lazy init dns, #121

zhboner · Feb 20, 2024 · dd96074 · dd96074
1 parent 882c2e3
commit dd96074
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Showing 2 changed files with 16 additions and 2 deletions.
diff --git a/realm_core/src/dns/mod.rs b/realm_core/src/dns/mod.rs
@@ -42,8 +42,23 @@ static mut DNS: Lazy<TokioAsyncResolver> = Lazy::new(|| {
     TokioAsyncResolver::tokio(conf, opts)
 });
 
+/// Force initialization.
+pub fn force_init() {
+    use std::ptr;
+    unsafe {
+        Lazy::force(&*ptr::addr_of!(DNS));
+    }
+}
+
 /// Setup global dns resolver. This is not thread-safe!
 pub fn build(conf: Option<ResolverConfig>, opts: Option<ResolverOpts>) {
+    build_lazy(conf, opts);
+    force_init();
+}
+
+/// Setup config of global dns resolver, without initialization.
+/// This is not thread-safe!
+pub fn build_lazy(conf: Option<ResolverConfig>, opts: Option<ResolverOpts>) {
     let mut dns_conf = DnsConf::default();
 
     if let Some(conf) = conf {
@@ -56,7 +71,6 @@ pub fn build(conf: Option<ResolverConfig>, opts: Option<ResolverOpts>) {
 
     unsafe {
         DNS_CONF.set(dns_conf).unwrap();
-        Lazy::force(&DNS);
     }
 }
 

diff --git a/src/bin.rs b/src/bin.rs
@@ -92,7 +92,7 @@ fn setup_dns(dns: DnsConf) {
     println!("dns: {}", &dns);
 
     let (conf, opts) = dns.build();
-    realm::core::dns::build(conf, opts);
+    realm::core::dns::build_lazy(conf, opts);
 }
 
 fn execute(eps: Vec<EndpointInfo>) {