pmix3x: dstore/pmix: flock portability

Using the fcntl-locking instead of the flock

(back-ported from upstream openpmix/openpmix@3030a0c)

Author: ggouaillardet

opal/mca/pmix/pmix3x/pmix/src/dstore/pmix_esh.c

@@ -61,6 +61,14 @@ pmix_dstore_base_module_t pmix_dstore_esh_module = {
 #define EXT_SLOT_SIZE (PMIX_MAX_KEYLEN + 1 + 2*sizeof(size_t)) /* in ext slot new offset will be stored in case if new data were added for the same process during next commit */
 #define KVAL_SIZE(size) (PMIX_MAX_KEYLEN + 1 + sizeof(size_t) + size)
 
+#define _ESH_LOCK(lockfd, operation) \
+do{ \
+    struct flock fl = {0}; \
+    fl.l_type = operation; \
+    fl.l_whence = SEEK_SET; \
+    fcntl(lockfd, F_SETLKW, &fl); \
+}while(0)
+
 static int _store_data_for_rank(ns_track_elem_t *ns_info, pmix_rank_t rank, pmix_buffer_t *buf);
 static seg_desc_t *_create_new_segment(segment_type type, char *nsname, uint32_t id);
 static seg_desc_t *_attach_new_segment(segment_type type, char *nsname, uint32_t id);
@@ -302,7 +310,7 @@ int _esh_store(const char *nspace, pmix_rank_t rank, pmix_kval_t *kv)
                          __FILE__, __LINE__, __func__, nspace, rank));
 
     /* set exclusive lock */
-    flock(_lockfd, LOCK_EX);
+    _ESH_LOCK(_lockfd, _ESH_LOCK_EX);
 
     /* First of all, we go through local track list (list of ns_track_elem_t structures)
      * and look for an element for the target namespace.
@@ -318,7 +326,7 @@ int _esh_store(const char *nspace, pmix_rank_t rank, pmix_kval_t *kv)
     if (NULL == elem) {
         PMIX_ERROR_LOG(PMIX_ERROR);
         /* unset lock */
-        flock(_lockfd, LOCK_UN);
+        _ESH_LOCK(_lockfd, _ESH_LOCK_UN);
         return PMIX_ERROR;
     }
 
@@ -332,7 +340,7 @@ int _esh_store(const char *nspace, pmix_rank_t rank, pmix_kval_t *kv)
         if (PMIX_SUCCESS != rc || NULL == elem->meta_seg || NULL == elem->data_seg) {
             PMIX_ERROR_LOG(rc);
             /* unset lock */
-            flock(_lockfd, LOCK_UN);
+            _ESH_LOCK(_lockfd, _ESH_LOCK_UN);
             return PMIX_ERROR;
         }
 
@@ -345,7 +353,7 @@ int _esh_store(const char *nspace, pmix_rank_t rank, pmix_kval_t *kv)
         if (PMIX_SUCCESS != rc) {
             PMIX_ERROR_LOG(rc);
             /* unset lock */
-            flock(_lockfd, LOCK_UN);
+            _ESH_LOCK(_lockfd, _ESH_LOCK_UN);
             return rc;
         }
     }
@@ -366,7 +374,7 @@ int _esh_store(const char *nspace, pmix_rank_t rank, pmix_kval_t *kv)
     PMIX_DESTRUCT(&pbkt);
 
     /* unset lock */
-    flock(_lockfd, LOCK_UN);
+    _ESH_LOCK(_lockfd, _ESH_LOCK_UN);
     return rc;
 }
 
@@ -407,7 +415,7 @@ int _esh_fetch(const char *nspace, pmix_rank_t rank, const char *key, pmix_value
     }
 
     /* set shared lock */
-    flock(_lockfd, LOCK_SH);
+    _ESH_LOCK(_lockfd, _ESH_LOCK_SH);
 
     /* First of all, we go through all initial segments and look at their field.
      * If it’s 1, then generate name of next initial segment incrementing id by one and attach to it.
@@ -432,7 +440,7 @@ int _esh_fetch(const char *nspace, pmix_rank_t rank, const char *key, pmix_value
                     "%s:%d:%s:  no data for ns %s is found in the shared memory.",
                     __FILE__, __LINE__, __func__, nspace));
         /* unset lock */
-        flock(_lockfd, LOCK_UN);
+        _ESH_LOCK(_lockfd, _ESH_LOCK_UN);
         return PMIX_ERROR;
     }
 
@@ -441,7 +449,7 @@ int _esh_fetch(const char *nspace, pmix_rank_t rank, const char *key, pmix_value
     if (NULL == elem) {
         PMIX_ERROR_LOG(PMIX_ERROR);
         /* unset lock */
-        flock(_lockfd, LOCK_UN);
+        _ESH_LOCK(_lockfd, _ESH_LOCK_UN);
         return PMIX_ERROR;
     }
     /* need to update tracker:
@@ -451,7 +459,7 @@ int _esh_fetch(const char *nspace, pmix_rank_t rank, const char *key, pmix_value
     if (PMIX_SUCCESS != rc) {
         PMIX_ERROR_LOG(PMIX_ERROR);
         /* unset lock */
-        flock(_lockfd, LOCK_UN);
+        _ESH_LOCK(_lockfd, _ESH_LOCK_UN);
         return PMIX_ERROR;
     }
 
@@ -558,7 +566,7 @@ int _esh_fetch(const char *nspace, pmix_rank_t rank, const char *key, pmix_value
 
 done:
     /* unset lock */
-    flock(_lockfd, LOCK_UN);
+    _ESH_LOCK(_lockfd, _ESH_LOCK_UN);
     return rc;
 }
 

opal/mca/pmix/pmix3x/pmix/src/dstore/pmix_esh.h

@@ -25,6 +25,10 @@ BEGIN_C_DECLS
 
 #define PMIX_DSTORE_ESH_BASE_PATH "PMIX_DSTORE_ESH_BASE_PATH"
 
+#define _ESH_LOCK_EX F_WRLCK
+#define _ESH_LOCK_SH F_RDLCK
+#define _ESH_LOCK_UN F_UNLCK
+
 typedef enum {
     INITIAL_SEGMENT,
     NS_META_SEGMENT,