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-rw-r--r--erts/doc/src/erlang.xml97
1 files changed, 86 insertions, 11 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 880c294c73..ba5f80a9c1 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -110,10 +110,17 @@
<note>
<p>The value of the <c>native</c> time unit gives
you more or less no information at all about the
- quality of time values. It sets an upper bound for
- the resolution as well as for the precision, but it
- gives absolutely no information at all about the
- accuracy.</p>
+ quality of time values. It sets a limit for
+ the
+ <seealso marker="time_correction#Time_Resolution">resolution</seealso>
+ as well as for the
+ <seealso marker="time_correction#Time_Precision">precision</seealso>
+ of time values,
+ but it gives absolutely no information at all about the
+ <seealso marker="time_correction#Time_Accuracy">accuracy</seealso>
+ of time values. The resolution of the <c>native</c> time
+ unit and the resolution of time values may differ
+ significantly.</p>
</note>
</item>
@@ -6038,6 +6045,8 @@ ok
<name name="system_info" arity="1" clause_i="62"/>
<name name="system_info" arity="1" clause_i="63"/>
<name name="system_info" arity="1" clause_i="64"/>
+ <name name="system_info" arity="1" clause_i="65"/>
+ <name name="system_info" arity="1" clause_i="66"/>
<fsummary>Information about the system</fsummary>
<desc>
<p>Returns various information about the current system
@@ -6449,20 +6458,33 @@ ok
<c>Function</c>.</p></item>
<tag><c>{resolution, OsMonotonicTimeResolution}</c></tag>
- <item><p>Highest possible resolution of current
- OS monotonic time source as parts per second. If
- no resolution information can be retreived from
- the OS, <c>OsMonotonicTimeResolution</c> will be
+ <item><p>Highest possible
+ <seealso marker="time_correction#Time_Resolution">resolution</seealso>
+ of current OS monotonic time source as parts per
+ second. If no resolution information can be retreived
+ from the OS, <c>OsMonotonicTimeResolution</c> will be
set to the resolution of the time unit of
<c>Function</c>s return value. That is, the actual
resolution may be lower than
<c>OsMonotonicTimeResolution</c>. Also note that
the resolution does not say anything about the
- accuracy, and that the precision might not align
- with the resolution. You do, however, know that the
- precision won't be higher than
+ <seealso marker="time_correction#Time_Accuracy">accuracy</seealso>,
+ and that the
+ <seealso marker="time_correction#Time_Precision">precision</seealso>
+ might not align with the resolution. You do,
+ however, know that the precision won't be
+ better than
<c>OsMonotonicTimeResolution</c>.</p></item>
+ <tag><c>{extended, Extended}</c></tag>
+ <item><p><c>Extended</c> equals <c>yes</c> if
+ the range of time values has been extended;
+ otherwise, <c>Extended</c> equals <c>no</c>. The
+ range needs to be extended if <c>Function</c>
+ returns values that wrap fast. This typically
+ is the case when the return value is a 32-bit
+ value.</p></item>
+
<tag><c>{parallel, Parallel}</c></tag>
<item><p><c>Parallel</c> equals <c>yes</c> if
<c>Function</c> is called in parallel from multiple
@@ -6476,6 +6498,59 @@ ok
<seealso marker="#type_time_unit">time unit</seealso>.</p></item>
</taglist>
</item>
+ <tag><marker id="system_info_os_system_time_source"><c>os_system_time_source</c></marker></tag>
+ <item>
+ <p>Returns a list containing information about the source of
+ <seealso marker="erts:time_correction#OS_System_Time">OS
+ system time</seealso> that is used by the runtime system.</p>
+ <p>The list contains two-tuples with <c>Key</c>s
+ as first element, and <c>Value</c>s as second element. The
+ order if these tuples is undefined. Currently the following
+ tuples may be part of the list, but more tuples may be
+ introduced in the future:</p>
+ <taglist>
+ <tag><c>{function, Function}</c></tag>
+ <item><p><c>Function</c> is the name of the funcion
+ used.</p></item>
+
+ <tag><c>{clock_id, ClockId}</c></tag>
+ <item><p>This tuple only exist if <c>Function</c>
+ can be used with different clocks. <c>ClockId</c>
+ corresponds to the clock identifer used when calling
+ <c>Function</c>.</p></item>
+
+ <tag><c>{resolution, OsSystemTimeResolution}</c></tag>
+ <item><p>Highest possible
+ <seealso marker="time_correction#Time_Resolution">resolution</seealso>
+ of current OS system time source as parts per
+ second. If no resolution information can be retreived
+ from the OS, <c>OsSystemTimeResolution</c> will be
+ set to the resolution of the time unit of
+ <c>Function</c>s return value. That is, the actual
+ resolution may be lower than
+ <c>OsSystemTimeResolution</c>. Also note that
+ the resolution does not say anything about the
+ <seealso marker="time_correction#Time_Accuracy">accuracy</seealso>,
+ and that the
+ <seealso marker="time_correction#Time_Precision">precision</seealso>
+ might not align with the resolution. You do,
+ however, know that the precision won't be
+ better than
+ <c>OsSystemTimeResolution</c>.</p></item>
+
+ <tag><c>{parallel, Parallel}</c></tag>
+ <item><p><c>Parallel</c> equals <c>yes</c> if
+ <c>Function</c> is called in parallel from multiple
+ threads. If it is not called in parallel, because
+ calls needs to be serialized, <c>Parallel</c> equals
+ <c>no</c>.</p></item>
+
+ <tag><c>{time, OsSystemTime}</c></tag>
+ <item><p><c>OsSystemTime</c> equals current OS
+ system time in <c>native</c>
+ <seealso marker="#type_time_unit">time unit</seealso>.</p></item>
+ </taglist>
+ </item>
<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