include/uapi/linux/mqueue.h

Source file repositories/reference/linux-study-clean/include/uapi/linux/mqueue.h

File Facts

System
Linux kernel
Corpus path
include/uapi/linux/mqueue.h
Extension
.h
Size
2201 bytes
Lines
57
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct mq_attr {
	__kernel_long_t	mq_flags;	/* message queue flags			*/
	__kernel_long_t	mq_maxmsg;	/* maximum number of messages		*/
	__kernel_long_t	mq_msgsize;	/* maximum message size			*/
	__kernel_long_t	mq_curmsgs;	/* number of messages currently queued	*/
	__kernel_long_t	__reserved[4];	/* ignored for input, zeroed for output */
};

/*
 * SIGEV_THREAD implementation:
 * SIGEV_THREAD must be implemented in user space. If SIGEV_THREAD is passed
 * to mq_notify, then
 * - sigev_signo must be the file descriptor of an AF_NETLINK socket. It's not
 *   necessary that the socket is bound.
 * - sigev_value.sival_ptr must point to a cookie that is NOTIFY_COOKIE_LEN
 *   bytes long.
 * If the notification is triggered, then the cookie is sent to the netlink
 * socket. The last byte of the cookie is replaced with the NOTIFY_?? codes:
 * NOTIFY_WOKENUP if the notification got triggered, NOTIFY_REMOVED if it was
 * removed, either due to a close() on the message queue fd or due to a
 * mq_notify() that removed the notification.
 */
#define NOTIFY_NONE	0
#define NOTIFY_WOKENUP	1
#define NOTIFY_REMOVED	2

#define NOTIFY_COOKIE_LEN	32

#endif

Annotation

Implementation Notes