Darwin porting patches from Peter Bierman <bierman@apple.com>

1 files changed, 374 insertions, 0 deletions

diff --git a/src/backend/port/darwin/sem.c b/src/backend/port/darwin/sem.c
new file mode 100644
index 00000000000..c55090cedc2
--- /dev/null
+++ b/src/backend/port/darwin/sem.c
@@ -0,0 +1,374 @@
+/*-------------------------------------------------------------------------
+ *
+ * sem.c
+ *	  System V Semaphore Emulation
+ *
+ * Copyright (c) 1999, repas AEG Automation GmbH
+ * 
+ * 2000-12-1 pmb@mac.com 
+ *   - 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 <errno.h>
+#include <semaphore.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#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;
+}