1 | /** |
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2 | * Copyright 2006 The Apache Software Foundation |
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3 | * |
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4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
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5 | * you may not use this file except in compliance with the License. |
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6 | * You may obtain a copy of the License at |
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7 | * |
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8 | * http://www.apache.org/licenses/LICENSE-2.0 |
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9 | * |
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10 | * Unless required by applicable law or agreed to in writing, software |
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11 | * distributed under the License is distributed on an "AS IS" BASIS, |
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12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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13 | * See the License for the specific language governing permissions and |
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14 | * limitations under the License. |
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15 | */ |
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16 | |
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17 | #include <string.h> |
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18 | #include <error.h> |
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19 | #include "hdfsJniHelper.h" |
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20 | |
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21 | static pthread_mutex_t hdfsHashMutex = PTHREAD_MUTEX_INITIALIZER; |
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22 | static pthread_mutex_t jvmMutex = PTHREAD_MUTEX_INITIALIZER; |
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23 | static volatile int hashTableInited = 0; |
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24 | |
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25 | #define LOCK_HASH_TABLE() pthread_mutex_lock(&hdfsHashMutex) |
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26 | #define UNLOCK_HASH_TABLE() pthread_mutex_unlock(&hdfsHashMutex) |
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27 | #define LOCK_JVM_MUTEX() pthread_mutex_lock(&jvmMutex) |
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28 | #define UNLOCK_JVM_MUTEX() pthread_mutex_unlock(&jvmMutex) |
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29 | |
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30 | |
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31 | /** The Native return types that methods could return */ |
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32 | #define VOID 'V' |
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33 | #define JOBJECT 'L' |
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34 | #define JARRAYOBJECT '[' |
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35 | #define JBOOLEAN 'Z' |
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36 | #define JBYTE 'B' |
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37 | #define JCHAR 'C' |
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38 | #define JSHORT 'S' |
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39 | #define JINT 'I' |
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40 | #define JLONG 'J' |
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41 | #define JFLOAT 'F' |
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42 | #define JDOUBLE 'D' |
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43 | |
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44 | |
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45 | /** |
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46 | * MAX_HASH_TABLE_ELEM: The maximum no. of entries in the hashtable. |
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47 | * It's set to 4096 to account for (classNames + No. of threads) |
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48 | */ |
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49 | #define MAX_HASH_TABLE_ELEM 4096 |
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50 | |
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51 | |
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52 | static int validateMethodType(MethType methType) |
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53 | { |
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54 | if (methType != STATIC && methType != INSTANCE) { |
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55 | fprintf(stderr, "Unimplemented method type\n"); |
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56 | return 0; |
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57 | } |
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58 | return 1; |
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59 | } |
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60 | |
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61 | |
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62 | static int hashTableInit(void) |
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63 | { |
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64 | if (!hashTableInited) { |
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65 | LOCK_HASH_TABLE(); |
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66 | if (!hashTableInited) { |
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67 | if (hcreate(MAX_HASH_TABLE_ELEM) == 0) { |
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68 | fprintf(stderr, "error creating hashtable, <%d>: %s\n", |
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69 | errno, strerror(errno)); |
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70 | return 0; |
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71 | } |
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72 | hashTableInited = 1; |
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73 | } |
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74 | UNLOCK_HASH_TABLE(); |
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75 | } |
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76 | return 1; |
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77 | } |
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78 | |
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79 | |
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80 | static int insertEntryIntoTable(const char *key, void *data) |
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81 | { |
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82 | ENTRY e, *ep; |
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83 | if (key == NULL || data == NULL) { |
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84 | return 0; |
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85 | } |
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86 | if (! hashTableInit()) { |
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87 | return -1; |
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88 | } |
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89 | e.data = data; |
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90 | e.key = (char*)key; |
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91 | LOCK_HASH_TABLE(); |
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92 | ep = hsearch(e, ENTER); |
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93 | UNLOCK_HASH_TABLE(); |
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94 | if (ep == NULL) { |
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95 | fprintf(stderr, "warn adding key (%s) to hash table, <%d>: %s\n", |
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96 | key, errno, strerror(errno)); |
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97 | } |
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98 | return 0; |
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99 | } |
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100 | |
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101 | |
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102 | |
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103 | static void* searchEntryFromTable(const char *key) |
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104 | { |
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105 | ENTRY e,*ep; |
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106 | if (key == NULL) { |
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107 | return NULL; |
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108 | } |
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109 | hashTableInit(); |
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110 | e.key = (char*)key; |
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111 | LOCK_HASH_TABLE(); |
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112 | ep = hsearch(e, FIND); |
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113 | UNLOCK_HASH_TABLE(); |
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114 | if (ep != NULL) { |
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115 | return ep->data; |
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116 | } |
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117 | return NULL; |
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118 | } |
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119 | |
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120 | |
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121 | |
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122 | int invokeMethod(JNIEnv *env, RetVal *retval, Exc *exc, MethType methType, |
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123 | jobject instObj, const char *className, |
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124 | const char *methName, const char *methSignature, ...) |
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125 | { |
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126 | va_list args; |
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127 | jclass cls; |
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128 | jmethodID mid; |
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129 | jthrowable jthr; |
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130 | const char *str; |
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131 | char returnType; |
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132 | |
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133 | if (! validateMethodType(methType)) { |
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134 | return -1; |
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135 | } |
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136 | cls = globalClassReference(className, env); |
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137 | if (cls == NULL) { |
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138 | return -2; |
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139 | } |
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140 | |
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141 | mid = methodIdFromClass(className, methName, methSignature, |
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142 | methType, env); |
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143 | if (mid == NULL) { |
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144 | (*env)->ExceptionDescribe(env); |
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145 | return -3; |
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146 | } |
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147 | |
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148 | str = methSignature; |
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149 | while (*str != ')') str++; |
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150 | str++; |
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151 | returnType = *str; |
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152 | va_start(args, methSignature); |
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153 | if (returnType == JOBJECT || returnType == JARRAYOBJECT) { |
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154 | jobject jobj = NULL; |
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155 | if (methType == STATIC) { |
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156 | jobj = (*env)->CallStaticObjectMethodV(env, cls, mid, args); |
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157 | } |
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158 | else if (methType == INSTANCE) { |
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159 | jobj = (*env)->CallObjectMethodV(env, instObj, mid, args); |
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160 | } |
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161 | retval->l = jobj; |
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162 | } |
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163 | else if (returnType == VOID) { |
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164 | if (methType == STATIC) { |
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165 | (*env)->CallStaticVoidMethodV(env, cls, mid, args); |
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166 | } |
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167 | else if (methType == INSTANCE) { |
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168 | (*env)->CallVoidMethodV(env, instObj, mid, args); |
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169 | } |
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170 | } |
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171 | else if (returnType == JBOOLEAN) { |
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172 | jboolean jbool = 0; |
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173 | if (methType == STATIC) { |
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174 | jbool = (*env)->CallStaticBooleanMethodV(env, cls, mid, args); |
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175 | } |
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176 | else if (methType == INSTANCE) { |
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177 | jbool = (*env)->CallBooleanMethodV(env, instObj, mid, args); |
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178 | } |
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179 | retval->z = jbool; |
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180 | } |
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181 | else if (returnType == JSHORT) { |
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182 | jshort js = 0; |
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183 | if (methType == STATIC) { |
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184 | js = (*env)->CallStaticShortMethodV(env, cls, mid, args); |
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185 | } |
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186 | else if (methType == INSTANCE) { |
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187 | js = (*env)->CallShortMethodV(env, instObj, mid, args); |
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188 | } |
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189 | retval->s = js; |
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190 | } |
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191 | else if (returnType == JLONG) { |
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192 | jlong jl = -1; |
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193 | if (methType == STATIC) { |
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194 | jl = (*env)->CallStaticLongMethodV(env, cls, mid, args); |
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195 | } |
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196 | else if (methType == INSTANCE) { |
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197 | jl = (*env)->CallLongMethodV(env, instObj, mid, args); |
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198 | } |
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199 | retval->j = jl; |
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200 | } |
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201 | else if (returnType == JINT) { |
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202 | jint ji = -1; |
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203 | if (methType == STATIC) { |
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204 | ji = (*env)->CallStaticIntMethodV(env, cls, mid, args); |
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205 | } |
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206 | else if (methType == INSTANCE) { |
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207 | ji = (*env)->CallIntMethodV(env, instObj, mid, args); |
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208 | } |
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209 | retval->i = ji; |
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210 | } |
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211 | va_end(args); |
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212 | |
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213 | jthr = (*env)->ExceptionOccurred(env); |
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214 | if (jthr != NULL) { |
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215 | if (exc != NULL) |
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216 | *exc = jthr; |
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217 | else |
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218 | (*env)->ExceptionDescribe(env); |
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219 | return -1; |
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220 | } |
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221 | return 0; |
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222 | } |
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223 | |
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224 | jarray constructNewArrayString(JNIEnv *env, Exc *exc, const char **elements, int size) { |
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225 | const char *className = "Ljava/lang/String;"; |
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226 | jobjectArray result; |
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227 | int i; |
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228 | jclass arrCls = (*env)->FindClass(env, className); |
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229 | if (arrCls == NULL) { |
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230 | fprintf(stderr, "could not find class %s\n",className); |
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231 | return NULL; /* exception thrown */ |
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232 | } |
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233 | result = (*env)->NewObjectArray(env, size, arrCls, |
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234 | NULL); |
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235 | if (result == NULL) { |
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236 | fprintf(stderr, "ERROR: could not construct new array\n"); |
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237 | return NULL; /* out of memory error thrown */ |
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238 | } |
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239 | for (i = 0; i < size; i++) { |
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240 | jstring jelem = (*env)->NewStringUTF(env,elements[i]); |
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241 | if (jelem == NULL) { |
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242 | fprintf(stderr, "ERROR: jelem == NULL\n"); |
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243 | } |
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244 | (*env)->SetObjectArrayElement(env, result, i, jelem); |
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245 | } |
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246 | return result; |
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247 | } |
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248 | |
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249 | jobject constructNewObjectOfClass(JNIEnv *env, Exc *exc, const char *className, |
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250 | const char *ctorSignature, ...) |
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251 | { |
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252 | va_list args; |
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253 | jclass cls; |
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254 | jmethodID mid; |
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255 | jobject jobj; |
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256 | jthrowable jthr; |
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257 | |
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258 | cls = globalClassReference(className, env); |
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259 | if (cls == NULL) { |
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260 | (*env)->ExceptionDescribe(env); |
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261 | return NULL; |
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262 | } |
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263 | |
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264 | mid = methodIdFromClass(className, "<init>", ctorSignature, |
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265 | INSTANCE, env); |
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266 | if (mid == NULL) { |
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267 | (*env)->ExceptionDescribe(env); |
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268 | return NULL; |
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269 | } |
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270 | va_start(args, ctorSignature); |
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271 | jobj = (*env)->NewObjectV(env, cls, mid, args); |
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272 | va_end(args); |
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273 | jthr = (*env)->ExceptionOccurred(env); |
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274 | if (jthr != NULL) { |
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275 | if (exc != NULL) |
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276 | *exc = jthr; |
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277 | else |
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278 | (*env)->ExceptionDescribe(env); |
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279 | } |
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280 | return jobj; |
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281 | } |
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282 | |
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283 | |
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284 | |
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285 | |
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286 | jmethodID methodIdFromClass(const char *className, const char *methName, |
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287 | const char *methSignature, MethType methType, |
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288 | JNIEnv *env) |
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289 | { |
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290 | jclass cls = globalClassReference(className, env); |
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291 | if (cls == NULL) { |
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292 | fprintf(stderr, "could not find class %s\n", className); |
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293 | return NULL; |
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294 | } |
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295 | |
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296 | jmethodID mid = 0; |
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297 | if (!validateMethodType(methType)) { |
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298 | fprintf(stderr, "invalid method type\n"); |
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299 | return NULL; |
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300 | } |
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301 | |
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302 | if (methType == STATIC) { |
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303 | mid = (*env)->GetStaticMethodID(env, cls, methName, methSignature); |
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304 | } |
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305 | else if (methType == INSTANCE) { |
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306 | mid = (*env)->GetMethodID(env, cls, methName, methSignature); |
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307 | } |
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308 | if (mid == NULL) { |
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309 | fprintf(stderr, "could not find method %s from class %s with signature %s\n",methName, className, methSignature); |
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310 | } |
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311 | return mid; |
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312 | } |
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313 | |
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314 | |
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315 | jclass globalClassReference(const char *className, JNIEnv *env) |
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316 | { |
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317 | jclass clsLocalRef; |
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318 | jclass cls = searchEntryFromTable(className); |
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319 | if (cls) { |
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320 | return cls; |
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321 | } |
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322 | |
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323 | clsLocalRef = (*env)->FindClass(env,className); |
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324 | if (clsLocalRef == NULL) { |
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325 | (*env)->ExceptionDescribe(env); |
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326 | return NULL; |
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327 | } |
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328 | cls = (*env)->NewGlobalRef(env, clsLocalRef); |
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329 | if (cls == NULL) { |
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330 | (*env)->ExceptionDescribe(env); |
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331 | return NULL; |
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332 | } |
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333 | (*env)->DeleteLocalRef(env, clsLocalRef); |
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334 | insertEntryIntoTable(className, cls); |
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335 | return cls; |
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336 | } |
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337 | |
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338 | |
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339 | char *classNameOfObject(jobject jobj, JNIEnv *env) { |
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340 | jclass cls, clsClass; |
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341 | jmethodID mid; |
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342 | jstring str; |
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343 | const char *cstr; |
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344 | char *newstr; |
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345 | |
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346 | cls = (*env)->GetObjectClass(env, jobj); |
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347 | if (cls == NULL) { |
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348 | (*env)->ExceptionDescribe(env); |
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349 | return NULL; |
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350 | } |
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351 | clsClass = (*env)->FindClass(env, "java/lang/Class"); |
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352 | if (clsClass == NULL) { |
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353 | (*env)->ExceptionDescribe(env); |
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354 | return NULL; |
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355 | } |
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356 | mid = (*env)->GetMethodID(env, clsClass, "getName", "()Ljava/lang/String;"); |
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357 | if (mid == NULL) { |
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358 | (*env)->ExceptionDescribe(env); |
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359 | return NULL; |
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360 | } |
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361 | str = (*env)->CallObjectMethod(env, cls, mid); |
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362 | if (str == NULL) { |
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363 | (*env)->ExceptionDescribe(env); |
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364 | return NULL; |
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365 | } |
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366 | |
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367 | cstr = (*env)->GetStringUTFChars(env, str, NULL); |
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368 | newstr = strdup(cstr); |
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369 | (*env)->ReleaseStringUTFChars(env, str, cstr); |
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370 | if (newstr == NULL) { |
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371 | perror("classNameOfObject: strdup"); |
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372 | return NULL; |
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373 | } |
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374 | return newstr; |
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375 | } |
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376 | |
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377 | |
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378 | |
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379 | |
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380 | /** |
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381 | * getJNIEnv: A helper function to get the JNIEnv* for the given thread. |
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382 | * If no JVM exists, then one will be created. JVM command line arguments |
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383 | * are obtained from the LIBHDFS_OPTS environment variable. |
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384 | * |
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385 | * @param: None. |
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386 | * @return The JNIEnv* corresponding to the thread. |
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387 | */ |
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388 | JNIEnv* getJNIEnv(void) |
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389 | { |
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390 | |
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391 | const jsize vmBufLength = 1; |
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392 | JavaVM* vmBuf[vmBufLength]; |
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393 | JNIEnv *env; |
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394 | jint rv = 0; |
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395 | jint noVMs = 0; |
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396 | |
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397 | // Only the first thread should create the JVM. The other trheads should |
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398 | // just use the JVM created by the first thread. |
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399 | LOCK_JVM_MUTEX(); |
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400 | |
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401 | rv = JNI_GetCreatedJavaVMs(&(vmBuf[0]), vmBufLength, &noVMs); |
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402 | if (rv != 0) { |
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403 | fprintf(stderr, "JNI_GetCreatedJavaVMs failed with error: %d\n", rv); |
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404 | UNLOCK_JVM_MUTEX(); |
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405 | return NULL; |
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406 | } |
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407 | |
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408 | if (noVMs == 0) { |
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409 | //Get the environment variables for initializing the JVM |
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410 | char *hadoopClassPath = getenv("CLASSPATH"); |
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411 | if (hadoopClassPath == NULL) { |
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412 | fprintf(stderr, "Environment variable CLASSPATH not set!\n"); |
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413 | UNLOCK_JVM_MUTEX(); |
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414 | return NULL; |
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415 | } |
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416 | char *hadoopClassPathVMArg = "-Djava.class.path="; |
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417 | size_t optHadoopClassPathLen = strlen(hadoopClassPath) + |
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418 | strlen(hadoopClassPathVMArg) + 1; |
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419 | char *optHadoopClassPath = malloc(sizeof(char)*optHadoopClassPathLen); |
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420 | snprintf(optHadoopClassPath, optHadoopClassPathLen, |
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421 | "%s%s", hadoopClassPathVMArg, hadoopClassPath); |
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422 | |
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423 | int noArgs = 1; |
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424 | //determine how many arguments were passed as LIBHDFS_OPTS env var |
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425 | char *hadoopJvmArgs = getenv("LIBHDFS_OPTS"); |
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426 | char jvmArgDelims[] = " "; |
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427 | if (hadoopJvmArgs != NULL) { |
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428 | char *result = NULL; |
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429 | result = strtok( hadoopJvmArgs, jvmArgDelims ); |
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430 | while ( result != NULL ) { |
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431 | noArgs++; |
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432 | result = strtok( NULL, jvmArgDelims); |
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433 | } |
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434 | } |
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435 | JavaVMOption options[noArgs]; |
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436 | options[0].optionString = optHadoopClassPath; |
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437 | //fill in any specified arguments |
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438 | if (hadoopJvmArgs != NULL) { |
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439 | char *result = NULL; |
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440 | result = strtok( hadoopJvmArgs, jvmArgDelims ); |
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441 | int argNum = 1; |
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442 | for (;argNum < noArgs ; argNum++) { |
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443 | options[argNum].optionString = result; //optHadoopArg; |
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444 | } |
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445 | } |
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446 | |
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447 | //Create the VM |
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448 | JavaVMInitArgs vm_args; |
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449 | JavaVM *vm; |
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450 | vm_args.version = JNI_VERSION_1_2; |
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451 | vm_args.options = options; |
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452 | vm_args.nOptions = noArgs; |
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453 | vm_args.ignoreUnrecognized = 1; |
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454 | |
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455 | rv = JNI_CreateJavaVM(&vm, (void*)&env, &vm_args); |
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456 | if (rv != 0) { |
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457 | fprintf(stderr, "Call to JNI_CreateJavaVM failed " |
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458 | "with error: %d\n", rv); |
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459 | UNLOCK_JVM_MUTEX(); |
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460 | return NULL; |
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461 | } |
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462 | |
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463 | free(optHadoopClassPath); |
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464 | } |
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465 | else { |
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466 | //Attach this thread to the VM |
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467 | JavaVM* vm = vmBuf[0]; |
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468 | rv = (*vm)->AttachCurrentThread(vm, (void*)&env, 0); |
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469 | if (rv != 0) { |
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470 | fprintf(stderr, "Call to AttachCurrentThread " |
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471 | "failed with error: %d\n", rv); |
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472 | UNLOCK_JVM_MUTEX(); |
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473 | return NULL; |
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474 | } |
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475 | } |
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476 | UNLOCK_JVM_MUTEX(); |
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477 | |
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478 | return env; |
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479 | } |
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