Trace.md

Trace module — pxr-usd-api 105.1 documentation

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Trace module

 

# Trace module

Summary: The Trace module provides performance tracking utility classes for counting, timing, measuring, recording, and reporting events.

Trace – Utilities for counting and recording events.
Classes:

AggregateNode
A representation of a call tree.

Collector
This is a singleton class that records TraceEvent instances and populates TraceCollection instances.

Reporter
This class converts streams of TraceEvent objects into call trees which can then be used as a data source to a GUI or written out to a file.

Functions:

TraceFunction(obj)
A decorator that enables tracing the function that it decorates.

TraceMethod(obj)
A convenience.

TraceScope(label)
A context manager that calls BeginEvent on the global collector on enter and EndEvent on exit.

class pxr.Trace.AggregateNode
A representation of a call tree. Each node represents one or more
calls that occurred in the trace. Multiple calls to a child node are
aggregated into one node.
Attributes:

children
list[TraceAggregateNodePtr]

count
int

exclusiveCount
int

exclusiveTime
TimeStamp

expanded
bool

expired
True if this object has expired, False otherwise.

id
Id

inclusiveTime
TimeStamp

key
str

property children
list[TraceAggregateNodePtr]

Type
type

property count
int
Returns the call count of this node.
recursive determines if recursive calls are counted.

Type
type

property exclusiveCount
int
Returns the exclusive count.

Type
type

property exclusiveTime
TimeStamp
Returns the time spent in this node but not its children.

Type
type

property expanded
bool
Returns whether this node is expanded in a gui.

type : None
Sets whether or not this node is expanded in a gui.

Type
type

property expired
True if this object has expired, False otherwise.

property id
Id
Returns the node’s id.

Type
type

property inclusiveTime
TimeStamp
Returns the total time of this node ands its children.

Type
type

property key
str
Returns the node’s key.

Type
type

class pxr.Trace.Collector
This is a singleton class that records TraceEvent instances and
populates TraceCollection instances.
All public methods of TraceCollector are safe to call from any thread.
Methods:

BeginEvent(key)
Record a begin event with key if Category is enabled.

BeginEventAtTime(key, ms)
Record a begin event with key at a specified time if Category is enabled.

Clear()
Clear all pending events from the collector.

EndEvent(key)
Record an end event with key if Category is enabled.

EndEventAtTime(key, ms)
Record an end event with key at a specified time if Category is enabled.

GetLabel()
Return the label associated with this collector.

Attributes:

enabled
bool

expired
True if this object has expired, False otherwise.

pythonTracingEnabled
None

BeginEvent(key) → TimeStamp
Record a begin event with key if Category is enabled.
A matching end event is expected some time in the future.
If the key is known at compile time BeginScope and Scope
methods are preferred because they have lower overhead.
The TimeStamp of the TraceEvent or 0 if the collector is disabled.
BeginScope
Scope

Parameters
key (Key) – 

BeginEventAtTime(key, ms) → None
Record a begin event with key at a specified time if Category is
enabled.
This version of the method allows the passing of a specific number of
elapsed milliseconds, ms, to use for this event. This method is used
for testing and debugging code.

Parameters

key (Key) – 
ms (float) – 

Clear() → None
Clear all pending events from the collector.
No TraceCollection will be made for these events.

EndEvent(key) → TimeStamp
Record an end event with key if Category is enabled.
A matching begin event must have preceded this end event.
If the key is known at compile time EndScope and Scope methods are
preferred because they have lower overhead.
The TimeStamp of the TraceEvent or 0 if the collector is disabled.
EndScope
Scope

Parameters
key (Key) – 

EndEventAtTime(key, ms) → None
Record an end event with key at a specified time if Category is
enabled.
This version of the method allows the passing of a specific number of
elapsed milliseconds, ms, to use for this event. This method is used
for testing and debugging code.

Parameters

key (Key) – 
ms (float) – 

GetLabel() → str
Return the label associated with this collector.

property enabled
bool
Returns whether collection of events is enabled for DefaultCategory.

type : None
Enables or disables collection of events for DefaultCategory.

Type
classmethod type

property expired
True if this object has expired, False otherwise.

property pythonTracingEnabled
None
Set whether automatic tracing of all python scopes is enabled.

type : bool
Returns whether automatic tracing of all python scopes is enabled.

Type
type

class pxr.Trace.Reporter
This class converts streams of TraceEvent objects into call trees
which can then be used as a data source to a GUI or written out to a
file.
Methods:

ClearTree()
Clears event tree and counters.

GetLabel()
Return the label associated with this reporter.

Report(s, iterationCount)
Generates a report to the ostream s, dividing all times by iterationCount.

ReportChromeTracing(s)
Generates a timeline trace report suitable for viewing in Chrome's trace viewer.

ReportChromeTracingToFile

ReportTimes(s)
Generates a report of the times to the ostream s.

UpdateTraceTrees()
This fully re-builds the event and aggregate trees from whatever the current collection holds.

Attributes:

aggregateTreeRoot
AggregateNode

expired
True if this object has expired, False otherwise.

foldRecursiveCalls
bool

globalReporter

groupByFunction
bool

shouldAdjustForOverheadAndNoise
None

ClearTree() → None
Clears event tree and counters.

GetLabel() → str
Return the label associated with this reporter.

Report(s, iterationCount) → None
Generates a report to the ostream s, dividing all times by
iterationCount.

Parameters

s (ostream) – 
iterationCount (int) – 

ReportChromeTracing(s) → None
Generates a timeline trace report suitable for viewing in Chrome’s
trace viewer.

Parameters
s (ostream) – 

ReportChromeTracingToFile()

ReportTimes(s) → None
Generates a report of the times to the ostream s.

Parameters
s (ostream) – 

UpdateTraceTrees() → None
This fully re-builds the event and aggregate trees from whatever the
current collection holds.
It is ok to call this multiple times in case the collection gets
appended on inbetween.
If we want to have multiple reporters per collector, this will need to
be changed so that all reporters reporting on a collector update their
respective trees.

property aggregateTreeRoot
AggregateNode
Returns the root node of the aggregated call tree.

Type
type

property expired
True if this object has expired, False otherwise.

property foldRecursiveCalls
bool
Returns the current setting for recursion folding for stack trace
event reporting.

type : None
When stack trace event reporting, this sets whether or not recursive
calls are folded in the output.
Recursion folding is useful when the stacks contain deep recursive
structures.

Type
type

globalReporter = <pxr.Trace.Reporter object>

property groupByFunction
bool
Returns the current group-by-function state.

type : None
This affects only stack trace event reporting.
If true then all events in a function are grouped together
otherwise events are split out by address.

Type
type

property shouldAdjustForOverheadAndNoise
None
Set whether or not the reporter should adjust scope times for overhead
and noise.

Type
type

pxr.Trace.TraceFunction(obj)
A decorator that enables tracing the function that it decorates.
If you decorate with ‘TraceFunction’ the function will be traced in the
global collector.

pxr.Trace.TraceMethod(obj)
A convenience.  Same as TraceFunction but changes the recorded
label to use the term ‘method’ rather than ‘function’.

pxr.Trace.TraceScope(label)
A context manager that calls BeginEvent on the global collector on enter
and EndEvent on exit.

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      Last updated on Nov 14, 2023.