Clean up SysV semaphore code.

Change MDB_LOCK_FORMAT to differ from Posix semaphores/mutexes.
Do not use array/member length 0 for MDB_txninfo.mt2.

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 9b7f65586ab7e68223ada7f6264316929ea4efd2..8c548366f241110582fa80e4e8353fca7d2379ac 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -684,18 +684,20 @@ typedef struct MDB_txninfo {
 #define mti_numreaders mt1.mtb.mtb_numreaders
                char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
        } mt1;
+#ifdef MDB_USE_SYSV_SEM
+#define        mti_semid       mt1.mtb.mtb_semid
+#else
        union {
 #if defined(_WIN32)
                char mt2_wmname[MNAME_LEN];
 #define        mti_wmname      mt2.mt2_wmname
-#elif defined(MDB_USE_SYSV_SEM)
-#define        mti_semid       mt1.mtb.mtb_semid
 #else
                pthread_mutex_t mt2_wmutex;
 #define mti_wmutex     mt2.mt2_wmutex
 #endif
                char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
        } mt2;
+#endif
        MDB_reader      mti_readers[1];
 } MDB_txninfo;
 
@@ -704,6 +706,7 @@ typedef struct MDB_txninfo {
        ((uint32_t) \
         ((MDB_LOCK_VERSION) \
          /* Flags which describe functionality */ \
+         + (((MNAME_LEN) == 0)   << 18) /* MDB_USE_SYSV_SEM */ \
          + (((MDB_PIDLOCK) != 0) << 16)))
 /** @} */