/**
* Read one byte from file.
*
* @param fd file descriptor
* @return data read (-3: error, -2: operation would block, -1: eof, >= 0: valid)
*/
EXTERNAL int sysReadByte(int fd)
{
unsigned char ch;
SYS_START();
TRACE_PRINTF("%s: sysReadByte %d\n", Me, fd);
#ifdef RVM_FOR_HARMONY
return hyfile_read(fd, &ch, 1);
#else
int rc;
again:
rc = read(fd, &ch, 1);
switch (rc)
{
case 1:
/*fprintf("%s: read (byte) ch is %d\n", Me, (int) ch);*/
return (int) ch;
case 0:
/*fprintf("%s: read (byte) rc is 0\n", Me);*/
return -1;
default:
/*fprintf("%s: read (byte) rc is %d\n", Me, rc);*/
if (errno == EAGAIN)
return -2; // Read would have blocked
else if (errno == EINTR)
goto again; // Read was interrupted; try again
else
return -3; // Some other error
}
#endif // RVM_FOR_HARMONY
}
/**
* Read multiple bytes from file or socket.
*
* @param fd file or socket descriptor
* @param buf buffer to be filled
* @param cnt number of bytes requested
* @return number of bytes delivered (-2: error, -1: socket would have blocked)
*/
EXTERNAL int sysReadBytes(int fd, char *buf, int cnt)
{
SYS_START();
TRACE_PRINTF("%s: sysReadBytes %d %p %d\n", Me, fd, buf, cnt);
#ifdef RVM_FOR_HARMONY
return hyfile_read(fd, buf, cnt);
#else
while (1) {
int rc = read(fd, buf, cnt);
if (rc >= 0)
return rc;
int err = errno;
if (err == EAGAIN) {
TRACE_PRINTF("%s: read on %d would have blocked: needs retry\n", Me, fd);
return -1;
}else if (err != EINTR) {
ERROR_PRINTF("%s: read error %d (%s) on %d\n", Me,
err, strerror(err), fd);
return -2;
} else {
// interrupted by signal; try again
}
}
#endif // RVM_FOR_HARMONY
}
/*
* Class: org_apache_harmony_luni_platform_OSFileSystem
* Method: readDirectImpl
* Signature: (JJI)J
*/
JNIEXPORT jlong JNICALL Java_org_apache_harmony_luni_platform_OSFileSystem_readDirectImpl
(JNIEnv * env, jobject thiz, jlong fd, jlong buf, jint offset, jint nbytes)
{
PORT_ACCESS_FROM_ENV (env);
return (jlong) hyfile_read ((IDATA) fd,
(void *) ((IDATA)(buf+offset)),
(IDATA) nbytes);
}
/*
* Class: org_apache_harmony_luni_platform_OSFileSystem
* Method: readImpl
* Signature: (J[BII)J
*/
JNIEXPORT jlong JNICALL Java_org_apache_harmony_luni_platform_OSFileSystem_readImpl
(JNIEnv * env, jobject thiz, jlong fd, jbyteArray byteArray, jint offset,
jint nbytes)
{
PORT_ACCESS_FROM_ENV (env);
jboolean isCopy;
jbyte *bytes = (*env)->GetByteArrayElements (env, byteArray, &isCopy);
jlong result;
result =
(jlong) hyfile_read ((IDATA) fd, (void *) (bytes + offset),
(IDATA) nbytes);
if(result == -1 && hyerror_last_error_number() == HYPORT_ERROR_FILE_LOCKED){
throwNewExceptionByName(env, "java/io/IOException", netLookupErrorString(env, HYPORT_ERROR_FILE_LOCKED));
}
(*env)->ReleaseByteArrayElements (env, byteArray, bytes,
result==0 || result==-1 ? JNI_ABORT : 0);
return result;
}