Import BSDDB 4.7.25 (as of svn r89086)

2017-09-04 13:40:25 -05:00
parent 4b29e0458f
commit 8f590873d0
4781 changed files with 2241032 additions and 6 deletions
--- a/mod_db4/sem_utils.c
+++ b/mod_db4/sem_utils.c
@@ -0,0 +1,115 @@
+/*-
+ * Copyright (c) 2004,2008 Oracle.  All rights reserved.
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0.txt
+ * 
+ * authors: George Schlossnagle <george@omniti.com>
+ */
+extern "C"
+{
+#include <sys/types.h>
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "config.h"
+#include "sem_utils.h"
+
+
+#include <errno.h>
+}
+extern int errno;
+
+#if HAVE_SEMUN
+/* we have semun, no need to define */
+#else
+union semun {
+    int val;                  /* value for SETVAL */
+    struct semid_ds *buf;     /* buffer for IPC_STAT, IPC_SET */
+    unsigned short *array;    /* array for GETALL, SETALL */
+                              /* Linux specific part: */
+    struct seminfo *__buf;    /* buffer for IPC_INFO */
+};
+#endif
+
+#ifndef SEM_R
+# define SEM_R 0444
+#endif
+#ifndef SEM_A
+# define SEM_A 0222
+#endif
+
+int md4_sem_create(int semnum, unsigned short *start)
+{
+    int semid;
+    int perms = 0777;
+    union semun arg;
+    key_t key = 12345;
+    int count = 0;
+    while((semid = semget(key, semnum, IPC_CREAT | IPC_EXCL | perms)) == -1) {
+      if(count++ > 2) {
+        return -1;
+      }
+      if (errno == EEXIST) {
+        semid = semget(key, 1, perms);
+        md4_sem_destroy(semid);
+      }
+    }  
+    arg.array = start;
+    if(semctl(semid, 0, SETALL, arg) < 0) {
+      /* destroy (FIXME) and return */
+      md4_sem_destroy(semid);
+      return -1;
+    }
+    return semid;
+}
+
+void md4_sem_destroy(int semid)
+{
+    union semun dummy;
+    /* semid should always be 0, this clobbers the whole set */
+    semctl(semid, 0, IPC_RMID, dummy);
+}
+
+void md4_sem_lock(int semid, int semnum)
+{
+    struct sembuf sops;
+    sops.sem_num = semnum;
+    sops.sem_op = -1;
+    sops.sem_flg = SEM_UNDO;
+    semop(semid, &sops, 1);
+}
+    
+void md4_sem_unlock(int semid, int semnum)
+{
+    struct sembuf sops;
+    sops.sem_num = semnum;
+    sops.sem_op = 1;
+    sops.sem_flg = SEM_UNDO;
+    semop(semid, &sops, 1);
+}
+
+void md4_sem_wait_for_zero(int semid, int semnum)
+{
+    struct sembuf sops;
+    sops.sem_num = semnum;
+    sops.sem_op = 0;
+    sops.sem_flg = SEM_UNDO;
+    semop(semid, &sops, 1);
+}
+
+void md4_sem_set(int semid, int semnum, int value)
+{
+    union semun arg;
+    arg.val = value;
+    semctl(semid, semnum, SETALL, arg);
+}
+
+int md4_sem_get(int semid, int semnum)
+{
+    union semun arg;
+    return semctl(semid, 0, GETVAL, arg);
+}
+
+/* vim: set ts=4 sts=4 expandtab bs=2 ai : */