Advanced Task Scheduler

System Overview

The Advanced Task Scheduler is a robust, multi-threaded task management system designed for high-reliability environments. It provides comprehensive task scheduling capabilities with built-in fault tolerance, real-time monitoring, and sophisticated resource management.

graph TD A[Client Interface] --> B[Unix Domain Socket] B --> C[Scheduler Server] C --> D[Task Manager] D --> E[Execution Engine] D --> F[Monitor Thread] D --> G[Cleanup Thread] E --> H[Task Workers] H --> I[System Resources] style A fill:#60a5fa style C fill:#2563eb,color:white style D fill:#3b82f6,color:white style E fill:#60a5fa style F fill:#60a5fa style G fill:#60a5fa

Core Features

Task Types

✓ One-shot tasks (relative time)
✓ One-shot tasks (absolute time)
✓ Periodic tasks with configurable intervals
✓ Priority-based execution
✓ Command with arguments support

Reliability Features

✓ Automatic task retry mechanism
✓ Configurable retry limits
✓ Comprehensive error handling
✓ Process isolation
✓ Graceful shutdown handling

Management

✓ Real-time task monitoring
✓ Task cancellation support
✓ Detailed status reporting
✓ Resource usage tracking
✓ Daemon mode operation

Technical Architecture

Task Lifecycle

stateDiagram-v2 [*] --> Pending: Schedule Pending --> Running: Execute Running --> Completed: Success Running --> Failed: Error Failed --> Retrying: Retry < Max Retrying --> Running: Retry Failed --> [*]: Max Retries Completed --> [*] Running --> Cancelled: Cancel Cancelled --> [*]

Function Interactions

sequenceDiagram participant Client participant Server participant TaskManager participant CleanupThread participant MonitorThread Client->>Server: scheduler_schedule_task() Server->>TaskManager: handle_client_message() TaskManager->>TaskManager: Find free slot TaskManager->>TaskManager: Initialize task TaskManager-->>Client: Return task_id loop Every Second Note over TaskManager: timer_callback() TaskManager->>TaskManager: Check task times end loop Continuous CleanupThread->>TaskManager: cleanup_thread_func() end loop Every 60 Seconds MonitorThread->>TaskManager: monitor_thread_func() end

Performance Optimizations

Memory Management

Efficient task pool with dynamic allocation
Zero-copy message passing for IPC
Optimized memory reuse strategies
Smart resource cleanup mechanisms
Memory leak prevention system

Concurrency Control

Reader-writer locks for task management
Lock-free operations using atomics
Fine-grained locking mechanisms
Thread-safe data structures
Deadlock prevention algorithms

Usage Guide

Command Line Interface

Usage:
  Start server:     scheduler --server [--daemon]
  Schedule task:    scheduler --schedule [--relative seconds | --absolute YYYY-MM-DD-HH:MM:SS | --periodic seconds] command [args...]
  Cancel task:      scheduler --cancel task_id
  List tasks:       scheduler --list
  Stop server:      scheduler --shutdown

Usage Examples

# Start scheduler in daemon mode
scheduler --server --daemon

# Schedule a task to run after 60 seconds
scheduler --schedule --relative 60 /bin/echo Hello World

# Schedule a task for New Year's Eve
scheduler --schedule --absolute 2024-12-31-23:59:59 /usr/bin/notify-send "Happy New Year!"

# Schedule a periodic task every hour
scheduler --schedule --periodic 3600 /bin/date