diff options
Diffstat (limited to 'erts/doc')
| -rw-r--r-- | erts/doc/src/erl.xml | 11 | ||||
| -rw-r--r-- | erts/doc/src/erl_driver.xml | 58 | ||||
| -rw-r--r-- | erts/doc/src/erlang.xml | 102 | ||||
| -rw-r--r-- | erts/doc/src/notes.xml | 4 |
4 files changed, 146 insertions, 29 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml index f354d68d45..5bfa518266 100644 --- a/erts/doc/src/erl.xml +++ b/erts/doc/src/erl.xml @@ -985,15 +985,12 @@ documentation of the <seealso marker="#+sbt">+sbt</seealso> flag. </p> </item> - <tag><marker id="+sws"><c>+sws default|legacy|proposal</c></marker></tag> + <tag><marker id="+sws"><c>+sws default|legacy</c></marker></tag> <item> - <p>Set scheduler wakeup strategy. Default is <c>legacy</c> (has been - used since OTP-R13B). The <c>proposal</c> strategy is the currently - proposed strategy for OTP-R16. Note that the <c>proposal</c> strategy - might change during OTP-R15. + <p> + Set scheduler wakeup strategy. Default strategy changed in erts-5.10/OTP-R16A. This strategy was previously known as <c>proposal</c> in OTP-R15. The <c>legacy</c> strategy was used as default from R13 up to and including R15. </p> - <p><em>NOTE:</em> This flag may be removed or changed at any time - without prior notice. + <p><em>NOTE:</em> This flag may be removed or changed at any time without prior notice. </p> </item> <tag><marker id="+swt"><c>+swt very_low|low|medium|high|very_high</c></marker></tag> diff --git a/erts/doc/src/erl_driver.xml b/erts/doc/src/erl_driver.xml index 0e27f8a5bd..636326e4e1 100644 --- a/erts/doc/src/erl_driver.xml +++ b/erts/doc/src/erl_driver.xml @@ -170,10 +170,13 @@ callback, the best approach is to divide the work into multiple chunks of work and trigger multiple calls to the <seealso marker="driver_entry#timeout">timeout callback</seealso> using - zero timeouts. This might, however, not always be possible, e.g. when - calling third party libraries. In this case you typically want to dispatch - the work to another thread. Information about thread primitives can be - found below.</p> + zero timeouts. The + <seealso marker="#erl_drv_consume_timeslice"><c>erl_drv_consume_timeslice()</c></seealso> + function can be useful in order to determine when to trigger such + timeout callback calls. It might, however, not always be possible to + implement it this way, e.g. when calling third party libraries. In this + case you typically want to dispatch the work to another thread. + Information about thread primitives can be found below.</p> </description> <section> @@ -2805,7 +2808,6 @@ ERL_DRV_EXT2TERM char *buf, ErlDrvUInt len <p>This function is thread-safe.</p> </desc> </func> - <func> <name><ret>int</ret><nametext>erl_drv_getenv(char *key, char *value, size_t *value_size)</nametext></name> <fsummary>Get the value of an environment variable</fsummary> @@ -2841,6 +2843,52 @@ ERL_DRV_EXT2TERM char *buf, ErlDrvUInt len <p>This function is thread-safe.</p> </desc> </func> + <func> + <name><ret>int</ret><nametext>erl_drv_consume_timeslice(ErlDrvPort port, int percent)</nametext></name> + <fsummary>Give the runtime system a hint about how much CPU time the + current driver callback call has consumed</fsummary> + <desc> + <marker id="erl_drv_consume_timeslice"></marker> + <p>Arguments:</p> + <taglist> + <tag><c>port</c></tag> + <item>Port handle of the executing port.</item> + <tag><c>percent</c></tag> + <item>Approximate consumed fraction of a full + time-slice in percent.</item> + </taglist> + <p>Give the runtime system a hint about how much CPU time the + current driver callback call has consumed since last hint, or + since the start of the callback if no previous hint has been given. + The time is given as a fraction, in percent, of a full time-slice + that a port is allowed to execute before it should surrender the + CPU to other runnable ports or processes. Valid range is + <c>[1, 100]</c>. The scheduling time-slice is not an exact entity, + but can usually be approximated to about 1 millisecond.</p> + + <p>Note that it is up to the runtime system to determine if and + how to use this information. Implementations on some platforms + may use other means in order to determine the consumed fraction + of the time-slice. Lengthy driver callbacks should regardless of + this frequently call the <c>erl_drv_consume_timeslice()</c> + function in order to determine if it is allowed to continue + execution or not.</p> + + <p><c>erl_drv_consume_timeslice()</c> returns a non-zero value + if the time-slice has been exhausted, and zero if the callback is + allowed to continue execution. If a non-zero value is + returned the driver callback should return as soon as possible in + order for the port to be able to yield.</p> + + <p>This function is provided to better support co-operative scheduling, + improve system responsiveness, and to make it easier to prevent + misbehaviors of the VM due to a port monopolizing a scheduler thread. + It can be used when dividing length work into a number of repeated + driver callback calls without the need to use threads. Also see the + important <seealso marker="#WARNING">warning</seealso> text at the + beginning of this document.</p> + </desc> + </func> </funcs> <section> diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 5a63aaadc6..06fefa8efb 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -300,6 +300,44 @@ </desc> </func> <func> + <name name="binary_to_float" arity="1"/> + <fsummary>Convert from text representation to a float</fsummary> + <desc> + <p>Returns the float whose text representation is <c><anno>Binary</anno></c>.</p> + <pre> +> <input>binary_to_float(<<"2.2017764e+0">>).</input> +2.2017764</pre> + <p>Failure: <c>badarg</c> if <c><anno>Binary</anno></c> contains a bad + representation of a float.</p> + </desc> + </func> + <func> + <name name="binary_to_integer" arity="1"/> + <fsummary>Convert from text representation to an integer</fsummary> + <desc> + <p>Returns an integer whose text representation is + <c><anno>Binary</anno></c>.</p> + <pre> +> <input>binary_to_integer(<<"123">>).</input> +123</pre> + <p>Failure: <c>badarg</c> if <c><anno>Binary</anno></c> contains a bad + representation of an integer.</p> + </desc> + </func> + <func> + <name name="binary_to_integer" arity="2"/> + <fsummary>Convert from text representation to an integer</fsummary> + <desc> + <p>Returns an integer whose text representation in base + <c><anno>Base</anno></c> is <c><anno>Binary</anno></c>.</p> + <pre> +> <input>binary_to_integer(<<"3FF">>, 16).</input> +1023</pre> + <p>Failure: <c>badarg</c> if <c><anno>Binary</anno></c> contains a bad + representation of an integer.</p> + </desc> + </func> + <func> <name name="binary_to_list" arity="1"/> <fsummary>Convert a binary to a list</fsummary> <desc> @@ -961,26 +999,38 @@ true </desc> </func> <func> - <name name="float_to_list" arity="1"/> + <name name="float_to_binary" arity="1"/> <fsummary>Text representation of a float</fsummary> <desc> - <p>Returns a string which corresponds to the text - representation of <c><anno>Float</anno></c>.</p> + <p>The same as <c>float_to_binary(<anno>Float</anno>,[{scientific,20}])</c>.</p> + </desc> + </func> + <func> + <name name="float_to_binary" arity="2"/> + <fsummary>Text representation of a float formatted using given options</fsummary> + <desc> + <p>Returns a binary which corresponds to the text + representation of <c><anno>Float</anno></c> using fixed decimal + point formatting. The <c><anno>Options</anno></c> behave in the same + way as <seealso marker="#float_to_list/2">float_to_list/2</seealso>. + </p> <pre> -> <input>float_to_list(7.0).</input> -"7.00000000000000000000e+00"</pre> +> <input>float_to_binary(7.12, [{decimals, 4}]).</input> +<<"7.1200">> +> <input>float_to_binary(7.12, [{decimals, 4}, compact]).</input> +<<"7.12">></pre> </desc> </func> <func> - <name>float_to_list(Float, Options) -> string()</name> + <name name="float_to_list" arity="1"/> + <fsummary>Text representation of a float</fsummary> + <desc> + <p>The same as <c>float_to_list(<anno>Float</anno>,[{scientific,20}])</c>.</p> + </desc> + </func> + <func> + <name name="float_to_list" arity="2"/> <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..253} | - {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. @@ -993,7 +1043,8 @@ true 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>. + <c>Options</c> is <c>[]</c> the function behaves like + <c><seealso marker="#float_to_list/1">float_to_list/1</seealso></c>. </p> <pre> > <input>float_to_list(7.12, [{decimals, 4}]).</input> @@ -1429,7 +1480,28 @@ os_prompt% </pre> {one,new,two,three}</pre> </desc> </func> - + <func> + <name name="integer_to_binary" arity="1"/> + <fsummary>Text representation of an integer</fsummary> + <desc> + <p>Returns a binary which corresponds to the text + representation of <c><anno>Integer</anno></c>.</p> + <pre> +> <input>integer_to_binary(77).</input> +<<"77">></pre> + </desc> + </func> + <func> + <name name="integer_to_binary" arity="2"/> + <fsummary>Text representation of an integer</fsummary> + <desc> + <p>Returns a binary which corresponds to the text + representation of <c><anno>Integer</anno></c> in base <c><anno>Base</anno></c>.</p> + <pre> +> <input>integer_to_binary(1023, 16).</input> +<<"3FF">></pre> + </desc> + </func> <func> <name name="integer_to_list" arity="1"/> <fsummary>Text representation of an integer</fsummary> diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml index 42298e4824..0363f0237e 100644 --- a/erts/doc/src/notes.xml +++ b/erts/doc/src/notes.xml @@ -144,7 +144,7 @@ spawning processes, terminating processes, sending messages, etc.</item> <item>Optimizations of run queue management reducing contention.</item> - <item>Optimizations of process state changes reducing + <item>Optimizations of process internal state changes reducing contention.</item> </list> <p>These changes imply changes of the characteristics the system. Most notable: changed timing in the system.</p> @@ -403,7 +403,7 @@ </item> <item> <p> - The <seealso marker="#+stbt">+stbt</seealso> command line + The <seealso marker="erl#+stbt">+stbt</seealso> command line argument of <c>erl</c> was added. This argument can be used for trying to set scheduler bind type. Upon failure unbound schedulers will be used.</p> |