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/*-------------------------------------------------------------------------
*
* proc.h
*
*
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: proc.h,v 1.22 1999/05/13 15:55:45 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef _PROC_H_
#define _PROC_H_
#include <storage/lock.h>
typedef struct
{
int sleeplock;
int semNum;
IpcSemaphoreId semId;
IpcSemaphoreKey semKey;
} SEMA;
/*
* Each backend has:
*/
typedef struct proc
{
/* proc->links MUST BE THE FIRST ELEMENT OF STRUCT (see ProcWakeup()) */
SHM_QUEUE links; /* proc can be waiting for one event(lock) */
SEMA sem; /* ONE semaphore to sleep on */
int errType; /* error code tells why we woke up */
int critSects; /* If critSects > 0, we are in sensitive
* routines that cannot be recovered when
* the process fails. */
int prio; /* priority for sleep queue */
TransactionId xid; /* transaction currently being executed by
* this proc */
TransactionId xmin; /* minimal running XID as it was when we
* were starting our xact: vacuum must not
* remove tuples deleted by xid >= xmin ! */
LOCK *waitLock; /* Lock we're sleeping on ... */
int token; /* type of lock we sleeping for */
int holdLock; /* while holding these locks */
int pid; /* This procs process id */
short sLocks[MAX_SPINS]; /* Spin lock stats */
SHM_QUEUE lockQueue; /* locks associated with current
* transaction */
} PROC;
/*
* PROC_NSEMS_PER_SET is the number of semaphores in each sys-V semaphore set
* we allocate. It must be *less than* 32 (or however many bits in an int
* on your machine), or our free-semaphores bitmap won't work. You also must
* not set it higher than your kernel's SEMMSL (max semaphores per set)
* parameter, which is often around 25.
* MAX_PROC_SEMS is the maximum number of per-process semaphores (those used
* by the lock mgr) we can keep track of. It must be a multiple of
* PROC_NSEMS_PER_SET.
*/
#define PROC_NSEMS_PER_SET 16
#define MAX_PROC_SEMS (((MAXBACKENDS-1)/PROC_NSEMS_PER_SET+1)*PROC_NSEMS_PER_SET)
typedef struct procglobal
{
SHMEM_OFFSET freeProcs;
IPCKey currKey;
int32 freeSemMap[MAX_PROC_SEMS / PROC_NSEMS_PER_SET];
/* In each freeSemMap entry, the PROC_NSEMS_PER_SET lsbs flag whether
* individual semaphores are in use, and the next higher bit is set to
* show that the entire set is allocated.
*/
} PROC_HDR;
extern PROC *MyProc;
#define PROC_INCR_SLOCK(lock) \
do { \
if (MyProc) (MyProc->sLocks[(lock)])++; \
} while (0)
#define PROC_DECR_SLOCK(lock) \
do { \
if (MyProc) (MyProc->sLocks[(lock)])--; \
} while (0)
/*
* flags explaining why process woke up
*/
#define NO_ERROR 0
#define ERR_TIMEOUT 1
#define ERR_BUFFER_IO 2
#define MAX_PRIO 50
#define MIN_PRIO (-1)
extern SPINLOCK ProcStructLock;
/*
* Function Prototypes
*/
extern void InitProcess(IPCKey key);
extern void ProcReleaseLocks(void);
extern bool ProcRemove(int pid);
/* extern bool ProcKill(int exitStatus, int pid); */
/* make static in storage/lmgr/proc.c -- jolly */
extern void ProcQueueInit(PROC_QUEUE *queue);
extern int ProcSleep(PROC_QUEUE *queue, LOCKMETHODCTL *lockctl, int token,
LOCK *lock);
extern PROC *ProcWakeup(PROC *proc, int errType);
extern int ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod,
LOCK *lock);
extern void ProcAddLock(SHM_QUEUE *elem);
extern void ProcReleaseSpins(PROC *proc);
#endif /* PROC_H */
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