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Diffstat (limited to 'erts/doc/src/erl_driver.xml')
| -rw-r--r-- | erts/doc/src/erl_driver.xml | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/erts/doc/src/erl_driver.xml b/erts/doc/src/erl_driver.xml index e717fc0c4e..34dc8af238 100644 --- a/erts/doc/src/erl_driver.xml +++ b/erts/doc/src/erl_driver.xml @@ -347,6 +347,16 @@ the driver does not handle sizes that overflow an <c>int</c> all will work as before.</p> </item> + <tag><marker id="time_measurement"/>Time Measurement</tag> + <item><p>Support for time measurement in drivers: + <list> + <item><seealso marker="#ErlDrvTime"><c>ErlDrvTime</c></seealso></item> + <item><seealso marker="#ErlDrvTimeUnit"><c>ErlDrvTimeUnit</c></seealso></item> + <item><seealso marker="#erl_drv_monotonic_time"><c>erl_drv_monotonic_time()</c></seealso></item> + <item><seealso marker="#erl_drv_time_offset"><c>erl_drv_time_offset()</c></seealso></item> + <item><seealso marker="#erl_drv_convert_time_unit"><c>erl_drv_convert_time_unit()</c></seealso></item> + </list></p> + </item> </taglist> </section> @@ -860,6 +870,24 @@ typedef struct ErlIOVec { <seealso marker="#erl_drv_tsd_get">erl_drv_tsd_get()</seealso>. </p> </item> + <tag><marker id="ErlDrvTime"/>ErlDrvTime</tag> + <item> + <p>A signed 64-bit integer type for representation of time.</p> + </item> + <tag><marker id="ErlDrvTimeUnit"/>ErlDrvTimeUnit</tag> + <item> + <p>An enumeration of time units supported by the driver API:</p> + <taglist> + <tag><c>ERL_DRV_SEC</c></tag> + <item><p>Seconds</p></item> + <tag><c>ERL_DRV_MSEC</c></tag> + <item><p>Milliseconds</p></item> + <tag><c>ERL_DRV_USEC</c></tag> + <item><p>Microseconds</p></item> + <tag><c>ERL_DRV_NSEC</c></tag> + <item><p>Nanoseconds</p></item> + </taglist> + </item> </taglist> </section> @@ -1023,6 +1051,11 @@ typedef struct ErlIOVec { <fsummary>Read a system timestamp</fsummary> <desc> <marker id="driver_get_now"></marker> + <warning><p><em>This function is deprecated! Do not use it!</em> + Use <seealso marker="#erl_drv_monotonic_time"><c>erl_drv_monotonic_time()</c></seealso> + (perhaps in combination with + <seealso marker="#erl_drv_time_offset"><c>erl_drv_time_offset()</c></seealso>) + instead.</p></warning> <p>This function reads a timestamp into the memory pointed to by the parameter <c>now</c>. See the description of <seealso marker="#ErlDrvNowData">ErlDrvNowData</seealso> for specification of its fields. </p> @@ -2997,6 +3030,86 @@ ERL_DRV_MAP int sz </desc> </func> + <func> + <name><ret>ErlDrvTime</ret><nametext>erl_drv_monotonic_time(ErlDrvTimeUnit time_unit)</nametext></name> + <fsummary>Get Erlang Monotonic Time</fsummary> + <desc> + <marker id="erl_drv_monotonic_time"></marker> + <p>Arguments:</p> + <taglist> + <tag><c>time_unit</c></tag> + <item>Time unit of returned value.</item> + </taglist> + <p> + Returns + <seealso marker="time_correction#Erlang_Monotonic_Time">Erlang + monotonic time</seealso>. Note that it is not uncommon with + negative values. + </p> + <p>Returns <c>ERL_DRV_TIME_ERROR</c> if called with an invalid + time unit argument, or if called from a thread that is not a + scheduler thread.</p> + <p>See also:</p> + <list> + <item><seealso marker="#ErlDrvTime"><c>ErlDrvTime</c></seealso></item> + <item><seealso marker="#ErlDrvTimeUnit"><c>ErlDrvTimeUnit</c></seealso></item> + </list> + </desc> + </func> + + <func> + <name><ret>ErlDrvTime</ret><nametext>erl_drv_time_offset(ErlDrvTimeUnit time_unit)</nametext></name> + <fsummary>Get current Time Offset</fsummary> + <desc> + <marker id="erl_drv_time_offset"></marker> + <p>Arguments:</p> + <taglist> + <tag><c>time_unit</c></tag> + <item>Time unit of returned value.</item> + </taglist> + <p>Returns the current time offset between + <seealso marker="time_correction#Erlang_Monotonic_Time">Erlang monotonic time</seealso> + and + <seealso marker="time_correction#Erlang_System_Time">Erlang system time</seealso> + converted into the <c>time_unit</c> passed as argument.</p> + <p>Returns <c>ERL_DRV_TIME_ERROR</c> if called with an invalid + time unit argument, or if called from a thread that is not a + scheduler thread.</p> + <p>See also:</p> + <list> + <item><seealso marker="#ErlDrvTime"><c>ErlDrvTime</c></seealso></item> + <item><seealso marker="#ErlDrvTimeUnit"><c>ErlDrvTimeUnit</c></seealso></item> + </list> + </desc> + </func> + + <func> + <name><ret>ErlDrvTime</ret><nametext>erl_drv_convert_time_unit(ErlDrvTime val, ErlDrvTimeUnit from, ErlDrvTimeUnit to)</nametext></name> + <fsummary>Convert time unit of a time value</fsummary> + <desc> + <marker id="erl_drv_convert_time_unit"></marker> + <p>Arguments:</p> + <taglist> + <tag><c>val</c></tag> + <item>Value to convert time unit for.</item> + <tag><c>from</c></tag> + <item>Time unit of <c>val</c>.</item> + <tag><c>to</c></tag> + <item>Time unit of returned value.</item> + </taglist> + <p>Converts the <c>val</c> value of time unit <c>from</c> to + the corresponding value of time unit <c>to</c>. The result is + rounded using the floor function.</p> + <p>Returns <c>ERL_DRV_TIME_ERROR</c> if called with an invalid + time unit argument.</p> + <p>See also:</p> + <list> + <item><seealso marker="#ErlDrvTime"><c>ErlDrvTime</c></seealso></item> + <item><seealso marker="#ErlDrvTimeUnit"><c>ErlDrvTimeUnit</c></seealso></item> + </list> + </desc> + </func> + </funcs> <section> <title>SEE ALSO</title> |