Gomu continuously visualizes the precise lifetime of your Go mutex locks in real-time, helping you eliminate heavy lock contention, resource leaks, and deadlocks before they hit production.
Install from the VS Code Marketplace
Why Gomu?
In high-concurrency Go applications, managing lock contention is critical. Holding a sync.Mutex or sync.RWMutex even a few lines too long can turn a highly parallel program into a sequential bottleneck.
While defer mu.Unlock() is a Go best practice for safety, it extends the lock's lifetime to the very end of the surrounding function. In long or complex functions, this often holds the lock through expensive I/O operations or heavy computations unnecessarily.
Gomu is different:
- Real-Time Visual Scopes: Instantly draws elegant, rainbow-colored vertical brackets in your editor margin that trace exactly where a lock begins and where it is released.
- Smart Defer Parsing: Automatically detects
defer calls and projects the bracket all the way to the end of the enclosing function scope.
- Zero Disk I/O: Analyzes your unsaved VS Code buffers directly in RAM on every keystroke. No temporary files, no waiting on saves.
- Persistent Daemon Architecture: Communicates with a highly optimized, persistent Go background daemon via lightning-fast Newline-Delimited JSON (NDJSON) over standard I/O streams for lag-free performance.
- Zero Setup: The extension bundles cross-compiled binaries for Windows, macOS, and Linux. No Go toolchain configurations required.
Features & Capabilities
- Rainbow-Style Highlighting: Automatically color-codes overlapping, nested, or multiple distinct locks using VS Code's bracket pair colors.
- Granular Lock Type Tracking: Accurately distinguishes and pairs write locks (
Lock / Unlock) and read locks (RLock / RUnlock).
- Complex Receiver Resolution: Correctly tracks lock scopes across local variables, package-level variables, struct fields, pointer dereferences, and slices (e.g.,
mu, state.mu, locks[i]).
- Aesthetic Customization: Fully customize the visual appearance of the scope lines to match your favorite coding font and theme thickness.
Configuration
You can configure Gomu via your VS Code settings.json (also available via the settings UI under Extensions -> Gomu).
{
"gomu.lineOpacity": 75,
"gomu.lineWidth": 2,
"gomu.lineSpacing": 6,
"gomu.baseOffset": 6
}
gomu.lineOpacity: Opacity of the scope lines, from 0 (fully transparent) to 100 (fully opaque). (Default: 75)gomu.lineWidth: Thickness of the scope lines in pixels. (Default: 2)gomu.lineSpacing: Horizontal clear space between nested scope lines in pixels. (Default: 6)gomu.baseOffset: Horizontal distance in pixels between the code text and the outermost scope line (the length of the bracket's foot). (Default: 6)
