Merge remote-tracking branch 'upstream/master'

java/org/rocksdb/BackupableDB.java

@@ -25,11 +25,14 @@ public class BackupableDB extends RocksDB {
   public static BackupableDB open(
       Options opt, BackupableDBOptions bopt, String db_path)
       throws RocksDBException {
-    // since BackupableDB c++ will handle the life cycle of
-    // the returned RocksDB of RocksDB.open(), here we store
-    // it as a BackupableDB member variable to avoid GC.
-    BackupableDB bdb = new BackupableDB(RocksDB.open(opt, db_path));
-    bdb.open(bdb.db_.nativeHandle_, bopt.nativeHandle_);
+
+    RocksDB db = RocksDB.open(opt, db_path);
+    BackupableDB bdb = new BackupableDB();
+    bdb.open(db.nativeHandle_, bopt.nativeHandle_);
+
+    // Prevent the RocksDB object from attempting to delete
+    // the underly C++ DB object.
+    db.disOwnNativeHandle();
 
     return bdb;
   }
@@ -64,9 +67,8 @@ public class BackupableDB extends RocksDB {
    * A protected construction that will be used in the static factory
    * method BackupableDB.open().
    */
-  protected BackupableDB(RocksDB db) {
+  protected BackupableDB() {
     super();
-    db_ = db;
   }
 
   @Override protected void finalize() {
@@ -75,6 +77,4 @@ public class BackupableDB extends RocksDB {
 
   protected native void open(long rocksDBHandle, long backupDBOptionsHandle);
   protected native void createNewBackup(long handle, boolean flag);
-
-  private final RocksDB db_;
 }

java/org/rocksdb/BackupableDBOptions.java

@@ -59,15 +59,14 @@ public class BackupableDBOptions extends RocksObject {
    * Release the memory allocated for the current instance
    * in the c++ side.
    */
-  @Override public synchronized void dispose() {
-    if (isInitialized()) {
-      dispose(nativeHandle_);
-    }
+  @Override protected void disposeInternal() {
+    assert(isInitialized());
+    disposeInternal(nativeHandle_);
   }
 
   private native void newBackupableDBOptions(String path,
       boolean shareTableFiles, boolean sync, boolean destroyOldData,
       boolean backupLogFiles, long backupRateLimit, long restoreRateLimit);
   private native String backupDir(long handle);
-  private native void dispose(long handle);
+  private native void disposeInternal(long handle);
 }

java/org/rocksdb/Filter.java

@@ -22,11 +22,10 @@ public abstract class Filter extends RocksObject {
    * RocksDB instances referencing the filter are closed.
    * Otherwise an undefined behavior will occur.
    */
-  @Override public synchronized void dispose() {
-    if (isInitialized()) {
-      dispose0(nativeHandle_);
-    }
+  @Override protected void disposeInternal() {
+    assert(isInitialized());
+    disposeInternal(nativeHandle_);
   }
 
-  private native void dispose0(long handle);
+  private native void disposeInternal(long handle);
 }

java/org/rocksdb/Options.java

@@ -2311,10 +2311,9 @@ public class Options extends RocksObject {
    * Release the memory allocated for the current instance
    * in the c++ side.
    */
-  @Override public synchronized void dispose() {
-    if (isInitialized()) {
-      dispose0();
-    }
+  @Override protected void disposeInternal() {
+    assert(isInitialized());
+    disposeInternal(nativeHandle_);
   }
 
   static final int DEFAULT_PLAIN_TABLE_BLOOM_BITS_PER_KEY = 10;
@@ -2322,7 +2321,7 @@ public class Options extends RocksObject {
   static final int DEFAULT_PLAIN_TABLE_INDEX_SPARSENESS = 16;
 
   private native void newOptions();
-  private native void dispose0();
+  private native void disposeInternal(long handle);
   private native void setCreateIfMissing(long handle, boolean flag);
   private native boolean createIfMissing(long handle);
   private native void setWriteBufferSize(long handle, long writeBufferSize);

java/org/rocksdb/ReadOptions.java

@@ -18,19 +18,6 @@ public class ReadOptions extends RocksObject {
   }
   private native void newReadOptions();
 
-  /**
-   * Release the memory allocated for the current instance
-   * in the c++ side.
-   *
-   * Calling other methods after dispose() leads to undefined behavior.
-   */
-  @Override public synchronized void dispose() {
-    if (isInitialized()) {
-      dispose(nativeHandle_);
-    }
-  }
-  private native void dispose(long handle);
-
   /**
    * If true, all data read from underlying storage will be
    * verified against corresponding checksums.
@@ -127,4 +114,12 @@ public class ReadOptions extends RocksObject {
   }
   private native void setTailing(
       long handle, boolean tailing);
+
+
+  @Override protected void disposeInternal() {
+    assert(isInitialized());
+    disposeInternal(nativeHandle_);
+  }
+  private native void disposeInternal(long handle);
+
 }

java/org/rocksdb/RocksDB.java

@@ -114,11 +114,9 @@ public class RocksDB extends RocksObject {
     return db;
   }
 
-  @Override public synchronized void dispose() {
-    if (isInitialized()) {
-      dispose(nativeHandle_);
-      nativeHandle_ = 0;
-    }
+  @Override protected void disposeInternal() {
+    assert(isInitialized());
+    disposeInternal(nativeHandle_);
   }
 
   /**
@@ -315,10 +313,6 @@ public class RocksDB extends RocksObject {
     return new RocksIterator(iterator0(nativeHandle_));
   }
 
-  @Override protected void finalize() {
-    close();
-  }
-
   /**
    * Private constructor.
    */
@@ -370,7 +364,7 @@ public class RocksDB extends RocksObject {
       long handle, long writeOptHandle,
       byte[] key, int keyLen) throws RocksDBException;
   protected native long iterator0(long optHandle);
-  protected native void dispose(long handle);
+  private native void disposeInternal(long handle);
 
   protected Filter filter_;
 }

java/org/rocksdb/RocksIterator.java

@@ -118,15 +118,13 @@ public class RocksIterator extends RocksObject {
   /**
    * Deletes underlying C++ iterator pointer.
    */
-  @Override public synchronized void dispose() {
-    if(isInitialized()) {
-      dispose(nativeHandle_);
-      nativeHandle_ = 0;
-    }
+  @Override protected void disposeInternal() {
+    assert(isInitialized());
+    disposeInternal(nativeHandle_);
   }
 
   private native boolean isValid0(long handle);
-  private native void dispose(long handle);
+  private native void disposeInternal(long handle);
   private native void seekToFirst0(long handle);
   private native void seekToLast0(long handle);
   private native void next0(long handle);

java/org/rocksdb/RocksObject.java

@@ -16,12 +16,48 @@ package org.rocksdb;
 public abstract class RocksObject {
   protected RocksObject() {
     nativeHandle_ = 0;
+    owningHandle_ = true;
   }
 
   /**
    * Release the c++ object pointed by the native handle.
+   *
+   * Note that once an instance of RocksObject has been disposed,
+   * calling its function will lead undefined behavior.
    */
-  public abstract void dispose();
+  public final synchronized void dispose() {
+    if (isOwningNativeHandle() && isInitialized()) {
+      disposeInternal();
+    }
+    nativeHandle_ = 0;
+    disOwnNativeHandle();
+  }
+
+  /**
+   * The helper function of dispose() which all subclasses of RocksObject
+   * must implement to release their associated C++ resource.
+   */
+  protected abstract void disposeInternal();
+
+  /**
+   * Revoke ownership of the native object.
+   *
+   * This will prevent the object from attempting to delete the underlying
+   * native object in its finalizer. This must be used when another object
+   * takes over ownership of the native object or both will attempt to delete
+   * the underlying object when garbage collected.
+   *
+   * When disOwnNativeHandle is called, dispose() will simply set nativeHandle_
+   * to 0 without releasing its associated C++ resource.  As a result,
+   * incorrectly use this function may cause memory leak.
+   */
+  protected void disOwnNativeHandle() {
+    owningHandle_ = false;
+  }
+
+  protected boolean isOwningNativeHandle() {
+    return owningHandle_;
+  }
 
   protected boolean isInitialized() {
     return (nativeHandle_ != 0);
@@ -32,4 +68,5 @@ public abstract class RocksObject {
   }
 
   protected long nativeHandle_;
+  private boolean owningHandle_;
 }

java/org/rocksdb/WriteBatch.java

@@ -86,10 +86,9 @@ public class WriteBatch extends RocksObject {
   /**
    * Delete the c++ side pointer.
    */
-  @Override public synchronized void dispose() {
-    if (isInitialized()) {
-      dispose0();
-    }
+  @Override protected void disposeInternal() {
+    assert(isInitialized());
+    disposeInternal(nativeHandle_);
   }
 
   private native void newWriteBatch(int reserved_bytes);
@@ -99,7 +98,7 @@ public class WriteBatch extends RocksObject {
                             byte[] value, int valueLen);
   private native void remove(byte[] key, int keyLen);
   private native void putLogData(byte[] blob, int blobLen);
-  private native void dispose0();
+  private native void disposeInternal(long handle);
 }
 
 /**

java/org/rocksdb/WriteOptions.java

@@ -17,10 +17,9 @@ public class WriteOptions extends RocksObject {
     newWriteOptions();
   }
 
-  @Override public synchronized void dispose() {
-    if (isInitialized()) {
-      dispose0(nativeHandle_);
-    }
+  @Override protected void disposeInternal() {
+    assert(isInitialized());
+    disposeInternal(nativeHandle_);
   }
 
   /**
@@ -96,5 +95,5 @@ public class WriteOptions extends RocksObject {
   private native boolean sync(long handle);
   private native void setDisableWAL(long handle, boolean flag);
   private native boolean disableWAL(long handle);
-  private native void dispose0(long handle);
+  private native void disposeInternal(long handle);
 }

java/org/rocksdb/benchmark/DbBenchmark.java

@@ -534,8 +534,6 @@ public class DbBenchmark {
         (Long)flags_.get(Flag.block_size));
     options.setMaxOpenFiles(
         (Integer)flags_.get(Flag.open_files));
-    options.setCreateIfMissing(
-        !(Boolean)flags_.get(Flag.use_existing_db));
     options.setTableCacheRemoveScanCountLimit(
         (Integer)flags_.get(Flag.cache_remove_scan_count_limit));
     options.setDisableDataSync(
@@ -939,7 +937,7 @@ public class DbBenchmark {
         "\tflag and also specify a benchmark that wants a fresh database,\n" +
         "\tthat benchmark will fail.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     num(1000000,
@@ -1028,7 +1026,7 @@ public class DbBenchmark {
     use_plain_table(false,
         "Use plain-table sst format.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     cache_size(-1L,
@@ -1085,7 +1083,7 @@ public class DbBenchmark {
     },
     histogram(false,"Print histogram of operation timings.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     min_write_buffer_number_to_merge(
@@ -1203,12 +1201,12 @@ public class DbBenchmark {
     verify_checksum(false,"Verify checksum for every block read\n" +
         "\tfrom storage.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     statistics(false,"Database statistics.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     writes(-1,"Number of write operations to do. If negative, do\n" +
@@ -1219,23 +1217,23 @@ public class DbBenchmark {
     },
     sync(false,"Sync all writes to disk.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     disable_data_sync(false,"If true, do not wait until data is\n" +
         "\tsynced to disk.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     use_fsync(false,"If true, issue fsync instead of fdatasync.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     disable_wal(false,"If true, do not write WAL for write.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     wal_dir("", "If not empty, use the given dir for WAL.") {
@@ -1312,7 +1310,7 @@ public class DbBenchmark {
     disable_seek_compaction(false,"Option to disable compaction\n" +
         "\ttriggered by read.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     delete_obsolete_files_period_micros(0,"Option to delete\n" +
@@ -1393,12 +1391,12 @@ public class DbBenchmark {
     },
     readonly(false,"Run read only benchmarks.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     disable_auto_compactions(false,"Do not auto trigger compactions.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     source_compaction_factor(1,"Cap the size of data in level-K for\n" +
@@ -1423,26 +1421,26 @@ public class DbBenchmark {
     bufferedio(rocksdb::EnvOptions().use_os_buffer,
         "Allow buffered io using OS buffers.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     */
     mmap_read(false,
         "Allow reads to occur via mmap-ing files.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     mmap_write(false,
         "Allow writes to occur via mmap-ing files.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     advise_random_on_open(defaultOptions_.adviseRandomOnOpen(),
         "Advise random access on table file open.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     compaction_fadvice("NORMAL",
@@ -1454,13 +1452,13 @@ public class DbBenchmark {
     use_tailing_iterator(false,
         "Use tailing iterator to access a series of keys instead of get.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     use_adaptive_mutex(defaultOptions_.useAdaptiveMutex(),
         "Use adaptive mutex.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     bytes_per_sync(defaultOptions_.bytesPerSync(),
@@ -1474,7 +1472,7 @@ public class DbBenchmark {
     filter_deletes(false," On true, deletes use bloom-filter and drop\n" +
         "\tthe delete if key not present.") {
       @Override public Object parseValue(String value) {
-        return Boolean.parseBoolean(value);
+        return parseBoolean(value);
       }
     },
     max_successive_merges(0,"Maximum number of successive merge\n" +
@@ -1495,8 +1493,6 @@ public class DbBenchmark {
       desc_ = desc;
     }
 
-    protected abstract Object parseValue(String value);
-
     public Object getDefaultValue() {
       return defaultValue_;
     }
@@ -1505,6 +1501,17 @@ public class DbBenchmark {
       return desc_;
     }
 
+    public boolean parseBoolean(String value) {
+      if (value.equals("1")) {
+        return true;
+      } else if (value.equals("0")) {
+        return false;
+      }
+      return Boolean.parseBoolean(value);
+    }
+
+    protected abstract Object parseValue(String value);
+
     private final Object defaultValue_;
     private final String desc_;
   }