ITS#7364 Remove POSIX semaphores when the last user closes the mdb environment.

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 0e0268546851453e6660de9cbfc9af140faf3117..a120a526486d4604b96a08147cdb771605901ddc 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -2648,6 +2648,39 @@ mdb_env_share_locks(MDB_env *env)
        }
 #endif
 }
+
+static int
+mdb_env_excl_lock(MDB_env *env, int *excl)
+{
+#ifdef _WIN32
+       if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
+               *excl = 1;
+       } else {
+               OVERLAPPED ov;
+               memset(&ov, 0, sizeof(ov));
+               if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
+                       return ErrCode();
+               }
+       }
+#else
+       struct flock lock_info;
+       memset((void *)&lock_info, 0, sizeof(lock_info));
+       lock_info.l_type = F_WRLCK;
+       lock_info.l_whence = SEEK_SET;
+       lock_info.l_start = 0;
+       lock_info.l_len = 1;
+       if (!fcntl(env->me_lfd, F_SETLK, &lock_info)) {
+               *excl = 1;
+       } else {
+               lock_info.l_type = F_RDLCK;
+               if (fcntl(env->me_lfd, F_SETLKW, &lock_info)) {
+                       return ErrCode();
+               }
+       }
+#endif
+       return 0;
+}
+
 #if defined(_WIN32) || defined(USE_POSIX_SEM)
 /*
  * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
@@ -2749,18 +2782,7 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
        /* Try to get exclusive lock. If we succeed, then
         * nobody is using the lock region and we should initialize it.
         */
-       {
-               if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
-                       *excl = 1;
-               } else {
-                       OVERLAPPED ov;
-                       memset(&ov, 0, sizeof(ov));
-                       if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
-                               rc = ErrCode();
-                               goto fail;
-                       }
-               }
-       }
+       if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
        size = GetFileSize(env->me_lfd, NULL);
 
 #else
@@ -2781,25 +2803,8 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
        /* Try to get exclusive lock. If we succeed, then
         * nobody is using the lock region and we should initialize it.
         */
-       {
-               struct flock lock_info;
-               memset((void *)&lock_info, 0, sizeof(lock_info));
-               lock_info.l_type = F_WRLCK;
-               lock_info.l_whence = SEEK_SET;
-               lock_info.l_start = 0;
-               lock_info.l_len = 1;
-               rc = fcntl(env->me_lfd, F_SETLK, &lock_info);
-               if (rc == 0) {
-                       *excl = 1;
-               } else {
-                       lock_info.l_type = F_RDLCK;
-                       rc = fcntl(env->me_lfd, F_SETLKW, &lock_info);
-                       if (rc) {
-                               rc = ErrCode();
-                               goto fail;
-                       }
-               }
-       }
+       if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
+
        size = lseek(env->me_lfd, 0, SEEK_END);
 #endif
        rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
@@ -3149,6 +3154,16 @@ mdb_env_close(MDB_env *env)
                for (i=0; i<env->me_txns->mti_numreaders; i++)
                        if (env->me_txns->mti_readers[i].mr_pid == pid)
                                env->me_txns->mti_readers[i].mr_pid = 0;
+#ifdef USE_POSIX_SEM
+               { int excl = 0;
+                       if (!mdb_env_excl_lock(env, &excl) && excl) {
+                               /* we are the only remaining user of the environment.
+                                  clean up semaphores. */
+                               sem_unlink(env->me_txns->mti_rmname);
+                               sem_unlink(env->me_txns->mti_wmname);
+                       }
+               }
+#endif
                munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
        }
        close(env->me_lfd);