Incorrect thread_safety plus performance tunning

[ospfranco]

Hi, I was doing some benchmarking between nitro-sqlite and op-sqlite and found the following

nitro-sqlite intends to always run in performance mode — RNNitroSQLite.podspec:8 hardcodes performance_mode = 1 with a comment "Used to create comparable benchmark results", and mode 1 would apply the same optimized flags plus SQLITE_THREADSAFE=0 — mutexes fully disabled, unsafe for concurrent access.

But there's a bug: performance_mode is set to the Ruby Integer 1, then checked against the String '1'/'2' ([lines 49/54]). In Ruby, 1 == '1' is always false — no coercion. So on iOS that branch never fires; nitro-sqlite currently compiles SQLite with no special flags at all, THREADSAFE left at its amalgamation default. On Android it's the same story for a different reason: the flags come from a nitroSqliteFlags Gradle property ([android/build.gradle:76]) that nothing in this project sets.

You also don't want to use SQLITE_THREADSAFE=0 as your ThreadPool implementation is using 3 threads and offers no safety, had to fix already a bunch of issues in op-sqlite.

[chrispader]

Hey, thanks for opening the issue! 🙌🏼

I've already addressed the performance mode issue in #291

Looking into the issue with SQLITE_THREADSAFE though...

[ospfranco]

You also probably want to prefix all the .cpp and .hpp filenames in the codebase, utils and macros and ThreadPool clashed with op-sqlite, but will probably clash with any library that has the same names. Same as react prefixes their files names with RCT

[carl-sauter]

Hey @chrispader the threadsafe issue leads to another problem, when using typeorm execute two queries at ones, the whole app crashes on ios (I think on android, thread safety is still enabled):

This works

const a = await datasource.getRepository(Foo).find()
const b = await datasource.getRepository(Foo).find()

This leads to a crash with nitro-thread-1: EXC_BAD_ACCESS (code=1, address=0x1f)

const a = datasource.getRepository(Foo).find()
const b = datasource.getRepository(Foo).find()
await Promise.all([a, b])

Edit: I would default to performance mode 2, to keep thread safety enabled by default, making non thread safe an opt in option