diff options
Diffstat (limited to 'cpukit/libfs/src/pipe/pipe.c')
-rw-r--r-- | cpukit/libfs/src/pipe/pipe.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/cpukit/libfs/src/pipe/pipe.c b/cpukit/libfs/src/pipe/pipe.c new file mode 100644 index 0000000000..63a294f5f8 --- /dev/null +++ b/cpukit/libfs/src/pipe/pipe.c @@ -0,0 +1,79 @@ +/* + * pipe.c: anonymous pipe + * + * Author: Wei Shen <cquark@gmail.com> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <stdio.h> +#include <fcntl.h> +#include <rtems/libio_.h> +#include <rtems/seterr.h> + +/* Incremental number added to names of anonymous pipe files */ +/* FIXME: This approach is questionable */ +static uint16_t rtems_pipe_no = 0; + +/* + * Called by pipe() to create an anonymous pipe. + */ +int pipe_create( + int filsdes[2] +) +{ + rtems_libio_t *iop; + int err = 0; + + if (rtems_mkdir("/tmp", S_IRWXU | S_IRWXG | S_IRWXO) != 0) + return -1; + + /* /tmp/.fifoXXXX */ + char fifopath[15]; + memcpy(fifopath, "/tmp/.fifo", 10); + sprintf(fifopath + 10, "%04x", rtems_pipe_no ++); + + /* Try creating FIFO file until find an available file name */ + while (mkfifo(fifopath, S_IRUSR|S_IWUSR) != 0) { + if (errno != EEXIST){ + return -1; + } + /* Just try once... */ + return -1; + /* sprintf(fifopath + 10, "%04x", rtems_pipe_no ++); */ + } + + /* Non-blocking open to avoid waiting for writers */ + filsdes[0] = open(fifopath, O_RDONLY | O_NONBLOCK); + if (filsdes[0] < 0) { + err = errno; + /* Delete file at errors, or else if pipe is successfully created + the file node will be deleted after it is closed by all. */ + unlink(fifopath); + } + else { + /* Reset open file to blocking mode */ + iop = rtems_libio_iop(filsdes[0]); + iop->flags &= ~LIBIO_FLAGS_NO_DELAY; + + filsdes[1] = open(fifopath, O_WRONLY); + + if (filsdes[1] < 0) { + err = errno; + close(filsdes[0]); + } + unlink(fifopath); + } + if(err != 0) + rtems_set_errno_and_return_minus_one(err); + return 0; +} + |