diff options
Diffstat (limited to 'erts/doc/src/erl.xml')
| -rw-r--r-- | erts/doc/src/erl.xml | 60 |
1 files changed, 48 insertions, 12 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml index f7d8d37fd3..85c6140b01 100644 --- a/erts/doc/src/erl.xml +++ b/erts/doc/src/erl.xml @@ -586,18 +586,38 @@ <seealso marker="erts_alloc">erts_alloc(3)</seealso> for further information.</p> </item> - <tag><c><![CDATA[+n]]></c></tag> - <item> - <p>Enable synchronous message passing to ports.</p> - <p>As of OTP-R16 message passing to ports are truly asynchronously - implemented. Correctly written Erlang programs should be able - to handle this without any issues. Bugs in existing Erlang - programs that make false assumptions about message passing to - ports may, however, be tricky to find. This switch has been - introduced in order to at least make it easier to compare - behaviors during a transition period. Note that this flag is - deprecated as of its introduction, and is scheduled for removal - in OTP-R17.</p> + <tag><c><![CDATA[+n Behavior]]></c></tag> + <item> + <p>Control behavior of signals to ports.</p> + <p>As of OTP-R16 signals to ports are truly asynchronously + delivered. Note that signals always have been documented as + asynchronous. The underlying implementation has, however, + previously delivered these signals synchronously. Correctly + written Erlang programs should be able to handle this without + any issues. Bugs in existing Erlang programs that make false + assumptions about signals to ports may, however, be tricky to + find. This switch has been introduced in order to at least + make it easier to compare behaviors during a transition period. + Note that <em>this flag is deprecated</em> as of its + introduction, and is scheduled for removal in OTP-R17. + <c>Behavior</c> should be one of the following characters:</p> + <taglist> + <tag><c>d</c></tag> + <item>The default. Asynchronous signals. A process that sends + a signal to a port may continue execution before the signal + has been delivered to the port.</item> + <tag><c>s</c></tag> + <item>Synchronous signals. A processes that sends a signal + to a port will not continue execution until the signal has + been delivered. Should <em>only</em> be used for testing and + debugging.</item> + <tag><c>a</c></tag> + <item>Asynchronous signals. As the default, but a processes + that sends a signal will even more frequently continue + execution before the signal has been delivered to the + port. Should <em>only</em> be used for testing and + debugging.</item> + </taglist> </item> <tag><marker id="max_processes"><c><![CDATA[+P Number]]></c></marker></tag> <item> @@ -948,6 +968,22 @@ without prior notice. </p> </item> + <tag><marker id="+spp"><c>+spp Bool</c></marker></tag> + <item> + <p>Set default 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 + improve latency at the expense of parallelism. If this + flag has not been passed, the default scheduler hint for port + parallelism is currently <c>false</c>. The default used can be + inspected in runtime by calling + <seealso marker="erlang#system_info_port_parallelism">erlang:system_info(port_parallelism)</seealso>. + The default can be overriden on port creation by passing the + <seealso marker="erlang#open_port_parallelism">parallelism</seealso> + option to + <seealso marker="erlang#open_port/2">open_port/2</seealso></p>. + </item> <tag><marker id="sched_thread_stack_size"><c><![CDATA[+sss size]]></c></marker></tag> <item> <p>Suggested stack size, in kilowords, for scheduler threads. |