Delete Instance Task only in exit handler.

We currently have a delete of instance task object after terminating the task
as well. This could result in accessing a deleted instance task object (eg. when
the small timeout value is configured or when task exit takes long). Changing
this to delete only via exit handler.

Change-Id: I062400dae5ba580a44fdb4ce0c4c48994e9c1b95
closes-bug: #1612354
(cherry picked from commit 361318f)

src/vnsw/agent/oper/instance_manager.cc

@@ -525,6 +525,8 @@ void InstanceManager::ScheduleNextTask(InstanceTaskQueue *task_queue) {
 
             if (delay >= (netns_timeout_ * 2)) {
                task->Terminate();
+               if (task->IsSetup())
+                   return;
             } else {
                task->Stop();
                return;

src/vnsw/agent/oper/instance_task.cc

@@ -15,7 +15,7 @@ InstanceTaskExecvp::InstanceTaskExecvp(const std::string &name,
                                        const std::string &cmd,
                                        int cmd_type, EventManager *evm) :
         name_(name), cmd_(cmd), input_(*(evm->io_service())),
-        pid_(0), cmd_type_(cmd_type), pipe_stdout_(false) {
+        setup_done_(false), pid_(0), cmd_type_(cmd_type), pipe_stdout_(false) {
 }
 
 void InstanceTaskExecvp::ReadData(const boost::system::error_code &ec,
@@ -54,6 +54,9 @@ void InstanceTaskExecvp::Terminate() {
     kill(pid_, SIGKILL);
 }
 
+bool InstanceTaskExecvp::IsSetup() {
+    return setup_done_;
+}
 
 // If there is an error before the fork, task is set to "not running"
 // and "false" is returned to caller so that caller can take appropriate
@@ -124,6 +127,7 @@ bool InstanceTaskExecvp::Run() {
         //the task again
         return false;
     }
+    setup_done_ = true;
 
     bzero(rx_buff_, sizeof(rx_buff_));
     input_.async_read_some(boost::asio::buffer(rx_buff_, kBufLen),

src/vnsw/agent/oper/instance_task.h

@@ -28,6 +28,7 @@ class InstanceTask {
     virtual bool Run() = 0;
     virtual void Stop() = 0;
     virtual void Terminate() = 0;
+    virtual bool IsSetup() = 0;
 
     // TODO reimplement instance_manager.cc to remove these two?
     virtual pid_t pid() const = 0;
@@ -77,6 +78,7 @@ class InstanceTaskExecvp : public InstanceTask {
     bool Run();
     void Stop();
     void Terminate();
+    bool IsSetup();
 
     pid_t pid() const {
         return pid_;
@@ -105,6 +107,7 @@ class InstanceTaskExecvp : public InstanceTask {
     const std::string name_;
     std::string cmd_;
     boost::asio::posix::stream_descriptor input_;
+    bool setup_done_; // indicates whether errors_ has a valid descriptor or not
     char rx_buff_[kBufLen];
 
     pid_t pid_;

src/vnsw/agent/oper/libvirt_instance_adapter.h

@@ -38,6 +38,7 @@ class LibvirtInstanceAdapter : public InstanceManagerAdapter {
         bool Run();
         void Stop() {}
         void Terminate() {}
+        bool IsSetup() { return true; }
 
         const std::string &cmd() const {
             static const std::string cmdstr =
@@ -77,6 +78,7 @@ class LibvirtInstanceAdapter : public InstanceManagerAdapter {
         bool Run();
         void Stop() {}
         void Terminate() {}
+        bool IsSetup() { return true; }
 
         const std::string &cmd() const {
             static const std::string cmdstr =