add periodic task

src/brpc/periodic_task.cpp

+// Copyright (c) 2018 brpc authors.
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Authors: Ge,Jun (gejun@baidu.com)
+
+#include <bthread/bthread.h>
+#include <bthread/unstable.h>
+#include "brpc/periodic_task.h"
+
+namespace brpc {
+
+
+PeriodicTask::~PeriodicTask() {
+}
+
+static void* PeriodicTaskThread(void* arg) {
+    PeriodicTask* task = static_cast<PeriodicTask*>(arg);
+    timespec abstime;
+    if (!task->DoPeriodicTask(&abstime)) { // end
+        task->DoPeriodicTask(NULL);
+        return NULL;
+    }
+    PeriodicTaskManager::StartTaskAt(task, abstime);
+    return NULL;
+}
+
+static void RunPeriodicTaskThread(void* arg) {
+    bthread_t th = 0;
+    int rc = bthread_start_background(
+        &th, &BTHREAD_ATTR_NORMAL, PeriodicTaskThread, arg);
+    if (rc != 0) {
+        LOG(ERROR) << "Fail to start PeriodicTaskThread";
+        static_cast<PeriodicTask*>(arg)->DoPeriodicTask(NULL);
+        return;
+    }
+}
+
+void PeriodicTaskManager::StartTaskAt(PeriodicTask* task, const timespec& abstime) {
+    if (task == NULL) {
+        LOG(ERROR) << "Param[task] is NULL";
+        return;
+    }
+    bthread_timer_t timer_id;
+    const int rc = bthread_timer_add(
+        &timer_id, abstime, RunPeriodicTaskThread, task);
+    if (rc != 0) {
+        LOG(ERROR) << "Fail to add timer for RunPerodicTaskThread";
+        task->DoPeriodicTask(NULL);
+        return;
+    }
+}
+
+} // namespace brpc

src/brpc/periodic_task.h

+// Copyright (c) 2018 brpc authors.
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Authors: Ge,Jun (gejun@baidu.com)
+
+#ifndef BRPC_HEALTH_CHECK_MANAGER_H
+#define BRPC_HEALTH_CHECK_MANAGER_H
+
+namespace brpc {
+
+
+// Override DoPeriodicTask() with code that needs to be periodically run. If
+// the task is completed, the method should return false; Otherwise the method
+// should return true and set `next_abstime' to the time that the task should
+// be run next time.
+// Each call to DoPeriodicTask() is run in a separated bthread which can be
+// suspended. To preserve states between different calls, put the states as
+// fields of (subclass of) PeriodicTask.
+// If any error occurs or DoPeriodicTask() returns false, the task is called
+// with DoPeriodicTask(NULL) and will not be scheduled anymore.
+class PeriodicTask {
+public:
+    virtual ~PeriodicTask();
+    virtual bool DoPeriodicTask(timespec* next_abstime) = 0;
+};
+
+class PeriodicTaskManager {
+public:
+    static void StartTaskAt(PeriodicTask* task, const timespec& abstime);
+};
+
+
+} // namespace brpc
+
+#endif  // BRPC_HEALTH_CHECK_MANAGER_H