JNI wrapper for the collective communicator (#8242)

2022-09-20 13:20:25 -07:00
parent fffb1fca52
commit 7d43e74e71
5 changed files with 570 additions and 0 deletions
--- a/jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/Communicator.java
+++ b/jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/Communicator.java
@@ -0,0 +1,152 @@
+package ml.dmlc.xgboost4j.java;
+
+import java.io.Serializable;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Collective communicator global class for synchronization.
+ *
+ * Currently the communicator API is experimental, function signatures may change in the future
+ * without notice.
+ */
+public class Communicator {
+
+  public enum OpType implements Serializable {
+    MAX(0), MIN(1), SUM(2);
+
+    private int op;
+
+    public int getOperand() {
+      return this.op;
+    }
+
+    OpType(int op) {
+      this.op = op;
+    }
+  }
+
+  public enum DataType implements Serializable {
+    INT8(0, 1), UINT8(1, 1), INT32(2, 4), UINT32(3, 4),
+    INT64(4, 8), UINT64(5, 8), FLOAT32(6, 4), FLOAT64(7, 8);
+
+    private final int enumOp;
+    private final int size;
+
+    public int getEnumOp() {
+      return this.enumOp;
+    }
+
+    public int getSize() {
+      return this.size;
+    }
+
+    DataType(int enumOp, int size) {
+      this.enumOp = enumOp;
+      this.size = size;
+    }
+  }
+
+  private static void checkCall(int ret) throws XGBoostError {
+    if (ret != 0) {
+      throw new XGBoostError(XGBoostJNI.XGBGetLastError());
+    }
+  }
+
+  // used as way to test/debug passed communicator init parameters
+  public static Map<String, String> communicatorEnvs;
+  public static List<String> mockList = new LinkedList<>();
+
+  /**
+   * Initialize the collective communicator on current working thread.
+   *
+   * @param envs The additional environment variables to pass to the communicator.
+   * @throws XGBoostError
+   */
+  public static void init(Map<String, String> envs) throws XGBoostError {
+    communicatorEnvs = envs;
+    String[] args = new String[envs.size() * 2 + mockList.size() * 2];
+    int idx = 0;
+    for (java.util.Map.Entry<String, String> e : envs.entrySet()) {
+      args[idx++] = e.getKey();
+      args[idx++] = e.getValue();
+    }
+    // pass list of rabit mock strings eg mock=0,1,0,0
+    for (String mock : mockList) {
+      args[idx++] = "mock";
+      args[idx++] = mock;
+    }
+    checkCall(XGBoostJNI.CommunicatorInit(args));
+  }
+
+  /**
+   * Shutdown the communicator in current working thread, equals to finalize.
+   *
+   * @throws XGBoostError
+   */
+  public static void shutdown() throws XGBoostError {
+    checkCall(XGBoostJNI.CommunicatorFinalize());
+  }
+
+  /**
+   * Print the message via the communicator.
+   *
+   * @param msg
+   * @throws XGBoostError
+   */
+  public static void communicatorPrint(String msg) throws XGBoostError {
+    checkCall(XGBoostJNI.CommunicatorPrint(msg));
+  }
+
+  /**
+   * get rank of current thread.
+   *
+   * @return the rank.
+   * @throws XGBoostError
+   */
+  public static int getRank() throws XGBoostError {
+    int[] out = new int[1];
+    checkCall(XGBoostJNI.CommunicatorGetRank(out));
+    return out[0];
+  }
+
+  /**
+   * get world size of current job.
+   *
+   * @return the worldsize
+   * @throws XGBoostError
+   */
+  public static int getWorldSize() throws XGBoostError {
+    int[] out = new int[1];
+    checkCall(XGBoostJNI.CommunicatorGetWorldSize(out));
+    return out[0];
+  }
+
+  /**
+   * perform Allreduce on distributed float vectors using operator op.
+   *
+   * @param elements local elements on distributed workers.
+   * @param op       operator used for Allreduce.
+   * @return All-reduced float elements according to the given operator.
+   */
+  public static float[] allReduce(float[] elements, OpType op) {
+    DataType dataType = DataType.FLOAT32;
+    ByteBuffer buffer = ByteBuffer.allocateDirect(dataType.getSize() * elements.length)
+            .order(ByteOrder.nativeOrder());
+
+    for (float el : elements) {
+      buffer.putFloat(el);
+    }
+    buffer.flip();
+
+    XGBoostJNI.CommunicatorAllreduce(buffer, elements.length, dataType.getEnumOp(),
+            op.getOperand());
+    float[] results = new float[elements.length];
+    buffer.asFloatBuffer().get(results);
+
+    return results;
+  }
+}
--- a/jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/XGBoostJNI.java
+++ b/jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/XGBoostJNI.java
@@ -148,6 +148,17 @@ class XGBoostJNI {
  final static native int RabitAllreduce(ByteBuffer sendrecvbuf, int count,
                                                int enum_dtype, int enum_op);

+  // communicator functions
+  public final static native int CommunicatorInit(String[] args);
+  public final static native int CommunicatorFinalize();
+  public final static native int CommunicatorPrint(String msg);
+  public final static native int CommunicatorGetRank(int[] out);
+  public final static native int CommunicatorGetWorldSize(int[] out);
+
+  // Perform Allreduce operation on data in sendrecvbuf.
+  final static native int CommunicatorAllreduce(ByteBuffer sendrecvbuf, int count,
+    int enum_dtype, int enum_op);
+
  public final static native int XGDMatrixSetInfoFromInterface(
    long handle, String field, String json);

--- a/jvm-packages/xgboost4j/src/native/xgboost4j.cpp
+++ b/jvm-packages/xgboost4j/src/native/xgboost4j.cpp
@@ -977,6 +977,89 @@ JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_RabitAllreduce
  return 0;
 }

+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorInit
+ * Signature: ([Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorInit
+  (JNIEnv *jenv, jclass jcls, jobjectArray jargs) {
+  xgboost::Json config{xgboost::Object{}};
+  bst_ulong len = (bst_ulong)jenv->GetArrayLength(jargs);
+  assert(len % 2 == 0);
+  for (bst_ulong i = 0; i < len / 2; ++i) {
+    jstring key = (jstring)jenv->GetObjectArrayElement(jargs, 2 * i);
+    std::string key_str(jenv->GetStringUTFChars(key, 0), jenv->GetStringLength(key));
+    jstring value = (jstring)jenv->GetObjectArrayElement(jargs, 2 * i + 1);
+    std::string value_str(jenv->GetStringUTFChars(value, 0), jenv->GetStringLength(value));
+    config[key_str] = xgboost::String(value_str);
+  }
+  std::string json_str;
+  xgboost::Json::Dump(config, &json_str);
+  JVM_CHECK_CALL(XGCommunicatorInit(json_str.c_str()));
+  return 0;
+}
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorFinalize
+ * Signature: ()I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorFinalize
+  (JNIEnv *jenv, jclass jcls) {
+  JVM_CHECK_CALL(XGCommunicatorFinalize());
+  return 0;
+}
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorPrint
+ * Signature: (Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorPrint
+  (JNIEnv *jenv, jclass jcls, jstring jmsg) {
+  std::string str(jenv->GetStringUTFChars(jmsg, 0),
+                  jenv->GetStringLength(jmsg));
+  JVM_CHECK_CALL(XGCommunicatorPrint(str.c_str()));
+  return 0;
+}
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorGetRank
+ * Signature: ([I)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorGetRank
+  (JNIEnv *jenv, jclass jcls, jintArray jout) {
+  jint rank = XGCommunicatorGetRank();
+  jenv->SetIntArrayRegion(jout, 0, 1, &rank);
+  return 0;
+}
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorGetWorldSize
+ * Signature: ([I)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorGetWorldSize
+  (JNIEnv *jenv, jclass jcls, jintArray jout) {
+  jint out = XGCommunicatorGetWorldSize();
+  jenv->SetIntArrayRegion(jout, 0, 1, &out);
+  return 0;
+}
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorAllreduce
+ * Signature: (Ljava/nio/ByteBuffer;III)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorAllreduce
+  (JNIEnv *jenv, jclass jcls, jobject jsendrecvbuf, jint jcount, jint jenum_dtype, jint jenum_op) {
+  void *ptr_sendrecvbuf = jenv->GetDirectBufferAddress(jsendrecvbuf);
+  JVM_CHECK_CALL(XGCommunicatorAllreduce(ptr_sendrecvbuf, (size_t) jcount, jenum_dtype, jenum_op));
+  return 0;
+}
+
 namespace xgboost {
 namespace jni {
  XGB_DLL int XGDeviceQuantileDMatrixCreateFromCallbackImpl(JNIEnv *jenv, jclass jcls,
--- a/jvm-packages/xgboost4j/src/native/xgboost4j.h
+++ b/jvm-packages/xgboost4j/src/native/xgboost4j.h
@@ -335,6 +335,54 @@ JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_RabitVersionNumber
 JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_RabitAllreduce
  (JNIEnv *, jclass, jobject, jint, jint, jint);

+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorInit
+ * Signature: ([Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorInit
+  (JNIEnv *, jclass, jobjectArray);
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorFinalize
+ * Signature: ()I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorFinalize
+  (JNIEnv *, jclass);
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorPrint
+ * Signature: (Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorPrint
+  (JNIEnv *, jclass, jstring);
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorGetRank
+ * Signature: ([I)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorGetRank
+  (JNIEnv *, jclass, jintArray);
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorGetWorldSize
+ * Signature: ([I)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorGetWorldSize
+  (JNIEnv *, jclass, jintArray);
+
+/*
+ * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
+ * Method:    CommunicatorAllreduce
+ * Signature: (Ljava/nio/ByteBuffer;III)I
+ */
+JNIEXPORT jint JNICALL Java_ml_dmlc_xgboost4j_java_XGBoostJNI_CommunicatorAllreduce
+  (JNIEnv *, jclass, jobject, jint, jint, jint);
+
 /*
 * Class:     ml_dmlc_xgboost4j_java_XGBoostJNI
 * Method:    XGDMatrixSetInfoFromInterface