rarias/ovni
rarias/ovni
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

Add trace diagram and organize concepts

Browse Source
This commit is contained in:
Rodrigo Arias 2024-09-17 14:30:43 +02:00
parent 5e502b67d2
commit cdc5b9b866
2 changed files with 524 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

86
doc/user/concepts/trace.md
View File

@ -3,7 +3,7 @@
When using libovni to generate traces or the emulator to process them, there are
several concepts to keep in mind.
## Trace
## Trace elements
The information generated by a program or later processed by other ovni tools is
known as a trace. A runtime trace stores the information as-is in disk from a
@ -13,7 +13,30 @@ for visualization with Paraver.
Both runtime and emulation traces are always stored inside the same directory,
by default `ovni/`, which is known as the *trace directory*.
## Event
Here are the components of a runtime trace, as generated by libovni:
<p align="center">
<img alt="Trace concepts" src="../trace.svg">
</p>
### Stream
A stream is a directory which contains a binary stream and the associated stream
metadata file. Each stream is associated with a given part of a system. As of
now, libovni can only generate streams associated to [threads](part-model.md#thread).
### Stream metadata
The stream metadata is a JSON file named `stream.json` which holds information
about the stream itself.
### Binary stream
A binary stream is a file named `stream.obs` (.obs stands for Ovni Binary
Stream) composed of a header and a concatenated array of events without padding.
Notice that each event may have different length.
### Event
An event is a point in time that has some information associated. Events written
at runtime by libovni have at MCV, a clock and a optional payload. The list of
@ -39,18 +62,7 @@ $ ovnidump ovni/loom.hop.nosv-u1000/proc.1121064 | grep -A 10 VTx | head
There are two types or events: normal and jumbo events, the latter can hold
large attached payloads.
## State
A state is a discrete value that can change over time based on the events the
emulator receives. Usually a single event causes a single state change, which is
then written to the Paraver traces. An example is the thread state, which can
change over time based on the events `OH*` that indicate a state transition
of the current thread.
In contrast with an event, states have a duration associated which can usually
be observed in Paraver.
## MCV
### MCV
The MCV acronym is the abbreviation of Model-Class-Value, which are a three
characters that identify any event. The MCV is shown in the ovnitop and ovnidump
@ -66,7 +78,7 @@ VTp 1
VTr 1
```
## Clock
### Clock
A clock is a 64 bit counter, which counts the number of nanoseconds from an
arbitrary point in time in the past. Each event has the value of the clock
@ -76,34 +88,36 @@ corrected so they all produce an ordered sequence of events. The ovnisync
program performs this correction by measuring the difference across clocks of
different nodes.
## Event model
An event model is composed of several components:
- A set of [events](#event) all with the same model identifier in the
[MCV](#mcv)
- The emulator code that processes those events.
- A human readable name, like `ovni` or `nanos6`.
## Payload
### Payload
Events may have associated additional information which is stored in the stream.
Normal events can hold up to 16 bytes, otherwise the jumbo events must be used
to hold additional payload.
## Stream
## Other related concepts
A stream is a directory which contains a binary stream and the associated stream
metadata file. Each stream is associated with a given part of a system. As of
now, libovni can only generate streams associated to [threads](part-model.md#thread).
Apart from the trace itself, there are other concepts to keep in mind when the
trace is being processed by the emulator.
## Binary stream
### Event model
A binary stream is a file named `stream.obs` (.obs stands for Ovni Binary
Stream) composed of a header and a concatenated array of events without padding.
Notice that each event may have different length.
Each event belongs to an event model, as identified by the model character in
the MCV. An event model is composed of several components:
## Stream metadata
- A set of [events](#event) all with the same model identifier in the
[MCV](#mcv)
- The emulator code that processes those events.
- A human readable name, like `ovni` or `nanos6`.
- A semantic version.
The stream metadata is a JSON file named `stream.json` which holds information
about the stream itself.
### State
A state is a discrete value that can change over time based on the events the
emulator receives. Usually a single event causes a single state change, which is
then written to the Paraver traces. An example is the thread state, which can
change over time based on the events `OH*` that indicate a state transition
of the current thread.
In contrast with an event, states have a duration associated which can usually
be observed in Paraver. Notice that the trace only contains events, the states
are computed at emulation.

474
doc/user/concepts/trace.svg Normal file
View File

@ -0,0 +1,474 @@
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!-- Created with Inkscape (http://www.inkscape.org/) -->
<svg
width="116.41666mm"
height="105.83334mm"
viewBox="0 0 116.41666 105.83334"
version="1.1"
id="svg1"
inkscape:version="1.3.2 (091e20ef0f, 2023-11-25, custom)"
sodipodi:docname="trace.svg"
xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
xmlns="http://www.w3.org/2000/svg"
xmlns:svg="http://www.w3.org/2000/svg">
<sodipodi:namedview
id="namedview1"
pagecolor="#ffffff"
bordercolor="#999999"
borderopacity="1"
inkscape:showpageshadow="0"
inkscape:pageopacity="0"
inkscape:pagecheckerboard="0"
inkscape:deskcolor="#d1d1d1"
inkscape:document-units="mm"
showgrid="true"
inkscape:zoom="1.4609989"
inkscape:cx="248.80238"
inkscape:cy="199.17879"
inkscape:window-width="1920"
inkscape:window-height="1031"
inkscape:window-x="0"
inkscape:window-y="24"
inkscape:window-maximized="1"
inkscape:current-layer="layer1">
<inkscape:grid
id="grid1"
units="px"
originx="-39.687498"
originy="-15.875"
spacingx="0.26458333"
spacingy="0.26458334"
empcolor="#7a7aff"
empopacity="0.25098039"
color="#6a6aff"
opacity="0.1254902"
empspacing="5"
dotted="false"
gridanglex="30"
gridanglez="30"
visible="true" />
</sodipodi:namedview>
<defs
id="defs1">
<rect
x="45"
y="370"
width="209.99998"
height="35"
id="rect15" />
</defs>
<g
inkscape:label="Layer 1"
inkscape:groupmode="layer"
id="layer1"
transform="translate(-39.687498,-15.875)">
<g
id="g59"
transform="translate(5.5781353,-0.74017783)"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="100.23113"
y="24.896034"
id="text22"><tspan
sodipodi:role="line"
id="tspan22"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="100.23113"
y="24.896034">Trace</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect32"
width="15.875"
height="7.9375005"
x="92.281235"
y="19.4142" />
</g>
<g
id="g57"
transform="translate(-0.84260657,-0.98969722)"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="106.39689"
y="46.186943"
id="text24"><tspan
sodipodi:role="line"
id="tspan24"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="106.39689"
y="46.186943">Stream</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect33"
width="21.166666"
height="7.9375019"
x="96.092606"
y="40.6772" />
</g>
<g
id="g56"
transform="translate(0.32292488,-0.89336269)"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="78.773026"
y="46.090603"
id="text23"><tspan
sodipodi:role="line"
id="tspan23"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="78.773026"
y="46.090603">Stream</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect34"
width="21.166666"
height="7.9375"
x="68.468742"
y="40.580864" />
</g>
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 100.80665,26.611522 84.365216,39.687501"
id="path35"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#rect32"
inkscape:connection-end="#rect34" />
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="m 105.80376,26.611522 0.0227,13.075981"
id="path36"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#rect32"
inkscape:connection-end="#rect33" />
<g
id="g54"
style="stroke-width:0.15875;stroke-dasharray:none"
transform="translate(-0.99999828,-3.5391978)">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="58.792854"
y="72.586143"
id="text25"><tspan
sodipodi:role="line"
id="tspan25"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="58.792854"
y="72.586143">Metadata</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect36"
width="26.458336"
height="7.9375"
x="45.979164"
y="67.0392" />
</g>
<g
id="g55"
style="stroke-width:0.15875;stroke-dasharray:none"
transform="translate(-0.99999828,-3.5391978)">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="97.157433"
y="72.175835"
id="text26"><tspan
sodipodi:role="line"
id="tspan26"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="97.157433"
y="72.175835">Binary stream</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect37"
width="34.395832"
height="7.9375"
x="80.374992"
y="67.0392" />
</g>
<rect
style="stroke-width:0.15875;stroke-dasharray:none;fill:none;stroke:none;stroke-linecap:square"
id="rect60"
width="116.41666"
height="105.83334"
x="40.687496"
y="19.414198"
inkscape:label="background"
transform="translate(-0.99999735,-3.5391979)" />
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 75.847223,47.625001 61.736111,63.500002"
id="path37"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#rect34"
inkscape:connection-end="#rect36" />
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 82.241318,47.625001 93.706592,63.500002"
id="path38"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#rect34"
inkscape:connection-end="#rect37" />
<g
id="g53"
style="stroke-width:0.15875;stroke-dasharray:none"
transform="translate(-8.2507438,-3.0742007)">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="62.074863"
y="95.933655"
id="text27"><tspan
sodipodi:role="line"
id="tspan27"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="62.074863"
y="95.933655">Header</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect38"
width="23.812506"
height="7.9375014"
x="50.584076"
y="90.386703" />
</g>
<g
id="g52"
transform="translate(-8.2507438,-3.3066989)"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="91.411552"
y="96.101036"
id="text28"><tspan
sodipodi:role="line"
id="tspan28"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="91.411552"
y="96.101036">Event</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect39"
width="23.812506"
height="7.9375014"
x="79.920769"
y="90.619202" />
</g>
<g
id="g51"
style="stroke-width:0.15875;stroke-dasharray:none"
transform="translate(-8.2507438,-3.0742007)">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="120.28321"
y="95.868538"
id="text29"><tspan
sodipodi:role="line"
id="tspan29"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="120.28321"
y="95.868538">Event</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect40"
width="23.812506"
height="7.9375014"
x="108.79243"
y="90.386703" />
</g>
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 89.517356,71.437502 61.29514,87.312503"
id="path40"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#rect37"
inkscape:connection-end="#rect38" />
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 94.406805,71.437502 85.742383,87.312503"
id="path41"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#rect37"
inkscape:connection-end="#rect39" />
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 99.218748,71.437502 109.8021,87.312503"
id="path42"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#rect37"
inkscape:connection-end="#rect40" />
<g
id="g46"
transform="translate(-68.659367,2.7781237)"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="123.93869"
y="113.98891"
id="text30"><tspan
sodipodi:role="line"
id="tspan30"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="123.93869"
y="113.98891">MCV</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect42"
width="15.875001"
height="7.9375038"
x="116.41666"
y="108.47917" />
</g>
<g
id="g45"
transform="translate(-68.659367,5.4239515)"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="147.92894"
y="111.38029"
id="text31"><tspan
sodipodi:role="line"
id="tspan31"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="147.92894"
y="111.38029">Clock</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect43"
width="15.875001"
height="7.9375038"
x="140.22916"
y="105.83334" />
</g>
<g
id="g44"
transform="translate(-66.112857,13.610614)"
style="stroke-width:0.15875;stroke-dasharray:none">
<g
id="g60"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="172.85362"
y="102.65102"
id="text32"><tspan
sodipodi:role="line"
id="tspan32"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="172.85362"
y="102.65102">Payload</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect44"
width="23.812506"
height="7.9375014"
x="161.36285"
y="97.514389" />
</g>
</g>
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 83.366344,95.250004 80.27399,111.2573"
id="path47"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-end="#g45" />
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 80.082847,95.250004 60.540101,111.2573"
id="path48"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-end="#g46" />
<g
id="g58"
transform="translate(-1.9073076,-1.4153422)"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="132.47266"
y="46.496338"
id="text49"><tspan
sodipodi:role="line"
id="tspan49"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="132.47266"
y="46.496338">...</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect49"
width="18.619415"
height="7.9374995"
x="123.61564"
y="41.102844" />
</g>
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="m 110.56031,26.611522 15.69429,13.07598"
id="path49"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-end="#rect49"
inkscape:connection-start="#rect32" />
<g
id="g50"
transform="translate(-8.2507438,-2.9293636)"
style="stroke-width:0.15875;stroke-dasharray:none">
<text
xml:space="preserve"
style="font-size:4.23333px;line-height:1.25;font-family:sans-serif;text-align:center;letter-spacing:0px;word-spacing:0px;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="149.35014"
y="95.635361"
id="text50"><tspan
sodipodi:role="line"
id="tspan50"
style="text-align:center;text-anchor:middle;stroke-width:0.15875;stroke-dasharray:none"
x="149.35014"
y="95.635361">...</tspan></text>
<rect
style="fill:none;stroke:#000000;stroke-width:0.15875;stroke-linecap:square;stroke-dasharray:none"
id="rect40-5"
width="23.812506"
height="7.9375014"
x="137.89658"
y="90.241867" />
</g>
<path
style="display:inline;fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="m 104.06944,71.437502 29.98612,15.875001"
id="path50"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#rect37"
inkscape:connection-end="#g50" />
<path
style="fill:none;fill-rule:evenodd;stroke:#000000;stroke-width:0.15875;stroke-linecap:butt;stroke-linejoin:miter;stroke-dasharray:none;stroke-opacity:1"
d="M 87.506274,95.250004 103.22625,111.125"
id="path60"
inkscape:connector-type="polyline"
inkscape:connector-curvature="0"
inkscape:connection-start="#g52"
inkscape:connection-end="#g44" />
</g>
</svg>
Side by Side

After

Width:  |  Height:  |  Size: 19 KiB