unsafe log init

Author: Dav1dde

relay-log/src/setup.rs

@@ -280,6 +280,11 @@ fn get_default_filters() -> EnvFilter {
 
 /// Initialize the logging system and reporting to Sentry.
 ///
+/// # Safety
+///
+/// The function is not safe to be called from a multi-threaded program,
+/// due to modifications of environment variables.
+///
 /// # Example
 ///
 /// ```
@@ -290,9 +295,9 @@ fn get_default_filters() -> EnvFilter {
 ///
 /// let sentry_config = relay_log::SentryConfig::default();
 ///
-/// relay_log::init(&log_config, &sentry_config);
+/// unsafe { relay_log::init(&log_config, &sentry_config) };
 /// ```
-pub fn init(config: &LogConfig, sentry: &SentryConfig) {
+pub unsafe fn init(config: &LogConfig, sentry: &SentryConfig) {
     if config.enable_backtraces {
         unsafe {
             env::set_var("RUST_BACKTRACE", "full");

relay/src/cli.rs

@@ -52,7 +52,11 @@ pub fn execute() -> Result<()> {
     let env_config = extract_config_env_vars();
     config.apply_override(env_config)?;
 
-    relay_log::init(config.logging(), config.sentry());
+    // SAFETY: The function cannot be called from a multi threaded environment,
+    // this is the main entry point where no other threads have been spawned yet.
+    unsafe {
+        relay_log::init(config.logging(), config.sentry());
+    }
 
     if let Some(matches) = matches.subcommand_matches("config") {
         manage_config(&config, matches)

tools/bench-buffer/src/main.rs

@@ -54,7 +54,9 @@ async fn main() {
         duration_secs,
         db,
     } = args;
-    relay_log::init(&Default::default(), &Default::default());
+    unsafe {
+        relay_log::init(&Default::default(), &Default::default());
+    }
 
     let dir = tempfile::tempdir().unwrap();
     let path = db.unwrap_or(dir.path().join("envelopes.db"));