修复setitimer无法限制子进程时间的BUG, 增加测试17

runner.c

@@ -31,7 +31,7 @@ void run(struct config *config, struct result *result) {
     int status;
     struct rusage resource_usage;
     struct timeval start, end;
-    struct rlimit memory_limit;
+    struct rlimit memory_limit, cpu_time_rlimit;
     int signal;
     int i;
     FILE* log_fp;
@@ -166,7 +166,7 @@ void run(struct config *config, struct result *result) {
         if (config->max_memory != MEMORY_UNLIMITED) {
             memory_limit.rlim_cur = memory_limit.rlim_max = (rlim_t) (config->max_memory) * 2;
             if (setrlimit(RLIMIT_AS, &memory_limit) == -1) {
-                LOG_FATAL(log_fp, "setrlimit failed, errno: %d", errno);
+                LOG_FATAL(log_fp, "setrlimit memory failed, errno: %d", errno);
                 ERROR(log_fp, SETRLIMIT_FAILED);
             }
         }
@@ -181,6 +181,14 @@ void run(struct config *config, struct result *result) {
                 LOG_FATAL(log_fp, "set real time timer failed");
                 ERROR(log_fp, SETITIMER_FAILED);
             }
+
+            // child process can not inherit timeout rules from parent process defined by setitimer, so we use setrlimit to
+            // control child process max running time
+            cpu_time_rlimit.rlim_cur = cpu_time_rlimit.rlim_max = (config->max_cpu_time + 1000) / 1000;
+            if (setrlimit(RLIMIT_CPU, &cpu_time_rlimit) == -1) {
+                LOG_FATAL(log_fp, "setrlimit cpu time failed, errno: %d", errno);
+                ERROR(log_fp, SETRLIMIT_FAILED);
+            }
         }
 
         // read stdin from in file

tests/17/Main.c

@@ -0,0 +1,29 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+
+int main()
+{
+    int status;
+    int pid;
+
+    if ((pid = fork()) < 0) {
+        perror("fork error");
+        return 0;
+    }
+
+    if (pid == 0) {
+        while (1) {};
+    }
+    else {
+        struct rusage resource_usage;
+        if (wait4(pid, &status, 0, &resource_usage) == -1) {
+            perror("wait4 error!");
+        }
+    }
+
+    return 0;
+}

tests/17/config

@@ -0,0 +1 @@
+{"language": "c", "max_cpu_time": 2000, "max_memory": 200000000, "use_sandbox": false}

tests/17/result

@@ -0,0 +1 @@
+{"flag": 0, "signal": 0}

tests/test.py

@@ -31,7 +31,7 @@ class JudgerTest(TestCase):
                 continue
             print "\n\nRunning test: ", i
             test_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), str(i))
-            exe_path = os.path.join("/tmp/judger_test", str(i))
+            exe_path = os.path.join(self.tmp_path, str(i))
             config = json.loads(open(os.path.join(test_dir, "config")).read())
             self.assertEqual(self.compile_src(os.path.join(test_dir, "Main.c"), config.pop("language"), exe_path), 0)
 
@@ -51,6 +51,7 @@ class JudgerTest(TestCase):
         self._judger_in_file_args_check()
         self._judger_args_args_check()
         self._judger_env_args_check()
+        self._judger_child_process_cpu_time_check()
         self._judger_user_args_check()
 
     def _judger_cpu_time_args_check(self):
@@ -129,6 +130,22 @@ class JudgerTest(TestCase):
                        out_file="/dev/null", max_cpu_time=2000, max_memory=200000000,
                        env=["aaa=123"], use_sandbox=True, use_nobody=True)
 
+    # child process can not inherit timeout rules from parent process defined by setitimer, so we use setrlimit to
+    # control child process max running time
+    def _judger_child_process_cpu_time_check(self):
+        try:
+            max_cpu_time = 2000
+            result = judger.run(path=os.path.join(self.tmp_path, "17"), in_file="/dev/null",
+                                out_file="/dev/null", max_cpu_time=max_cpu_time, max_memory=200000000,
+                                env=["aaa=123"], use_sandbox=False, use_nobody=True)
+            expected_cpu_time = (max_cpu_time + 1000) / 1000 * 1000
+            if result["cpu_time"] > expected_cpu_time * 1.1:
+                self.fail("cpu time exceeded")
+            if result["real_time"] >= max_cpu_time * 3:
+                self.fail("real time exceeded")
+        except Exception as e:
+            self.fail(e.message)
+
 
 if __name__ == "__main__":
     main()