File Descriptor Diagnostics

Inspect process-level iOS file descriptor counts, limits, utilization, and open descriptor metadata through read-scoped remote tools.

The iOS file-descriptor suite helps diagnose leaked files, sockets, pipes, and other process resources. It is included in the aggregate Ansight product and can also be installed as AnsightToolsFileDescriptorDiagnostics.

Register the Suite

import AnsightCore
import AnsightToolsFileDescriptorDiagnostics

let diagnosticOptions = AnsightFileDescriptorDiagnosticsOptions(
    includeTargets: false
)

try AnsightRuntime.shared.registerFileDescriptorDiagnosticsTools(
    options: diagnosticOptions
)

Set includeTargets to false to suppress resolved file paths and socket metadata. The options also support a custom maximum scanned descriptor range. If that range is below the process descriptor range, the count tool fails rather than returning a misleading undercount.

Tool Reference

Tool	Tool id	Scope	Result	Security
List Open Descriptors	`file_descriptors.list_open`	`Read`	Filterable descriptor records with kind, flags, position, inode, and optional target.	High
Count Open Descriptors	`file_descriptors.count_open`	`Read`	Only `{ "count": number }`; it does not resolve targets or collect descriptor details.	Medium
Inspect Descriptor	`file_descriptors.inspect`	`Read`	One descriptor record by non-negative descriptor number.	High
Get Descriptor Usage	`file_descriptors.get_usage`	`Read`	Open count, process limits, remaining capacity, and utilization.	Medium

file_descriptors.list_open accepts:

kind: optional resource-kind filter
targetContains: optional case-insensitive target substring
maxEntries: maximum records to return after filtering

Snapshot results indicate whether collection was complete, the scanned descriptor limit, and the capture time.

Security

All four tools are read-scoped, but listing and inspection can disclose file paths and socket metadata. Prefer count and usage for routine leak detection, disable targets when paths are unnecessary, and keep the suite limited to controlled development or QA builds.