include/linux/msg.h
changeset 0 aa628870c1d3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/linux/msg.h	Sun Jan 11 20:20:11 2009 +0100
@@ -0,0 +1,112 @@
+#ifndef _LINUX_MSG_H
+#define _LINUX_MSG_H
+
+#include <linux/ipc.h>
+
+/* ipcs ctl commands */
+#define MSG_STAT 11
+#define MSG_INFO 12
+
+/* msgrcv options */
+#define MSG_NOERROR     010000  /* no error if message is too big */
+#define MSG_EXCEPT      020000  /* recv any msg except of specified type.*/
+
+/* Obsolete, used only for backwards compatibility and libc5 compiles */
+struct msqid_ds {
+	struct ipc_perm msg_perm;
+	struct msg *msg_first;		/* first message on queue,unused  */
+	struct msg *msg_last;		/* last message in queue,unused */
+	__kernel_time_t msg_stime;	/* last msgsnd time */
+	__kernel_time_t msg_rtime;	/* last msgrcv time */
+	__kernel_time_t msg_ctime;	/* last change time */
+	unsigned long  msg_lcbytes;	/* Reuse junk fields for 32 bit */
+	unsigned long  msg_lqbytes;	/* ditto */
+	unsigned short msg_cbytes;	/* current number of bytes on queue */
+	unsigned short msg_qnum;	/* number of messages in queue */
+	unsigned short msg_qbytes;	/* max number of bytes on queue */
+	__kernel_ipc_pid_t msg_lspid;	/* pid of last msgsnd */
+	__kernel_ipc_pid_t msg_lrpid;	/* last receive pid */
+};
+
+/* Include the definition of msqid64_ds */
+#include <asm/msgbuf.h>
+
+/* message buffer for msgsnd and msgrcv calls */
+struct msgbuf {
+	long mtype;         /* type of message */
+	char mtext[1];      /* message text */
+};
+
+/* buffer for msgctl calls IPC_INFO, MSG_INFO */
+struct msginfo {
+	int msgpool;
+	int msgmap; 
+	int msgmax; 
+	int msgmnb; 
+	int msgmni; 
+	int msgssz; 
+	int msgtql; 
+	unsigned short  msgseg; 
+};
+
+/*
+ * Scaling factor to compute msgmni:
+ * the memory dedicated to msg queues (msgmni * msgmnb) should occupy
+ * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
+ * up to 8MB       : msgmni = 16 (MSGMNI)
+ * 4 GB            : msgmni = 8K
+ * more than 16 GB : msgmni = 32K (IPCMNI)
+ */
+#define MSG_MEM_SCALE 32
+
+#define MSGMNI    16   /* <= IPCMNI */     /* max # of msg queue identifiers */
+#define MSGMAX  8192   /* <= INT_MAX */   /* max size of message (bytes) */
+#define MSGMNB 16384   /* <= INT_MAX */   /* default max size of a message queue */
+
+/* unused */
+#define MSGPOOL (MSGMNI * MSGMNB / 1024) /* size in kbytes of message pool */
+#define MSGTQL  MSGMNB            /* number of system message headers */
+#define MSGMAP  MSGMNB            /* number of entries in message map */
+#define MSGSSZ  16                /* message segment size */
+#define __MSGSEG ((MSGPOOL * 1024) / MSGSSZ) /* max no. of segments */
+#define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)
+
+#ifdef __KERNEL__
+#include <linux/list.h>
+
+/* one msg_msg structure for each message */
+struct msg_msg {
+	struct list_head m_list; 
+	long  m_type;          
+	int m_ts;           /* message text size */
+	struct msg_msgseg* next;
+	void *security;
+	/* the actual message follows immediately */
+};
+
+/* one msq_queue structure for each present queue on the system */
+struct msg_queue {
+	struct kern_ipc_perm q_perm;
+	time_t q_stime;			/* last msgsnd time */
+	time_t q_rtime;			/* last msgrcv time */
+	time_t q_ctime;			/* last change time */
+	unsigned long q_cbytes;		/* current number of bytes on queue */
+	unsigned long q_qnum;		/* number of messages in queue */
+	unsigned long q_qbytes;		/* max number of bytes on queue */
+	pid_t q_lspid;			/* pid of last msgsnd */
+	pid_t q_lrpid;			/* last receive pid */
+
+	struct list_head q_messages;
+	struct list_head q_receivers;
+	struct list_head q_senders;
+};
+
+/* Helper routines for sys_msgsnd and sys_msgrcv */
+extern long do_msgsnd(int msqid, long mtype, void __user *mtext,
+			size_t msgsz, int msgflg);
+extern long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
+			size_t msgsz, long msgtyp, int msgflg);
+
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_MSG_H */