom, or a list of flags. The available flags are: </p> <taglist> <tag><c>s (send)</c></tag> <item> - <p>Traces the messages the process sends.</p> + <p>Traces the messages the process or port sends.</p> </item> <tag><c>r (receive)</c></tag> <item> - <p>Traces the messages the process receives.</p> + <p>Traces the messages the process or port receives.</p> </item> <tag><c>m (messages)</c></tag> <item> - <p>Traces the messages the process receives and sends.</p> + <p>Traces the messages the process or port receives and sends.</p> </item> <tag><c>c (call)</c></tag> <item> @@ -221,6 +250,10 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <item> <p>Traces process related events to the process.</p> </item> + <tag><c>ports</c></tag> + <item> + <p>Traces port related events to the port.</p> + </item> <tag><c>sos (set on spawn)</c></tag> <item> <p>Lets all processes created by the traced @@ -241,8 +274,8 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <tag><c>sofl (set on first link)</c></tag> <item> <p>This is the same as <c>sol</c>, but only for - the first call to - <c>link/1</c> by the traced process.</p> + the first call to + <c><seealso marker="erts:erlang#link-1">link/1</seealso></c> by the traced process.</p> </item> <tag><c>all</c></tag> <item> @@ -258,7 +291,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <c>erlang:trace/3</c></p> <p>The function returns either an error tuple or a tuple <c>{ok, List}</c>. The <c>List</c> consists of - specifications of how many processes that matched (in the + specifications of how many processes and ports that matched (in the case of a pure pid() exactly 1). The specification of matched processes is <c>{matched, Node, N}</c>. If the remote processor call,<c>rpc</c>, to a remote node fails, @@ -286,9 +319,9 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ </func> <func> <name>i() -> ok</name> - <fsummary>Display information about all traced processes.</fsummary> + <fsummary>Display information about all traced processes and ports.</fsummary> <desc> - <p>Displays information about all traced processes.</p> + <p>Displays information about all traced processes and ports.</p> </desc> </func> <func> @@ -327,35 +360,41 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ </type> <desc> <p>This function enables call trace for one or more - functions. All exported functions matching the <c>{Module, Function, Arity}</c> argument will be concerned, but the + functions. All exported functions matching the <c>{Module, Function, Arity}</c> + argument will be concerned, but the <c>match_spec()</c> may further narrow down the set of function calls generating trace messages.</p> <p>For a description of the <c>match_spec()</c> syntax, please turn to the <em>User's guide</em> part of the online documentation for the runtime system (<em>erts</em>). The - chapter <em>Match Specification in Erlang</em> explains the - general match specification "language".</p> + chapter <em><seealso marker="erts:match_spec">Match Specifications in Erlang</seealso></em> + explains the general match specification "language". + The most common generic match specifications used can be + found as <c>Built-inAlias</c>', see + <c><seealso marker="#ltp-0">ltp/0</seealso></c> below for details. + </p> <p>The Module, Function and/or Arity parts of the tuple may be specified as the atom <c>'_'</c> which is a "wild-card" matching all modules/functions/arities. Note, if the Module is specified as <c>'_'</c>, the Function and Arity parts have to be specified as '_' too. The same holds for the Functions relation to the Arity.</p> - <p>All nodes added with <c>n/1</c> or <c>tracer/0/2/3</c> will + <p>All nodes added with <c><seealso marker="#n-1">n/1</seealso></c> or + <c><seealso marker="#tracer-3">tracer/3</seealso></c> will be affected by this call, and if Module is not <c>'_'</c> the module will be loaded on all nodes.</p> <p>The function returns either an error tuple or a tuple <c>{ok, List}</c>. The <c>List</c> consists of specifications of how - many functions that matched, in the same way as the processes - are presented in the return value of <c>p/2</c>. </p> + many functions that matched, in the same way as the processes and ports + are presented in the return value of <c><seealso marker="#p-2">p/2</seealso></c>. </p> <p>There may be a tuple <c>{saved, N}</c> in the return value, if the MatchSpec is other than []. The integer <c>N</c> may then be used in subsequent calls to this function and will stand as an "alias" for the given expression. There are also a couple of - built-in aliases for common expressions, see <c>ltp/0</c> below - for details.</p> + built-in aliases for common expressions, see + <c><seealso marker="#ltp-0">ltp/0</seealso></c> below for details.</p> <p>If an error is returned, it can be due to errors in compilation of the match specification. Such errors are presented as a list of tuples <c>{error, string()}</c> where @@ -394,7 +433,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <name>tpl({Module, Function, Arity}, MatchSpec) -> {ok, MatchDesc} | {error, term()}</name> <fsummary>Set pattern for traced local (as well as global) function calls</fsummary> <desc> - <p>This function works as <c>tp/2</c>, but enables + <p>This function works as <c><seealso marker="#tp-2">tp/2</seealso></c>, but enables tracing for local calls (and local functions) as well as for global calls (and functions).</p> </desc> @@ -441,10 +480,10 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <p>This function disables call tracing on the specified functions. The semantics of the parameter is the same as for the corresponding function specification in - <c>tp/2</c> or <c>tpl/2</c>. Both local and global call trace + <c><seealso marker="#tp-2">tp/2</seealso></c> or <c><seealso marker="#tpl-2">tpl/2</seealso></c>. Both local and global call trace is disabled. </p> <p>The return value reflects how many functions that matched, - and is constructed as described in <c>tp/2</c>. No tuple + and is constructed as described in <c><seealso marker="#tp-2">tp/2</seealso></c>. No tuple <c>{saved, N}</c> is however ever returned (for obvious reasons).</p> </desc> </func> @@ -480,8 +519,8 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <name>ctpl({Module, Function, Arity}) -> {ok, MatchDesc} | {error, term()}</name> <fsummary>Clear call trace pattern for the specified functions</fsummary> <desc> - <p>This function works as <c>ctp/1</c>, but only disables - tracing set up with <c>tpl/2</c> (not with <c>tp/2</c>).</p> + <p>This function works as <c><seealso marker="#ctp-1">ctp/1</seealso></c>, but only disables + tracing set up with <c><seealso marker="#tpl-2">tpl/2</seealso></c> (not with <c><seealso marker="#tp-2">tp/2</seealso></c>).</p> </desc> </func> <func> @@ -516,8 +555,8 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <name>ctpg({Module, Function, Arity}) -> {ok, MatchDesc} | {error, term()}</name> <fsummary>Clear call trace pattern for the specified functions</fsummary> <desc> - <p>This function works as <c>ctp/1</c>, but only disables - tracing set up with <c>tp/2</c> (not with <c>tpl/2</c>).</p> + <p>This function works as <c><seealso marker="#ctp-1">ctp/1</seealso></c>, but only disables + tracing set up with <c><seealso marker="#tp-2">tp/2</seealso></c> (not with <c><seealso marker="#tpl-2">tpl/2</seealso></c>).</p> </desc> </func> <func> @@ -526,13 +565,13 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <desc> <p>Use this function to recall all match specifications previously used in the session (i. e. previously saved during calls - to <c>tp/2</c>, and built-in match specifications. + to <c><seealso marker="#tp-2">tp/2</seealso></c>, and built-in match specifications. This is very useful, as a complicated match_spec can be quite awkward to write. Note that the - match specifications are lost if <c>stop/0</c> is called.</p> + match specifications are lost if <c><seealso marker="#stop-0">stop/0</seealso></c> is called.</p> <p>Match specifications used can be saved in a file (if a read-write file system is present) for use in later - debugging sessions, see <c>wtp/1</c> and <c>rtp/1</c></p> + debugging sessions, see <c><seealso marker="#wtp-1">wtp/1</seealso></c> and <c><seealso marker="#rtp-1">rtp/1</seealso></c></p> <p>There are three built-in trace patterns: <c>exception_trace</c>, <c>caller_trace</c> and <c>caller_exception_trace</c> (or <c>x</c>, <c>c</c> and @@ -555,10 +594,10 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <fsummary>Delete all saved match specifications.</fsummary> <desc> <p>Use this function to "forget" all match specifications - saved during calls to <c>tp/2</c>. + saved during calls to <c><seealso marker="#tp-2">tp/2</seealso></c>. This is useful when one wants to restore other match - specifications from a file with <c>rtp/1</c>. Use - <c>dtp/1</c> to delete specific saved match specifications. </p> + specifications from a file with <c><seealso marker="#rtp-1">rtp/1</seealso></c>. Use + <c><seealso marker="#dtp-1">dtp/1</seealso></c> to delete specific saved match specifications. </p> </desc> </func> <func> @@ -569,7 +608,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ </type> <desc> <p>Use this function to "forget" a specific match specification - saved during calls to <c>tp/2</c>.</p> + saved during calls to <c><seealso marker="#tp-2">tp/2</seealso></c>.</p> </desc> </func> <func> @@ -581,12 +620,12 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ </type> <desc> <p>This function will save all match specifications saved - during the session (during calls to <c>tp/2</c>) + during the session (during calls to <c><seealso marker="#tp-2">tp/2</seealso></c>) and built-in match specifications in a text file with the name designated by <c>Name</c>. The format of the file is textual, why it can be edited with an ordinary text editor, and then restored with - <c>rtp/1</c>. </p> + <c><seealso marker="#rtp-1">rtp/1</seealso></c>. </p> <p>Each match spec in the file ends with a full stop (<c>.</c>) and new (syntactically correct) match specifications can be added to the file manually.</p> @@ -604,7 +643,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ </type> <desc> <p>This function reads match specifications from a file - (possibly) generated by the <c>wtp/1</c> function. It checks + (possibly) generated by the <c><seealso marker="#wtp-1">wtp/1</seealso></c> function. It checks the syntax of all match specifications and verifies that they are correct. The error handling principle is "all or nothing", i. e. if some of the match specifications are @@ -612,14 +651,14 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ saved match specifications for the running system. </p> <p>The match specifications in the file are <em>merged</em> with the current match specifications, so that no duplicates - are generated. Use <c>ltp/0</c> to see what numbers were + are generated. Use <c><seealso marker="#ltp-0">ltp/0</seealso></c> to see what numbers were assigned to the specifications from the file.</p> <p>The function will return an error, either due to I/O problems (like a non existing or non readable file) or due to file format problems. The errors from a bad format file are in a more or less textual format, which will give a hint - to what's causing the problem. <marker id="n"></marker> -</p> + to what's causing the problem. + </p> </desc> </func> <func> @@ -631,12 +670,12 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ </type> <desc> <p>The <c>dbg</c> server keeps a list of nodes where tracing - should be performed. Whenever a <c>tp/2</c> call or a - <c>p/2</c> call is made, it is executed for all nodes in this - list including the local node (except for <c>p/2</c> with a - specific <c>pid()</c> as first argument, in which case the + should be performed. Whenever a <c><seealso marker="#tp-2">tp/2</seealso></c> call or a + <c><seealso marker="#p-2">p/2</seealso></c> call is made, it is executed for all nodes in this + list including the local node (except for <c><seealso marker="#p-2">p/2</seealso></c> with a + specific <c>pid()</c> or <c>port()</c> as first argument, in which case the command is executed only on the node where the designated - process resides). + process or port resides). </p> <p>This function adds a remote node (<c>Nodename</c>) to the list of nodes where tracing is performed. It starts a tracer @@ -645,17 +684,17 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ distribution). If no tracer process is running on the local node, the error reason <c>no_local_tracer</c> is returned. The tracer process on the local node must be started with the - <c>tracer/0/2</c> function. + <c><seealso marker="#tracer-2">tracer/0/2</seealso></c> function. </p> <p>If <c>Nodename</c> is the local node, the error reason <c>cant_add_local_node</c> is returned. </p> - <p>If a trace port (see <seealso marker="#trace_port"><c>trace_port/2</c></seealso>) is + <p>If a trace port (see <seealso marker="#trace_port-2"><c>trace_port/2</c></seealso>) is running on the local node, remote nodes can not be traced with a tracer process. The error reason <c>cant_trace_remote_pid_to_local_port</c> is returned. A trace port can however be started on the remote node with the - <c>tracer/3</c> function. + <c><seealso marker="#tracer-3">tracer/3</seealso></c> function. </p> <p>The function will also return an error if the node <c>Nodename</c> is not reachable.</p> @@ -669,7 +708,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ </type> <desc> <p>Clears a node from the list of traced nodes. Subsequent - calls to <c>tp/2</c> and <c>p/2</c> will not consider that + calls to <c><seealso marker="#tp-2">tp/2</seealso></c> and <c><seealso marker="#p-2">p/2</seealso></c> will not consider that node, but tracing already activated on the node will continue to be in effect.</p> <p>Returns <c>ok</c>, cannot fail.</p> @@ -688,37 +727,42 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <desc> <p>This function starts a server on the local node that will be the recipient of all trace messages. All subsequent calls - to <c>p/2</c> will result in messages sent to the newly + to <c><seealso marker="#p-2">p/2</seealso></c> will result in messages sent to the newly started trace server.</p> <p>A trace server started in this way will simply display the trace messages in a formatted way in the Erlang shell - (i. e. use io:format). See <c>tracer/2</c> for a description - of how the trace message handler can be customized. <marker id="tracer2"></marker> -</p> - <p>To start a similar tracer on a remote node, use <c>n/1</c>.</p> + (i. e. use io:format). See <c><seealso marker="#tracer-2">tracer/2</seealso></c> for a description + of how the trace message handler can be customized. + </p> + <p>To start a similar tracer on a remote node, use <c><seealso marker="#n-1">n/1</seealso></c>.</p> </desc> </func> <func> <name>tracer(Type, Data) -> {ok, pid()} | {error, Error}</name> <fsummary>Start a tracer server with additional parameters</fsummary> <type> - <v>Type = port | process</v> - <v>Data = PortGenerator | HandlerSpec</v> - <v>HandlerSpec = {HandlerFun, InitialData}</v> - <v>HandlerFun = fun() (two arguments)</v> - <v>InitialData = term()</v> + <v>Type = port | process | module</v> + <v>Data = PortGenerator | HandlerSpec | ModuleSpec</v> <v>PortGenerator = fun() (no arguments)</v> <v>Error = term()</v> + <v>HandlerSpec = {HandlerFun, InitialData}</v> + <v>HandlerFun = fun() (two arguments)</v> + <v>ModuleSpec = {TracerModule, TracerState}</v> + <v>ModuleModule = atom()</v> + <v>InitialData = TracerState = term()</v> </type> <desc> <p>This function starts a tracer server with additional parameters on the local node. The first parameter, the <c>Type</c>, indicates if trace messages should be handled - by a receiving process (<c>process</c>) or by a tracer port - (<c>port</c>). For a description about tracer ports see - <c>trace_port/2</c>. + by a receiving process (<c>process</c>), by a tracer port + (<c>port</c>) or by a tracer module + (<c>module</c>). For a description about tracer ports see + <c><seealso marker="#trace_port-2">trace_port/2</seealso></c> + and for a tracer modules see + <c><seealso marker="erts:erl_tracer">erl_tracer</seealso>.</c> </p> - <p>If <c>Type</c> is a process, a message handler function can + <p>If <c>Type</c> is <c>process</c>, a message handler function can be specified (<c>HandlerSpec</c>). The handler function, which should be a <c>fun</c> taking two arguments, will be called for each trace message, with the first argument containing the @@ -729,18 +773,22 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ choose any appropriate action to take when invoked, and can save a state for the next invocation by returning it. </p> - <p>If <c>Type</c> is a port, then the second parameter should + <p>If <c>Type</c> is <c>port</c>, then the second parameter should be a <em>fun</em> which takes no arguments and returns a newly opened trace port when called. Such a <em>fun</em> is - preferably generated by calling <c>trace_port/2</c>. + preferably generated by calling <c><seealso marker="#trace_port-2">trace_port/2</seealso></c>. </p> + <p>if <c>Type</c> is <c>module</c>, then the second parameter should + be a tuple describing the <c><seealso marker="erts:erl_tracer">erl_tracer</seealso></c> + module to be used for tracing and the state to be used for + that tracer module.</p> <p>If an error is returned, it can either be due to a tracer server already running (<c>{error,already_started}</c>) or due to the <c>HandlerFun</c> throwing an exception. </p> <p>To start a similar tracer on a remote node, use - <c>tracer/3</c>. <marker id="trace_port"></marker> -</p> + <c><seealso marker="#tracer-3">tracer/3</seealso></c>. + </p> </desc> </func> <func> @@ -750,20 +798,20 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <v>Nodename = atom()</v> </type> <desc> - <p>This function is equivalent to <c>tracer/2</c>, but acts on + <p>This function is equivalent to <c><seealso marker="#tracer-2">tracer/2</seealso></c>, but acts on the given node. A tracer is started on the node (<c>Nodename</c>) and the node is added to the list of traced nodes. </p> <note> - <p>This function is not equivalent to <c>n/1</c>. While - <c>n/1</c> starts a process tracer which redirects all trace + <p>This function is not equivalent to <c><seealso marker="#n-1">n/1</seealso></c>. While + <c><seealso marker="#n-1">n/1</seealso></c> starts a process tracer which redirects all trace information to a process tracer on the local node (i.e. the - trace control node), <c>tracer/3</c> starts a tracer of any + trace control node), <c><seealso marker="#tracer-3">tracer/3</seealso></c> starts a tracer of any type which is independent of the tracer on the trace control node.</p> </note> - <p>For details, see <seealso marker="#tracer2"><c>tracer/2</c></seealso>.</p> + <p>For details, see <c><seealso marker="#tracer-2">tracer/2</seealso></c>.</p> </desc> </func> <func> @@ -795,9 +843,9 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <c>file</c> and the <c>ip</c> trace drivers. The file driver sends all trace messages into one or several binary files, from where they later can be fetched and processed with the - <c>trace_client/2</c> function. The ip driver opens a TCP/IP + <c><seealso marker="#trace_client-2">trace_client/2</seealso></c> function. The ip driver opens a TCP/IP port where it listens for connections. When a client - (preferably started by calling <c>trace_client/2</c> on + (preferably started by calling <c><seealso marker="#trace_client-2">trace_client/2</seealso></c> on another Erlang node) connects, all trace messages are sent over the IP network for further processing by the remote client. </p> @@ -836,7 +884,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ as fast as they are produced by the runtime system, a special message is sent, which indicates how many messages that are dropped. That message will arrive at the handler function - specified in <c>trace_client/3</c> as the tuple <c>{drop, N}</c> where <c>N</c> is the number of consecutive messages + specified in <c><seealso marker="#trace_client-3">trace_client/3</seealso></c> as the tuple <c>{drop, N}</c> where <c>N</c> is the number of consecutive messages dropped. In case of heavy tracing, drop's are likely to occur, and they surely occur if no client is reading the trace messages.</p> @@ -890,7 +938,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ </item> <tag><c>get_listen_port</c></tag> <item> - <p>Returns <c>{ok, IpPort}</c> where <c>IpPort</c>is + <p>Returns <c>{ok, IpPort}</c> where <c>IpPort</c> is the IP port number used by the driver listen socket. Only the ip trace driver supports this operation.</p> </item> @@ -913,7 +961,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <desc> <p>This function starts a trace client that reads the output created by a trace port driver and handles it in mostly the - same way as a tracer process created by the <c>tracer/0</c> + same way as a tracer process created by the <c><seealso marker="#tracer-0">tracer/0</seealso></c> function.</p> <p>If <c>Type</c> is <c>file</c>, the client reads all trace messages stored in the file named <c>Filename</c> or @@ -925,7 +973,7 @@ Error: fun containing local erlang function calls ('is_atomm' called in guard)\ <p>If <c>Type</c> is <c>follow_file</c>, the client behaves as in the <c>file</c> case, but keeps trying to read (and process) more data - from the file until stopped by <c>stop_trace_client/1</c>. + from the file until stopped by <c><seealso marker="#stop_trace_client-1">stop_trace_client/1</seealso></c>. <c>WrapFilesSpec</c> is not allowed as second argument for this <c>Type</c>.</p> <p>If <c>Type</c> is <c>ip</c>, the client connects to the @@ -981,10 +1029,10 @@ hello</pre> <v>InitialData = term()</v> </type> <desc> - <p>This function works exactly as <c>trace_client/2</c>, but + <p>This function works exactly as <c><seealso marker="#trace_client-2">trace_client/2</seealso></c>, but allows you to write your own handler function. The handler function works mostly as the one described in - <c>tracer/2</c>, but will also have to be prepared to handle + <c><seealso marker="#tracer-2">tracer/2</seealso></c>, but will also have to be prepared to handle trace messages of the form <c>{drop, N}</c>, where <c>N</c> is the number of dropped messages. This pseudo trace message will only occur if the ip trace driver is used.</p> @@ -1003,7 +1051,7 @@ hello</pre> <desc> <p>This function shuts down a previously started trace client. The <c>Pid</c> argument is the process id returned - from the <c>trace_client/2</c> or <c>trace_client/3</c> call.</p> + from the <c><seealso marker="#trace_client-2">trace_client/2</seealso></c> or <c><seealso marker="#trace_client-3">trace_client/3</seealso></c> call.</p> </desc> </func> <func> @@ -1156,8 +1204,9 @@ SeqTrace [0]: (<0.30.0>) <0.25.0> ! {dbg,{ok,<0.31.0>}} [Serial: {4,5}] of causing a deadlock. This will happen if a group leader process generates a trace message and the tracer process, by calling the trace handler function, sends an IO request to the same group leader. The problem can only occur if the trace handler - prints to tty using an <c>io</c> function such as <c>format/2</c>. Note that when - <c>dbg:p(all,call)</c> is called, IO processes are also traced. + prints to tty using an <c>io</c> function such as <c><seealso marker="stdlib:io#format-2">format/2</seealso></c>. + Note that when + <c>dbg:p(all,call)</c> is called, IO processes are also traced. Here's an example:</p> <pre> %% Using a default line editing shell |