On Mon, Jun 24, 2024 at 01:29:38PM +0300, Heikki Linnakangas wrote: > InjectionPointRun() acquires InjectionPointLock, looks up the hash entry, > and releases the lock: > > > LWLockAcquire(InjectionPointLock, LW_SHARED); > > entry_by_name = (InjectionPointEntry *) > > hash_search(InjectionPointHash, name, > > HASH_FIND, &found); > > LWLockRelease(InjectionPointLock); > > Later, it reads fields from the entry it looked up: > > > /* not found in local cache, so load and register */ > > snprintf(path, MAXPGPATH, "%s/%s%s", pkglib_path, > > entry_by_name->library, DLSUFFIX); > > Isn't that a straightforward race condition, if the injection point is > detached in between?
This is a feature, not a bug :) Jokes apart, this is a behavior that Noah was looking for so as it is possible to detach a point to emulate what a debugger would do with a breakpoint for some of his tests with concurrent DDL bugs, so not taking a lock while running a point is important. It's true, though, that we could always delay the LWLock release once the local cache is loaded, but would it really matter? -- Michael
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