Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2016 Juniper Networks, Inc. All rights reserved.
       3             :  */
       4             : 
       5             : #include "db/db_table_walk_mgr.h"
       6             : 
       7             : #include <boost/bind/bind.hpp>
       8             : #include <boost/foreach.hpp>
       9             : 
      10             : #include "base/logging.h"
      11             : #include "base/task.h"
      12             : #include "base/task_annotations.h"
      13             : #include "db/db.h"
      14             : #include "db/db_partition.h"
      15             : #include "db/db_table.h"
      16             : #include "db/db_table_partition.h"
      17             : 
      18             : using namespace boost::placeholders;
      19             : 
      20         285 : DBTableWalkMgr::DBTableWalkMgr()
      21         570 :     : walk_request_trigger_(new TaskTrigger(
      22             :         boost::bind(&DBTableWalkMgr::ProcessWalkRequestList, this),
      23         570 :         TaskScheduler::GetInstance()->GetTaskId("db::Walker"), 0)),
      24         570 :       walk_done_trigger_(new TaskTrigger(
      25             :         boost::bind(&DBTableWalkMgr::ProcessWalkDone, this),
      26         570 :         TaskScheduler::GetInstance()->GetTaskId("db::Walker"), 0)) {
      27         285 : }
      28             : 
      29         724 : bool DBTableWalkMgr::ProcessWalkRequestList() {
      30         724 :     CHECK_CONCURRENCY("db::Walker");
      31         724 :     std::scoped_lock lock(mutex_);
      32         724 :     if (!current_table_walk_.empty()) return true;
      33             :     while (true) {
      34         687 :         if (walk_request_list_.empty()) break;
      35         500 :         WalkRequestInfoPtr info = walk_request_list_.front();
      36         500 :         walk_request_set_.erase(info.get());
      37         500 :         walk_request_list_.pop_front();
      38         500 :         current_table_walk_.swap(info->pending_requests);
      39         500 :         DBTable *table = info->table;
      40         500 :         bool walk_table = false;
      41        1000 :         for (auto walker : current_table_walk_) {
      42         500 :             if (walker->stopped()) continue;
      43         500 :             walker->set_in_progress();
      44         500 :             walker->reset_walk_again();
      45         500 :             walk_table = true;
      46         500 :         }
      47         500 :         if (walk_table) {
      48             :             // start the walk
      49         500 :             table->StartWalk();
      50         500 :             break;
      51             :         } else {
      52           0 :             current_table_walk_.clear();
      53             :         }
      54         500 :     }
      55         687 :     return true;
      56         724 : }
      57             : 
      58         500 : bool DBTableWalkMgr::ProcessWalkDone() {
      59         500 :     CHECK_CONCURRENCY("db::Walker");
      60         500 :     assert(!current_table_walk_.empty());
      61        1000 :     for (auto walker : current_table_walk_) {
      62         500 :         if (walker->walk_again())
      63           0 :             walker->set_walk_requested();
      64         500 :         else if (!walker->stopped())
      65         500 :             walker->set_walk_done();
      66         500 :         if (walker->stopped() || walker->walk_again()) continue;
      67         500 :         walker->walk_complete()(walker, walker->table());
      68         500 :     }
      69         500 :     current_table_walk_.clear();
      70         500 :     walk_request_trigger_->Set();
      71         500 :     return true;
      72             : }
      73             : 
      74         500 : DBTable::DBTableWalkRef DBTableWalkMgr::AllocWalker(DBTable *table,
      75             :                DBTable::WalkFn walk_fn, DBTable::WalkCompleteFn walk_complete) {
      76         500 :     table->incr_walker_count();
      77         500 :     DBTableWalk *walker = new DBTableWalk(table, walk_fn, walk_complete);
      78         500 :     return DBTable::DBTableWalkRef(walker);
      79             : }
      80             : 
      81         404 : void DBTableWalkMgr::ReleaseWalker(DBTable::DBTableWalkRef &ref) {
      82         404 :     ref->set_walk_stopped();
      83         404 :     ref.reset();
      84         404 : }
      85             : 
      86         116 : void DBTableWalkMgr::WalkAgain(DBTable::DBTableWalkRef ref) {
      87         116 :     WalkTable(ref);
      88         116 : }
      89             : 
      90         616 : void DBTableWalkMgr::WalkTable(DBTable::DBTableWalkRef walk) {
      91         616 :     std::scoped_lock lock(mutex_);
      92         616 :     DBTable *table = walk->table();
      93             : 
      94         616 :     if (walk->in_progress()) {
      95           0 :         table->incr_walk_again_count();
      96           0 :         walk->set_walk_again();
      97             :     } else {
      98         616 :         table->incr_walk_request_count();
      99         616 :         walk->set_walk_requested();
     100             :     }
     101             : 
     102         616 :     WalkRequestInfo tmp_info = WalkRequestInfo(table);
     103         616 :     WalkRequestInfoSet::iterator it = walk_request_set_.find(&tmp_info);
     104         616 :     if (it != walk_request_set_.end()) {
     105         116 :         (*it)->AppendWalkReq(walk);
     106         116 :         return;
     107             :     }
     108             : 
     109         500 :     WalkRequestInfo *new_info = new WalkRequestInfo(table);
     110         500 :     new_info->AppendWalkReq(walk);
     111         500 :     walk_request_list_.push_back(WalkRequestInfoPtr(new_info));
     112         500 :     walk_request_set_.insert(new_info);
     113         500 :     walk_request_trigger_->Set();
     114         732 : }
     115             : 
     116         500 : void DBTableWalkMgr::WalkDone() {
     117         500 :     walk_done_trigger_->Set();
     118         500 : }
     119             : 
     120         459 : bool DBTableWalkMgr::InvokeWalkCb(DBTablePartBase *part, DBEntryBase *entry) {
     121         459 :     uint32_t skip_walk_count = 0;
     122         918 :     for (auto walker : current_table_walk_) {
     123         459 :         if (walker->done() || walker->stopped() || walker->walk_again()) {
     124           0 :             skip_walk_count++;
     125           0 :             continue;
     126             :         }
     127         459 :         bool more = walker->walk_fn()(part, entry);
     128         459 :         if (!more) {
     129           0 :             skip_walk_count++;
     130           0 :             if (!walker->stopped()) walker->set_walk_done();
     131             :         }
     132         459 :     }
     133         459 :     return (skip_walk_count < current_table_walk_.size());
     134             : }