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authorRickard Green <[email protected]>2016-01-19 17:05:55 +0100
committerRickard Green <[email protected]>2016-01-21 15:10:09 +0100
commit3f33428db9aea0d767295322c4e882a5c6bbf7db (patch)
tree331741cf9e941f15f689f790d0f2e354450bf25b /erts/doc
parentdc8e62f33ad0ca7a772ec74d67b6d3e157f639b4 (diff)
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Introduce time management in native APIs
Diffstat (limited to 'erts/doc')
-rw-r--r--erts/doc/src/erl_driver.xml112
-rw-r--r--erts/doc/src/erl_nif.xml112
2 files changed, 224 insertions, 0 deletions
diff --git a/erts/doc/src/erl_driver.xml b/erts/doc/src/erl_driver.xml
index e717fc0c4e..e338e95938 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 +1051,10 @@ 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 the documented
+ <seealso marker="#time_measurement">time measurement functionality</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 +3029,86 @@ 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>
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml
index 2d8706169f..420c9fea38 100644
--- a/erts/doc/src/erl_nif.xml
+++ b/erts/doc/src/erl_nif.xml
@@ -317,6 +317,17 @@ ok
libraries might however fail if deprecated features are used.
</p></item>
+ <tag><marker id="time_measurement"/>Time Measurement</tag>
+ <item><p>Support for time measurement in NIF libraries:
+ <list>
+ <item><seealso marker="#ErlNifTime"><c>ErlNifTime</c></seealso></item>
+ <item><seealso marker="#ErlNifTimeUnit"><c>ErlNifTimeUnit</c></seealso></item>
+ <item><seealso marker="#enif_monotonic_time"><c>enif_monotonic_time()</c></seealso></item>
+ <item><seealso marker="#enif_time_offset"><c>enif_time_offset()</c></seealso></item>
+ <item><seealso marker="#enif_convert_time_unit"><c>enif_convert_time_unit()</c></seealso></item>
+ </list></p>
+ </item>
+
<tag>Long-running NIFs</tag>
<item><p><marker id="dirty_nifs"/>Native functions
<seealso marker="#lengthy_work">
@@ -560,6 +571,25 @@ typedef enum {
<item><p>A native signed 64-bit integer type.</p></item>
<tag><marker id="ErlNifUInt64"/>ErlNifUInt64</tag>
<item><p>A native unsigned 64-bit integer type.</p></item>
+
+ <tag><marker id="ErlNifTime"/>ErlNifTime</tag>
+ <item>
+ <p>A signed 64-bit integer type for representation of time.</p>
+ </item>
+ <tag><marker id="ErlNifTimeUnit"/>ErlNifTimeUnit</tag>
+ <item>
+ <p>An enumeration of time units supported by the NIF API:</p>
+ <taglist>
+ <tag><c>ERL_NIF_SEC</c></tag>
+ <item><p>Seconds</p></item>
+ <tag><c>ERL_NIF_MSEC</c></tag>
+ <item><p>Milliseconds</p></item>
+ <tag><c>ERL_NIF_USEC</c></tag>
+ <item><p>Microseconds</p></item>
+ <tag><c>ERL_NIF_NSEC</c></tag>
+ <item><p>Nanoseconds</p></item>
+ </taglist>
+ </item>
</taglist>
</section>
@@ -1486,6 +1516,88 @@ enif_map_iterator_destroy(env, &amp;iter);
<desc><p>Same as <seealso marker="erl_driver#erl_drv_tsd_set">erl_drv_tsd_set</seealso>.
</p></desc>
</func>
+
+
+ <func>
+ <name><ret>ErlNifTime</ret><nametext>enif_monotonic_time(ErlNifTimeUnit time_unit)</nametext></name>
+ <fsummary>Get Erlang Monotonic Time</fsummary>
+ <desc>
+ <marker id="enif_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_NIF_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="#ErlNifTime"><c>ErlNifTime</c></seealso></item>
+ <item><seealso marker="#ErlNifTimeUnit"><c>ErlNifTimeUnit</c></seealso></item>
+ </list>
+ </desc>
+ </func>
+
+ <func>
+ <name><ret>ErlNifTime</ret><nametext>enif_time_offset(ErlNifTimeUnit time_unit)</nametext></name>
+ <fsummary>Get current Time Offset</fsummary>
+ <desc>
+ <marker id="enif_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_NIF_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="#ErlNifTime"><c>ErlNifTime</c></seealso></item>
+ <item><seealso marker="#ErlNifTimeUnit"><c>ErlNifTimeUnit</c></seealso></item>
+ </list>
+ </desc>
+ </func>
+
+ <func>
+ <name><ret>ErlNifTime</ret><nametext>enif_convert_time_unit(ErlNifTime val, ErlNifTimeUnit from, ErlNifTimeUnit to)</nametext></name>
+ <fsummary>Convert time unit of a time value</fsummary>
+ <desc>
+ <marker id="enif_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_NIF_TIME_ERROR</c> if called with an invalid
+ time unit argument.</p>
+ <p>See also:</p>
+ <list>
+ <item><seealso marker="#ErlNifTime"><c>ErlNifTime</c></seealso></item>
+ <item><seealso marker="#ErlNifTimeUnit"><c>ErlNifTimeUnit</c></seealso></item>
+ </list>
+ </desc>
+ </func>
+
</funcs>
<section>
<title>SEE ALSO</title>