Profiler
SharpLsp exposes .NET trace, counter, dump, and heap-analysis workflows in the VS Code sidebar. These operations run in the Rust host and do not depend on either language sidecar.
Required Tools
Install the Microsoft diagnostic tools you need:
dotnet tool install -g dotnet-trace
dotnet tool install -g dotnet-counters
dotnet tool install -g dotnet-dumpSharpLsp checks PATH first and then the conventional .dotnet/tools directories under the current user's home. It does not run dotnet tool list -g. A missing tool produces an error containing the corresponding install command.
Profiler View
The Profiler view shows:
- active trace and counter sessions;
- discoverable .NET processes with PID and command line;
- per-session output paths and controls.
Refresh updates the process list. Process context actions can start a trace, start counters, collect a dump, copy the PID, or terminate the process.
Traces
- Run SharpLsp: Start Performance Trace and select a .NET process.
- Run SharpLsp: Stop Performance Trace, or stop the session from its tree item.
- SharpLsp finalizes the
.nettrace, converts it to SpeedScope JSON, and opens the SpeedScope viewer.
With no explicit request values, the current trace request defaults to 30 seconds and writes under .sharplsp/profiles. Opening an existing .nettrace can also convert it to SpeedScope format.
Live Counters
Start Counter Monitoring launches dotnet-counters for a selected process and opens a live webview. The default provider is System.Runtime with a one-second refresh interval. Counter updates arrive through sharplsp/profiler/counterUpdate notifications until the session stops.
Dumps and Heap Analysis
The extension can:
- collect Heap, Full, or Mini dumps;
- run
dumpheap -statand display type counts and sizes; - compare two dump snapshots;
- guide a baseline → exercise → comparison leak-detection workflow;
- inspect an object by address;
- build a bounded object-reference graph and identify GC roots.
Heap diffing classifies growth suspects from count and size deltas. These are heuristics, not proof of a leak; confirm a suspect with retention paths and application behavior.
Main Commands
| Command | Purpose |
|---|---|
SharpLsp: Refresh Profiler |
Refresh processes and sessions |
SharpLsp: Start Performance Trace / Stop Performance Trace |
Record and finish a trace |
SharpLsp: Open Trace File… / Convert .nettrace to SpeedScope |
Open or convert trace files |
SharpLsp: Start Counter Monitoring / Stop Counter Monitoring |
Monitor runtime counters |
SharpLsp: Collect Memory Dump |
Capture a memory dump |
SharpLsp: Analyze Heap Dump |
Display heap statistics |
SharpLsp: Compare Heap Snapshots |
Diff two dumps |
SharpLsp: Detect Memory Leaks |
Run the guided snapshot workflow |
SharpLsp: Show Object Retention Graph |
Visualize object references |
SharpLsp: Inspect Object |
Show one object's fields and references |
Configuration Status
sharplsp.toml accepts the complete profiler schema shown on the Configuration page. Currently only profiler.max_concurrent_sessions is applied to runtime behavior. The other profiler default fields are parsed but commands still use their built-in request defaults; changing them does not yet reconfigure trace duration, output format, counter providers/interval, or output directory.
The default session limit is five. Exceeding it returns an error rather than replacing an existing session.
Safety and Errors
Profiler commands validate PIDs, files, session IDs, and tool availability and return errors through LSP. The process tree also has an explicit terminate action; use it carefully because it ends the selected external process.