drmHandleEvent(3)

🌸 Name 🌸

okay so this is drmHandleEvent(3) from the Direct Rendering Manager manual 💖 — and drmHandleEvent reads and processes pending DRM events, periodt. main character energy for your event handling, it’s giving realness, fr fr.

✨ Synopsis ✨

       #include <xf86drm.h>

       int drmHandleEvent(int fd, drmEventContextPtr evctx);

🦋 Description 🦋

bestie, here’s the tea: drmHandleEvent processes the outstanding DRM events on the DRM file-descriptor you pass as fd. Call it after that DRM file-descriptor has polled readable — it reads the events and uses the passed-in evctx structure to call function pointers with the parameters noted below. no cap, this struct is literally right here:

          typedef struct _drmEventContext {
              int version;
              void (*vblank_handler) (int fd,
                                      unsigned int sequence,
                                      unsigned int tv_sec,
                                      unsigned int tv_usec,
                                      void *user_data)
              void (*page_flip_handler) (int fd,
                                         unsigned int sequence,
                                         unsigned int tv_sec,
                                         unsigned int tv_usec,
                                         void *user_data)
          } drmEventContext, *drmEventContextPtr;

So there’s the version field, plus the vblank_handler and page_flip_handler function pointers, and the callbacks get fd, sequence, tv_sec, tv_usec, and user_data. iykyk ✨ highkey obsessed with how tidy that is 💅 not me getting emotional over a struct, honestly.

💅 Return Value 💅

drmHandleEvent returns 0 on success, or if there is no data to read from the file-descriptor. It returns -1 if the read on the file-descriptor fails or returns less than a full event record. ngl, the way that -1 can show up is your vibe check you do not wanna fail 😭

🎀 Reporting Bugs 🎀

Found a bug? not cute, but valid. Bugs in this function should be reported to <https://gitlab.freedesktop.org/mesa/libdrm/-/issues> 🫶

🌈 See Also 🌈

Go give these lowkey iconic pages a vibe check too 💖

• drm(7)
• drm-kms(7)
• drmModePageFlip(3)
• drmWaitVBlank(3)

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that’s the whole page — it’s from the Direct Rendering Manager manual and it’s dated September 2012. drmHandleEvent(3) out, bestie — go read those events and slay 💅✨🫶