6.4.3 Semaphores

• Basic Concepts
• Internal Data Structures
  • Kernel semid_ds structure
  • Kernel sem structure
• SYSTEM CALL: semget()
• SYSTEM CALL: semop()
• SYSTEM CALL: semctl()
• semtool: An interactive semaphore manipulator
  • Background
  • Command Line Syntax
    • Creating a Semaphore Set
    • Locking a Semaphore
    • Unlocking a Semaphore
    • Changing the Permissions (mode)
    • Deleting a Semaphore Set
  • Examples
  • The Source
• semstat: A semtool companion program