/**
* Read bytes from a file descriptor into a user provided buffer.
*
* @param[in] portLibrary The port library
* @param[in] fd The file descriptor.
* @param[in,out] buf Buffer to read into.
* @param[in] nbytes Size of buffer.
*
* @return The number of bytes read, or -1 on failure.
*/
intptr_t
omrfile_read(struct OMRPortLibrary *portLibrary, intptr_t inFD, void *buf, intptr_t nbytes)
{
int fd = (int)inFD;
intptr_t result;
Trc_PRT_file_read_Entry(fd, buf, nbytes);
if (nbytes == 0) {
Trc_PRT_file_read_Exit(0);
return 0;
}
#ifdef J9ZOS390
if (fd == OMRPORT_TTY_IN) {
result = fread(buf, sizeof(char), nbytes, stdin);
} else if (fd < FD_BIAS) {
/* Cannot read from STDOUT/ERR, and no other FD's should exist <FD_BIAS */
Trc_PRT_file_read_Exit(-1);
return -1;
} else
#elif (FD_BIAS != 0)
#error FD_BIAS must be 0
#endif
{
/* CMVC 178203 - Restart system calls interrupted by EINTR */
do {
result = read(fd - FD_BIAS, buf, nbytes);
} while ((-1 == result) && (EINTR == errno));
}
if ((0 == result) || (-1 == result)) {
if (-1 == result) {
portLibrary->error_set_last_error(portLibrary, errno, findError(errno));
}
result = -1;
}
Trc_PRT_file_read_Exit(result);
return result;
}
intptr_t
omrfile_read(struct OMRPortLibrary *portLibrary, intptr_t fd, void *buf, intptr_t nbytes)
{
DWORD bytesRead;
HANDLE handle;
int32_t errorCode = 0;
Trc_PRT_file_read_Entry(fd, buf, nbytes);
if (OMRPORT_TTY_IN == fd) {
handle = PPG_tty_consoleInputHd;
} else {
handle = (HANDLE)fd;
}
if (0 == nbytes) {
Trc_PRT_file_read_Exit(0);
return 0;
}
/* ReadFile limits the buffer to DWORD size and returns the number of bytes read,
* so the (DWORD)nbytes cast is functionally correct, though less than ideal.
* If the caller wants to read more than 2^32 bytes they will have to make more than one call,
* but the logic of the calling code should already account for this.
*/
if (FALSE == ReadFile(handle, buf, (DWORD)nbytes, &bytesRead, NULL)) {
int32_t error = GetLastError();
errorCode = portLibrary->error_set_last_error(portLibrary, error, findError(error));
Trc_PRT_file_read_Exit(errorCode);
return -1;
}
if (0 == bytesRead) {
errorCode = portLibrary->error_set_last_error(portLibrary, -1, OMRPORT_ERROR_FILE_READ_NO_BYTES_READ);
Trc_PRT_file_read_Exit(errorCode);
return -1;
}
Trc_PRT_file_read_Exit(bytesRead);
return bytesRead;
}