From e55750f146db201494002545fda1b9bfec2a98db Mon Sep 17 00:00:00 2001 From: Sami Imseih Date: Tue, 26 Aug 2025 16:58:29 -0500 Subject: [PATCH v13 3/3] Remove the DSA suffix for tranches created with GetNamedDSHash The previous commit fe07100 increased the tranche name length to 128 bytes, but there is no reason to exceed the tranche name length defined in lwlock.h. This change restores the limit to NAMEDATALEN for tranches created with GetNamedDSHash. This also removes the separate DSA tranche name. DSA and DSH will now share the same tranche name, reducing complexity. Discussion: https://www.postgresql.org/message-id/aKzIg1JryN1qhNuy@nathan --- src/backend/storage/ipc/dsm_registry.c | 16 ++++++---------- src/backend/storage/lmgr/lwlock.c | 2 -- src/include/storage/lwlock.h | 3 +++ 3 files changed, 9 insertions(+), 12 deletions(-) diff --git a/src/backend/storage/ipc/dsm_registry.c b/src/backend/storage/ipc/dsm_registry.c index cc0adc19971..9b50e212270 100644 --- a/src/backend/storage/ipc/dsm_registry.c +++ b/src/backend/storage/ipc/dsm_registry.c @@ -48,11 +48,7 @@ #include "utils/builtins.h" #include "utils/memutils.h" -#define DSMR_NAME_LEN 128 - -#define DSMR_DSA_TRANCHE_SUFFIX " DSA" -#define DSMR_DSA_TRANCHE_SUFFIX_LEN (sizeof(DSMR_DSA_TRANCHE_SUFFIX) - 1) -#define DSMR_DSA_TRANCHE_NAME_LEN (DSMR_NAME_LEN + DSMR_DSA_TRANCHE_SUFFIX_LEN) +#define DSMR_NAME_LEN MAX_NAMED_TRANCHES_NAME_LEN typedef struct DSMRegistryCtxStruct { @@ -72,7 +68,7 @@ typedef struct NamedDSAState { dsa_handle handle; int tranche; - char tranche_name[DSMR_DSA_TRANCHE_NAME_LEN]; + char tranche_name[DSMR_NAME_LEN]; } NamedDSAState; typedef struct NamedDSHState @@ -384,14 +380,14 @@ GetNamedDSHash(const char *name, const dshash_parameters *params, bool *found) entry->type = DSMR_ENTRY_TYPE_DSH; - /* Initialize the LWLock tranche for the DSA. */ - sprintf(dsa_state->tranche_name, "%s%s", name, DSMR_DSA_TRANCHE_SUFFIX); - dsa_state->tranche = LWLockNewTrancheId(dsa_state->tranche_name); - /* Initialize the LWLock tranche for the dshash table. */ strcpy(dsh_state->tranche_name, name); dsh_state->tranche = LWLockNewTrancheId(dsh_state->tranche_name); + /* DSA uses the same tranche as DSH */ + strcpy(dsa_state->tranche_name, dsh_state->tranche_name); + dsa_state->tranche = dsh_state->tranche; + /* Initialize the DSA for the hash table. */ dsa = dsa_create(dsa_state->tranche); dsa_pin(dsa); diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c index 81f9914bf08..041aebf101e 100644 --- a/src/backend/storage/lmgr/lwlock.c +++ b/src/backend/storage/lmgr/lwlock.c @@ -106,8 +106,6 @@ #define LW_LOCK_MASK (MAX_BACKENDS | LW_VAL_EXCLUSIVE) #define MAX_NAMED_TRANCHES 1024 -#define MAX_NAMED_TRANCHES_NAME_LEN NAMEDATALEN - StaticAssertDecl(((MAX_BACKENDS + 1) & MAX_BACKENDS) == 0, "MAX_BACKENDS + 1 needs to be a power of 2"); diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h index 1ba77cb3658..a514960fe29 100644 --- a/src/include/storage/lwlock.h +++ b/src/include/storage/lwlock.h @@ -83,6 +83,9 @@ typedef struct NamedLWLockTranche extern PGDLLIMPORT const char *NamedLWLockTrancheArray; extern PGDLLIMPORT int NamedLWLockTrancheRequests; +/* Maximum length of a named tranche */ +#define MAX_NAMED_TRANCHES_NAME_LEN NAMEDATALEN + /* * It's a bit odd to declare NUM_BUFFER_PARTITIONS and NUM_LOCK_PARTITIONS * here, but we need them to figure out offsets within MainLWLockArray, and -- 2.39.5 (Apple Git-154)