Move domain setup checking to a new runner function `InitializeForExe…

…cution()`.

The function is called in `RunnerMain()` immediately before we start executing
inputs. This allows long-running initialization (e.g., one that triggers loading
large seeds into a seeded domain) to happen separately, and thus not to be timed
as part of executing an input.

PiperOrigin-RevId: 726191912

centipede/runner.cc

@@ -1153,6 +1153,8 @@ int RunnerMain(int argc, char **argv, RunnerCallbacks &callbacks) {
     WriteFailureDescription(std::string(failure_description).c_str());
   });
 
+  callbacks.InitializeForExecution();
+
   // Inputs / outputs from shmem.
   if (state.HasFlag(":shmem:")) {
     if (!state.arg1 || !state.arg2) return EXIT_FAILURE;

centipede/runner_interface.h

@@ -134,6 +134,9 @@ namespace centipede {
 // no stability is guaranteed for other usages.
 class RunnerCallbacks {
  public:
+  // Runs any initialization logic that should happen once before subsequent
+  // calls to `Execute()`.
+  virtual void InitializeForExecution() {}
   // Attempts to execute the test logic using `input`, and returns false if the
   // input should be ignored from the corpus, true otherwise.
   virtual bool Execute(ByteSpan input) = 0;

fuzztest/internal/centipede_adaptor.cc

@@ -305,14 +305,16 @@ class CentipedeAdaptorRunnerCallbacks : public centipede::RunnerCallbacks {
         cmp_tables_(std::make_unique<TablesOfRecentCompares>()),
         prng_(GetRandomSeed()) {}
 
-  bool Execute(centipede::ByteSpan input) override {
+  void InitializeForExecution() override {
     if (!domain_setup_is_checked_) {
       // Create a new domain input to trigger any domain setup
       // failures here. (e.g. Ineffective Filter)
       fuzzer_impl_.params_domain_.Init(prng_);
       domain_setup_is_checked_ = true;
     }
+  }
 
+  bool Execute(centipede::ByteSpan input) override {
     auto parsed_input =
         fuzzer_impl_.TryParse({(char*)input.data(), input.size()});
     if (parsed_input.ok()) {