made PeriodicTask more explicity

mongodb · May 17, 2011 · ec72258 · ec72258
1 parent fc2f623
commit ec72258
Show file tree

Hide file tree

Showing 4 changed files with 48 additions and 15 deletions.
diff --git a/s/d_writeback.cpp b/s/d_writeback.cpp
@@ -109,7 +109,7 @@ namespace mongo {
         return false;
     }
 
-    void WriteBackManager::Cleaner::doWork() { 
+    void WriteBackManager::Cleaner::taskDoWork() { 
         for ( int i=0; i<1000; i++ ) {
             if ( ! writeBackManager.cleanupOldQueues() )
                 break;

diff --git a/s/d_writeback.h b/s/d_writeback.h
@@ -93,8 +93,8 @@ namespace mongo {
 
         class Cleaner : public PeriodicTask {
         public:
-            virtual string name() const { return "WriteBackManager::cleaner"; }
-            virtual void doWork();
+            virtual string taskName() const { return "WriteBackManager::cleaner"; }
+            virtual void taskDoWork();
         };
 
         Cleaner _cleaner;

diff --git a/util/background.cpp b/util/background.cpp
@@ -18,6 +18,7 @@
 #include "pch.h"
 
 #include "concurrency/mutex.h"
+#include "concurrency/spin_lock.h"
 
 #include "background.h"
 #include "time_support.h"
@@ -125,38 +126,61 @@ namespace mongo {
     PeriodicTask::PeriodicTask() {
         if ( ! theRunner )
             theRunner = new Runner();
-        theRunner->_tasks.push_back( this );
+        theRunner->add( this );
     }
 
     PeriodicTask::~PeriodicTask() {
+        theRunner->remove( this );
+    }
+
+    void PeriodicTask::Runner::add( PeriodicTask* task ) {
+        scoped_spinlock lk( _lock );
+        _tasks.push_back( task );
+    }
+
+    void PeriodicTask::Runner::remove( PeriodicTask* task ) {
+        scoped_spinlock lk( _lock );
+        for ( size_t i=0; i<_tasks.size(); i++ ) {
+            if ( _tasks[i] == task ) {
+                _tasks[i] = 0;
+                break;
+            }
+        }
     }
 
     void PeriodicTask::Runner::run() { 
+        int sleeptime = 60;
+        DEV sleeptime = 5; // to catch race conditions
+
         while ( ! inShutdown() ) {
 
-            sleepsecs( 60 );
+            sleepsecs( sleeptime );
+
+            scoped_spinlock lk( _lock );
 
             size_t size = _tasks.size();
 
             for ( size_t i=0; i<size; i++ ) {
-                if ( inShutdown() )
-                    break;
-
                 PeriodicTask * t = _tasks[i];
+                if ( ! t )
+                    continue;
 
+                if ( inShutdown() )
+                    break;
+
                 Timer timer;
                 try {
-                    t->doWork();
+                    t->taskDoWork();
                 }
                 catch ( std::exception& e ) {
-                    error() << "task: " << t->name() << " failed: " << e.what() << endl;
+                    error() << "task: " << t->taskName() << " failed: " << e.what() << endl;
                 }
                 catch ( ... ) {
-                    error() << "task: " << t->name() << " failed with unknown error" << endl;
+                    error() << "task: " << t->taskName() << " failed with unknown error" << endl;
                 }
 
                 int ms = timer.millis();
-                LOG( ms <= 3 ) << "task: " << t->name() << " took: " << ms << "ms" << endl;
+                LOG( ms <= 3 ) << "task: " << t->taskName() << " took: " << ms << "ms" << endl;
             }
         }
     }

diff --git a/util/background.h b/util/background.h
@@ -17,6 +17,8 @@
 
 #pragma once
 
+#include "concurrency/spin_lock.h"
+
 namespace mongo {
 
     /**
@@ -117,8 +119,8 @@ namespace mongo {
         PeriodicTask();
         virtual ~PeriodicTask();
 
-        virtual void doWork() = 0;
-        virtual string name() const = 0;
+        virtual void taskDoWork() = 0;
+        virtual string taskName() const = 0;
 
         class Runner : public BackgroundJob {
         public:
@@ -127,13 +129,20 @@ namespace mongo {
             virtual string name() const { return "PeriodicTask::Runner"; }
 
             virtual void run();
+
+            void add( PeriodicTask* task );
+            void remove( PeriodicTask* task );
 
         private:
+
+            SpinLock _lock;
+
             // these are NOT owned by Runner
             // Runner will not delete these
+            // this never gets smaller
+            // only fields replaced with nulls
             vector<PeriodicTask*> _tasks;
 
-            friend class PeriodicTask;
         };
 
         static Runner* theRunner;