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-rw-r--r--erts/doc/src/erlang.xml414
1 files changed, 323 insertions, 91 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 0077c0096c..315dc323ba 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -628,6 +628,22 @@ false</pre>
{more,6}</pre>
</desc>
</func>
+
+ <func>
+ <name name="delete_element" arity="2"/>
+ <fsummary>Delete element at index in a tuple</fsummary>
+ <type_desc variable="Index">1..tuple_size(<anno>Tuple1</anno>)</type_desc>
+ <desc>
+ <p>
+ Returns a new tuple with element at <c><anno>Index</anno></c> removed from
+ tuple <c><anno>Tuple1</anno></c>.
+ </p>
+ <pre>
+> <input>erlang:delete_element(2, {one, two, three}).</input>
+{one,three}</pre>
+ </desc>
+ </func>
+
<func>
<name name="delete_module" arity="1"/>
<fsummary>Make the current code for a module old</fsummary>
@@ -856,10 +872,10 @@ b</pre>
</func>
<func>
<name name="exit" arity="2"/>
- <fsummary>Send an exit signal to a process</fsummary>
+ <fsummary>Send an exit signal to a process or a port</fsummary>
<desc>
<p>Sends an exit signal with exit reason <c><anno>Reason</anno></c> to
- the process <c><anno>Pid</anno></c>.</p>
+ the process or port identified by <c><anno>Pid</anno></c>.</p>
<p>The following behavior apply if <c><anno>Reason</anno></c> is any term
except <c>normal</c> or <c>kill</c>:</p>
<p>If <c><anno>Pid</anno></c> is not trapping exits, <c><anno>Pid</anno></c> itself will
@@ -954,6 +970,37 @@ true
</desc>
</func>
<func>
+ <name>float_to_list(Float, Options) -> string()</name>
+ <fsummary>Text representation of a float formatted using given options</fsummary>
+ <type>
+ <v>Float = float()</v>
+ <v>Options = [Option]</v>
+ <v>Option = {decimals, Decimals::0..249} |
+ {scientific, Decimals::0..249} |
+ compact</v>
+ </type>
+ <desc>
+ <p>Returns a string which corresponds to the text
+ representation of <c>Float</c> using fixed decimal point formatting.
+ When <c>decimals</c> option is specified
+ the returned value will contain at most <c>Decimals</c> number of
+ digits past the decimal point. If the number doesn't fit in the
+ internal static buffer of 256 bytes, the function throws <c>badarg</c>.
+ When <c>compact</c> option is provided
+ the trailing zeros at the end of the list are truncated (this option is
+ only meaningful together with the <c>decimals</c> option). When
+ <c>scientific</c> option is provided, the float will be formatted using
+ scientific notation with <c>Decimals</c> digits of precision. If
+ <c>Options</c> is <c>[]</c> the function behaves like <c>float_to_list/1</c>.
+ </p>
+ <pre>
+> <input>float_to_list(7.12, [{decimals, 4}]).</input>
+"7.1200"
+> <input>float_to_list(7.12, [{decimals, 4}, compact]).</input>
+"7.12"</pre>
+ </desc>
+ </func>
+ <func>
<name name="fun_info" arity="1"/>
<fsummary>Information about a fun</fsummary>
<desc>
@@ -1363,6 +1410,24 @@ os_prompt% </pre>
when the process wakes up.</p>
</desc>
</func>
+
+ <func>
+ <name name="insert_element" arity="3"/>
+ <fsummary>Insert an element at index in a tuple</fsummary>
+ <type_desc variable="Index">1..tuple_size(<anno>Tuple1</anno>) + 1</type_desc>
+ <desc>
+ <p>
+ Returns a new tuple with element <c><anno>Term</anno></c> insert at position
+ <c><anno>Index</anno></c> in tuple <c><anno>Tuple1</anno></c>.
+ All elements from position <c><anno>Index</anno></c> and upwards are subsequently
+ pushed one step higher in the new tuple <c><anno>Tuple2</anno></c>.
+ </p>
+ <pre>
+> <input>erlang:insert_element(2, {one, two, three}, new).</input>
+{one,new,two,three}</pre>
+ </desc>
+ </func>
+
<func>
<name name="integer_to_list" arity="1"/>
<fsummary>Text representation of an integer</fsummary>
@@ -2764,6 +2829,18 @@ os_prompt% </pre>
console window when spawning the port program.
(This option has no effect on other platforms.)</p>
</item>
+ <tag><marker id="open_port_parallelism"><c>{parallelism, Boolean}</c></marker></tag>
+ <item>
+ <p>Set scheduler hint for port parallelism. If set to <c>true</c>,
+ the VM will schedule port tasks when it by this can improve the
+ parallelism in the system. If set to <c>false</c>, the VM will
+ try to perform port tasks immediately and by this improving the
+ latency at the expense of parallelism. The default can be set on
+ system startup by passing the
+ <seealso marker="erl#+spp">+spp</seealso> command line argument
+ to <seealso marker="erl">erl(1)</seealso>.
+ </p>
+ </item>
</taglist>
<p>The default is <c>stream</c> for all types of port and
<c>use_stdio</c> for spawned ports.</p>
@@ -2816,10 +2893,11 @@ os_prompt% </pre>
the owning process using signals of the form
<c>{'EXIT', Port, PosixCode}</c>. See <c>file(3)</c> for
possible values of <c>PosixCode</c>.</p>
- <p><marker id="ERL_MAX_PORTS"></marker>
- The maximum number of ports that can be open at the same
- time is 1024 by default, but can be configured by
- the environment variable <c>ERL_MAX_PORTS</c>.</p>
+ <p>The maximum number of ports that can be open at the same
+ time can be configured by passing the
+ <seealso marker="erl#max_ports"><c>+Q</c></seealso>
+ command line flag to
+ <seealso marker="erl"><c>erl(1)</c></seealso>.</p>
</desc>
</func>
<func>
@@ -2877,10 +2955,10 @@ os_prompt% </pre>
<desc>
<p>Closes an open port. Roughly the same as
<c><anno>Port</anno> ! {self(), close}</c> except for the error behaviour
- (see below), and that the port does <em>not</em> reply with
- <c>{Port, closed}</c>. Any process may close a port with
- <c>port_close/1</c>, not only the port owner (the connected
- process).</p>
+ (see below), being synchronous, and that the port does
+ <em>not</em> reply with <c>{Port, closed}</c>. Any process may
+ close a port with <c>port_close/1</c>, not only the port owner
+ (the connected process).</p>
<p>For comparison: <c><anno>Port</anno> ! {self(), close}</c> fails with
<c>badarg</c> if <c><anno>Port</anno></c> cannot be sent to (i.e.,
<c><anno>Port</anno></c> refers neither to a port nor to a process). If
@@ -2892,8 +2970,12 @@ os_prompt% </pre>
<p>Note that any process can close a port using
<c><anno>Port</anno> ! {PortOwner, close}</c> just as if it itself was
the port owner, but the reply always goes to the port owner.</p>
- <p>In short: <c>port_close(Port)</c> has a cleaner and more
- logical behaviour than <c><anno>Port</anno> ! {self(), close}</c>.</p>
+ <p>As of OTP-R16 <c><anno>Port</anno> ! {PortOwner, close}</c> is truly
+ asynchronous. Note that this operation has always been
+ documented as an asynchronous operation, while the underlying
+ implementation has been synchronous. <c>port_close/1</c> is
+ however still fully synchronous. This due to its error
+ behavior.</p>
<p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not an open port or
the registered name of an open port.</p>
</desc>
@@ -2903,11 +2985,11 @@ os_prompt% </pre>
<fsummary>Send data to a port</fsummary>
<desc>
<p>Sends data to a port. Same as
- <c><anno>Port</anno> ! {self(), {command, Data}}</c> except for the error
- behaviour (see below). Any process may send data to a port
- with <c>port_command/2</c>, not only the port owner
- (the connected process).</p>
- <p>For comparison: <c><anno>Port</anno> ! {self(), {command, Data}}</c>
+ <c><anno>Port</anno> ! {PortOwner, {command, Data}}</c> except for the error
+ behaviour and being synchronous (see below). Any process may
+ send data to a port with <c>port_command/2</c>, not only the
+ port owner (the connected process).</p>
+ <p>For comparison: <c><anno>Port</anno> ! {PortOwner, {command, Data}}</c>
fails with <c>badarg</c> if <c><anno>Port</anno></c> cannot be sent to
(i.e., <c><anno>Port</anno></c> refers neither to a port nor to a process).
If <c><anno>Port</anno></c> is a closed port the data message disappears
@@ -2918,11 +3000,14 @@ os_prompt% </pre>
<p>Note that any process can send to a port using
<c><anno>Port</anno> ! {PortOwner, {command, <anno>Data</anno>}}</c> just as if it
itself was the port owner.</p>
- <p>In short: <c>port_command(<anno>Port</anno>, <anno>Data</anno>)</c> has a cleaner and
- more logical behaviour than
- <c><anno>Port</anno> ! {self(), {command, Data}}</c>.</p>
<p>If the port is busy, the calling process will be suspended
until the port is not busy anymore.</p>
+ <p>As of OTP-R16 <c><anno>Port</anno> ! {PortOwner, {command, Data}}</c> is
+ truly asynchronous. Note that this operation has always been
+ documented as an asynchronous operation, while the underlying
+ implementation has been synchronous. <c>port_command/2</c> is
+ however still fully synchronous. This due to its error
+ behavior.</p>
<p>Failures:</p>
<taglist>
<tag><c>badarg</c></tag>
@@ -2996,7 +3081,7 @@ os_prompt% </pre>
<fsummary>Set the owner of a port</fsummary>
<desc>
<p>Sets the port owner (the connected port) to <c><anno>Pid</anno></c>.
- Roughly the same as <c><anno>Port</anno> ! {self(), {connect, <anno>Pid</anno>}}</c>
+ Roughly the same as <c><anno>Port</anno> ! {Owner, {connect, <anno>Pid</anno>}}</c>
except for the following:</p>
<list type="bulleted">
<item>
@@ -3007,6 +3092,9 @@ os_prompt% </pre>
<c>{Port,connected}</c>.</p>
</item>
<item>
+ <p><c>port_connect/1</c> is synchronous, see below.</p>
+ </item>
+ <item>
<p>The new port owner gets linked to the port.</p>
</item>
</list>
@@ -3030,11 +3118,14 @@ os_prompt% </pre>
<c><anno>Port</anno> ! {PortOwner, {connect, <anno>Pid</anno>}}</c> just as if it
itself was the port owner, but the reply always goes to
the port owner.</p>
- <p>In short: <c>port_connect(<anno>Port</anno>, <anno>Pid</anno>)</c> has a cleaner and
- more logical behaviour than
- <c><anno>Port</anno> ! {self(),{connect,<anno>Pid</anno>}}</c>.</p>
+ <p>As of OTP-R16 <c><anno>Port</anno> ! {PortOwner, {connect, <anno>Pid</anno>}}</c> is
+ truly asynchronous. Note that this operation has always been
+ documented as an asynchronous operation, while the underlying
+ implementation has been synchronous. <c>port_connect/2</c> is
+ however still fully synchronous. This due to its error
+ behavior.</p>
<p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not an open port
- or the registered name of an open port, or if <c><anno>Pid</anno></c> is
+ or the registered name of an open port, or if <c>Pid</c> is
not an existing local pid.</p>
</desc>
</func>
@@ -3081,71 +3172,187 @@ os_prompt% </pre>
</func>
<func>
<name name="port_info" arity="1"/>
- <type name="port_info_result_item"/>
<fsummary>Information about a port</fsummary>
<desc>
<p>Returns a list containing tuples with information about
the <c><anno>Port</anno></c>, or <c>undefined</c> if the port is not open.
The order of the tuples is not defined, nor are all the
tuples mandatory.</p>
- <taglist>
- <tag><c>{registered_name, <anno>RegName</anno>}</c></tag>
- <item>
- <p><c><anno>RegName</anno></c> (an atom) is the registered name of
- the port. If the port has no registered name, this tuple
- is not present in the list.</p>
- </item>
- <tag><c>{id, <anno>Index</anno>}</c></tag>
- <item>
- <p><c><anno>Index</anno></c> (an integer) is the internal index of the
- port. This index may be used to separate ports.</p>
- </item>
- <tag><c>{connected, <anno>Pid</anno>}</c></tag>
- <item>
- <p><c><anno>Pid</anno></c> is the process connected to the port.</p>
- </item>
- <tag><c>{links, <anno>Pids</anno>}</c></tag>
- <item>
- <p><c><anno>Pids</anno></c> is a list of pids to which processes the
- port is linked.</p>
- </item>
- <tag><c>{name, <anno>String</anno>}</c></tag>
- <item>
- <p><c><anno>String</anno></c> is the command name set by
- <c>open_port</c>.</p>
- </item>
- <tag><c>{input, <anno>Bytes</anno>}</c></tag>
- <item>
- <p><c><anno>Bytes</anno></c> is the total number of bytes read from
- the port.</p>
- </item>
- <tag><c>{output, <anno>Bytes</anno>}</c></tag>
- <item>
- <p><c><anno>Bytes</anno></c> is the total number of bytes written to
- the port.</p>
- </item>
- <tag><c>{os_pid, <anno>OsPid</anno> | undefined}</c></tag>
- <item>
- <p><c> <anno>OsPid</anno></c> is the process identifier (or equivalent) of an OS process created with <c>open_port({spawn | spawn_executable, Command}, Options)</c>. If the port is not the result of spawning an OS process, the value is <c>undefined</c>.</p>
- </item>
- </taglist>
- <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local port.</p>
+ <p>Currently the result will containt information about the
+ following <c>Item</c>s: <c>registered_name</c> (if the port has
+ a registered name), <c>id</c>, <c>connected</c>, <c>links</c>,
+ <c>name</c>, <c>input</c>, and <c>output</c>. For more information
+ about the different <c>Item</c>s, see
+ <seealso marker="#port_info/2">port_info/2</seealso>.</p>
+ <p>Failure: <c>badarg</c> if <c>Port</c> is not a local port
+ identifier, or an atom.</p>
</desc>
</func>
<func>
- <name name="port_info" arity="2"/>
- <type name="port_info_item"/>
- <type name="port_info_result_item"/>
- <fsummary>Information about a port</fsummary>
+ <name name="port_info" arity="2" clause_i="1"/>
+ <fsummary>Information about the connected process of a port</fsummary>
<desc>
- <p>Returns information about <c><anno>Port</anno></c> as specified
- by <c><anno>Item</anno></c>, or <c>undefined</c> if the port is not open.
- Also, if <c>Item =:= registered_name</c> and the port has no
- registered name, <c>[]</c> is returned.</p>
- <p>For valid values of <c><anno>Item</anno></c>, and corresponding
- values of <c><anno>Result</anno></c>, see
- <seealso marker="#port_info/1">erlang:port_info/1</seealso>.</p>
- <p>Failure: <c>badarg</c> if <c><anno>Port</anno></c> is not a local port.</p>
+ <p><c><anno>Pid</anno></c> is the process identifier of the process
+ connected to the port.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="2"/>
+ <fsummary>Information about the internal index of a port</fsummary>
+ <desc>
+ <p><c><anno>Index</anno></c> is the internal index of the port. This
+ index may be used to separate ports.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="3"/>
+ <fsummary>Information about the input of a port</fsummary>
+ <desc>
+ <p><c><anno>Bytes</anno></c> is the total number of bytes
+ read from the port.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="4"/>
+ <fsummary>Information about the links of a port</fsummary>
+ <desc>
+ <p><c><anno>Pids</anno></c> is a list of the process identifiers
+ of the processes that the port is linked to.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="5"/>
+ <fsummary>Information about the locking of a port</fsummary>
+ <desc>
+ <p><c><anno>Locking</anno></c> is currently either <c>false</c>
+ (emulator without SMP support), <c>port_level</c> (port specific
+ locking), or <c>driver_level</c> (driver specific locking). Note
+ that these results are highly implementation specific and might
+ change in the future.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="6"/>
+ <fsummary>Information about the memory size of a port</fsummary>
+ <desc>
+ <p><c><anno>Bytes</anno></c> is the total amount of memory,
+ in bytes, allocated for this port by the runtime system. Note
+ that the port itself might have allocated memory which is not
+ included in <c><anno>Bytes</anno></c>.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="7"/>
+ <fsummary>Information about the monitors of a port</fsummary>
+ <desc>
+ <p><c><anno>Monitors</anno></c> represent processes that this port
+ is monitoring.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="8"/>
+ <fsummary>Information about the name of a port</fsummary>
+ <desc>
+ <p><c><anno>Name</anno></c> is the command name set by
+ <seealso marker="#open_port/2">open_port/2</seealso>.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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 OS pid of a port</fsummary>
+ <desc>
+ <p><c><anno>OsPid</anno></c> is the process identifier (or equivalent)
+ of an OS process created with
+ <seealso marker="#open_port/2">open_port({spawn | spawn_executable,
+ Command}, Options)</seealso>. If the port is not the result of spawning
+ an OS process, the value is <c>undefined</c>.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="10"/>
+ <fsummary>Information about the output of a port</fsummary>
+ <desc>
+ <p><c><anno>Bytes</anno></c> is the total number of bytes written
+ to the port from Erlang processes using either
+ <seealso marker="#port_command/2">port_command/2</seealso>,
+ <seealso marker="#port_command/3">port_command/3</seealso>,
+ or <c><anno>Port</anno> ! {Owner, {command, Data}</c>.
+ </p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="11"/>
+ <fsummary>Information about the parallelism hint of a port</fsummary>
+ <desc>
+ <p><c><anno>Boolean</anno></c> corresponds to the port parallelism
+ hint being used by this port. For more information see
+ the <seealso marker="#open_port_parallelism">parallelism</seealso>
+ option of <seealso marker="#open_port/2">open_port/2</seealso>.</p>
+ </desc>
+ </func>
+ <func>
+ <name name="port_info" arity="2" clause_i="12"/>
+ <fsummary>Information about the queue size of a port</fsummary>
+ <desc>
+ <p><c><anno>Bytes</anno></c> is the total amount of data,
+ in bytes, queued by the port using the ERTS driver queue
+ implementation.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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="13"/>
+ <fsummary>Information about the registered name of a port</fsummary>
+ <desc>
+ <p><c><anno>RegisteredName</anno></c> is the registered name of
+ the port. If the port has no registered name, <c>[]</c> is returned.</p>
+ <p>If the port identified by <c><anno>Port</anno></c> is not open,
+ <c>undefined</c> is returned.</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>
@@ -3165,7 +3372,10 @@ os_prompt% </pre>
<name name="ports" arity="0"/>
<fsummary>All open ports</fsummary>
<desc>
- <p>Returns a list of all ports on the local node.</p>
+ <p>Returns a list of port identifiers corresponding to all the
+ ports currently existing on the local node.</p>
+
+ <p>Note that a port that is exiting, exists but is not open.</p>
</desc>
</func>
<func>
@@ -3531,10 +3741,11 @@ os_prompt% </pre>
the initial function call with which the process was
spawned.</p>
</item>
- <tag><c>{links, <anno>Pids</anno>}</c></tag>
+ <tag><c>{links, <anno>PidsAndPorts</anno>}</c></tag>
<item>
- <p><c><anno>Pids</anno></c> is a list of pids, with processes to
- which the process has a link.</p>
+ <p><c><anno>PidsAndPorts</anno></c> is a list of pids and
+ port identifiers, with processes or ports to which the process
+ has a link.</p>
</item>
<tag><c>{last_calls, false|Calls}</c></tag>
<item>
@@ -5498,19 +5709,40 @@ ok
<item>
<p>Returns a string containing the OTP release number.</p>
</item>
- <tag><c>process_count</c></tag>
+ <tag><marker id="system_info_port_parallelism"><c>port_parallelism</c></marker></tag>
+ <item><p>Returns the default port parallelism scheduling hint used.
+ For more information see the
+ <seealso marker="erl#+spp">+spp</seealso> command line argument
+ of <seealso marker="erl">erl(1)</seealso>.</p></item>
+ <tag><marker id="system_info_port_count"/><c>port_count</c></tag>
+ <item>
+ <p>Returns the number of ports currently existing at
+ the local node as an integer. The same value as
+ <c>length(erlang:ports())</c> returns, but more efficient.</p>
+ </item>
+ <tag><marker id="system_info_port_limit"><c>port_limit</c></marker></tag>
+ <item>
+ <p>Returns the maximum number of simultaneously existing
+ ports at the local node as an integer. This limit
+ can be configured at startup by using the
+ <seealso marker="erl#+Q">+Q</seealso>
+ command line flag of
+ <seealso marker="erl">erl(1)</seealso>.</p>
+ </item>
+ <tag><marker id="system_info_process_count"/><c>process_count</c></tag>
<item>
<p>Returns the number of processes currently existing at
the local node as an integer. The same value as
- <c>length(processes())</c> returns.</p>
+ <c>length(processes())</c> returns, but more efficient.</p>
</item>
- <tag><c>process_limit</c></tag>
+ <tag><marker id="system_info_process_limit"><c>process_limit</c></marker></tag>
<item>
- <p>Returns the maximum number of concurrently existing
+ <p>Returns the maximum number of simultaneously existing
processes at the local node as an integer. This limit
- can be configured at startup by using the command line
- flag <c>+P</c>, see
- <seealso marker="erts:erl#max_processes">erl(1)</seealso>.</p>
+ can be configured at startup by using the
+ <seealso marker="erl#+P">+P</seealso>
+ command line flag of
+ <seealso marker="erl">erl(1)</seealso>.</p>
</item>
<tag><c>procs</c></tag>
<item>