STRUCT POSIX_CLOCK_OPERATIONS(9)

Hey bestie 💖 this is struct posix_clock_operations(9) from the Kernel API Manual, and it’s literally the functional interface to the clock. Let’s get into it ✨

💖 NAME 💖

struct posix_clock_operations — functional interface to the clock 🕰️

✨ SYNOPSIS ✨

okay so here’s the struct, exactly as it shows up — no edits, no cap:

       struct posix_clock_operations {
           struct module *owner;
           int (*clock_adjtime)(struct posix_clock *pc, struct __kernel_timex
       *tx);
           int (*clock_gettime)(struct posix_clock *pc, struct timespec64 *ts);
           int (*clock_getres) (struct posix_clock *pc, struct timespec64 *ts);
           int (*clock_settime)(struct posix_clock *pc, const struct timespec64
       *ts);
           long (*ioctl)(struct posix_clock_context *pccontext, unsigned int
       cmd, unsigned long arg);
           int (*open)(struct posix_clock_context *pccontext, fmode_t f_mode);
           __poll_t (*poll)(struct posix_clock_context *pccontext, struct file
       *file, poll_table *wait);
           int (*release)(struct posix_clock_context *pccontext);
           ssize_t (*read)(struct posix_clock_context *pccontext, uint flags,
       char __user *buf, size_t cnt);
        };

🫶 Members 🫶

These are the members, bestie — keep the names exactly as written, iykyk:

• owner — the clock driver should set this to THIS_MODULE 👑
• clock_adjtime — adjust the clock ⏰
• clock_gettime — read the current time 📖
• clock_getres — get the clock resolution 🔍
• clock_settime — set the current time value ✍️
• ioctl — optional character device ioctl method 🎛️
• open — optional character device open method 🚪
• poll — optional character device poll method 👀
• release — optional character device release method 🫶
• read — optional character device read method 📚

🌸 Description 🌸

Every posix clock is represented by a character device — that’s the whole vibe. Drivers may optionally offer extended capabilities by implementing the character device methods. The character device file operations are first handled by the clock device layer, then passed on to the driver by calling these functions. Periodt. 💅

🦋 SEE ALSO 🦋

Kernel file ./include/linux/posix-clock.h plus these icons:

• struct posix_clock(9)
• struct posix_clock_context(9)
• posix_clock_register(9)
• posix_clock_unregister(9)

Catch you later, bestie 🫶 this page is from ./include/linux, dated October 2026, and the footer tag is struct posi...k_operations(9) 💅✨