diff options
Diffstat (limited to 'erts/doc')
| -rw-r--r-- | erts/doc/src/erlang.xml | 33 | ||||
| -rw-r--r-- | erts/doc/src/time_correction.xml | 29 |
2 files changed, 49 insertions, 13 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 98c0ef5f81..7cb417ac92 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> @@ -6435,18 +6442,22 @@ 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> diff --git a/erts/doc/src/time_correction.xml b/erts/doc/src/time_correction.xml index 3bc3d04186..ed658ff58c 100644 --- a/erts/doc/src/time_correction.xml +++ b/erts/doc/src/time_correction.xml @@ -114,6 +114,29 @@ happened yet), POSIX time would make a one second leap forward.</p> </section> + <marker id="Time_Resolution"/> + <section> + <title>Time Resolution</title> + <p>The shortest time interval that can be distinguished when + reading time values.</p> + </section> + + <marker id="Time_Precision"/> + <section> + <title>Time Precision</title> + <p>The shortest time interval that can be be distinguished + repeatedly and reliably when reading time values. Precision + is limited by the + <seealso marker="#Time_Resolution">resolution</seealso>, but + resolution and precision might differ significantly.</p> + </section> + + <marker id="Time_Accuracy"/> + <section> + <title>Time Accuracy</title> + <p>The correctness of time values.</p> + </section> + <marker id="OS_System_Time"/> <section> <title>OS System Time</title> @@ -162,8 +185,10 @@ Erlang runtime system. The Erlang monotonic time increase since some unspecified point in time. It can be retrieved by calling <seealso marker="erlang#monotonic_time/0"><c>erlang:monotonic_time()</c></seealso>. - The accuracy, and precision of Erlang monotonic time heavily - depends on the accuracy and precision of + The + <seealso marker="#Time_Accuracy">accuracy</seealso>, and + <seealso marker="#Time_Precision">precision</seealso> of Erlang + monotonic time heavily depends on the accuracy and precision of <seealso marker="#OS_Monotonic_Time">OS monotonic time</seealso>, the accuracy and precision of <seealso marker="#OS_System_Time">OS system time</seealso> as well |