Use the stop time as the deadline for the seeding command.

This avoids hanging forever when the seeding command does so.

PiperOrigin-RevId: 861226695

centipede/centipede_callbacks.cc

diff --git a/centipede/centipede_callbacks.cc b/centipede/centipede_callbacks.cc
index a9e0d7d..3f6f817 100644
--- a/centipede/centipede_callbacks.cc
+++ b/centipede/centipede_callbacks.cc
@@ -631,9 +631,22 @@
   cmd_options.stderr_file = execute_log_path_;
   cmd_options.temp_file_path = temp_input_file_path_;
   Command cmd{binary, std::move(cmd_options)};
-  const int retval = cmd.Execute();
+  const int retval = [&] {
+    if (!cmd.ExecuteAsync()) {
+      FUZZTEST_LOG(ERROR) << "Failed to execute seeding command "
+                          << cmd.ToString();
+      return EXIT_FAILURE;
+    }
+    const auto wait_result = cmd.Wait(GetStopTime());
+    if (!wait_result.has_value()) {
+      FUZZTEST_LOG(ERROR) << "Failed to wait for the seeding command "
+                          << cmd.ToString();
+      return EXIT_FAILURE;
+    }
+    return *wait_result;
+  }();
 
-  if (env_.print_runner_log) {
+  if (env_.print_runner_log || retval != EXIT_SUCCESS) {
     FUZZTEST_LOG(INFO) << "Getting seeds via external binary returns "
                        << retval;
     PrintExecutionLog();
@@ -659,7 +672,7 @@
   FUZZTEST_LOG_IF(ERROR, error)
       << "Failed to remove seed inputs directory: " << error.message();
 
-  return retval == 0;
+  return retval == EXIT_SUCCESS;
 }
 
 // See also: `DumpSerializedTargetConfigToFile()`.

centipede/centipede_test.cc

diff --git a/centipede/centipede_test.cc b/centipede/centipede_test.cc
index dac4302..c06298b 100644
--- a/centipede/centipede_test.cc
+++ b/centipede/centipede_test.cc
@@ -31,6 +31,7 @@
 #include "gtest/gtest.h"
 #include "absl/container/flat_hash_set.h"
 #include "absl/strings/str_cat.h"
+#include "absl/time/clock.h"
 #include "absl/time/time.h"
 #include "./centipede/centipede_callbacks.h"
 #include "./centipede/centipede_default_callbacks.h"
@@ -1200,6 +1201,20 @@
   EXPECT_NE(inputs, mutants);
 }
 
+TEST_F(CentipedeWithTemporaryLocalDir,
+       GetsSeedViaExternalBinaryStopsAfterStopTime) {
+  Environment env;
+  env.binary = "sleep 100";
+  CentipedeDefaultCallbacks callbacks(env);
+  const auto start = absl::Now();
+  ClearEarlyStopRequestAndSetStopTime(start + absl::Seconds(3));
+  std::vector<ByteArray> seeds;
+  callbacks.GetSeeds(/*num_seeds=*/1, seeds);
+  // Give it some slack to stop in 5s.
+  EXPECT_LE(absl::Now() - start, absl::Seconds(5));
+  ClearEarlyStopRequestAndSetStopTime(absl::InfiniteFuture());
+}
+
 TEST_F(CentipedeWithTemporaryLocalDir, HangingFuzzTargetExitsAfterTimeout) {
   Environment env;
   env.binary =