每次有判题任务完成的时候，递归调用自己判断还有没有等待的任务

judge_dispatcher/migrations/0002_auto_20151207_2310.py

@@ -0,0 +1,32 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('judge_dispatcher', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='judgewaitingqueue',
+            name='memory_limit',
+            field=models.IntegerField(default=1),
+            preserve_default=False,
+        ),
+        migrations.AddField(
+            model_name='judgewaitingqueue',
+            name='test_case_id',
+            field=models.CharField(default=1, max_length=40),
+            preserve_default=False,
+        ),
+        migrations.AddField(
+            model_name='judgewaitingqueue',
+            name='time_limit',
+            field=models.IntegerField(default=1),
+            preserve_default=False,
+        ),
+    ]

judge_dispatcher/models.py

@@ -17,7 +17,14 @@ class JudgeServer(models.Model):
 
     def use_judge_instance(self):
         self.left_instance_number -= 1
-        self.workload = 100 - int(self.left_instance_number / self.max_instance_number)
+        self.workload = 100 - int(float(self.left_instance_number) / self.max_instance_number * 100)
+        print self.left_instance_number, self.workload
+        self.save()
+
+    def release_judge_instance(self):
+        self.left_instance_number += 1
+        self.workload = 100 - int(float(self.left_instance_number) / self.max_instance_number * 100)
+        print self.left_instance_number, self.workload
         self.save()
 
     class Meta:
@@ -26,6 +33,9 @@ class JudgeServer(models.Model):
 
 class JudgeWaitingQueue(models.Model):
     submission_id = models.CharField(max_length=40)
+    time_limit = models.IntegerField()
+    memory_limit = models.IntegerField()
+    test_case_id = models.CharField(max_length=40)
     create_time = models.DateTimeField(auto_now_add=True)
 
     class Meta:

judge_dispatcher/tasks.py

@@ -13,7 +13,8 @@ from problem.models import Problem
 from submission.models import Submission
 from account.models import User
 from utils.cache import get_cache_redis
-from .models import JudgeServer,JudgeWaitingQueue
+
+from .models import JudgeServer, JudgeWaitingQueue
 
 logger = logging.getLogger("app_info")
 
@@ -25,25 +26,31 @@ class JudgeDispatcher(object):
         self.memory_limit = memory_limit
         self.test_case_id = test_case_id
         self.user = User.objects.get(id=submission.user_id)
-    
+
     def choose_judge_server(self):
         servers = JudgeServer.objects.filter(workload__lt=100, lock=False, status=True).order_by("-workload")
         if servers.exists():
-            return servers[0]
-    
-    def judge(self):
+            server = servers[0]
+            server.use_judge_instance()
+            return server
+
+    def judge(self, is_waiting_task=False):
         self.submission.judge_start_time = int(time.time() * 1000)
         try:
             judge_server = self.choose_judge_server()
             # 如果没有合适的判题服务器，就放入等待队列中等待判题
             if not judge_server:
-                JudgeWaitingQueue.objects.create(submission_id=self.submission.id)
+                if not is_waiting_task:
+                    JudgeWaitingQueue.objects.create(submission_id=self.submission.id, time_limit=self.time_limit,
+                                                     memory_limit=self.memory_limit, test_case_id=self.test_case_id)
                 return
 
             s = TimeoutServerProxy("http://" + judge_server.ip + ":" + str(judge_server.port), timeout=20)
 
             data = s.run(judge_server.token, self.submission.id, self.submission.language,
                          self.submission.code, self.time_limit, self.memory_limit, self.test_case_id)
+
+            judge_server.release_judge_instance()
             # 编译错误
             if data["code"] == 1:
                 self.submission.result = result["compile_error"]
@@ -67,7 +74,19 @@ class JudgeDispatcher(object):
             self.update_contest_problem_status()
         else:
             self.update_problem_status()
-    
+
+        if is_waiting_task:
+            JudgeWaitingQueue.objects.filter(submission_id=self.submission.id).delete()
+
+        waiting_submissions = JudgeWaitingQueue.objects.all()
+        if waiting_submissions.exists():
+            submission = waiting_submissions.first()
+            # 防止循环依赖
+            from submission.tasks import _judge
+            _judge(Submission.objects.get(id=submission.submission_id), time_limit=submission.time_limit,
+                   memory_limit=submission.memory_limit, test_case_id=submission.test_case_id,
+                   is_waiting_task=True)
+
     def update_problem_status(self):
         problem = Problem.objects.get(id=self.submission.problem_id)
 
@@ -109,7 +128,7 @@ class JudgeDispatcher(object):
         self.user.save()
 
         self.update_contest_rank(contest)
-    
+
     def update_contest_rank(self, contest):
         if contest.real_time_rank:
             get_cache_redis().delete(str(contest.id) + "_rank_cache")

submission/tasks.py

@@ -5,5 +5,5 @@ from judge_dispatcher.tasks import JudgeDispatcher
 
 
 @task()
-def _judge(submission, time_limit, memory_limit, test_case_id):
-    JudgeDispatcher(submission, time_limit, memory_limit, test_case_id).judge()
+def _judge(submission, time_limit, memory_limit, test_case_id, is_waiting_task=False):
+    JudgeDispatcher(submission, time_limit, memory_limit, test_case_id).judge(is_waiting_task)

submission/views.py

@@ -13,7 +13,7 @@ from problem.models import Problem
 from contest.models import ContestProblem, Contest
 from contest.decorators import check_user_contest_permission
 from utils.shortcuts import serializer_invalid_response, error_response, success_response, error_page, paginate
-from .task import _judge
+from .tasks import _judge
 from .models import Submission
 from .serializers import (CreateSubmissionSerializer, SubmissionSerializer,
                           SubmissionhareSerializer, SubmissionRejudgeSerializer,