Re: Better shared data structure management and resizable shared data structures

Hello

dsm_shmem_init(void)
{
size_t size = dsm_estimate_size();
- bool found;

if (size == 0)
return;

Isn't there an assignment missing from this function now? Size is
calculated but never used. With the current code if
min_dynamic_shared_memory > 0 the server can crash.

+static ShmemHashDesc WaitEventCustomHashByNameDesc =
+{
+ .name = "WaitEventCustom hash by name",
+ .ptr = &WaitEventCustomHashByName,
+
+ .init_size = WAIT_EVENT_CUSTOM_HASH_INIT_SIZE,
+ .max_size = WAIT_EVENT_CUSTOM_HASH_MAX_SIZE,
+ /* key is a NULL-terminated string */
+ .hash_info.keysize = sizeof(char[NAMEDATALEN]),
+ .hash_info.entrysize = sizeof(WaitEventCustomEntryByName),
+ .hash_flags = HASH_ELEM | HASH_BLOBS,
+};

This was HASH_STRINGS originally, and it is used with plain const
char* parameters. Shouldn't it use HASH_SRINGS as before?

size = add_size(size, ShmemRegisteredSize());

size = add_size(size, dsm_estimate_size());
- size = add_size(size, DSMRegistryShmemSize());
+
+ size = add_size(size, ShmemRegisteredSize());

ShmemRegisteredSize is now called twice.

+ /* Initialize the lock */
+ tranche_id = LWLockNewTrancheId("my tranche name");
+ LWLockInitialize(&MyShmem->lock);

Second parameter is missing for LWLockInitialize