corda/classpath/java-lang.cpp

/* Copyright (c) 2008-2011, Avian Contributors

   Permission to use, copy, modify, and/or distribute this software
   for any purpose with or without fee is hereby granted, provided
   that the above copyright notice and this permission notice appear
   in all copies.

   There is NO WARRANTY for this software.  See license.txt for
   details. */
   
#include "math.h"
#include "stdlib.h"
#include "time.h"
#include "string.h"
#include "stdio.h"
#include "jni.h"
#include "jni-util.h"
#include "errno.h"
#include "fcntl.h"
#include "ctype.h"

#ifdef PLATFORM_WINDOWS

#  include "windows.h"
#  include "winbase.h"
#  include "io.h"
#  include "tchar.h"
#  include "float.h"
#  include "sys/types.h"
#  include "sys/timeb.h"
#  define SO_PREFIX ""
#  define SO_SUFFIX ".dll"

#  ifdef _MSC_VER
#    define snprintf sprintf_s
#    define isnan _isnan
#    define isfinite _finite
#    define strtof strtod
#  endif

#else // not PLATFORM_WINDOWS

#  define SO_PREFIX "lib"
#  ifdef __APPLE__
#    define SO_SUFFIX ".jnilib"
#    ifndef ARCH_arm
#      include <CoreServices/CoreServices.h>
#    endif
#  else
#    define SO_SUFFIX ".so"
#  endif
#  include "unistd.h"
#  include "limits.h"
#  include "signal.h"
#  include "sys/time.h"
#  include "sys/types.h"
#  include "sys/sysctl.h"
#  include "sys/utsname.h"
#  include "sys/wait.h"

#endif // not PLATFORM_WINDOWS

namespace {
#ifdef PLATFORM_WINDOWS
  char* getErrorStr(DWORD err){
    // The poor man's error string, just print the error code 
    char * errStr = (char*) malloc(9 * sizeof(char));
    snprintf(errStr, 9, "%d", (int) err);
    return errStr;
    
    // The better way to do this, if I could figure out how to convert LPTSTR to char*
    //char* errStr;
    //LPTSTR s;
    //if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
    //                 FORMAT_MESSAGE_IGNORE_INSERTS, NULL, err, 0, &s, 0, NULL) == 0)
    //{
    //  errStr.Format("Unknown error occurred (%08x)", err);
    //} else {
    //  errStr = s;
    //}
    //return errStr;
  }

  void makePipe(JNIEnv* e, HANDLE p[2])
  {
    SECURITY_ATTRIBUTES sa;
    sa.nLength = sizeof(sa);
    sa.bInheritHandle = 1;
    sa.lpSecurityDescriptor = 0;
  
    BOOL success = CreatePipe(p, p + 1, &sa, 0);
    if (not success) {
      throwNew(e, "java/io/IOException", getErrorStr(GetLastError()));
    }
  }
  
  int descriptor(JNIEnv* e, HANDLE h)
  {
    int fd = _open_osfhandle(reinterpret_cast<intptr_t>(h), 0);
    if (fd == -1) {
      throwNewErrno(e, "java/io/IOException");
    }
    return fd;
  }
#else
  void makePipe(JNIEnv* e, int p[2])
  {
    if(pipe(p) != 0) {
      throwNewErrno(e, "java/io/IOException");
    }
  }
  
  void safeClose(int &fd)
  {
    if(fd != -1) close(fd);
    fd = -1;
  }
  
  void close(int p[2])
  {
    ::close(p[0]);
    ::close(p[1]);
  }
  
  void clean(JNIEnv* e, jobjectArray command, char** p)
  {
    int i = 0;
    for(char** x = p; *x; ++x, ++i){
      jstring element = (jstring) e->GetObjectArrayElement(command, i);
      e->ReleaseStringUTFChars(element, *x);
    }
    free(p);
  }
#endif  
}

class Locale { // represents an ISO two-char language/country pair
  static const unsigned FIELDLEN = 2;
  static const unsigned FIELDSIZE = FIELDLEN + 1;

  static const char* DEFAULT_LANGUAGE;
  static const char* DEFAULT_REGION;

  char language[FIELDSIZE];
  char region[FIELDSIZE];

  bool isLanguage(const char* language) {
    if (!language) return false;
    unsigned len = strlen(language);
    if (len != FIELDLEN) return false;
    const char* p = language - 1;
    while (islower(*++p)) ;
    if (*p != '\0') return false;
    return true;
  }

  bool isRegion(const char* region) {
    if (!region) return false;
    unsigned len = strlen(region);
    if (len != FIELDLEN) return false;
    const char* p = region - 1;
    while (isupper(*++p)) ;
    if (*p != '\0') return false;
    return true;
  }

public:
  Locale(const char* language = "") {
    Locale l(language, "");
    *this = l;
  }

  Locale(const char* language, const char* region) {
    language = isLanguage(language) ? language : DEFAULT_LANGUAGE;
    region = isRegion(region) ? region : DEFAULT_REGION;
    memcpy(this->language, language, FIELDSIZE);
    memcpy(this->region, region, FIELDSIZE);
  }

  Locale& operator=(const Locale& l) {
    memcpy(language, l.language, FIELDSIZE);
    memcpy(region, l.region, FIELDSIZE);
    return *this;
  }

  const char* getLanguage() { return reinterpret_cast<const char*>(language); }
  const char* getRegion() { return reinterpret_cast<const char*>(region); }
};
const char* Locale::DEFAULT_LANGUAGE = "en";
const char* Locale::DEFAULT_REGION = "";

#ifdef PLATFORM_WINDOWS
extern "C" JNIEXPORT void JNICALL 
Java_java_lang_Runtime_exec(JNIEnv* e, jclass, 
                            jobjectArray command, jlongArray process)
{
  
  int size = 0;
  for (int i = 0; i < e->GetArrayLength(command); ++i){
    jstring element = (jstring) e->GetObjectArrayElement(command, i);
    size += e->GetStringUTFLength(element) + 1;
  } 
   
  RUNTIME_ARRAY(char, line, size);
  char* linep = RUNTIME_ARRAY_BODY(line);
  for (int i = 0; i < e->GetArrayLength(command); ++i) {
    if (i) *(linep++) = _T(' ');
    jstring element = (jstring) e->GetObjectArrayElement(command, i);
    const char* s =  e->GetStringUTFChars(element, 0);
#ifdef _MSC_VER
    _tcscpy_s(linep, size - (linep - RUNTIME_ARRAY_BODY(line)), s);
#else
    _tcscpy(linep, s);
#endif
    e->ReleaseStringUTFChars(element, s);
    linep += e->GetStringUTFLength(element);
  }
  *(linep++) = _T('\0');
 
  HANDLE in[] = { 0, 0 };
  HANDLE out[] = { 0, 0 };
  HANDLE err[] = { 0, 0 };
  
  makePipe(e, in);
  SetHandleInformation(in[0], HANDLE_FLAG_INHERIT, 0);
  jlong inDescriptor = static_cast<jlong>(descriptor(e, in[0]));
  if(e->ExceptionCheck()) return;
  e->SetLongArrayRegion(process, 2, 1, &inDescriptor);
  makePipe(e, out);
  SetHandleInformation(out[1], HANDLE_FLAG_INHERIT, 0);
  jlong outDescriptor = static_cast<jlong>(descriptor(e, out[1]));
  if(e->ExceptionCheck()) return;
  e->SetLongArrayRegion(process, 3, 1, &outDescriptor);
  makePipe(e, err);
  SetHandleInformation(err[0], HANDLE_FLAG_INHERIT, 0);
  jlong errDescriptor = static_cast<jlong>(descriptor(e, err[0]));
  if(e->ExceptionCheck()) return;
  e->SetLongArrayRegion(process, 4, 1, &errDescriptor);
  
  PROCESS_INFORMATION pi;
  ZeroMemory(&pi, sizeof(pi));
 
  STARTUPINFO si;
  ZeroMemory(&si, sizeof(si));
  si.cb = sizeof(si);
  si.dwFlags = STARTF_USESTDHANDLES;
  si.hStdOutput = in[1];
  si.hStdInput = out[0];
  si.hStdError = err[1];
 
  BOOL success = CreateProcess(0, (LPSTR) RUNTIME_ARRAY_BODY(line), 0, 0, 1,
                               CREATE_NO_WINDOW | CREATE_UNICODE_ENVIRONMENT,
                               0, 0, &si, &pi);

  CloseHandle(in[1]);
  CloseHandle(out[0]);
  CloseHandle(err[1]);
  
  if (not success) {
    throwNew(e, "java/io/IOException", getErrorStr(GetLastError()));
    return;
  }
  
  jlong pid = reinterpret_cast<jlong>(pi.hProcess);
  e->SetLongArrayRegion(process, 0, 1, &pid);
  jlong tid = reinterpret_cast<jlong>(pi.hThread);  
  e->SetLongArrayRegion(process, 1, 1, &tid);
}

extern "C" JNIEXPORT jint JNICALL 
Java_java_lang_Runtime_waitFor(JNIEnv* e, jclass, jlong pid, jlong tid)
{
  DWORD exitCode;
  WaitForSingleObject(reinterpret_cast<HANDLE>(pid), INFINITE);
  BOOL success = GetExitCodeProcess(reinterpret_cast<HANDLE>(pid), &exitCode);
  if(not success){
    throwNew(e, "java/lang/Exception", getErrorStr(GetLastError()));
  }

  CloseHandle(reinterpret_cast<HANDLE>(pid));
  CloseHandle(reinterpret_cast<HANDLE>(tid));

  return exitCode;
}

extern "C" JNIEXPORT void JNICALL
Java_java_lang_Runtime_kill(JNIEnv*, jclass, jlong pid) {
  TerminateProcess(reinterpret_cast<HANDLE>(pid), 1);
}

Locale getLocale() {
  const char* lang = "";
  const char* reg = "";
  unsigned langid = GetUserDefaultUILanguage();
  unsigned prilang = langid & 0x3ff;
  unsigned sublang = langid >> 10;

  switch (prilang) {
    case 0x004: {
      lang = "zh";
      switch (sublang) {
        case 0x01: reg = "CN"; break;
        case 0x02: reg = "TW"; break;
        case 0x03: reg = "HK"; break;
        case 0x04: reg = "SG"; break;
      }
    } break;
    case 0x006: lang = "da"; reg = "DK"; break;
    case 0x007: lang = "de"; reg = "DE"; break;
    case 0x009: {
      lang = "en";
      switch (sublang) {
        case 0x01: reg = "US"; break;
        case 0x02: reg = "GB"; break;
        case 0x03: reg = "AU"; break;
        case 0x04: reg = "CA"; break;
        case 0x05: reg = "NZ"; break;
        case 0x06: reg = "IE"; break;
        case 0x07: reg = "ZA"; break;
        case 0x10: reg = "IN"; break;
      }
    } break;
    case 0x00a: {
      lang = "es";
      switch (sublang) {
        case 0x01: case 0x03: reg = "ES"; break;
        case 0x02: reg = "MX"; break;
      }
    } break;
    case 0x00c: {
      lang = "fr";
      switch (sublang) {
        case 0x01: reg = "FR"; break;
        case 0x02: reg = "BE"; break;
        case 0x03: reg = "CA"; break;
      }
    } break;
    case 0x010: lang = "it"; reg = "IT"; break;
    case 0x011: lang = "ja"; reg = "JP"; break;
    case 0x012: lang = "ko"; reg = "KR"; break;
    case 0x013: {
      lang = "nl";
      switch (sublang) {
        case 0x01: reg = "NL"; break;
        case 0x02: reg = "BE"; break;
      }
    } break;
    case 0x014: lang = "no"; reg = "NO"; break;
    case 0x015: lang = "pl"; reg = "PL"; break;
    case 0x016: {
      lang = "pt";
      switch (sublang) {
        case 0x01: reg = "BR"; break;
        case 0x02: reg = "PT"; break;
      }
    } break;
    case 0x018: lang = "ro"; reg = "RO"; break;
    case 0x019: lang = "ru"; reg = "RU"; break;
    case 0x01d: lang = "sv"; reg = "SE"; break;
    default: lang = "en";
  }

  Locale locale(lang, reg);
  return locale;
}
#else
extern "C" JNIEXPORT void JNICALL 
Java_java_lang_Runtime_exec(JNIEnv* e, jclass, 
                            jobjectArray command, jlongArray process)
{
  char** argv = static_cast<char**>
    (malloc((e->GetArrayLength(command) + 1) * sizeof(char*)));
  int i;
  for(i = 0; i < e->GetArrayLength(command); i++){
    jstring element = (jstring) e->GetObjectArrayElement(command, i);
    char* s = const_cast<char*>(e->GetStringUTFChars(element, 0));
    argv[i] = s;
  }
  argv[i] = 0;
  
  int in[] = { -1, -1 };
  int out[] = { -1, -1 };
  int err[] = { -1, -1 };
  int msg[] = { -1, -1 };
  
  makePipe(e, in);
  if(e->ExceptionCheck()) return;
  jlong inDescriptor = static_cast<jlong>(in[0]);
  e->SetLongArrayRegion(process, 2, 1, &inDescriptor);
  makePipe(e, out);
  if(e->ExceptionCheck()) return;
  jlong outDescriptor = static_cast<jlong>(out[1]);
  e->SetLongArrayRegion(process, 3, 1, &outDescriptor);
  makePipe(e, err);
  if(e->ExceptionCheck()) return;
  jlong errDescriptor = static_cast<jlong>(err[0]);
  e->SetLongArrayRegion(process, 4, 1, &errDescriptor);
  makePipe(e, msg);
  if(e->ExceptionCheck()) return;
  if(fcntl(msg[1], F_SETFD, FD_CLOEXEC) != 0) {
    throwNewErrno(e, "java/io/IOException");
    return;
  }
  
  pid_t pid = fork();
  switch(pid){
  case -1: // error
    throwNewErrno(e, "java/io/IOException");
    return;
  case 0: { // child
    // Setup stdin, stdout and stderr
    dup2(in[1], 1);
    close(in);
    dup2(out[0], 0);
    close(out);
    dup2(err[1], 2);
    close(err);
    close(msg[0]);
    
    execvp(argv[0], argv);
    
    // Error if here
    int val = errno;
    ssize_t rv UNUSED = write(msg[1], &val, sizeof(val));
    exit(127);
  } break;
    
  default: { //parent
    jlong JNIPid = static_cast<jlong>(pid);
    e->SetLongArrayRegion(process, 0, 1, &JNIPid);
    
    safeClose(in[1]);
    safeClose(out[0]);
    safeClose(err[1]);
    safeClose(msg[1]);
      
    int val;
    int r = read(msg[0], &val, sizeof(val));
    if(r == -1) {
      throwNewErrno(e, "java/io/IOException");
      return;
    } else if(r) {
      errno = val;
      throwNewErrno(e, "java/io/IOException");
      return;
    }
  } break;
  }
  
  safeClose(msg[0]);
  clean(e, command, argv);
  
  fcntl(in[0], F_SETFD, FD_CLOEXEC);
  fcntl(out[1], F_SETFD, FD_CLOEXEC);
  fcntl(err[0], F_SETFD, FD_CLOEXEC);
}

extern "C" JNIEXPORT jint JNICALL 
Java_java_lang_Runtime_waitFor(JNIEnv*, jclass, jlong pid, jlong)
{
  bool finished = false;
  int status;
  int exitCode;
  while(!finished){
    waitpid(pid, &status, 0);
    if(WIFEXITED(status)){
      finished = true;
      exitCode = WEXITSTATUS(status);
    } else if(WIFSIGNALED(status)){
      finished = true;
      exitCode = -1;
    }
  }
  
  return exitCode;
}

extern "C" JNIEXPORT void JNICALL
Java_java_lang_Runtime_kill(JNIEnv*, jclass, jlong pid) {
  kill((pid_t)pid, SIGTERM);
}

Locale getLocale() {
  Locale fallback;

  const char* LANG = getenv("LANG");
  if (!LANG || strcmp(LANG, "C") == 0) return fallback;

  int len = strlen(LANG);
  char buf[len + 1]; // + 1 for the '\0' char
  memcpy(buf, LANG, len + 1);

  char* tracer = buf;
  const char* reg;

  while (*tracer && *tracer != '_') ++tracer;
  if (!*tracer) return fallback;
  *tracer = '\0';
  reg = ++tracer;

  while (*tracer && *tracer != '.') ++tracer;
  if (tracer == reg) return fallback;
  *tracer = '\0';

  Locale locale(buf, reg);
  return locale;
}
#endif

extern "C" JNIEXPORT jstring JNICALL
Java_java_lang_System_getProperty(JNIEnv* e, jclass, jstring name,
                                  jbooleanArray found)
{
  jstring r = 0;
  const char* chars = e->GetStringUTFChars(name, 0);
  if (chars) {
#ifdef PLATFORM_WINDOWS 
    if (strcmp(chars, "line.separator") == 0) {
      r = e->NewStringUTF("\r\n");
    } else if (strcmp(chars, "file.separator") == 0) {
      r = e->NewStringUTF("\\");
    } else if (strcmp(chars, "os.name") == 0) {
      r = e->NewStringUTF("Windows");
    } else if (strcmp(chars, "os.version") == 0) {
      unsigned size = 32;
      RUNTIME_ARRAY(char, buffer, size);
      OSVERSIONINFO OSversion;
      OSversion.dwOSVersionInfoSize=sizeof(OSVERSIONINFO);
      ::GetVersionEx(&OSversion);
      snprintf(RUNTIME_ARRAY_BODY(buffer), size, "%i.%i", (int)OSversion.dwMajorVersion, (int)OSversion.dwMinorVersion);
      r = e->NewStringUTF(RUNTIME_ARRAY_BODY(buffer));
    } else if (strcmp(chars, "os.arch") == 0) {
#ifdef ARCH_x86_32
      r = e->NewStringUTF("x86");
#elif defined ARCH_x86_64
      r = e->NewStringUTF("x86_64");
#elif defined ARCH_powerpc
      r = e->NewStringUTF("ppc");
#elif defined ARCH_arm
      r = e->NewStringUTF("arm");
#endif
    } else if (strcmp(chars, "java.io.tmpdir") == 0) {
      TCHAR buffer[MAX_PATH];
      GetTempPath(MAX_PATH, buffer);
      r = e->NewStringUTF(buffer);
    } else if (strcmp(chars, "user.dir") == 0) {
      TCHAR buffer[MAX_PATH];
      GetCurrentDirectory(MAX_PATH, buffer);
      r = e->NewStringUTF(buffer);
    } else if (strcmp(chars, "user.home") == 0) {
#  ifdef _MSC_VER
      WCHAR buffer[MAX_PATH];
      size_t needed;
      if (_wgetenv_s(&needed, buffer, MAX_PATH, L"USERPROFILE") == 0) {
        r = e->NewString(reinterpret_cast<jchar*>(buffer), lstrlenW(buffer));
      } else {
        r = 0;
      }
#  else
      LPWSTR home = _wgetenv(L"USERPROFILE");
      r = e->NewString(reinterpret_cast<jchar*>(home), lstrlenW(home));
#  endif
    }
#else
    if (strcmp(chars, "line.separator") == 0) {
      r = e->NewStringUTF("\n");
    } else if (strcmp(chars, "file.separator") == 0) {
      r = e->NewStringUTF("/");
    } else if (strcmp(chars, "os.name") == 0) {
#ifdef __APPLE__
      r = e->NewStringUTF("Mac OS X");
#else
      r = e->NewStringUTF("Linux");
#endif
    } else if (strcmp(chars, "os.version") == 0) {
#if (defined __APPLE__) && (! defined AVIAN_IOS)
      unsigned size = 32;
      char buffer[size];
#ifdef ARCH_x86_64
      int32_t minorVersion, majorVersion;
#else
      long minorVersion, majorVersion;
#endif
      
      Gestalt(gestaltSystemVersionMajor, &majorVersion);
      Gestalt(gestaltSystemVersionMinor, &minorVersion);
      
      snprintf(buffer, size, "%d.%d", static_cast<int32_t>(majorVersion),
               static_cast<int32_t>(minorVersion));
      r = e->NewStringUTF(buffer);
#else
      struct utsname system_id; 
      uname(&system_id);
      r = e->NewStringUTF(system_id.release);
#endif
    } else if (strcmp(chars, "os.arch") == 0) {
#ifdef ARCH_x86_32
      r = e->NewStringUTF("x86");
#elif defined ARCH_x86_64
      r = e->NewStringUTF("x86_64");
#elif defined ARCH_powerpc
      r = e->NewStringUTF("ppc");
#elif defined ARCH_arm
      r = e->NewStringUTF("arm");
#endif
    } else if (strcmp(chars, "java.io.tmpdir") == 0) {
      r = e->NewStringUTF("/tmp");
    } else if (strcmp(chars, "user.dir") == 0) {
      char buffer[PATH_MAX];
      r = e->NewStringUTF(getcwd(buffer, PATH_MAX));
    } else if (strcmp(chars, "user.home") == 0) {
      r = e->NewStringUTF(getenv("HOME"));
    }
#endif
    else if (strcmp(chars, "user.language") == 0) {
      Locale locale = getLocale();
      if (strlen(locale.getLanguage())) r = e->NewStringUTF(locale.getLanguage());
    } else if (strcmp(chars, "user.region") == 0) {
      Locale locale = getLocale();
      if (strlen(locale.getRegion())) r = e->NewStringUTF(locale.getRegion());
    }

    e->ReleaseStringUTFChars(name, chars);
  }

  if (r) {
    jboolean v = true;
    e->SetBooleanArrayRegion(found, 0, 1, &v);
  }

  return r;
}

extern "C" JNIEXPORT jlong JNICALL
Java_java_lang_System_currentTimeMillis(JNIEnv*, jclass)
{
#ifdef PLATFORM_WINDOWS
  // We used to use _ftime here, but that only gives us 1-second
  // resolution on Windows 7.  _ftime_s might work better, but MinGW
  // doesn't have it as of this writing.  So we use this mess instead:
  FILETIME time;
  GetSystemTimeAsFileTime(&time);
  return (((static_cast<jlong>(time.dwHighDateTime) << 32)
           | time.dwLowDateTime) / 10000) - 11644473600000LL;
#else
  timeval tv = { 0, 0 };
  gettimeofday(&tv, 0);
  return (static_cast<jlong>(tv.tv_sec) * 1000) +
    (static_cast<jlong>(tv.tv_usec) / 1000);
#endif
}

extern "C" JNIEXPORT jstring JNICALL
Java_java_lang_System_doMapLibraryName(JNIEnv* e, jclass, jstring name)
{
  jstring r = 0;
  const char* chars = e->GetStringUTFChars(name, 0);
  if (chars) {
    unsigned nameLength = strlen(chars);
    unsigned size = sizeof(SO_PREFIX) + nameLength + sizeof(SO_SUFFIX);
    RUNTIME_ARRAY(char, buffer, size);
    snprintf
      (RUNTIME_ARRAY_BODY(buffer), size, SO_PREFIX "%s" SO_SUFFIX, chars);
    r = e->NewStringUTF(RUNTIME_ARRAY_BODY(buffer));

    e->ReleaseStringUTFChars(name, chars);
  }
  return r;
}

extern "C" JNIEXPORT jboolean JNICALL
Java_java_lang_Double_isInfinite(JNIEnv*, jclass, jdouble val)
{
  return !isfinite(val);
}

extern "C" JNIEXPORT jboolean JNICALL
Java_java_lang_Double_isNaN(JNIEnv*, jclass, jdouble val)
{
  return isnan(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Double_doubleFromString(JNIEnv*e, jclass, jstring s,
				       jintArray numDoublesRead)
{
  const char* chars = e->GetStringUTFChars(s, 0);
  double d = 0.0;
  jint numRead = 0;

  if (chars) {
    char* lastRead;
    d = strtod(chars, &lastRead);
    if ((lastRead != chars) && ((chars + strlen(chars)) == lastRead)) {
      numRead = 1;
    }
    e->ReleaseStringUTFChars(s, chars);
  }
  e->SetIntArrayRegion(numDoublesRead, 0, 1, &numRead);
  return d;
}

extern "C" JNIEXPORT jboolean JNICALL
Java_java_lang_Float_isInfinite(JNIEnv*, jclass, jfloat val)
{
  return !isfinite(val);
}

extern "C" JNIEXPORT jboolean JNICALL
Java_java_lang_Float_isNaN(JNIEnv*, jclass, jfloat val)
{
  return isnan(val);
}

extern "C" JNIEXPORT jfloat JNICALL
Java_java_lang_Float_floatFromString(JNIEnv*e, jclass, jstring s,
				     jintArray numFloatsRead)
{
  const char* chars = e->GetStringUTFChars(s, 0);
  float f = 0.0;
  jint numRead = 0;

  if (chars) {
    char* lastRead;
    f = strtof(chars, &lastRead);
    if ((lastRead != chars) && ((chars + strlen(chars)) == lastRead)) {
      numRead = 1;
    }
    e->ReleaseStringUTFChars(s, chars);
  }
  e->SetIntArrayRegion(numFloatsRead, 0, 1, &numRead);
  return f;
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_sin(JNIEnv*, jclass, jdouble val)
{
  return sin(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_cos(JNIEnv*, jclass, jdouble val)
{
  return cos(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_sqrt(JNIEnv*, jclass, jdouble val)
{
  return sqrt(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_pow(JNIEnv*, jclass, jdouble val, jdouble exp)
{
  return pow(val, exp);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_floor(JNIEnv*, jclass, jdouble val)
{
  return floor(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_ceil(JNIEnv*, jclass, jdouble val)
{
  return ceil(val);
}

extern "C" JNIEXPORT jint JNICALL
Java_java_lang_Double_fillBufferWithDouble(JNIEnv* e, jclass, jdouble val,
					   jbyteArray buffer, jint bufferSize) {
  jboolean isCopy;
  jbyte* buf = e->GetByteArrayElements(buffer, &isCopy);
  jint count = snprintf(reinterpret_cast<char*>(buf), bufferSize, "%g", val);
  e->ReleaseByteArrayElements(buffer, buf, 0);
  return count;
}