/* * Add or update an entry in the Global MDVSN cache for a versioning event * found in the event list. Reconcile with current contents of the cache * if needed. * event: The event containing the versioning information for an update */ static void mdver_globalhandler_add_version(mdver_event *event) { Assert(NULL != event); Cache *glob_mdvsn = mdver_get_glob_mdvsn(); if (mdver_is_nuke_event(event)) { mdver_glob_mdvsn_nuke(); return; } mdver_entry mdver = { InvalidOid, INVALID_MD_VERSION, INVALID_MD_VERSION }; mdver.key = event->key; mdver.ddl_version = INVALID_MD_VERSION; mdver.dml_version = INVALID_MD_VERSION; /* FIXME gcaragea 04/14/2014: Trigger evictions if cache is full (MPP-22923) */ CacheEntry *acquired_entry = Cache_AcquireEntry(glob_mdvsn, &mdver); Assert(NULL != acquired_entry); /* * We're about to look-up and insert/update a shared cache entry. * Grab writer lock in exclusive mode, so that no other backend * tries to insert or update the same entry at the same time. */ LWLockAcquire(MDVerWriteLock, LW_EXCLUSIVE); CacheEntry *cached_entry = Cache_Lookup(glob_mdvsn, acquired_entry); if (NULL != cached_entry) { mdver_globalhandler_reconcile(event, cached_entry); /* Done with the looked-up entry. Release it */ Cache_Release(glob_mdvsn, cached_entry); } else { /* Entry not found, insert new entry */ mdver_entry *new_mdver_entry = CACHE_ENTRY_PAYLOAD(acquired_entry); #ifdef MD_VERSIONING_INSTRUMENTATION elog(gp_mdversioning_loglevel, "Inserting into GlobalMDVSN entry %d: (%d,%d)", event->key, (int) event->new_ddl_version, (int) event->new_dml_version); #endif new_mdver_entry->ddl_version = event->new_ddl_version; new_mdver_entry->dml_version = event->new_dml_version; Cache_Insert(glob_mdvsn, acquired_entry); } Cache_Release(glob_mdvsn, acquired_entry); LWLockRelease(MDVerWriteLock); }
/* * Look up file set the cache given a certain PlanState. * Return NULL if not found. */ static workfile_set * workfile_mgr_lookup_set(PlanState *ps) { Assert(NULL != ps); Assert(NULL != workfile_mgr_cache); Assert(NULL != ps->plan); Assert(nodeTag(ps->plan) >= T_Plan && nodeTag(ps->plan) < T_PlanInvalItem); /* Create parameter info for the populate function */ workset_info set_info; set_info.dir_path = NULL; set_info.operator_work_mem = get_operator_work_mem(ps); set_info.on_disk = false; CacheEntry *localEntry = acquire_entry_retry(workfile_mgr_cache, &set_info); Assert(localEntry != NULL); workfile_set *local_work_set = (workfile_set *) CACHE_ENTRY_PAYLOAD(localEntry); /* Populate the rest of the entries needed for look-up * Allocate the serialized plan in the TopMemoryContext since this memory * context is still available when calling the transaction callback at the * time when the transaction aborts. */ MemoryContext oldcxt = MemoryContextSwitchTo(TopMemoryContext); workfile_set_plan *s_plan = workfile_mgr_serialize_plan(ps); MemoryContextSwitchTo(oldcxt); Assert(s_plan != NULL); local_work_set->set_plan = s_plan; local_work_set->key = workfile_mgr_hash_key(s_plan); CacheEntry *cachedEntry = Cache_Lookup(workfile_mgr_cache, localEntry); /* Release local entry and free up plan memory. We don't need it anymore */ Cache_Release(workfile_mgr_cache, localEntry); workfile_set *work_set = NULL; if (NULL != cachedEntry) { work_set = (workfile_set *) CACHE_ENTRY_PAYLOAD(cachedEntry); } return work_set; }
/* * Look up an entry in the Global MDVSN component. * To avoid any concurrency issues, this returns a copy of the entry, * palloc'ed in the current memory context. The caller is responsible * for freeing this copy. * * Returns a copy of the entry if found, NULL otherwise. * */ mdver_entry * mdver_glob_mdvsn_find(Oid oid) { Assert(NULL != mdver_glob_mdvsn); mdver_entry mdver_info; mdver_info.key = oid; /* FIXME gcaragea 03/18/2014: Trigger evictions if cache is full (MPP-22923) */ CacheEntry *localEntry = Cache_AcquireEntry(mdver_glob_mdvsn, &mdver_info); Assert(NULL != localEntry); CacheEntry *cachedEntry = Cache_Lookup(mdver_glob_mdvsn, localEntry); /* Release local entry. We don't need it anymore */ Cache_Release(mdver_glob_mdvsn, localEntry); mdver_entry *mdver_copy = NULL; if (NULL != cachedEntry) { /* Found a match. Make a local copy */ mdver_entry *shared_mdver = (mdver_entry *) CACHE_ENTRY_PAYLOAD(cachedEntry); mdver_copy = (mdver_entry *) palloc0(sizeof(mdver_entry)); /* Lock entry to ensure atomicity of copy */ Cache_LockEntry(mdver_glob_mdvsn, cachedEntry); memcpy(mdver_copy, shared_mdver, sizeof(mdver_entry)); /* Got the copy, unlock entry */ Cache_UnlockEntry(mdver_glob_mdvsn, cachedEntry); /* * We're also done with the entry, release our pincount on it * * TODO gcaragea 05/02/2014: Are there cases where we need to hold the * entry past this point? (MPP-22923) */ Cache_Release(mdver_glob_mdvsn, cachedEntry); } return mdver_copy; }
/* * When a backend is requesting the more recent version of an object, * if the Local MDVSN cache doesn't have the version, and if a NUKE event * hasn't been encountered in the current transaction, it is looked up * in the Global MDVSN shared cache. * * If the object is found in Global MDVSN, return the global version. * If the object is not found, generate a new version, record it in Global MDVSN * and then return it. * * key: The key of the looked-up object * ddl_version: used to return the ddl version for the object * dml_version: used to return the dml version for the object * */ static void mdver_request_from_global(Oid key, uint64 *ddl_version, uint64 *dml_version) { Assert(NULL != ddl_version); Assert(NULL != dml_version); Cache *mdver_glob_mdvsn = mdver_get_glob_mdvsn(); Assert(NULL != mdver_glob_mdvsn); mdver_entry entry = {key, INVALID_MD_VERSION, INVALID_MD_VERSION}; /* FIXME gcaragea 06/03/2014: Trigger evictions if cache is full (MPP-22923) */ CacheEntry *localEntry = Cache_AcquireEntry(mdver_glob_mdvsn, &entry); Assert(NULL != localEntry); /* * We're about to look-up and insert a shared cache entry. * Grab writer lock in exclusive mode, so that no other backend * can insert or update the same entry at the same time. */ LWLockAcquire(MDVerWriteLock, LW_EXCLUSIVE); CacheEntry *cachedEntry = Cache_Lookup(mdver_glob_mdvsn, localEntry); if (NULL != cachedEntry) { /* Not found in LVSN, not nuke happened, eventually found in GVSN */ mdver_entry *crt_entry = CACHE_ENTRY_PAYLOAD(cachedEntry); *ddl_version = crt_entry->ddl_version; *dml_version = crt_entry->dml_version; #ifdef MD_VERSIONING_INSTRUMENTATION elog(gp_mdversioning_loglevel, "Found version in Global MDVSN: (%d, " UINT64_FORMAT ", " UINT64_FORMAT "). Adding it to Local MDVSN", key, crt_entry->ddl_version, crt_entry->dml_version); #endif /* * We're also done with the entry, release our pincount on it * * TODO gcaragea 05/02/2014: Are there cases where we need to hold the * entry past this point? (MPP-22923) */ Cache_Release(mdver_glob_mdvsn, cachedEntry); } else { /* Not found in LVSN, not nuke happened, not found in GVSN either */ /* Generate new version */ *ddl_version = mdver_next_global_version(); *dml_version = mdver_next_global_version(); /* Add to GVSN */ mdver_entry *new_entry = CACHE_ENTRY_PAYLOAD(localEntry); new_entry->ddl_version = *ddl_version; new_entry->dml_version = *dml_version; #ifdef MD_VERSIONING_INSTRUMENTATION elog(gp_mdversioning_loglevel, "Inserting new version in Global MDVSN: (%d, " UINT64_FORMAT ", " UINT64_FORMAT "). Adding it to Local MDVSN", key, new_entry->ddl_version, new_entry->dml_version); #endif Cache_Insert(mdver_glob_mdvsn, localEntry); } LWLockRelease(MDVerWriteLock); /* Release local entry. We don't need it anymore */ Cache_Release(mdver_glob_mdvsn, localEntry); }