Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 12/16/2022
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

Example for lio_listio Function

The following example illustrates how the lio_listio() function can be used.

int aio_ex_5(HANDLE fd) { static struct aiocb aio[2]; static struct aiocb *aio_list[2] = {&aio[0], &aio[1]}; int i, ret; /* ** Data initialization and Synchronously writing */ IC_AIO_DATA_INIT(aio[0], fd, "rec#1\n", strlen("rec#1\n"), 0) IC_AIO_DATA_INIT(aio[1], fd, "rec#2\n", strlen("rec#2\n"), aio[0].aio_nbytes) aio[0].aio_lio_opcode = aio[1].aio_lio_opcode = LIO_WRITE; ret = lio_listio(LIO_WAIT, aio_list, 2, 0); if (ret) return ret; return 0; }/* aio_ex_5 */

Result upon execution:

-bash-3.00$ ./a.out -bash-3.00$ cat dat rec#1 rec#2 -bash-3.00$

Remarks:

  1. In the example, the IC_AIO_DATA_INIT is defined as follows:
    #define IC_AIO_DATA_INIT(_aio, _fd, _dat, _len, _off)\ {memset(&_aio, 0, sizeof(_aio)); \ _aio.aio_fildes = _fd; \ _aio.aio_buf = _dat; \ _aio.aio_nbytes = _len; \ _aio.aio_offset = _off;}
  2. The file descriptor fd is obtained as:
    HANDLE fd = CreateFile("dat", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL/*|FILE_FLAG_OVERLAPPED*/, NULL);
  3. The aio_lio_opcode refers to the field of each aiocb structure that specifies the operation to be performed. The supported operations are LIO_READ (do a 'read' operation), LIO_WRITE (do a 'write' operation), and LIO_NOP (do no operation); these symbols are defined in <aio.h>.

See Also