Merge pull request #1051 from casperisfine/fix-async_cb_dispatcher_mark

Handle null pointer in async_cb_dispatcher mark and free
ffi · Sep 25, 2023 · b7d7c21 · b7d7c21
2 parents 0e9a39b + 97ce4ef
commit b7d7c21
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Showing 2 changed files with 15 additions and 2 deletions.
diff --git a/ext/ffi_c/Function.c b/ext/ffi_c/Function.c
@@ -166,14 +166,18 @@ static void
 async_cb_dispatcher_mark(void *ptr)
 {
     struct async_cb_dispatcher *ctx = (struct async_cb_dispatcher *)ptr;
-    rb_gc_mark(ctx->thread);
+    if (ctx) {
+        rb_gc_mark(ctx->thread);
+    }
 }
 
 static void
 async_cb_dispatcher_free(void *ptr)
 {
     struct async_cb_dispatcher *ctx = (struct async_cb_dispatcher *)ptr;
-    xfree(ctx);
+    if (ctx) {
+        xfree(ctx);
+    }
 }
 
 struct rb_ractor_local_storage_type async_cb_dispatcher_key_type = {

diff --git a/spec/ffi/fork_spec.rb b/spec/ffi/fork_spec.rb
@@ -62,5 +62,14 @@ def run_async_callback(libtest)
 
       expect(Process.wait2[1].exitstatus).to eq(44)
     end
+
+    it "GC doesn't crash when the dispatcher thread was stopped. #1050" do
+      FFI::Function.new(:int, [], proc{})
+      fork do
+        GC.start
+        Process.exit 45
+      end
+      expect(Process.wait2[1].exitstatus).to eq(45)
+    end
   end
 end