HADOOP-9759. Add support for NativeCodeLoader#getLibraryName on Windows. Contributed by Chuan Liu.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1506325 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -635,6 +635,9 @@ Release 2.1.0-beta - 2013-07-02
 
     HADOOP-9738. TestDistCh fails. (jing9 via kihwal)
 
+    HADOOP-9759. Add support for NativeCodeLoader#getLibraryName on Windows.
+    (Chuan Liu via cnauroth)
+
   BREAKDOWN OF HADOOP-8562 SUBTASKS AND RELATED JIRAS
 
     HADOOP-8924. Hadoop Common creating package-info.java must not depend on

hadoop-common-project/hadoop-common/src/main/native/src/org/apache/hadoop/util/NativeCodeLoader.c

@@ -38,9 +38,41 @@ JNIEXPORT jboolean JNICALL Java_org_apache_hadoop_util_NativeCodeLoader_buildSup
 JNIEXPORT jstring JNICALL Java_org_apache_hadoop_util_NativeCodeLoader_getLibraryName
   (JNIEnv *env, jclass clazz)
 {
+#ifdef UNIX
   Dl_info dl_info;
   int ret = dladdr(
       Java_org_apache_hadoop_util_NativeCodeLoader_getLibraryName,
       &dl_info);
   return (*env)->NewStringUTF(env, ret==0 ? "Unavailable" : dl_info.dli_fname);
+#endif
+
+#ifdef WINDOWS
+  SIZE_T ret = 0;
+  DWORD size = MAX_PATH;
+  LPWSTR filename = NULL;
+  HMODULE mod = NULL;
+  DWORD err = ERROR_SUCCESS;
+
+  MEMORY_BASIC_INFORMATION mbi;
+  ret = VirtualQuery(Java_org_apache_hadoop_util_NativeCodeLoader_getLibraryName,
+    &mbi, sizeof(mbi));
+  if (ret == 0) goto cleanup;
+  mod = mbi.AllocationBase;
+
+  do {
+    filename = (LPWSTR) realloc(filename, size * sizeof(WCHAR));
+    if (filename == NULL) goto cleanup;
+    GetModuleFileName(mod, filename, size);
+    size <<= 1;
+    err = GetLastError();
+  } while (err == ERROR_INSUFFICIENT_BUFFER);
+  
+  if (err != ERROR_SUCCESS) goto cleanup;
+
+  return (*env)->NewString(env, filename, (jsize) wcslen(filename));
+
+cleanup:
+  if (filename != NULL) free(filename);
+  return (*env)->NewStringUTF(env, "Unavailable");
+#endif
 }