Merge remote-tracking branch 'origin/master'

db/vlog.h

@@ -68,8 +68,29 @@ struct vlog_info {
 };
 
 struct vlog_handler {
+  std::mutex vlog_handler_latch_;
+  size_t curr_access_thread_nums;
   SharedLock vlog_latch_; // 表明当前vlog上的并发情况，读上soft_lock，写上hard_lock
-  vlog_handler() {}
+  vlog_handler() : curr_access_thread_nums(0) {}
+  inline void incre_access_thread_nums() {
+    vlog_handler_latch_.lock();
+    curr_access_thread_nums ++;
+    vlog_handler_latch_.unlock();
+  }
+  inline void decre_access_thread_nums() {
+    vlog_handler_latch_.lock();
+    curr_access_thread_nums --;
+    vlog_handler_latch_.unlock();
+  }
+  inline bool non_access_thread() {
+    bool flag = false;
+    vlog_handler_latch_.lock();
+    if (!curr_access_thread_nums) {
+      flag = true;
+    }
+    vlog_handler_latch_.unlock();
+    return flag;
+  }
 };
 
 

db/vlog_gc.h

@@ -8,6 +8,8 @@
 
 #include <string>
 #include <mutex>
+#include <thread>
+#include <chrono>
 #include "../db/slotpage.h"
 #include "../db/vlog.h"
 #include "../db/gc_executor.h"
@@ -22,7 +24,18 @@ friend class gc_executor;
  public:
   VlogGC(SlotPage *s, VlogSet *vs) : slot_page_(s), vlog_set(vs),max_thread_nums_(THREAD_NUM),
                                      curr_thread_nums_(0), gc_num(0) {}
-  ~VlogGC() {}
+  ~VlogGC() {
+    while (true) {
+      curr_thread_nums_latch_.lock();
+      if (curr_thread_nums_) {
+        curr_thread_nums_latch_.unlock();
+        std::this_thread::sleep_for(std::chrono::milliseconds(2));
+      } else {
+        curr_thread_nums_latch_.unlock();
+        break;
+      }
+    }
+  }
 
   void do_gc(size_t old_vlog_num, size_t new_vlog_num);
 

db/vlog_set.cpp

@@ -107,9 +107,11 @@ void VlogSet::get_value(const struct slot_content &sc, std::string *value) {
     vhandler = get_vlog_handler(vinfo->vlog_num_for_gc);
   }
   vhandler->vlog_latch_.soft_lock();
+  vhandler->incre_access_thread_nums(); // FIXME: increase thread nums
   mtx.unlock(); // for better performance
   vinfo->vlog_info_latch_.unlock();
   read_vlog_value(sc, value);
+  vhandler->decre_access_thread_nums(); // FIXME: decrease thread nums
   vhandler->vlog_latch_.soft_unlock();
 }
 
@@ -154,9 +156,11 @@ void VlogSet::put_value(struct slot_content &sc, size_t slot_num, const leveldb:
   }
 
   vhandler->vlog_latch_.hard_lock();
+  vhandler->incre_access_thread_nums(); // FIXME: increase thread nums
   mtx.unlock(); // for better performance
   vinfo->vlog_info_latch_.unlock();
   write_vlog_value(sc, slot_num, value);
+  vhandler->decre_access_thread_nums(); // FIXME: decrease thread nums
   vhandler->vlog_latch_.hard_unlock();
 }
 
@@ -171,9 +175,11 @@ void VlogSet::del_value(const struct slot_content &sc) {
   }
 
   vhandler->vlog_latch_.hard_lock();
+  vhandler->decre_access_thread_nums(); // FIXME: increase thread nums
   mtx.unlock();  // for better performance
   vinfo->vlog_info_latch_.unlock();
   mark_del_value(sc);
+  vhandler->decre_access_thread_nums(); // FIXME: decrease thread nums
   vhandler->vlog_latch_.hard_unlock();
 }
 

test/db_test1.cc

@@ -37,7 +37,7 @@ int test2() {
   assert(status.ok());
 
   const std::string value_prefix = "value_";
-  const size_t loop_times = 1000;
+  const size_t loop_times = 100000;
   for (auto i = 0; i < loop_times; i++) {
     auto key = std::to_string(i);
     auto value = value_prefix + key;