# Hierarchical Profiler

- Introduction
- Installing/Configuring
  - Requirements
  - Installation
  - Runtime Configuration
  - Resource Types
- Predefined Constants
- Examples
- Xhprof Functions
  - xhprof_disable — Stops xhprof profiler
  - xhprof_enable — Start xhprof profiler
  - xhprof_sample_disable — Stops xhprof sample profiler
  - xhprof_sample_enable — Start XHProf profiling in sampling mode