diff options
Diffstat (limited to 'erts/doc/src/erlang.xml')
| -rw-r--r-- | erts/doc/src/erlang.xml | 1547 |
1 files changed, 1227 insertions, 320 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 30e6751f41..fa13e4c142 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2015</year> + <year>1996</year><year>2016</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -52,13 +52,18 @@ <datatype> <name>ext_binary()</name> <desc> - <marker id="type-ext_binary"></marker> <p>A binary data object, structured according to the Erlang external term format.</p> </desc> </datatype> <datatype> + <name name="message_queue_data"></name> + <desc><p>See <seealso marker="#process_flag_message_queue_data"><c>erlang:process_flag(message_queue_data, MQD)</c></seealso>.</p> + </desc> + </datatype> + + <datatype> <name name="timestamp"></name> <desc><p>See <seealso marker="#timestamp/0">erlang:timestamp/0</seealso>.</p> </desc> @@ -125,6 +130,17 @@ </note> </item> + <tag><c>perf_counter</c></tag> + <item><p>Symbolic representation of the performance counter + time unit used by the Erlang runtime system.</p> + + <p>The <c>perf_counter</c> time unit behaves much in the same way + as the <c>native</c> time unit. That is it might differ inbetween + run-time restarts. You get values of this type by calling + <seealso marker="kernel:os#perf_counter/0"><c>os:perf_counter()</c></seealso> + </p> + </item> + </taglist> <p>The <c>time_unit/0</c> type may be extended. Use @@ -1105,7 +1121,7 @@ <fsummary>Prints a term on standard output.</fsummary> <desc> <p>Prints a text representation of <c><anno>Term</anno></c> on the - standard output. On OSE, the term is printed to the ramlog.</p> + standard output.</p> <warning> <p>This BIF is intended for debugging only.</p> </warning> @@ -1786,6 +1802,8 @@ os_prompt% </pre> <tag>string()</tag> <item>An Erlang crash dump is produced with <c><anno>Status</anno></c> as slogan. Then the runtime system exits with status code <c>1</c>. + Note that only code points in the range 0-255 may be used + and the string will be truncated if longer than 200 characters. </item> <tag><c>abort</c></tag> <item> @@ -2596,6 +2614,48 @@ 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> @@ -2856,107 +2916,105 @@ os_prompt% </pre> <func> <name name="monitor" arity="2" clause_i="1"/> <name name="monitor" arity="2" clause_i="2"/> + <name name="monitor" arity="2" clause_i="3"/> <fsummary>Starts monitoring.</fsummary> <type name="registered_name"/> <type name="registered_process_identifier"/> <type name="monitor_process_identifier"/> + <type name="monitor_port_identifier"/> <desc> - <p>Send a monitor request of type <c><anno>Type</anno></c> to the - entity identified by <c><anno>Item</anno></c>. The caller of - <c>monitor/2</c> will later be notified by a monitor message on the - following format if the monitored state is changed:</p> + <p>Sends a monitor request of type <c><anno>Type</anno></c> to the + entity identified by <c><anno>Item</anno></c>. If the monitored entity + does not exist or when it dies, the caller of <c>monitor/2</c> will + be notified by a message on the following format:</p> <code type="none">{Tag, <anno>MonitorRef</anno>, <anno>Type</anno>, Object, Info}</code> <note><p>The monitor request is an asynchronous signal. That is, it takes time before the signal reaches its destination.</p></note> - <p>Valid <c><anno>Type</anno></c>s:</p> - <taglist> - <tag><marker id="monitor_process"/><c>process</c></tag> - <item> - <p>Monitor the existence of the process identified by - <c><anno>Item</anno></c>. Valid - <c><anno>Item</anno></c>s in combination with the - <c>process <anno>Type</anno></c> can be any of the following:</p> - <taglist> - <tag><c>pid()</c></tag> - <item> - <p>The process identifier of the process to monitor.</p> - </item> - <tag><c>{RegisteredName, Node}</c></tag> - <item> - <p>A tuple consisting of a registered name of a process and - a node name. The process residing on the node <c>Node</c> - with the registered name <c>{RegisteredName, Node}</c> will - be monitored.</p> - </item> - <tag><c>RegisteredName</c></tag> - <item> - <p>The process locally registered as <c>RegisteredName</c> - will become monitored.</p> - </item> - </taglist> - <note><p>When a registered name is used, the - process that has the registered name when the - monitor request reach its destination will be monitored. - The monitor is not effected if the registered name is - unregistered, or unregistered and later registered on another - process.</p></note> - <p>The monitor is triggered either when the monitored process - terminates, is non existing, or if the connection to it is - lost. In the case the connection to it is lost, we do not know - if it still exist or not. After this type of monitor has been - triggered, the monitor is automatically removed.</p> - <p>When the monitor is triggered a <c>'DOWN'</c> message is - sent to the monitoring process. A <c>'DOWN'</c> message has - the following pattern:</p> - <code type="none">{'DOWN', MonitorRef, Type, Object, Info}</code> - <p>Here <c>MonitorRef</c> and <c>Type</c> are the same as - described earlier, and:</p> - <taglist> - <tag><c>Object</c></tag> - <item> - <p>equals:</p> - <taglist> - <tag><c><anno>Item</anno></c></tag> - <item>If <c><anno>Item</anno></c> is specified by a - process identifier.</item> - <tag><c>{RegisteredName, Node}</c></tag> - <item>If <c><anno>Item</anno></c> is specified as - <c>RegisteredName</c>, or <c>{RegisteredName, Node}</c> - where <c>Node</c> corresponds to the node that the - monitored process resides on.</item> - </taglist> - </item> - <tag><c>Info</c></tag> - <item> - <p>Either the exit reason of the process, <c>noproc</c> - (non-existing process), or <c>noconnection</c> (no - connection to the node where the monitored process - resides).</p></item> - </taglist> - <p>The monitoring is turned off when the <c>'DOWN'</c> - message is sent or when - <seealso marker="#demonitor/1">demonitor/1</seealso> - is called.</p> - <p>If an attempt is made to monitor a process on an older node - (where remote process monitoring is not implemented or - where remote process monitoring by registered name is not - implemented), the call fails with <c>badarg</c>.</p> - <note> - <p>The format of the <c>'DOWN'</c> message changed in ERTS - version 5.2 (OTP R9B) for monitoring - <em>by registered name</em>. Element <c>Object</c> of - the <c>'DOWN'</c> message could in earlier versions - sometimes be the process identifier of the monitored process and sometimes - be the registered name. Now element <c>Object</c> is - always a tuple consisting of the registered name and - the node name. Processes on new nodes (ERTS version 5.2 - or higher) always get <c>'DOWN'</c> messages on - the new format even if they are monitoring processes on old - nodes. Processes on old nodes always get <c>'DOWN'</c> - messages on the old format.</p> - </note> - </item> - <tag><marker id="monitor_time_offset"/><c>time_offset</c></tag> + + <p><c><anno>Type</anno></c> can be one of the following atoms: + <c>process</c>, <c>port</c> or <c>time_offset</c>.</p> + + <p>A monitor is triggered only once, after that it is removed from + both monitoring process and the monitored entity. + Monitors are fired when the monitored process or port terminates, + does not exist at the moment of creation, or if the connection to + it is lost. In the case with connection, we lose knowledge about + the fact if it still exists or not. The monitoring is also turned off + when <seealso marker="#demonitor/1">demonitor/1</seealso> + is called.</p> + + <p>When monitoring by name please note, that the <c>RegisteredName</c> + is resolved to <c>pid()</c> or <c>port()</c> only once + at the moment of monitor instantiation, later changes to the name + registration will not affect the existing monitor.</p> + + <p>When a monitor is triggered, a <c>'DOWN'</c> message that has the + following pattern <c>{'DOWN', MonitorRef, Type, Object, Info}</c> + is sent to the monitoring process.</p> + + <p>In monitor message <c>MonitorRef</c> and <c>Type</c> are the same as + described earlier, and:</p> + <taglist> + <tag><c>Object</c></tag> + <item> + <p>The monitored entity, which triggered the event. When monitoring + a local process or port, <c>Object</c> will be equal to the + <c>pid()</c> or <c>port()</c> that was being monitored. When + monitoring process or port by name, <c>Object</c> will have format + <c>{RegisteredName, Node}</c> where <c>RegisteredName</c> is the + name which has been used with <c>monitor/2</c> call and + <c>Node</c> is local or remote node name (for ports monitored by + name, <c>Node</c> is always local node name).</p> + </item> + <tag><c>Info</c></tag> + <item> + <p>Either the exit reason of the process, <c>noproc</c> + (process or port did not exist at the time of monitor creation), + or <c>noconnection</c> (no connection to the node where the + monitored process resides). </p></item> + </taglist> + + <p>If an attempt is made to monitor a process on an older node + (where remote process monitoring is not implemented or + where remote process monitoring by registered name is not + implemented), the call fails with <c>badarg</c>.</p> + <note> + <p>The format of the <c>'DOWN'</c> message changed in ERTS + version 5.2 (OTP R9B) for monitoring + <em>by registered name</em>. Element <c>Object</c> of + the <c>'DOWN'</c> message could in earlier versions + sometimes be the process identifier of the monitored process and sometimes + be the registered name. Now element <c>Object</c> is + always a tuple consisting of the registered name and + the node name. Processes on new nodes (ERTS version 5.2 + or higher) always get <c>'DOWN'</c> messages on + the new format even if they are monitoring processes on old + nodes. Processes on old nodes always get <c>'DOWN'</c> + messages on the old format.</p> + </note> + + <taglist> + <tag>Monitoring a <marker id="monitor_process"/><c>process</c></tag> + <item> + <p>Creates monitor between the current process and another + process identified by <c><anno>Item</anno></c>, which can be a + <c>pid()</c> (local or remote), an atom <c>RegisteredName</c> or + a tuple <c>{RegisteredName, Node}</c> for a registered process, + located elsewhere.</p> + </item> + + <tag>Monitoring a <marker id="monitor_port"/><c>port</c></tag> + <item> + <p>Creates monitor between the current process and a port + identified by <c><anno>Item</anno></c>, which can be a + <c>port()</c> (only local), an atom <c>RegisteredName</c> or + a tuple <c>{RegisteredName, Node}</c> for a registered port, + located on this node. Note, that attempt to monitor a remote port + will result in <c>badarg</c>.</p> + </item> + + <tag>Monitoring a + <marker id="monitor_time_offset"/><c>time_offset</c></tag> <item> <p>Monitor changes in <seealso marker="#time_offset/0">time offset</seealso> @@ -3012,15 +3070,17 @@ os_prompt% </pre> Note that you can observe the change of the time offset when calling <c>erlang:time_offset()</c> before you get the <c>'CHANGE'</c> message.</p> - </item> </taglist> + <p>Making several calls to <c>monitor/2</c> for the same - <c><anno>Item</anno></c> and/or <c><anno>Type</anno></c> is not - an error; it results in as many independent monitoring instances.</p> + <c><anno>Item</anno></c> and/or <c><anno>Type</anno></c> is not + an error; it results in as many independent monitoring instances.</p> + <p>The monitor functionality is expected to be extended. That is, - other <c><anno>Type</anno></c>s and <c><anno>Item</anno></c>s - are expected to be supported in a future release.</p> + other <c><anno>Type</anno></c>s and <c><anno>Item</anno></c>s + are expected to be supported in a future release.</p> + <note> <p>If or when <c>monitor/2</c> is extended, other possible values for <c>Tag</c>, <c>Object</c> and @@ -4090,6 +4150,22 @@ os_prompt% </pre> <func> <name name="port_info" arity="2" clause_i="8"/> + <fsummary>Which processes are monitoring this port.</fsummary> + <desc> + <p>Returns list of pids that are monitoring given port at the + moment.</p> + <p>If the port identified by <c><anno>Port</anno></c> is not open, + <c>undefined</c> is returned. If the port is closed and the + calling process was previously linked to the port, the exit + signal from the port is guaranteed to be delivered before + <c>port_info/2</c> returns <c>undefined</c>.</p> + <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local + port identifier, or an atom.</p> + </desc> + </func> + + <func> + <name name="port_info" arity="2" clause_i="9"/> <fsummary>Information about the name of a port.</fsummary> <desc> <p><c><anno>Name</anno></c> is the command name set by @@ -4105,7 +4181,7 @@ os_prompt% </pre> </func> <func> - <name name="port_info" arity="2" clause_i="9"/> + <name name="port_info" arity="2" clause_i="10"/> <fsummary>Information about the OS pid of a port.</fsummary> <desc> <p><c><anno>OsPid</anno></c> is the process identifier (or equivalent) @@ -4124,7 +4200,7 @@ os_prompt% </pre> </func> <func> - <name name="port_info" arity="2" clause_i="10"/> + <name name="port_info" arity="2" clause_i="11"/> <fsummary>Information about the output of a port.</fsummary> <desc> <p><c><anno>Bytes</anno></c> is the total number of bytes written @@ -4143,7 +4219,7 @@ os_prompt% </pre> </func> <func> - <name name="port_info" arity="2" clause_i="11"/> + <name name="port_info" arity="2" clause_i="12"/> <fsummary>Information about the parallelism hint of a port.</fsummary> <desc> <p><c><anno>Boolean</anno></c> corresponds to the port parallelism @@ -4154,7 +4230,7 @@ os_prompt% </pre> </func> <func> - <name name="port_info" arity="2" clause_i="12"/> + <name name="port_info" arity="2" clause_i="13"/> <fsummary>Information about the queue size of a port.</fsummary> <desc> <p><c><anno>Bytes</anno></c> is the total number @@ -4171,7 +4247,7 @@ os_prompt% </pre> </func> <func> - <name name="port_info" arity="2" clause_i="13"/> + <name name="port_info" arity="2" clause_i="14"/> <fsummary>Information about the registered name of a port.</fsummary> <desc> <p><c><anno>RegisteredName</anno></c> is the registered name of @@ -4263,6 +4339,7 @@ os_prompt% </pre> </desc> </func> + <marker id="process_flag_min_heap_size"/> <func> <name name="process_flag" arity="2" clause_i="3"/> <fsummary>Sets process flag <c>min_heap_size</c> for the calling process.</fsummary> @@ -4281,9 +4358,140 @@ os_prompt% </pre> <p>Returns the old value of the flag.</p> </desc> </func> - + <marker id="process_flag_max_heap_size"/> <func> <name name="process_flag" arity="2" clause_i="5"/> + <type name="max_heap_size"/> + <fsummary>Sets process flag <c>max_heap_size</c> for the calling process.</fsummary> + <desc> + <p> + This flag sets the maximum heap size for the calling process. + If <c><anno>MaxHeapSize</anno></c> is an integer, the system default + values for <c>kill</c> and <c>error_logger</c> are used. + <taglist> + <tag><c>size</c></tag> + <item> + <p> + The maximum size in words of the process. If set to zero, the + heap size limit is disabled. Badarg will be thrown if the value is + smaller than + <seealso marker="#process_flag_min_heap_size"><c>min_heap_size</c></seealso>. + The size check is only done when a garbage collection is triggered. + </p> + <p> + <c>size</c> is the entire heap of the process when garbage collection + is triggered, this includes all generational heaps, the process stack, + any <seealso marker="#process_flag_message_queue_data"> + messages that are considered to be part of the heap</seealso> and any + extra memory that the garbage collector needs during collection. + </p> + <p> + <c>size</c> is the same as can be retrieved using + <seealso marker="#process_info_total_heap_size"> + <c>erlang:process_info(Pid, total_heap_size)</c></seealso>, + or by adding <c>heap_block_size</c>, <c>old_heap_block_size</c> + and <c>mbuf_size</c> from <seealso marker="#process_info_garbage_collection_info"> + <c>erlang:process_info(Pid, garbage_collection_info)</c></seealso>. + </p> + </item> + <tag><c>kill</c></tag> + <item> + <p> + When set to <c>true</c> the runtime system will send an + untrappable exit signal with reason <c>kill</c> to the process + if the maximum heap size is reached. The garbage collection + that triggered the <c>kill</c> will not be completed, instead the + process will exit as soon as is possible. When set to <c>false</c> + no exit signal will be sent to the process, instead it will + continue executing. + </p> + <p> + If <c>kill</c> is not defined in the map + the system default will be used. The default system default + is <c>true</c>. It can be changed by either the erl + <seealso marker="erl#+hmaxk">+hmaxk</seealso> option, + or <seealso marker="#system_flag_max_heap_size"><c> + erlang:system_flag(max_heap_size, MaxHeapSize)</c></seealso>. + </p> + </item> + <tag><c>error_logger</c></tag> + <item> + <p> + When set to <c>true</c> the runtime system will send a + message to the current <seealso marker="kernel:error_logger"><c>error_logger</c></seealso> + containing details about the process when the maximum + heap size is reached. One <c>error_logger</c> report will + be sent each time the limit is reached. + </p> + <p> + If <c>error_logger</c> is not defined in the map the system + default will be used. The default system default is <c>true</c>. + It can be changed by either the erl <seealso marker="erl#+hmaxel">+hmaxel</seealso> + option, or <seealso marker="#system_flag_max_heap_size"><c> + erlang:system_flag(max_heap_size, MaxHeapSize)</c></seealso>. + </p> + </item> + <p> + The heap size of a process is quite hard to predict, especially the + amount of memory that is used during the garbage collection. When + contemplating using this option, it is recommended to first run + it in production with <c>kill</c> set to <c>false</c> and inspect + the <c>error_logger</c> reports to see what the normal peak sizes + of the processes in the system is and then tune the value + accordingly. + </p> + </taglist> + </p> + </desc> + </func> + <marker id="process_flag_message_queue_data"/> + <func> + <name name="process_flag" arity="2" clause_i="6"/> + <fsummary>Set process flag <c>message_queue_data</c> for the calling process</fsummary> + <type name="message_queue_data"/> + <desc> + <p>This flag determines how messages in the message queue + are stored. When the flag is:</p> + <taglist> + <tag><c>off_heap</c></tag> + <item><p> + <em>All</em> messages in the message queue will be stored + outside of the process heap. This implies that <em>no</em> + messages in the message queue will be part of a garbage + collection of the process. + </p></item> + <tag><c>on_heap</c></tag> + <item><p> + All messages in the message queue will eventually be + placed on heap. They may however temporarily be stored + off heap. This is how messages always have been stored + up until ERTS version 8.0. + </p></item> + </taglist> + <p> + The default <c>message_queue_data</c> process flag is determined + by the <seealso marker="erl#+hmqd"><c>+hmqd</c></seealso> + <c>erl</c> command line argument. + </p> + <p> + If the process potentially may get a hugh amount of messages, + you are recommended to set the flag to <c>off_heap</c>. This + since a garbage collection with lots of messages placed on + the heap may become extremly expensive and the process may + consume large amounts of memory. Performance of the + actual message passing is however generally better when not + using the <c>off_heap</c> flag. + </p> + <p> + When changing this flag messages will be moved. This work + has been initiated but not completed when this function + call returns. + </p> + <p>Returns the old value of the flag.</p> + </desc> + </func> + <func> + <name name="process_flag" arity="2" clause_i="7"/> <fsummary>Sets process flag <c>priority</c> for the calling process.</fsummary> <type name="priority_level"/> <desc> @@ -4357,7 +4565,7 @@ os_prompt% </pre> </func> <func> - <name name="process_flag" arity="2" clause_i="6"/> + <name name="process_flag" arity="2" clause_i="8"/> <fsummary>Sets process flag <c>save_calls</c> for the calling process.</fsummary> <desc> <p><c><anno>N</anno></c> must be an integer in the interval 0..10000. @@ -4388,7 +4596,7 @@ os_prompt% </pre> </func> <func> - <name name="process_flag" arity="2" clause_i="7"/> + <name name="process_flag" arity="2" clause_i="9"/> <fsummary>Sets process flag <c>sensitive</c> for the calling process.</fsummary> <desc> <p>Sets or clears flag <c>sensitive</c> for the current process. @@ -4442,6 +4650,8 @@ os_prompt% </pre> <type name="process_info_result_item"/> <type name="priority_level"/> <type name="stack_item"/> + <type name="max_heap_size" /> + <type name="message_queue_data" /> <desc> <p>Returns a list containing <c><anno>InfoTuple</anno></c>s with miscellaneous information about the process identified by @@ -4494,6 +4704,8 @@ os_prompt% </pre> <type name="process_info_result_item"/> <type name="stack_item"/> <type name="priority_level"/> + <type name="max_heap_size" /> + <type name="message_queue_data" /> <desc> <p>Returns information about the process identified by <c><anno>Pid</anno></c>, as specified by @@ -4585,6 +4797,18 @@ os_prompt% </pre> The content of <c><anno>GCInfo</anno></c> can be changed without prior notice.</p> </item> + <marker id="process_info_garbage_collection_info"/> + <tag><c>{garbage_collection_info, <anno>GCInfo</anno>}</c></tag> + <item> + <p><c><anno>GCInfo</anno></c> is a list containing miscellaneous + detailed information about garbage collection for this process. + The content of <c><anno>GCInfo</anno></c> can be changed without + prior notice. + See <seealso marker="#gc_minor_start">gc_minor_start</seealso> in + <seealso marker="#trace/3">erlang:trace/3</seealso> for details about + what each item means. + </p> + </item> <tag><c>{group_leader, <anno>GroupLeader</anno>}</c></tag> <item> <p><c><anno>GroupLeader</anno></c> is group leader for the I/O of @@ -4657,10 +4881,28 @@ os_prompt% </pre> <p>A list of monitors (started by <c>monitor/2</c>) that are active for the process. For a local process monitor or a remote process monitor by a process - identifier, the list item is <c>{process, <anno>Pid</anno>}</c>. - For a remote process - monitor by name, the list item is - <c>{process, {<anno>RegName</anno>, <anno>Node</anno>}}</c>.</p> + identifier, the list consists of:</p> + <taglist> + <tag><c>{process, <anno>Pid</anno>}</c></tag> + <item>Process is monitored by pid.</item> + <tag><c>{process, {<anno>RegName</anno>, <anno>Node</anno>}}</c></tag> + <item>Local or remote process is monitored by name.</item> + <tag><c>{port, PortId}</c></tag> + <item>Local port is monitored by port id.</item> + <tag><c>{port, {<anno>RegName</anno>, <anno>Node</anno>}}</c></tag> + <item>Local port is monitored by name. Please note, that + remote port monitors are not supported, so <c>Node</c> will + always be the local node name.</item> + </taglist> + </item> + <tag><c>{message_queue_data, <anno>MQD</anno>}</c></tag> + <item> + <p>Returns the current state of the <c>message_queue_data</c> + process flag. <c><anno>MQD</anno></c> is either <c>off_heap</c>, + or <c>on_heap</c>. For more information, see the + documentation of + <seealso marker="#process_flag_message_queue_data"><c>process_flag(message_queue_data, + MQD)</c></seealso>.</p> </item> <tag><c>{priority, <anno>Level</anno>}</c></tag> <item> @@ -4744,10 +4986,13 @@ os_prompt% </pre> total suspend count on <c><anno>Suspendee</anno></c>, only the parts contributed by <c><anno>Pid</anno></c>.</p> </item> + <marker id="process_info_total_heap_size"/> <tag><c>{total_heap_size, <anno>Size</anno>}</c></tag> <item> <p><c><anno>Size</anno></c> is the total size, in words, of all heap - fragments of the process. This includes the process stack.</p> + fragments of the process. This includes the process stack and + any unreceived messages that are considered to be part of the + heap. </p> </item> <tag><c>{trace, <anno>InternalTraceFlags</anno>}</c></tag> <item> @@ -4804,6 +5049,12 @@ os_prompt% </pre> <seealso marker="kernel:code">code(3)</seealso>) and is not to be used elsewhere.</p> </warning> + <note> + <p>As from <c>ERTS</c> 8.0 (OTP 19), any lingering processes + that still execute the old code will be killed by this function. + In earlier versions, such incorrect use could cause much + more fatal failures, like emulator crash.</p> + </note> <p>Failure: <c>badarg</c> if there is no old code for <c><anno>Module</anno></c>.</p> </desc> @@ -4840,10 +5091,6 @@ os_prompt% </pre> <p>Stops the execution of the calling process with an exception of given class, reason, and call stack backtrace (<em>stacktrace</em>).</p> - <warning> - <p>This BIF is intended for debugging. Avoid to use it in applications, - unless you really know what you are doing.</p> - </warning> <p><c><anno>Class</anno></c> is <c>error</c>, <c>exit</c>, or <c>throw</c>. So, if it were not for the stacktrace, <c>erlang:raise(<anno>Class</anno>, <anno>Reason</anno>, @@ -5430,6 +5677,9 @@ true</pre> <name name="spawn_opt" arity="2"/> <fsummary>Creates a new process with a fun as entry point.</fsummary> <type name="priority_level"/> + <type name="max_heap_size" /> + <type name="message_queue_data" /> + <type name="spawn_opt_option" /> <desc> <p>Returns the process identifier (pid) of a new process started by the application of <c><anno>Fun</anno></c> @@ -5445,6 +5695,9 @@ true</pre> <name name="spawn_opt" arity="3"/> <fsummary>Creates a new process with a fun as entry point on a given node.</fsummary> <type name="priority_level"/> + <type name="max_heap_size" /> + <type name="message_queue_data" /> + <type name="spawn_opt_option" /> <desc> <p>Returns the process identifier (pid) of a new process started by the application of <c><anno>Fun</anno></c> to the @@ -5459,6 +5712,9 @@ true</pre> <name name="spawn_opt" arity="4"/> <fsummary>Creates a new process with a function as entry point.</fsummary> <type name="priority_level"/> + <type name="max_heap_size" /> + <type name="message_queue_data" /> + <type name="spawn_opt_option" /> <desc> <p>Works as <seealso marker="#spawn/3">spawn/3</seealso>, except that an @@ -5560,6 +5816,28 @@ true</pre> fine-tuning an application and to measure the execution time with various <c><anno>VSize</anno></c> values.</p> </item> + <tag><c>{max_heap_size, <anno>Size</anno>}</c></tag> + <item> + <p>Sets the <c>max_heap_size</c> process flag. The default + <c>max_heap_size</c> is determined by the + <seealso marker="erl#+hmax"><c>+hmax</c></seealso> <c>erl</c> + command line argument. For more information, see the + documentation of + <seealso marker="#process_flag_max_heap_size"><c>process_flag(max_heap_size, + <anno>Size</anno>)</c></seealso>.</p> + </item> + <tag><c>{message_queue_data, <anno>MQD</anno>}</c></tag> + <item> + <p>Sets the state of the <c>message_queue_data</c> process + flag. <c><anno>MQD</anno></c> should be either <c>off_heap</c>, + or <c>on_heap</c>. The default + <c>message_queue_data</c> process flag is determined by the + <seealso marker="erl#+hmqd"><c>+hmqd</c></seealso> <c>erl</c> + command line argument. For more information, see the + documentation of + <seealso marker="#process_flag_message_queue_data"><c>process_flag(message_queue_data, + <anno>MQD</anno>)</c></seealso>.</p> + </item> </taglist> </desc> </func> @@ -5568,6 +5846,9 @@ true</pre> <name name="spawn_opt" arity="5"/> <fsummary>Creates a new process with a function as entry point on a given node.</fsummary> <type name="priority_level"/> + <type name="max_heap_size" /> + <type name="message_queue_data" /> + <type name="spawn_opt_option" /> <desc> <p>Returns the process identifier (pid) of a new process started by the application @@ -5756,6 +6037,146 @@ true</pre> <func> <name name="statistics" arity="1" clause_i="6"/> + <fsummary>Information about microstate accounting.</fsummary> + <desc> + <marker id="statistics_microstate_accounting"></marker> + <p> + Microstate accounting can be used to measure how much time the Erlang + runtime system spends doing various tasks. It is designed to be as + lightweight as possible, but there will be some overhead when this + is enabled. Microstate accounting is meant to be a profiling tool + to help figure out performance bottlenecks. + To <c>start</c>/<c>stop</c>/<c>reset</c> microstate_accounting you use + the system_flag + <seealso marker="#system_flag_microstate_accounting"> + <c>microstate_accounting</c></seealso>. + </p> + <p> + <c>erlang:statistics(microstate_accounting)</c> returns a list of maps + representing some of the OS threads within ERTS. Each map contains + <c>type</c> and <c>id</c> fields that can be used to identify what + thread it is, and also a counters field that contains data about how + much time has been spent in the various states.</p> + <pre> +> <input>erlang:statistics(microstate_accounting).</input> +[#{counters => #{aux => 1899182914, + check_io => 2605863602, + emulator => 45731880463, + gc => 1512206910, + other => 5421338456, + port => 221631, + sleep => 5150294100}, + id => 1, + type => scheduler}|...] + </pre> + <p>The time unit is the same as returned by + <seealso marker="kernel:os#perf_counter/0"> + <c>os:perf_counter/0</c></seealso>. + So to convert it to milliseconds you could do something like this:</p> + <pre> +lists:map( + fun(#{ counters := Cnt } = M) -> + MsCnt = maps:map(fun(_K, PerfCount) -> + erlang:convert_time_unit(PerfCount, perf_counter, 1000) + end, Cnt), + M#{ counters := MsCnt } + end, erlang:statistics(microstate_accounting)). + </pre> + <p> + It is important to note that these values are not guaranteed to be + the exact time spent in each state. This is because of various + optimisation done in order to keep the overhead as small as possible. + </p> + + <p>Currently the following <c><anno>MSAcc_Thread_Type</anno></c> are available:</p> + <taglist> + <tag><c>scheduler</c></tag> + <item>The main execution threads that do most of the work.</item> + <tag><c>async</c></tag><item>Async threads are used by various + linked-in drivers (mainly the file drivers) do offload non-cpu + intensive work.</item> + <tag><c>aux</c></tag><item>Takes care of any work that is not + specifically assigned to a scheduler.</item> + </taglist> + <p>Currently the following <c><anno>MSAcc_Thread_State</anno></c>s are available. + All states are exclusive, meaning that a thread cannot be in two states + at once. So if you add the numbers of all counters in a thread + you will get the total run-time for that thread.</p> + <taglist> + <tag><c>aux</c></tag> + <item>Time spent handling auxiliary jobs.</item> + <tag><c>check_io</c></tag> + <item>Time spent checking for new I/O events.</item> + <tag><c>emulator</c></tag> + <item>Time spent executing erlang processes.</item> + <tag><c>gc</c></tag> + <item>Time spent doing garbage collection. When extra states are + enabled this is the time spent doing non-fullsweep garbage + collections.</item> + <tag><c>other</c></tag> + <item>Time spent doing unaccounted things.</item> + <tag><c>port</c></tag> + <item>Time spent executing ports.</item> + <tag><c>sleep</c></tag> + <item>Time spent sleeping.</item> + </taglist> + <p>It is possible to add more fine grained <c><anno>MSAcc_Thread_State</anno></c>s + through configure. + (e.g. <c>./configure --with-microstate-accounting=extra</c>). + Enabling these states will cause a performance degradation when + microstate accounting is turned off and increase the overhead when + it is turned on.</p> + <taglist> + <tag><c>alloc</c></tag> + <item>Time spent managing memory. Without extra states this time is + spread out over all other states.</item> + <tag><c>bif</c></tag> + <item>Time spent in bifs. Without extra states this time is part of + the <c>emulator</c> state.</item> + <tag><c>busy_wait</c></tag> + <item>Time spent busy waiting. This is also the state where a + scheduler no longer reports that it is active when using + <seealso marker="#statistics_scheduler_wall_time"> + <c>erlang:statistics(scheduler_wall_time)</c></seealso>. + So if you add all other states but this and sleep and then divide that + by all time in the thread you should get something very similar to the + scheduler_wall_time fraction. Without extra states this time is part + of the <c>other</c> state.</item> + <tag><c>ets</c></tag> + <item>Time spent executing ETS bifs. Without extra states this time is + part of the <c>emulator</c> state.</item> + <tag><c>gc_full</c></tag> + <item>Time spent doing fullsweep garbage collection. Without extra + states this time is part of the <c>gc</c> state.</item> + <tag><c>nif</c></tag> + <item>Time spent in nifs. Without extra states this time is part of + the <c>emulator</c> state.</item> + <tag><c>send</c></tag> + <item>Time spent sending messages (processes only). Without extra + states this time is part of the <c>emulator</c> state.</item> + <tag><c>timers</c></tag> + <item>Time spent managing timers. Without extra states this time is + part of the <c>other</c> state.</item> + </taglist> + <p>There is a utility module called + <seealso marker="runtime_tools:msacc"><c>msacc</c></seealso> in + runtime_tools that can be used to more easily analyse these + statistics.</p> + + <p> + Returns <c>undefined</c> if the system flag + <seealso marker="#system_flag_microstate_accounting"> + <c>microstate_accounting</c></seealso> + is turned off. + </p> + <p>The list of thread information is unsorted and may appear in + different order between calls.</p> + <note><p>The threads and states are subject to change without any + prior notice.</p></note> + </desc> + </func> + <func> + <name name="statistics" arity="1" clause_i="7"/> <fsummary>Information about reductions.</fsummary> <desc> <marker id="statistics_reductions"></marker> @@ -5773,7 +6194,7 @@ true</pre> </func> <func> - <name name="statistics" arity="1" clause_i="7"/> + <name name="statistics" arity="1" clause_i="8"/> <fsummary>Information about the run-queues.</fsummary> <desc><marker id="statistics_run_queue"></marker> <p> @@ -5789,7 +6210,7 @@ true</pre> </func> <func> - <name name="statistics" arity="1" clause_i="8"/> + <name name="statistics" arity="1" clause_i="9"/> <fsummary>Information about the run-queue lengths.</fsummary> <desc><marker id="statistics_run_queue_lengths"></marker> <p> @@ -5809,7 +6230,7 @@ true</pre> </func> <func> - <name name="statistics" arity="1" clause_i="9"/> + <name name="statistics" arity="1" clause_i="10"/> <fsummary>Information about runtime.</fsummary> <desc> <p>Returns information about runtime, in milliseconds.</p> @@ -5824,7 +6245,7 @@ true</pre> </func> <func> - <name name="statistics" arity="1" clause_i="10"/> + <name name="statistics" arity="1" clause_i="11"/> <fsummary>Information about each schedulers work time.</fsummary> <desc> <marker id="statistics_scheduler_wall_time"></marker> @@ -5895,7 +6316,7 @@ ok </func> <func> - <name name="statistics" arity="1" clause_i="11"/> + <name name="statistics" arity="1" clause_i="12"/> <fsummary>Information about active processes and ports.</fsummary> <desc><marker id="statistics_total_active_tasks"></marker> <p> @@ -5913,7 +6334,7 @@ ok </func> <func> - <name name="statistics" arity="1" clause_i="12"/> + <name name="statistics" arity="1" clause_i="13"/> <fsummary>Information about the run-queue lengths.</fsummary> <desc><marker id="statistics_total_run_queue_lengths"></marker> <p> @@ -5932,7 +6353,7 @@ ok </func> <func> - <name name="statistics" arity="1" clause_i="13"/> + <name name="statistics" arity="1" clause_i="14"/> <fsummary>Information about wall clock.</fsummary> <desc> <p>Returns information about wall clock. <c>wall_clock</c> can @@ -6166,6 +6587,17 @@ ok <func> <name name="system_flag" arity="2" clause_i="5"/> + <fsummary>Set system flag microstate_accounting</fsummary> + <desc><p><marker id="system_flag_microstate_accounting"></marker> + Turns on/off microstate accounting measurements. By passing reset it is possible to reset + all counters to 0.</p> + <p>For more information see, + <seealso marker="#statistics_microstate_accounting">erlang:statistics(microstate_accounting)</seealso>. + </p> + </desc> + </func> + <func> + <name name="system_flag" arity="2" clause_i="6"/> <fsummary>Sets system flag <c>min_heap_size</c>.</fsummary> <desc> <p>Sets the default minimum heap size for processes. The size @@ -6180,7 +6612,7 @@ ok </func> <func> - <name name="system_flag" arity="2" clause_i="6"/> + <name name="system_flag" arity="2" clause_i="7"/> <fsummary>Sets system flag <c>min_bin_vheap_size</c>.</fsummary> <desc> <p>Sets the default minimum binary virtual heap size for @@ -6196,46 +6628,75 @@ ok </desc> </func> + <marker id="system_flag_max_heap_size"></marker> <func> - <name name="system_flag" arity="2" clause_i="7"/> + <name name="system_flag" arity="2" clause_i="8"/> + <type name="max_heap_size"/> + <fsummary>Sets system flag <c>max_heap_size</c></fsummary> + <desc> + <p> + Sets the default maximum heap size settings for processes. + The size is given in words. The new <c>max_heap_size</c> + effects only processes spawned efter the change has been made. + <c>max_heap_size</c> can be set for individual processes using + <seealso marker="#spawn_opt/4">spawn_opt/N</seealso> or + <seealso marker="#process_flag_message_queue_data">process_flag/2</seealso>.</p> + <p>Returns the old value of the flag.</p> + </desc> + </func> + + <func> + <name name="system_flag" arity="2" clause_i="9"/> <fsummary>Sets system flag <c>multi_scheduling</c>.</fsummary> <desc> <p><marker id="system_flag_multi_scheduling"></marker> If multi-scheduling is enabled, more than one scheduler thread is used by the emulator. Multi-scheduling can be - blocked. When multi-scheduling is blocked, only - one scheduler thread schedules Erlang processes.</p> + blocked in two different ways. Either all schedulers but + one is blocked, or all <em>normal</em> schedulers but + one is blocked. When only normal schedulers are blocked + dirty schedulers are free to continue to schedule + processes.</p> <p>If <c><anno>BlockState</anno> =:= block</c>, multi-scheduling is - blocked. If <c><anno>BlockState</anno> =:= unblock</c> and no one + blocked. That is, one and only one scheduler thread will + execute. If <c><anno>BlockState</anno> =:= unblock</c> and no one else blocks multi-scheduling, and this process has blocked only once, multi-scheduling is unblocked.</p> - <p>One process can block multi-scheduling multiple times. - If a process has blocked multiple times, it must - unblock exactly as many times as it has blocked before it - has released its multi-scheduling block. If a process that - has blocked multi-scheduling exits, it releases its - blocking of multi-scheduling.</p> + <p>If <c><anno>BlockState</anno> =:= block_normal</c>, normal + multi-scheduling is blocked. That is, only one normal scheduler + thread will execute, but multiple dirty schedulers may execute. + If <c><anno>BlockState</anno> =:= unblock_normal</c> and no one + else blocks normal multi-scheduling, and this process has + blocked only once, normal multi-scheduling is unblocked.</p> + <p>One process can block multi-scheduling as well as normal + multi-scheduling multiple times. If a process has blocked + multiple times, it must unblock exactly as many times as it + has blocked before it has released its multi-scheduling + block. If a process that has blocked multi-scheduling or normal + multi scheduling exits, it automatically releases its blocking + of multi-scheduling and normal multi-scheduling.</p> <p>The return values are <c>disabled</c>, <c>blocked</c>, - or <c>enabled</c>. The returned value describes the - state just after the call to + <c>blocked_normal</c>, or <c>enabled</c>. The returned value + describes the state just after the call to <c>erlang:system_flag(multi_scheduling, <anno>BlockState</anno>)</c> has been made. For information about the return values, see <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>.</p> - <note><p>Blocking of multi-scheduling is normally not needed. - If you feel that you need to block multi-scheduling, - consider it a few more times again. Blocking multi-scheduling - is only to be used as a last resort, as it is most likely - a <em>very inefficient</em> way to solve the problem.</p> + <note><p>Blocking of multi-scheduling and normal multi-scheduling + is normally not needed. If you feel that you need to use these + features, consider it a few more times again. Blocking + multi-scheduling is only to be used as a last resort, as it is + most likely a <em>very inefficient</em> way to solve the problem.</p> </note> <p>See also <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, + <seealso marker="#system_info_normal_multi_scheduling_blockers">erlang:system_info(normal_multi_scheduling_blockers)</seealso>, <seealso marker="#system_info_multi_scheduling_blockers">erlang:system_info(multi_scheduling_blockers)</seealso>, and <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.</p> </desc> </func> <func> - <name name="system_flag" arity="2" clause_i="8"/> + <name name="system_flag" arity="2" clause_i="10"/> <fsummary>Sets system flag <c>scheduler_bind_type</c>.</fsummary> <type name="scheduler_bind_type"/> <desc> @@ -6353,7 +6814,7 @@ ok </func> <func> - <name name="system_flag" arity="2" clause_i="9"/> + <name name="system_flag" arity="2" clause_i="11"/> <fsummary>Sets system flag <c>scheduler_wall_time</c>.</fsummary> <desc><p><marker id="system_flag_scheduler_wall_time"></marker> Turns on or off scheduler wall time measurements.</p> @@ -6363,7 +6824,7 @@ ok </func> <func> - <name name="system_flag" arity="2" clause_i="10"/> + <name name="system_flag" arity="2" clause_i="12"/> <fsummary>Sets system flag <c>schedulers_online</c>.</fsummary> <desc> <p><marker id="system_flag_schedulers_online"></marker> @@ -6388,7 +6849,7 @@ ok </func> <func> - <name name="system_flag" arity="2" clause_i="11"/> + <name name="system_flag" arity="2" clause_i="13"/> <fsummary>Sets system flag <c>trace_control_word</c>.</fsummary> <desc> <p>Sets the value of the node trace control word to @@ -6402,7 +6863,7 @@ ok </func> <func> - <name name="system_flag" arity="2" clause_i="12"/> + <name name="system_flag" arity="2" clause_i="14"/> <fsummary>Finalize the Time Offset</fsummary> <desc> <p><marker id="system_flag_time_offset"></marker> @@ -6519,11 +6980,7 @@ ok As from <c>ERTS</c> 5.6.1, the return value is a list of <c>{instance, InstanceNo, InstanceInfo}</c> tuples, where <c>InstanceInfo</c> contains information about - a specific instance of the allocator. As from - <c>ERTS</c> 5.10.4, the returned list when calling - <c>erlang:system_info({allocator, mseg_alloc})</c> also - includes an <c>{erts_mmap, _}</c> tuple as one element - in the list. If <c><anno>Alloc</anno></c> is not a + a specific instance of the allocator. If <c><anno>Alloc</anno></c> is not a recognized allocator, <c>undefined</c> is returned. If <c><anno>Alloc</anno></c> is disabled, <c>false</c> is returned.</p> @@ -6535,7 +6992,13 @@ ok briefly documented.</p> <p>The recognized allocators are listed in <seealso marker="erts:erts_alloc">erts_alloc(3)</seealso>. - After reading the <c>erts_alloc(3)</c> documentation, + Information about super carriers can be obtained from + <c>ERTS</c> 8.0 with <c>{allocator, erts_mmap}</c> or from + <c>ERTS</c> 5.10.4, the returned list when calling with + <c>{allocator, mseg_alloc}</c> also includes an + <c>{erts_mmap, _}</c> tuple as one element in the list.</p> + + <p>After reading the <c>erts_alloc(3)</c> documentation, the returned information more or less speaks for itself, but it can be worth explaining some things. Call counts are presented by two @@ -6667,6 +7130,81 @@ ok </func> <func> + <name name="system_info" arity="1" clause_i="27"/> + <name name="system_info" arity="1" clause_i="28"/> + <name name="system_info" arity="1" clause_i="36"/> + <name name="system_info" arity="1" clause_i="37"/> + <name name="system_info" arity="1" clause_i="38"/> + <name name="system_info" arity="1" clause_i="39"/> + <type name="message_queue_data"/> + <type name="max_heap_size"/> + <fsummary>Information about the default process heap settings.</fsummary> + <desc> + <taglist> + <tag><c>fullsweep_after</c></tag> + <item> + <p>Returns <c>{fullsweep_after, integer() >= 0}</c>, which is + the <c>fullsweep_after</c> garbage collection setting used + by default. For more information, see + <c>garbage_collection</c> described in the following.</p> + </item> + <tag><c>garbage_collection</c></tag> + <item> + <p>Returns a list describing the default garbage collection + settings. A process spawned on the local node by a + <c>spawn</c> or <c>spawn_link</c> uses these + garbage collection settings. The default settings can be + changed by using + <seealso marker="#system_flag/2">system_flag/2</seealso>. + <seealso marker="#spawn_opt/4">spawn_opt/4</seealso> + can spawn a process that does not use the default + settings.</p> + </item> + <tag><c>max_heap_size</c></tag> + <item> + <p>Returns <c>{max_heap_size, <anno>MaxHeapSize</anno>}</c>, + where <c><anno>MaxHeapSize</anno></c> is the current + system-wide max heap size settings for spawned processes. + This setting can be set using the <c>erl</c> command line + flags <seealso marker="erl#+hmax"><c>+hmax</c></seealso>, + <seealso marker="erl#+hmaxk"><c>+hmaxk</c></seealso> and + <seealso marker="erl#+hmaxel"><c>+hmaxel</c></seealso>. It can + also be changed at run-time using + <seealso marker="#system_flag_max_heap_size"> + <c>erlang:system_flag(max_heap_size, MaxHeapSize)</c></seealso>. + For more details about the <c>max_heap_size</c> process flag + see <seealso marker="#process_flag_max_heap_size"> + <c>process_flag(max_heap_size, MaxHeapSize)</c></seealso>. + </p> + </item> + <tag><c>min_heap_size</c></tag> + <item> + <p>Returns <c>{min_heap_size, <anno>MinHeapSize</anno>}</c>, + where <c><anno>MinHeapSize</anno></c> is the current + system-wide minimum heap size for spawned processes.</p> + </item> + <tag><marker id="system_info_message_queue_data"><c>message_queue_data</c></marker></tag> + <item> + <p>Returns the default value of the <c>message_queue_data</c> + process flag which is either <c>off_heap</c>, or <c>on_heap</c>. + This default is set by the <c>erl</c> command line argument + <seealso marker="erl#+hmqd"><c>+hmqd</c></seealso>. For more information on the + <c>message_queue_data</c> process flag, see documentation of + <seealso marker="#process_flag_message_queue_data"><c>process_flag(message_queue_data, + MQD)</c></seealso>.</p> + </item> + <tag><c>min_bin_vheap_size</c></tag> + <item> + <p>Returns <c>{min_bin_vheap_size, + <anno>MinBinVHeapSize</anno>}</c>, where + <c><anno>MinBinVHeapSize</anno></c> is the current system-wide + minimum binary virtual heap size for spawned processes.</p> + </item> + </taglist> + </desc> + </func> + + <func> <name name="system_info" arity="1" clause_i="6"/> <name name="system_info" arity="1" clause_i="7"/> <name name="system_info" arity="1" clause_i="8"/> @@ -6686,8 +7224,6 @@ ok <name name="system_info" arity="1" clause_i="24"/> <name name="system_info" arity="1" clause_i="25"/> <name name="system_info" arity="1" clause_i="26"/> - <name name="system_info" arity="1" clause_i="27"/> - <name name="system_info" arity="1" clause_i="28"/> <name name="system_info" arity="1" clause_i="29"/> <name name="system_info" arity="1" clause_i="30"/> <name name="system_info" arity="1" clause_i="31"/> @@ -6695,10 +7231,6 @@ ok <name name="system_info" arity="1" clause_i="33"/> <name name="system_info" arity="1" clause_i="34"/> <name name="system_info" arity="1" clause_i="35"/> - <name name="system_info" arity="1" clause_i="36"/> - <name name="system_info" arity="1" clause_i="37"/> - <name name="system_info" arity="1" clause_i="38"/> - <name name="system_info" arity="1" clause_i="39"/> <name name="system_info" arity="1" clause_i="40"/> <name name="system_info" arity="1" clause_i="41"/> <name name="system_info" arity="1" clause_i="42"/> @@ -6727,6 +7259,8 @@ ok <name name="system_info" arity="1" clause_i="65"/> <name name="system_info" arity="1" clause_i="66"/> <name name="system_info" arity="1" clause_i="67"/> + <name name="system_info" arity="1" clause_i="68"/> + <name name="system_info" arity="1" clause_i="69"/> <fsummary>Information about the system.</fsummary> <desc> <p>Returns various information about the current system @@ -6963,25 +7497,6 @@ ok <c>ERL_MAX_ETS_TABLES</c> before starting the Erlang runtime system.</p> </item> - <tag><c>fullsweep_after</c></tag> - <item> - <p>Returns <c>{fullsweep_after, integer() >= 0}</c>, which is - the <c>fullsweep_after</c> garbage collection setting used - by default. For more information, see - <c>garbage_collection</c> described in the following.</p> - </item> - <tag><c>garbage_collection</c></tag> - <item> - <p>Returns a list describing the default garbage collection - settings. A process spawned on the local node by a - <c>spawn</c> or <c>spawn_link</c> uses these - garbage collection settings. The default settings can be - changed by using - <seealso marker="#system_flag/2">system_flag/2</seealso>. - <seealso marker="#spawn_opt/4">spawn_opt/4</seealso> - can spawn a process that does not use the default - settings.</p> - </item> <tag><c>heap_sizes</c></tag> <item> <p>Returns a list of integers representing valid heap sizes @@ -7056,19 +7571,6 @@ ok <item> <p>Returns a string containing the Erlang machine name.</p> </item> - <tag><c>min_heap_size</c></tag> - <item> - <p>Returns <c>{min_heap_size, <anno>MinHeapSize</anno>}</c>, - where <c><anno>MinHeapSize</anno></c> is the current - system-wide minimum heap size for spawned processes.</p> - </item> - <tag><c>min_bin_vheap_size</c></tag> - <item> - <p>Returns <c>{min_bin_vheap_size, - <anno>MinBinVHeapSize</anno>}</c>, where - <c><anno>MinBinVHeapSize</anno></c> is the current system-wide - minimum binary virtual heap size for spawned processes.</p> - </item> <tag><c>modified_timing_level</c></tag> <item> <p>Returns the modified timing-level (an integer) if @@ -7081,7 +7583,8 @@ ok <tag><c>multi_scheduling</c></tag> <item> <marker id="system_info_multi_scheduling"></marker> - <p>Returns <c>disabled</c>, <c>blocked</c>, or <c>enabled</c>:</p> + <p>Returns <c>disabled</c>, <c>blocked</c>, <c>blocked_normal</c>, + or <c>enabled</c>:</p> <taglist> <tag><c>disabled</c></tag> <item> @@ -7092,14 +7595,22 @@ ok <tag><c>blocked</c></tag> <item> <p>The emulator has more than one scheduler thread, - but all scheduler threads except one are blocked, - that is, only one scheduler thread schedules + but all scheduler threads except one are blocked. + That is, only one scheduler thread schedules Erlang processes and executes Erlang code.</p> </item> + <tag><c>blocked_normal</c></tag> + <item> + <p>The emulator has more than one scheduler thread, + but all normal scheduler threads except one are + blocked. Note that dirty schedulers are not + blocked, and may schedule Erlang processes and + execute native code.</p> + </item> <tag><c>enabled</c></tag> <item> <p>The emulator has more than one scheduler thread, - and no scheduler threads are blocked, that is, + and no scheduler threads are blocked. That is, all available scheduler threads schedule Erlang processes and execute Erlang code.</p> </item> @@ -7107,6 +7618,7 @@ ok <p>See also <seealso marker="#system_flag_multi_scheduling">erlang:system_flag(multi_scheduling, BlockState)</seealso>, <seealso marker="#system_info_multi_scheduling_blockers">erlang:system_info(multi_scheduling_blockers)</seealso>, + <seealso marker="#system_info_normal_multi_scheduling_blockers">erlang:system_info(normal_multi_scheduling_blockers)</seealso>, and <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.</p> </item> @@ -7123,6 +7635,8 @@ ok <p>See also <seealso marker="#system_flag_multi_scheduling">erlang:system_flag(multi_scheduling, BlockState)</seealso>, <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, + <seealso marker="#system_info_normal_multi_scheduling_blockers">erlang:system_info(normal_multi_scheduling_blockers)</seealso>, + and <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.</p> </item> @@ -7132,7 +7646,25 @@ ok used by the runtime system. It is on the form "<major ver>.<minor ver>".</p> </item> - <tag><c>otp_release</c></tag> + <tag><c>normal_multi_scheduling_blockers</c></tag> + <item> + <marker id="system_info_normal_multi_scheduling_blockers"></marker> + <p>Returns a list of <c><anno>Pid</anno></c>s when + normal multi-scheduling is blocked (i.e. all normal schedulers + but one is blocked), otherwise the empty list is returned. + The <c><anno>Pid</anno></c>s in the list represent all the + processes currently blocking normal multi-scheduling. + A <c><anno>Pid</anno></c> occurs only once in the list, even if + the corresponding process has blocked multiple times.</p> + <p>See also + <seealso marker="#system_flag_multi_scheduling">erlang:system_flag(multi_scheduling, BlockState)</seealso>, + <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, + <seealso marker="#system_info_multi_scheduling_blockers">erlang:system_info(multi_scheduling_blockers)</seealso>, + + and + <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.</p> + </item> + <tag><marker id="system_info_otp_release"><c>otp_release</c></marker></tag> <item> <marker id="system_info_otp_release"></marker> <p>Returns a string containing the OTP release number of the @@ -7373,6 +7905,7 @@ ok <seealso marker="#system_info_scheduler_id">erlang:system_info(scheduler_id)</seealso>, <seealso marker="#system_flag_multi_scheduling">erlang:system_flag(multi_scheduling, BlockState)</seealso>, <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, + <seealso marker="#system_info_normal_multi_scheduling_blockers">erlang:system_info(normal_multi_scheduling_blockers)</seealso> and <seealso marker="#system_info_multi_scheduling_blockers">erlang:system_info(multi_scheduling_blockers)</seealso>.</p> </item> @@ -7604,7 +8137,7 @@ ok <c>stack_size</c>, <c>mbuf_size</c>, <c>old_heap_size</c>, and <c>old_heap_block_size</c>. These tuples are explained in the description of trace message - <seealso marker="#gc_start">gc_start</seealso> (see + <seealso marker="#gc_minor_start">gc_minor_start</seealso> (see <seealso marker="#trace/3">erlang:trace/3</seealso>). New tuples can be added, and the order of the tuples in the <c>Info</c> list can be changed at any time without @@ -7662,12 +8195,13 @@ ok <c>GcPid</c> and <c>Info</c> are the same as for <c>long_gc</c> earlier, except that the tuple tagged with <c>timeout</c> is not present.</p> - <p>As of <c>ERTS</c> 5.6, the monitor message is sent - if the sum of the sizes of all memory blocks allocated - for all heap generations is equal to or higher than <c>Size</c>. - Previously the monitor message was sent if the memory block - allocated for the youngest generation was equal to or higher - than <c>Size</c>.</p> + <p>The monitor message is sent if the sum of the sizes of + all memory blocks allocated for all heap generations after + a garbage collection is equal to or higher than <c>Size</c>.</p> + <p>When a process is killed by <seealso marker="#process_flag_max_heap_size"> + <c>max_heap_size</c></seealso>, it is killed before the + garbage collection is complete and thus no large heap message + will be sent.</p> </item> <tag><c>busy_port</c></tag> <item> @@ -8027,22 +8561,47 @@ 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 @@ -8051,35 +8610,28 @@ 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> - </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> + <p>Message tags: <c><seealso marker="#trace_3_trace_messages_receive">'receive'</seealso></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> @@ -8097,8 +8649,9 @@ 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> @@ -8119,23 +8672,65 @@ 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_minor_start">gc_minor_start</seealso></c>, + <c><seealso marker="#trace_3_trace_messages_gc_max_heap_size">gc_max_heap_size</seealso></c> and + <c><seealso marker="#trace_3_trace_messages_gc_minor_end">gc_minor_end</seealso></c>.</p> </item> <tag><c>timestamp</c></tag> <item> @@ -8150,8 +8745,8 @@ 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 @@ -8163,8 +8758,8 @@ 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> @@ -8173,9 +8768,9 @@ 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> @@ -8209,12 +8804,20 @@ 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="erts:erl_tracer"><c>erl_tracer</c></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 @@ -8235,21 +8838,36 @@ 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 @@ -8258,7 +8876,10 @@ 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 @@ -8270,76 +8891,175 @@ 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_minor_start"></marker> + <c>{trace, Pid, gc_minor_start, Info}</c> + </tag> <item> - <marker id="gc_start"></marker> - <p>Sent when garbage collection is about to be started. + <marker id="gc_minor_start"></marker> + <p>Sent when a young garbage collection is about to be started. <c>Info</c> is a list of two-element tuples, where the first element is a key, and the second is the value. Do not depend on any order of the tuples. @@ -8378,26 +9098,59 @@ 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_max_heap_size"></marker> + <c>{trace, Pid, gc_max_heap_size, 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>, + <p> + Sent when the <seealso marker="#process_flag_max_heap_size"><c>max_heap_size</c></seealso> + is reached during garbage collection. <c>Info</c> contains the + same kind of list as in message <c>gc_start</c>, + but the sizes reflect the sizes that triggered max_heap_size to + be reached. + </p> + </item> + <tag> + <marker id="trace_3_trace_messages_gc_minor_end"></marker> + <c>{trace, Pid, gc_minor_end, Info}</c> + </tag> + <item> + <p>Sent when young garbage collection is finished. <c>Info</c> + contains the same kind of list as in message <c>gc_minor_start</c>, but the sizes reflect the new sizes after garbage collection.</p> </item> + <tag> + <marker id="trace_3_trace_messages_gc_major_start"></marker> + <c>{trace, Pid, gc_major_start, Info}</c> + </tag> + <item> + <p>Sent when fullsweep garbage collection is about to be started. <c>Info</c> + contains the same kind of list as in message <c>gc_minor_start</c>.</p> + </item> + <tag> + <marker id="trace_3_trace_messages_gc_major_end"></marker> + <c>{trace, Pid, gc_major_end, Info}</c> + </tag> + <item> + <p>Sent when fullsweep garbage collection is finished. <c>Info</c> + contains the same kind of list as in message <c>gc_minor_start</c> + but the sizes reflect the new sizes after a fullsweep 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 @@ -8409,7 +9162,11 @@ 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, @@ -8430,13 +9187,16 @@ 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="erts: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 @@ -8459,13 +9219,16 @@ 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>The following <c>Item</c>s are valid:</p> + <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 for ports and processes:</p> <taglist> <tag><c>flags</c></tag> <item> @@ -8474,24 +9237,30 @@ 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><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> @@ -8510,8 +9279,8 @@ 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> @@ -8550,39 +9319,177 @@ 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>PidOrFunc</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 @@ -8637,7 +9544,8 @@ 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> @@ -8679,13 +9587,12 @@ 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>, @@ -8693,7 +9600,7 @@ 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> |