Add function to close all Db's and reload the databae environment

Adds a ReloadDbEnv function to BerkeleyEnvironment in order to close all Db
instances, closes the environment, resets it, and then reopens
the BerkeleyEnvironment.

Also adds a ReloadDbEnv function to BerkeleyDatabase that calls
BerkeleyEnvironment's ReloadDbEnv.

1 files changed, 34 insertions, 0 deletions

diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index 536243be4f..2d57c92ccc 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -556,6 +556,7 @@ void BerkeleyBatch::Close()
         LOCK(cs_db);
         --env->mapFileUseCount[strFile];
     }
+    env->m_db_in_use.notify_all();
 }
 
 void BerkeleyEnvironment::CloseDb(const std::string& strFile)
@@ -572,6 +573,32 @@ void BerkeleyEnvironment::CloseDb(const std::string& strFile)
     }
 }
 
+void BerkeleyEnvironment::ReloadDbEnv()
+{
+    // Make sure that no Db's are in use
+    AssertLockNotHeld(cs_db);
+    std::unique_lock<CCriticalSection> lock(cs_db);
+    m_db_in_use.wait(lock, [this](){
+        for (auto& count : mapFileUseCount) {
+            if (count.second > 0) return false;
+        }
+        return true;
+    });
+
+    std::vector<std::string> filenames;
+    for (auto it : mapDb) {
+        filenames.push_back(it.first);
+    }
+    // Close the individual Db's
+    for (const std::string& filename : filenames) {
+        CloseDb(filename);
+    }
+    // Reset the environment
+    Flush(true); // This will flush and close the environment
+    Reset();
+    Open(true);
+}
+
 bool BerkeleyBatch::Rewrite(BerkeleyDatabase& database, const char* pszSkip)
 {
     if (database.IsDummy()) {
@@ -802,3 +829,10 @@ void BerkeleyDatabase::Flush(bool shutdown)
         }
     }
 }
+
+void BerkeleyDatabase::ReloadDbEnv()
+{
+    if (!IsDummy()) {
+        env->ReloadDbEnv();
+    }
+}