Abstract directory locking into util.cpp

Author: meshcollider

src/init.cpp

@@ -1143,23 +1143,10 @@ bool AppInitParameterInteraction()
 
 static bool LockDataDirectory(bool probeOnly)
 {
-    std::string strDataDir = GetDataDir().string();
-
     // Make sure only a single Bitcoin process is using the data directory.
-    fs::path pathLockFile = GetDataDir() / ".lock";
-    FILE* file = fsbridge::fopen(pathLockFile, "a"); // empty lock file; created if it doesn't exist.
-    if (file) fclose(file);
-
-    try {
-        static boost::interprocess::file_lock lock(pathLockFile.string().c_str());
-        if (!lock.try_lock()) {
-            return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running."), strDataDir, _(PACKAGE_NAME)));
-        }
-        if (probeOnly) {
-            lock.unlock();
-        }
-    } catch(const boost::interprocess::interprocess_exception& e) {
-        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running.") + " %s.", strDataDir, _(PACKAGE_NAME), e.what()));
+    fs::path datadir = GetDataDir();
+    if (!LockDirectory(datadir, ".lock", probeOnly)) {
+        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running."), datadir.string(), _(PACKAGE_NAME)));
     }
     return true;
 }

src/util.cpp

@@ -72,6 +72,7 @@
 
 #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
 #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
+#include <boost/interprocess/sync/file_lock.hpp>
 #include <boost/program_options/detail/config_file.hpp>
 #include <boost/thread.hpp>
 #include <openssl/crypto.h>
@@ -375,6 +376,27 @@ int LogPrintStr(const std::string &str)
     return ret;
 }
 
+bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only)
+{
+    fs::path pathLockFile = directory / lockfile_name;
+    FILE* file = fsbridge::fopen(pathLockFile, "a"); // empty lock file; created if it doesn't exist.
+    if (file) fclose(file);
+
+    try {
+        static std::map<std::string, boost::interprocess::file_lock> locks;
+        boost::interprocess::file_lock& lock = locks.emplace(pathLockFile.string(), pathLockFile.string().c_str()).first->second;
+        if (!lock.try_lock()) {
+            return false;
+        }
+        if (probe_only) {
+            lock.unlock();
+        }
+    } catch (const boost::interprocess::interprocess_exception& e) {
+        return error("Error while attempting to lock directory %s: %s", directory.string(), e.what());
+    }
+    return true;
+}
+
 /** Interpret string as boolean, for argument parsing */
 static bool InterpretBool(const std::string& strValue)
 {

src/util.h

@@ -173,6 +173,7 @@ bool TruncateFile(FILE *file, unsigned int length);
 int RaiseFileDescriptorLimit(int nMinFD);
 void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length);
 bool RenameOver(fs::path src, fs::path dest);
+bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only=false);
 bool TryCreateDirectories(const fs::path& p);
 fs::path GetDefaultDataDir();
 const fs::path &GetDataDir(bool fNetSpecific = true);

src/wallet/db.cpp

@@ -18,7 +18,6 @@
 #include <sys/stat.h>
 #endif
 
-#include <boost/interprocess/sync/file_lock.hpp>
 #include <boost/thread.hpp>
 
 namespace {
@@ -53,24 +52,6 @@ void CheckUniqueFileid(const CDBEnv& env, const std::string& filename, Db& db)
         }
     }
 }
-
-bool LockEnvDirectory(const fs::path& env_path)
-{
-    // Make sure only a single Bitcoin process is using the wallet directory.
-    fs::path lock_file_path = env_path / ".walletlock";
-    FILE* file = fsbridge::fopen(lock_file_path, "a"); // empty lock file; created if it doesn't exist.
-    if (file) fclose(file);
-
-    try {
-        static boost::interprocess::file_lock lock(lock_file_path.string().c_str());
-        if (!lock.try_lock()) {
-            return false;
-        }
-    } catch (const boost::interprocess::interprocess_exception& e) {
-        return error("Error obtaining lock on wallet directory %s: %s.", env_path.string(), e.what());
-    }
-    return true;
-}
 } // namespace
 
 //
@@ -122,7 +103,7 @@ bool CDBEnv::Open(const fs::path& pathIn, bool retry)
     boost::this_thread::interruption_point();
 
     strPath = pathIn.string();
-    if (!LockEnvDirectory(pathIn)) {
+    if (!LockDirectory(pathIn, ".walletlock")) {
         LogPrintf("Cannot obtain a lock on wallet directory %s. Another instance of bitcoin may be using it.\n", strPath);
         return false;
     }