| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #include <string.h> |
| #include "hdfsJniHelper.h" |
| |
| static pthread_mutex_t hdfsHashMutex = PTHREAD_MUTEX_INITIALIZER; |
| static pthread_mutex_t jvmMutex = PTHREAD_MUTEX_INITIALIZER; |
| static volatile int hashTableInited = 0; |
| |
| #define LOCK_HASH_TABLE() pthread_mutex_lock(&hdfsHashMutex) |
| #define UNLOCK_HASH_TABLE() pthread_mutex_unlock(&hdfsHashMutex) |
| #define LOCK_JVM_MUTEX() pthread_mutex_lock(&jvmMutex) |
| #define UNLOCK_JVM_MUTEX() pthread_mutex_unlock(&jvmMutex) |
| |
| |
| /** The Native return types that methods could return */ |
| #define VOID 'V' |
| #define JOBJECT 'L' |
| #define JARRAYOBJECT '[' |
| #define JBOOLEAN 'Z' |
| #define JBYTE 'B' |
| #define JCHAR 'C' |
| #define JSHORT 'S' |
| #define JINT 'I' |
| #define JLONG 'J' |
| #define JFLOAT 'F' |
| #define JDOUBLE 'D' |
| |
| |
| /** |
| * MAX_HASH_TABLE_ELEM: The maximum no. of entries in the hashtable. |
| * It's set to 4096 to account for (classNames + No. of threads) |
| */ |
| #define MAX_HASH_TABLE_ELEM 4096 |
| |
| |
| static int validateMethodType(MethType methType) |
| { |
| if (methType != STATIC && methType != INSTANCE) { |
| fprintf(stderr, "Unimplemented method type\n"); |
| return 0; |
| } |
| return 1; |
| } |
| |
| |
| static int hashTableInit(void) |
| { |
| if (!hashTableInited) { |
| LOCK_HASH_TABLE(); |
| if (!hashTableInited) { |
| if (hcreate(MAX_HASH_TABLE_ELEM) == 0) { |
| fprintf(stderr, "error creating hashtable, <%d>: %s\n", |
| errno, strerror(errno)); |
| return 0; |
| } |
| hashTableInited = 1; |
| } |
| UNLOCK_HASH_TABLE(); |
| } |
| return 1; |
| } |
| |
| |
| static int insertEntryIntoTable(const char *key, void *data) |
| { |
| ENTRY e, *ep; |
| if (key == NULL || data == NULL) { |
| return 0; |
| } |
| if (! hashTableInit()) { |
| return -1; |
| } |
| e.data = data; |
| e.key = (char*)key; |
| LOCK_HASH_TABLE(); |
| ep = hsearch(e, ENTER); |
| UNLOCK_HASH_TABLE(); |
| if (ep == NULL) { |
| fprintf(stderr, "warn adding key (%s) to hash table, <%d>: %s\n", |
| key, errno, strerror(errno)); |
| } |
| return 0; |
| } |
| |
| |
| |
| static void* searchEntryFromTable(const char *key) |
| { |
| ENTRY e,*ep; |
| if (key == NULL) { |
| return NULL; |
| } |
| hashTableInit(); |
| e.key = (char*)key; |
| LOCK_HASH_TABLE(); |
| ep = hsearch(e, FIND); |
| UNLOCK_HASH_TABLE(); |
| if (ep != NULL) { |
| return ep->data; |
| } |
| return NULL; |
| } |
| |
| |
| |
| int invokeMethod(JNIEnv *env, RetVal *retval, Exc *exc, MethType methType, |
| jobject instObj, const char *className, |
| const char *methName, const char *methSignature, ...) |
| { |
| va_list args; |
| jclass cls; |
| jmethodID mid; |
| jthrowable jthr; |
| const char *str; |
| char returnType; |
| |
| if (! validateMethodType(methType)) { |
| return -1; |
| } |
| cls = globalClassReference(className, env); |
| if (cls == NULL) { |
| return -2; |
| } |
| |
| mid = methodIdFromClass(className, methName, methSignature, |
| methType, env); |
| if (mid == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return -3; |
| } |
| |
| str = methSignature; |
| while (*str != ')') str++; |
| str++; |
| returnType = *str; |
| va_start(args, methSignature); |
| if (returnType == JOBJECT || returnType == JARRAYOBJECT) { |
| jobject jobj = NULL; |
| if (methType == STATIC) { |
| jobj = (*env)->CallStaticObjectMethodV(env, cls, mid, args); |
| } |
| else if (methType == INSTANCE) { |
| jobj = (*env)->CallObjectMethodV(env, instObj, mid, args); |
| } |
| retval->l = jobj; |
| } |
| else if (returnType == VOID) { |
| if (methType == STATIC) { |
| (*env)->CallStaticVoidMethodV(env, cls, mid, args); |
| } |
| else if (methType == INSTANCE) { |
| (*env)->CallVoidMethodV(env, instObj, mid, args); |
| } |
| } |
| else if (returnType == JBOOLEAN) { |
| jboolean jbool = 0; |
| if (methType == STATIC) { |
| jbool = (*env)->CallStaticBooleanMethodV(env, cls, mid, args); |
| } |
| else if (methType == INSTANCE) { |
| jbool = (*env)->CallBooleanMethodV(env, instObj, mid, args); |
| } |
| retval->z = jbool; |
| } |
| else if (returnType == JSHORT) { |
| jshort js = 0; |
| if (methType == STATIC) { |
| js = (*env)->CallStaticShortMethodV(env, cls, mid, args); |
| } |
| else if (methType == INSTANCE) { |
| js = (*env)->CallShortMethodV(env, instObj, mid, args); |
| } |
| retval->s = js; |
| } |
| else if (returnType == JLONG) { |
| jlong jl = -1; |
| if (methType == STATIC) { |
| jl = (*env)->CallStaticLongMethodV(env, cls, mid, args); |
| } |
| else if (methType == INSTANCE) { |
| jl = (*env)->CallLongMethodV(env, instObj, mid, args); |
| } |
| retval->j = jl; |
| } |
| else if (returnType == JINT) { |
| jint ji = -1; |
| if (methType == STATIC) { |
| ji = (*env)->CallStaticIntMethodV(env, cls, mid, args); |
| } |
| else if (methType == INSTANCE) { |
| ji = (*env)->CallIntMethodV(env, instObj, mid, args); |
| } |
| retval->i = ji; |
| } |
| va_end(args); |
| |
| jthr = (*env)->ExceptionOccurred(env); |
| if (jthr != NULL) { |
| if (exc != NULL) |
| *exc = jthr; |
| else |
| (*env)->ExceptionDescribe(env); |
| return -1; |
| } |
| return 0; |
| } |
| |
| jarray constructNewArrayString(JNIEnv *env, Exc *exc, const char **elements, int size) { |
| const char *className = "java/lang/String"; |
| jobjectArray result; |
| int i; |
| jclass arrCls = (*env)->FindClass(env, className); |
| if (arrCls == NULL) { |
| fprintf(stderr, "could not find class %s\n",className); |
| return NULL; /* exception thrown */ |
| } |
| result = (*env)->NewObjectArray(env, size, arrCls, |
| NULL); |
| if (result == NULL) { |
| fprintf(stderr, "ERROR: could not construct new array\n"); |
| return NULL; /* out of memory error thrown */ |
| } |
| for (i = 0; i < size; i++) { |
| jstring jelem = (*env)->NewStringUTF(env,elements[i]); |
| if (jelem == NULL) { |
| fprintf(stderr, "ERROR: jelem == NULL\n"); |
| } |
| (*env)->SetObjectArrayElement(env, result, i, jelem); |
| (*env)->DeleteLocalRef(env, jelem); |
| } |
| return result; |
| } |
| |
| jobject constructNewObjectOfClass(JNIEnv *env, Exc *exc, const char *className, |
| const char *ctorSignature, ...) |
| { |
| va_list args; |
| jclass cls; |
| jmethodID mid; |
| jobject jobj; |
| jthrowable jthr; |
| |
| cls = globalClassReference(className, env); |
| if (cls == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return NULL; |
| } |
| |
| mid = methodIdFromClass(className, "<init>", ctorSignature, |
| INSTANCE, env); |
| if (mid == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return NULL; |
| } |
| va_start(args, ctorSignature); |
| jobj = (*env)->NewObjectV(env, cls, mid, args); |
| va_end(args); |
| jthr = (*env)->ExceptionOccurred(env); |
| if (jthr != NULL) { |
| if (exc != NULL) |
| *exc = jthr; |
| else |
| (*env)->ExceptionDescribe(env); |
| } |
| return jobj; |
| } |
| |
| |
| |
| |
| jmethodID methodIdFromClass(const char *className, const char *methName, |
| const char *methSignature, MethType methType, |
| JNIEnv *env) |
| { |
| jclass cls = globalClassReference(className, env); |
| if (cls == NULL) { |
| fprintf(stderr, "could not find class %s\n", className); |
| return NULL; |
| } |
| |
| jmethodID mid = 0; |
| if (!validateMethodType(methType)) { |
| fprintf(stderr, "invalid method type\n"); |
| return NULL; |
| } |
| |
| if (methType == STATIC) { |
| mid = (*env)->GetStaticMethodID(env, cls, methName, methSignature); |
| } |
| else if (methType == INSTANCE) { |
| mid = (*env)->GetMethodID(env, cls, methName, methSignature); |
| } |
| if (mid == NULL) { |
| fprintf(stderr, "could not find method %s from class %s with signature %s\n",methName, className, methSignature); |
| } |
| return mid; |
| } |
| |
| |
| jclass globalClassReference(const char *className, JNIEnv *env) |
| { |
| jclass clsLocalRef; |
| jclass cls = searchEntryFromTable(className); |
| if (cls) { |
| return cls; |
| } |
| |
| clsLocalRef = (*env)->FindClass(env,className); |
| if (clsLocalRef == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return NULL; |
| } |
| cls = (*env)->NewGlobalRef(env, clsLocalRef); |
| if (cls == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return NULL; |
| } |
| (*env)->DeleteLocalRef(env, clsLocalRef); |
| insertEntryIntoTable(className, cls); |
| return cls; |
| } |
| |
| |
| char *classNameOfObject(jobject jobj, JNIEnv *env) { |
| jclass cls, clsClass; |
| jmethodID mid; |
| jstring str; |
| const char *cstr; |
| char *newstr; |
| |
| cls = (*env)->GetObjectClass(env, jobj); |
| if (cls == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return NULL; |
| } |
| clsClass = (*env)->FindClass(env, "java/lang/Class"); |
| if (clsClass == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return NULL; |
| } |
| mid = (*env)->GetMethodID(env, clsClass, "getName", "()Ljava/lang/String;"); |
| if (mid == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return NULL; |
| } |
| str = (*env)->CallObjectMethod(env, cls, mid); |
| if (str == NULL) { |
| (*env)->ExceptionDescribe(env); |
| return NULL; |
| } |
| |
| cstr = (*env)->GetStringUTFChars(env, str, NULL); |
| newstr = strdup(cstr); |
| (*env)->ReleaseStringUTFChars(env, str, cstr); |
| if (newstr == NULL) { |
| perror("classNameOfObject: strdup"); |
| return NULL; |
| } |
| return newstr; |
| } |
| |
| |
| |
| |
| /** |
| * getJNIEnv: A helper function to get the JNIEnv* for the given thread. |
| * If no JVM exists, then one will be created. JVM command line arguments |
| * are obtained from the LIBHDFS_OPTS environment variable. |
| * |
| * @param: None. |
| * @return The JNIEnv* corresponding to the thread. |
| */ |
| JNIEnv* getJNIEnv(void) |
| { |
| |
| const jsize vmBufLength = 1; |
| JavaVM* vmBuf[vmBufLength]; |
| JNIEnv *env; |
| jint rv = 0; |
| jint noVMs = 0; |
| |
| // Only the first thread should create the JVM. The other trheads should |
| // just use the JVM created by the first thread. |
| LOCK_JVM_MUTEX(); |
| |
| rv = JNI_GetCreatedJavaVMs(&(vmBuf[0]), vmBufLength, &noVMs); |
| if (rv != 0) { |
| fprintf(stderr, "JNI_GetCreatedJavaVMs failed with error: %d\n", rv); |
| UNLOCK_JVM_MUTEX(); |
| return NULL; |
| } |
| |
| if (noVMs == 0) { |
| //Get the environment variables for initializing the JVM |
| char *hadoopClassPath = getenv("CLASSPATH"); |
| if (hadoopClassPath == NULL) { |
| fprintf(stderr, "Environment variable CLASSPATH not set!\n"); |
| UNLOCK_JVM_MUTEX(); |
| return NULL; |
| } |
| char *hadoopClassPathVMArg = "-Djava.class.path="; |
| size_t optHadoopClassPathLen = strlen(hadoopClassPath) + |
| strlen(hadoopClassPathVMArg) + 1; |
| char *optHadoopClassPath = malloc(sizeof(char)*optHadoopClassPathLen); |
| snprintf(optHadoopClassPath, optHadoopClassPathLen, |
| "%s%s", hadoopClassPathVMArg, hadoopClassPath); |
| |
| // Determine the # of LIBHDFS_OPTS args |
| int noArgs = 1; |
| char *hadoopJvmArgs = getenv("LIBHDFS_OPTS"); |
| char jvmArgDelims[] = " "; |
| char *str, *token, *savePtr; |
| if (hadoopJvmArgs != NULL) { |
| hadoopJvmArgs = strdup(hadoopJvmArgs); |
| for (noArgs = 1, str = hadoopJvmArgs; ; noArgs++, str = NULL) { |
| token = strtok_r(str, jvmArgDelims, &savePtr); |
| if (NULL == token) { |
| break; |
| } |
| } |
| free(hadoopJvmArgs); |
| } |
| |
| // Now that we know the # args, populate the options array |
| JavaVMOption options[noArgs]; |
| options[0].optionString = optHadoopClassPath; |
| hadoopJvmArgs = getenv("LIBHDFS_OPTS"); |
| if (hadoopJvmArgs != NULL) { |
| hadoopJvmArgs = strdup(hadoopJvmArgs); |
| for (noArgs = 1, str = hadoopJvmArgs; ; noArgs++, str = NULL) { |
| token = strtok_r(str, jvmArgDelims, &savePtr); |
| if (NULL == token) { |
| break; |
| } |
| options[noArgs].optionString = token; |
| } |
| } |
| |
| //Create the VM |
| JavaVMInitArgs vm_args; |
| JavaVM *vm; |
| vm_args.version = JNI_VERSION_1_2; |
| vm_args.options = options; |
| vm_args.nOptions = noArgs; |
| vm_args.ignoreUnrecognized = 1; |
| |
| rv = JNI_CreateJavaVM(&vm, (void*)&env, &vm_args); |
| |
| if (hadoopJvmArgs != NULL) { |
| free(hadoopJvmArgs); |
| } |
| free(optHadoopClassPath); |
| |
| if (rv != 0) { |
| fprintf(stderr, "Call to JNI_CreateJavaVM failed " |
| "with error: %d\n", rv); |
| UNLOCK_JVM_MUTEX(); |
| return NULL; |
| } |
| } |
| else { |
| //Attach this thread to the VM |
| JavaVM* vm = vmBuf[0]; |
| rv = (*vm)->AttachCurrentThread(vm, (void*)&env, 0); |
| if (rv != 0) { |
| fprintf(stderr, "Call to AttachCurrentThread " |
| "failed with error: %d\n", rv); |
| UNLOCK_JVM_MUTEX(); |
| return NULL; |
| } |
| } |
| UNLOCK_JVM_MUTEX(); |
| |
| return env; |
| } |