--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * sem.c
+ * System V Semaphore Emulation
+ *
+ * Copyright (c) 1999, repas AEG Automation GmbH
+ *
+ * - changed from anonymous to named semaphores for darwin
+ * - this required changing sem_info from containig an array of sem_t to an array of sem_t*
+ *
+ * IDENTIFICATION
+ * $Header: /cvsroot/pgsql/src/backend/port/darwin/Attic/sem.c,v 1.1 2000/12/11 00:49:54 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include "postgres.h"
+#include "storage/ipc.h"
+#include "storage/proc.h"
+#include "port/darwin/sem.h"
+
+#define SEMMAX IPC_NMAXSEM
+#define SETMAX ((MAXBACKENDS + SEMMAX - 1) / SEMMAX)
+#define OPMAX 8
+
+#define MODE 0700
+#define SHM_INFO_NAME "SysV_Sem_Info"
+#define SEM_NAME "/pgsql-darwin"
+
+struct pending_ops
+{
+ int op[OPMAX]; /* array of pending operations */
+ int idx; /* index of first free array member */
+};
+
+struct sem_info
+{
+ sem_t* sem;
+ struct
+ {
+ key_t key;
+ int nsems;
+ sem_t* sem[SEMMAX];/* array of POSIX semaphores */
+ struct sem semV[SEMMAX]; /* array of System V semaphore
+ * structures */
+ struct pending_ops pendingOps[SEMMAX]; /* array of pending
+ * operations */
+ } set[SETMAX];
+};
+
+static struct sem_info *SemInfo = (struct sem_info *) - 1;
+
+
+int
+semctl(int semid, int semnum, int cmd, /* ... */ union semun arg)
+{
+ int r = 0;
+
+ sem_wait(SemInfo->sem);
+
+ if (semid < 0 || semid >= SETMAX ||
+ semnum < 0 || semnum >= SemInfo->set[semid].nsems)
+ {
+ sem_post(SemInfo->sem);
+ errno = EINVAL;
+ return -1;
+ }
+
+ switch (cmd)
+ {
+ case GETNCNT:
+ r = SemInfo->set[semid].semV[semnum].semncnt;
+ break;
+
+ case GETPID:
+ r = SemInfo->set[semid].semV[semnum].sempid;
+ break;
+
+ case GETVAL:
+ r = SemInfo->set[semid].semV[semnum].semval;
+ break;
+
+ case GETALL:
+ for (semnum = 0; semnum < SemInfo->set[semid].nsems; semnum++)
+ arg.array[semnum] = SemInfo->set[semid].semV[semnum].semval;
+ break;
+
+ case SETVAL:
+ SemInfo->set[semid].semV[semnum].semval = arg.val;
+ break;
+
+ case SETALL:
+ for (semnum = 0; semnum < SemInfo->set[semid].nsems; semnum++)
+ SemInfo->set[semid].semV[semnum].semval = arg.array[semnum];
+ break;
+
+ case GETZCNT:
+ r = SemInfo->set[semid].semV[semnum].semzcnt;
+ break;
+
+ case IPC_RMID:
+ for (semnum = 0; semnum < SemInfo->set[semid].nsems; semnum++)
+ {
+ if (sem_close(SemInfo->set[semid].sem[semnum]) == -1)
+ r = -1;
+ }
+ SemInfo->set[semid].key = -1;
+ SemInfo->set[semid].nsems = 0;
+ break;
+
+ default:
+ sem_post(SemInfo->sem);
+ errno = EINVAL;
+ return -1;
+ }
+
+ sem_post(SemInfo->sem);
+
+ return r;
+}
+
+int
+semget(key_t key, int nsems, int semflg)
+{
+ int fd,
+ semid,
+ semnum /* , semnum1 */ ;
+ int exist = 0;
+ char semname[64];
+
+ if (nsems < 0 || nsems > SEMMAX)
+ {
+#ifdef DEBUG_IPC
+ fprintf(stderr, "darwin semget aborting because nsems out of range. (%d)\n", nsems);
+#endif
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* open and map shared memory */
+ if (SemInfo == (struct sem_info *) - 1)
+ {
+#ifdef DEBUG_IPC
+ fprintf(stderr, "darwin initializing shared mem for semaphore shim.\n");
+#endif
+ /* test if the shared memory already exists */
+ fd = shm_open(SHM_INFO_NAME, O_RDWR | O_CREAT | O_EXCL, MODE);
+ if (fd == -1 && errno == EEXIST)
+ {
+ exist = 1;
+ fd = shm_open(SHM_INFO_NAME, O_RDWR | O_CREAT, MODE);
+ }
+ if (fd == -1)
+ return fd;
+ /* The size may only be set once. Ignore errors. */
+ ftruncate(fd, sizeof(struct sem_info));
+ SemInfo = mmap(NULL, sizeof(struct sem_info),
+ PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (SemInfo == MAP_FAILED)
+ return -1;
+ if (!exist)
+ {
+ /* create semaphore for locking */
+ sprintf(semname, "%s-map", SEM_NAME);
+#ifdef DEBUG_IPC
+ fprintf(stderr, "darwin creating sem %s to cover shared mem.\n", semname);
+#endif
+ SemInfo->sem = sem_open(semname, O_CREAT, semflg & 0777, 1);
+ sem_wait(SemInfo->sem);
+ /* initilize shared memory */
+ memset(SemInfo->set, 0, sizeof(SemInfo->set));
+ for (semid = 0; semid < SETMAX; semid++)
+ SemInfo->set[semid].key = -1;
+ sem_post(SemInfo->sem);
+ }
+ }
+
+ sem_wait(SemInfo->sem);
+
+ if (key != IPC_PRIVATE)
+ {
+ /* search existing element */
+ semid = 0;
+ while (semid < SETMAX && SemInfo->set[semid].key != key)
+ semid++;
+ if (!(semflg & IPC_CREAT) && semid >= SETMAX)
+ {
+ sem_post(SemInfo->sem);
+ errno = ENOENT;
+ return -1;
+ }
+ else if (semid < SETMAX)
+ {
+ if (semflg & IPC_CREAT && semflg & IPC_EXCL)
+ {
+ sem_post(SemInfo->sem);
+ errno = EEXIST;
+ return -1;
+ }
+ else
+ {
+ if (nsems != 0 && SemInfo->set[semid].nsems < nsems)
+ {
+#ifdef DEBUG_IPC
+fprintf(stderr, "darwin semget failed because if (nsems != 0 && SemInfo->set[semid].nsems < nsems) %d %d\n",
+ nsems, SemInfo->set[semid].nsems);
+#endif
+ sem_post(SemInfo->sem);
+ errno = EINVAL;
+ return -1;
+ }
+ sem_post(SemInfo->sem);
+ return semid;
+ }
+ }
+ }
+
+ /* search first free element */
+ semid = 0;
+ while (semid < SETMAX && SemInfo->set[semid].key != -1)
+ semid++;
+ if (semid >= SETMAX)
+ {
+#ifdef DEBUG_IPC
+ fprintf(stderr, "darwin semget failed because all keys were -1 up to SETMAX\n");
+#endif
+ sem_post(SemInfo->sem);
+ errno = ENOSPC;
+ return -1;
+ }
+
+ for (semnum = 0; semnum < nsems; semnum++)
+ {
+ sprintf(semname, "%s-%d-%d", SEM_NAME, semid, semnum);
+#ifdef DEBUG_IPC
+ fprintf(stderr, "darwin creating sem %s to cover set %d num %dm.\n", semname, semid, semnum);
+#endif
+ SemInfo->set[semid].sem[semnum] = sem_open(semname, O_CREAT, semflg & 0777, 0);
+
+/* Currently sem_init always returns -1.
+ if( sem_init( &SemInfo->set[semid].sem[semnum], 1, 0 ) == -1 ) {
+ for( semnum1 = 0; semnum1 < semnum; semnum1++ ) {
+ sem_close( SemInfo->set[semid].sem[semnum1] );
+ }
+ sem_post( SemInfo->sem );
+ return -1;
+ }
+*/
+ }
+
+ SemInfo->set[semid].key = key;
+ SemInfo->set[semid].nsems = nsems;
+
+ sem_post(SemInfo->sem);
+
+ return semid;
+}
+
+int
+semop(int semid, struct sembuf * sops, size_t nsops)
+{
+ int i,
+ r = 0,
+ r1,
+ errno1 = 0,
+ op;
+
+ sem_wait(SemInfo->sem);
+
+ if (semid < 0 || semid >= SETMAX)
+ {
+ sem_post(SemInfo->sem);
+ errno = EINVAL;
+ return -1;
+ }
+ for (i = 0; i < nsops; i++)
+ {
+ if ( /* sops[i].sem_num < 0 || */ sops[i].sem_num >= SemInfo->set[semid].nsems)
+ {
+ sem_post(SemInfo->sem);
+ errno = EFBIG;
+ return -1;
+ }
+ }
+
+ for (i = 0; i < nsops; i++)
+ {
+ if (sops[i].sem_op < 0)
+ {
+ if (SemInfo->set[semid].semV[sops[i].sem_num].semval < -sops[i].sem_op)
+ {
+ if (sops[i].sem_flg & IPC_NOWAIT)
+ {
+ sem_post(SemInfo->sem);
+ errno = EAGAIN;
+ return -1;
+ }
+ SemInfo->set[semid].semV[sops[i].sem_num].semncnt++;
+ if (SemInfo->set[semid].pendingOps[sops[i].sem_num].idx >= OPMAX)
+ {
+ /* pending operations array overflow */
+ sem_post(SemInfo->sem);
+ errno = ERANGE;
+ return -1;
+ }
+ SemInfo->set[semid].pendingOps[sops[i].sem_num].op[SemInfo->set[semid].pendingOps[sops[i].sem_num].idx++] = sops[i].sem_op;
+ /* suspend */
+ sem_post(SemInfo->sem); /* avoid deadlock */
+ r1 = sem_wait(SemInfo->set[semid].sem[sops[i].sem_num]);
+ sem_wait(SemInfo->sem);
+ if (r1)
+ {
+ errno1 = errno;
+ r = r1;
+ /* remove pending operation */
+ SemInfo->set[semid].pendingOps[sops[i].sem_num].op[--SemInfo->set[semid].pendingOps[sops[i].sem_num].idx] = 0;
+ }
+ else
+ SemInfo->set[semid].semV[sops[i].sem_num].semval -= -sops[i].sem_op;
+ SemInfo->set[semid].semV[sops[i].sem_num].semncnt--;
+ }
+ else
+ SemInfo->set[semid].semV[sops[i].sem_num].semval -= -sops[i].sem_op;
+ }
+ else if (sops[i].sem_op > 0)
+ {
+ SemInfo->set[semid].semV[sops[i].sem_num].semval += sops[i].sem_op;
+ op = sops[i].sem_op;
+ while (op > 0 && SemInfo->set[semid].pendingOps[sops[i].sem_num].idx > 0)
+ { /* operations pending */
+ if (SemInfo->set[semid].pendingOps[sops[i].sem_num].op[SemInfo->set[semid].pendingOps[sops[i].sem_num].idx - 1] + op >= 0)
+ {
+ /* unsuspend processes */
+ if (sem_post(SemInfo->set[semid].sem[sops[i].sem_num]))
+ {
+ errno1 = errno;
+ r = -1;
+ }
+ /* adjust pending operations */
+ op += SemInfo->set[semid].pendingOps[sops[i].sem_num].op[--SemInfo->set[semid].pendingOps[sops[i].sem_num].idx];
+ SemInfo->set[semid].pendingOps[sops[i].sem_num].op[SemInfo->set[semid].pendingOps[sops[i].sem_num].idx] = 0;
+ }
+ else
+ {
+ /* adjust pending operations */
+ SemInfo->set[semid].pendingOps[sops[i].sem_num].op[SemInfo->set[semid].pendingOps[sops[i].sem_num].idx - 1] += op;
+ op = 0;
+ }
+ }
+ }
+ else
+ /* sops[i].sem_op == 0 */
+ {
+ /* not supported */
+ sem_post(SemInfo->sem);
+ errno = ENOSYS;
+ return -1;
+ }
+ SemInfo->set[semid].semV[sops[i].sem_num].sempid = getpid();
+ }
+
+ sem_post(SemInfo->sem);
+
+ errno = errno1;
+ return r;
+}
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * sem.h
+ * System V Semaphore Emulation
+ *
+ * Copyright (c) 1999, repas AEG Automation GmbH
+ *
+ *
+ * IDENTIFICATION
+ * $Header: /cvsroot/pgsql/src/include/port/darwin/Attic/sem.h,v 1.1 2000/12/11 00:49:53 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef _SYS_SEM_H
+#define _SYS_SEM_H
+
+/* #define DEBUG_IPC here if you want to see the shim in action */
+
+#include
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/*
+ * Semctl Command Definitions.
+ */
+
+#define GETNCNT 3 /* get semncnt */
+#define GETPID 4 /* get sempid */
+#define GETVAL 5 /* get semval */
+#define GETALL 6 /* get all semval's */
+#define GETZCNT 7 /* get semzcnt */
+#define SETVAL 8 /* set semval */
+#define SETALL 9 /* set all semval's */
+
+#ifndef ushort_t
+#define ushort_t unsigned int
+#endif
+
+/*
+ * There is one semaphore structure for each semaphore in the system.
+ */
+
+ struct sem
+ {
+ ushort_t semval; /* semaphore text map address */
+ pid_t sempid; /* pid of last operation */
+ ushort_t semncnt; /* # awaiting semval > cval */
+ ushort_t semzcnt; /* # awaiting semval = 0 */
+ };
+
+/*
+ * User semaphore template for semop system calls.
+ */
+
+ struct sembuf
+ {
+ ushort_t sem_num; /* semaphore # */
+ short sem_op; /* semaphore operation */
+ short sem_flg; /* operation flags */
+ };
+
+ extern int semctl(int semid, int semnum, int cmd, /* ... */ union semun arg);
+ extern int semget(key_t key, int nsems, int semflg);
+ extern int semop(int semid, struct sembuf * sops, size_t nsops);
+
+#ifdef __cplusplus
+}
+
+#endif
+
+#endif /* _SYS_SEM_H */
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