feat!(ffi): rename setup_tracing into init_platform (#4790)

And make it take a boolean indicating whether we want to set up a
lightweight tokio runtime or not, instead of having
`setup_lightweight_tokio_runtime` as a public function + another
function, both of which would have to be called anyways.

cc @stefanceriu @jmartinesp

bindings/matrix-sdk-ffi/CHANGELOG.md

@@ -2,6 +2,11 @@
 
 Breaking changes:
 
+- `setup_tracing` has been renamed `init_platform`; in addition to the `TracingConfiguration`
+  parameter it also now takes a boolean indicating whether to spawn a minimal tokio runtime for the
+  application; in general for main app processes this can be set to `false`, and memory-constrained
+  programs can set it to `true`.
+
 - Matrix client API errors coming from API responses will now be mapped to `ClientError::MatrixApi`, containing both the
   original message and the associated error code and kind. 
 

bindings/matrix-sdk-ffi/src/platform.rs

@@ -348,20 +348,39 @@ fn build_tracing_filter(config: &TracingConfiguration) -> String {
     filters.join(",")
 }
 
+/// Sets up logs and the tokio runtime for the current application.
+///
+/// If `use_lightweight_tokio_runtime` is set to true, this will set up a
+/// lightweight tokio runtime, for processes that have memory limitations (like
+/// the NSE process on iOS). Otherwise, this can remain false, in which case a
+/// multithreaded tokio runtime will be set up.
 #[matrix_sdk_ffi_macros::export]
-pub fn setup_tracing(config: TracingConfiguration) {
+pub fn init_platform(config: TracingConfiguration, use_lightweight_tokio_runtime: bool) {
     log_panics();
 
     tracing_subscriber::registry()
         .with(EnvFilter::new(build_tracing_filter(&config)))
         .with(text_layers(config))
         .init();
+
+    if use_lightweight_tokio_runtime {
+        setup_lightweight_tokio_runtime();
+    } else {
+        setup_multithreaded_tokio_runtime();
+    }
 }
 
-/// Set up a lightweight tokio runtime, for processes that have memory
-/// limitations (like the NSE process on iOS).
-#[matrix_sdk_ffi_macros::export]
-pub fn setup_lightweight_tokio_runtime() {
+fn setup_multithreaded_tokio_runtime() {
+    async_compat::set_runtime_builder(Box::new(|| {
+        eprintln!("spawning a multithreaded tokio runtime");
+
+        let mut builder = tokio::runtime::Builder::new_multi_thread();
+        builder.enable_all();
+        builder
+    }));
+}
+
+fn setup_lightweight_tokio_runtime() {
     async_compat::set_runtime_builder(Box::new(|| {
         eprintln!("spawning a lightweight tokio runtime");