summaryrefslogtreecommitdiff
path: root/include/linux/sem.h
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/sem.h
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/linux/sem.h')
-rw-r--r--include/linux/sem.h157
1 files changed, 157 insertions, 0 deletions
diff --git a/include/linux/sem.h b/include/linux/sem.h
new file mode 100644
index 000000000000..2d8516be9fd7
--- /dev/null
+++ b/include/linux/sem.h
@@ -0,0 +1,157 @@
+#ifndef _LINUX_SEM_H
+#define _LINUX_SEM_H
+
+#include <linux/ipc.h>
+#include <asm/atomic.h>
+
+/* semop flags */
+#define SEM_UNDO 0x1000 /* undo the operation on exit */
+
+/* semctl Command Definitions. */
+#define GETPID 11 /* get sempid */
+#define GETVAL 12 /* get semval */
+#define GETALL 13 /* get all semval's */
+#define GETNCNT 14 /* get semncnt */
+#define GETZCNT 15 /* get semzcnt */
+#define SETVAL 16 /* set semval */
+#define SETALL 17 /* set all semval's */
+
+/* ipcs ctl cmds */
+#define SEM_STAT 18
+#define SEM_INFO 19
+
+/* Obsolete, used only for backwards compatibility and libc5 compiles */
+struct semid_ds {
+ struct ipc_perm sem_perm; /* permissions .. see ipc.h */
+ __kernel_time_t sem_otime; /* last semop time */
+ __kernel_time_t sem_ctime; /* last change time */
+ struct sem *sem_base; /* ptr to first semaphore in array */
+ struct sem_queue *sem_pending; /* pending operations to be processed */
+ struct sem_queue **sem_pending_last; /* last pending operation */
+ struct sem_undo *undo; /* undo requests on this array */
+ unsigned short sem_nsems; /* no. of semaphores in array */
+};
+
+/* Include the definition of semid64_ds */
+#include <asm/sembuf.h>
+
+/* semop system calls takes an array of these. */
+struct sembuf {
+ unsigned short sem_num; /* semaphore index in array */
+ short sem_op; /* semaphore operation */
+ short sem_flg; /* operation flags */
+};
+
+/* arg for semctl system calls. */
+union semun {
+ int val; /* value for SETVAL */
+ struct semid_ds __user *buf; /* buffer for IPC_STAT & IPC_SET */
+ unsigned short __user *array; /* array for GETALL & SETALL */
+ struct seminfo __user *__buf; /* buffer for IPC_INFO */
+ void __user *__pad;
+};
+
+struct seminfo {
+ int semmap;
+ int semmni;
+ int semmns;
+ int semmnu;
+ int semmsl;
+ int semopm;
+ int semume;
+ int semusz;
+ int semvmx;
+ int semaem;
+};
+
+#define SEMMNI 128 /* <= IPCMNI max # of semaphore identifiers */
+#define SEMMSL 250 /* <= 8 000 max num of semaphores per id */
+#define SEMMNS (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
+#define SEMOPM 32 /* <= 1 000 max num of ops per semop call */
+#define SEMVMX 32767 /* <= 32767 semaphore maximum value */
+#define SEMAEM SEMVMX /* adjust on exit max value */
+
+/* unused */
+#define SEMUME SEMOPM /* max num of undo entries per process */
+#define SEMMNU SEMMNS /* num of undo structures system wide */
+#define SEMMAP SEMMNS /* # of entries in semaphore map */
+#define SEMUSZ 20 /* sizeof struct sem_undo */
+
+#ifdef __KERNEL__
+
+/* One semaphore structure for each semaphore in the system. */
+struct sem {
+ int semval; /* current value */
+ int sempid; /* pid of last operation */
+};
+
+/* One sem_array data structure for each set of semaphores in the system. */
+struct sem_array {
+ struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
+ time_t sem_otime; /* last semop time */
+ time_t sem_ctime; /* last change time */
+ struct sem *sem_base; /* ptr to first semaphore in array */
+ struct sem_queue *sem_pending; /* pending operations to be processed */
+ struct sem_queue **sem_pending_last; /* last pending operation */
+ struct sem_undo *undo; /* undo requests on this array */
+ unsigned long sem_nsems; /* no. of semaphores in array */
+};
+
+/* One queue for each sleeping process in the system. */
+struct sem_queue {
+ struct sem_queue * next; /* next entry in the queue */
+ struct sem_queue ** prev; /* previous entry in the queue, *(q->prev) == q */
+ struct task_struct* sleeper; /* this process */
+ struct sem_undo * undo; /* undo structure */
+ int pid; /* process id of requesting process */
+ int status; /* completion status of operation */
+ struct sem_array * sma; /* semaphore array for operations */
+ int id; /* internal sem id */
+ struct sembuf * sops; /* array of pending operations */
+ int nsops; /* number of operations */
+ int alter; /* does the operation alter the array? */
+};
+
+/* Each task has a list of undo requests. They are executed automatically
+ * when the process exits.
+ */
+struct sem_undo {
+ struct sem_undo * proc_next; /* next entry on this process */
+ struct sem_undo * id_next; /* next entry on this semaphore set */
+ int semid; /* semaphore set identifier */
+ short * semadj; /* array of adjustments, one per semaphore */
+};
+
+/* sem_undo_list controls shared access to the list of sem_undo structures
+ * that may be shared among all a CLONE_SYSVSEM task group.
+ */
+struct sem_undo_list {
+ atomic_t refcnt;
+ spinlock_t lock;
+ struct sem_undo *proc_list;
+};
+
+struct sysv_sem {
+ struct sem_undo_list *undo_list;
+};
+
+#ifdef CONFIG_SYSVIPC
+
+extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
+extern void exit_sem(struct task_struct *tsk);
+
+#else
+static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
+{
+ return 0;
+}
+
+static inline void exit_sem(struct task_struct *tsk)
+{
+ return;
+}
+#endif
+
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_SEM_H */