#include <xf86drm.h>
drmHandleEvent
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;
drmHandleEvent returns 0 on success, or if there is no data to read from the file-descriptor. Returns -1 if the read on the file-descriptor fails or returns less than a full event record.
Bugs in this function should be reported to https://gitlab.freedesktop.org/mesa/drm/-/issues
drm(7), drm-kms(7), drmModePageFlip(3), drmWaitVBlank(3)