Changes between Version 3 and Version 4 of Prefs2

Timestamp:

Sep 9, 2019, 11:51:43 AM (5 years ago)

Author:

davea

Comment:

--

Prefs2

@@ -3 +3 @@
 == Static and dynamic parameters ==
 
-"Dynamic" parameters limit BOINC activity
-and change in response to various factors external to BOINC.
-Examples include limits on #CPUs, RAM usage, network usage, etc.
+Various parameters control and limit
+BOINC's use of computing, memory, storage, and network communication.
+"Static parameters" don't vary over time;
+for example storage-related parameters are static.
+"Dynamic" parameters can change in response to factors external to BOINC
+(such as time of day, non-BOINC CPU usage, etc.).
+Dynamic parameters include limits on #CPUs, RAM usage, network throughput, etc.
+
+This document describes a new system for "computing preferences" in BOINC.
+This system lets users express, using a set of logical rules,
+how dynamic parameters change in response
+to external factors.
+
+The goals of this system include:
+
+ * Generality: allow the expression of any preferences.
+ * Extensibility: make it possible to add new external factors
+   (such as the current cost of electricity) without modifying the client.
+
+The XML representations of parameters:
+{{{
+<static_params>
+   [ <disk_max_used_gb>x</disk_max_used_gb> ]
+   ...
+</static_params>
+
+<dynamic_params>
+   [ <max_ncpus_pct>x</max_ncpus_pct> ]
+   ...
+</dynamic_params>
+}}}
+
+All elements are optional;
+a parameter set can define some elements but not others.
+If A and B are parameter sets, the "overlay" of A on B is defined as
+A together with any elements in B that are not defined in A.
 
 == Prefs dictionary ==
@@ -19 +52 @@
  * "non_boinc_cpu_usage": fraction of CPU used for non-BOINC apps recently
 
-These values are updated by the client.
+These values are updated periodically by the client.
 In addition, external programs can add items to the dictionary,
 and update their values, via GUI RPCs.
@@ -32 +65 @@
 
 Each term is an assertion about a dictionary item.
-There are three types of terms:
+There are three types of assertions:
 
  * "greater than": the value of the item is greater than a number X.
@@ -40 +73 @@
 A term can also have a "negate" flag, which if set reverses its sense.
 
-The XML representation of a term is
+The XML representation of a term:
 {{{
 <term>
    <item>item-name</item>
-   <type>x</type>                  // 0 = greater than, 1 = nonzero, 2 = time range
+   <type>x</type>                  // 1 = greater than, 2 = nonzero, 3 = time range
    [<negate/>]
    [<thresh>x</thresh>]            // if greater than
@@ -50 +83 @@
 </term>
 }}}
-and the representation of a time range is
+The representation of a time range:
 {{{
 <time_range>
-   <start_hour>x</start_hour>
-   <end_hour>y</end_hour>
+   <start>x</start>
+   <end>y</end>
    [
-   <day>
-      <day_of_week>x</day_of_week>    // 0 .. 6
-      <start_hour>x</start_hour>
-      <end_hour>y</end_hour>
+   <day_of_week>
+      <day>x</day>                 // 0 .. 6
+      <start>x</start>
+      <end>y</end>
    <day>
 </time_range>
@@ -76 +109 @@
 }}}
 
-If the set if empty, the condition is always true.
+The conjunction of an empty set of terms is true.
 
 == Clauses ==
@@ -104 +137 @@
 The clauses are processed in order.
 For each clause C, we evaluate its condition.
-If the condition is true, we overwrite X with C's dynamic parameters.
+If the condition is true, we overlay X with C's dynamic parameters.
 At the conclusion, X is the dynamic parameters to be enforced by the client.