-
-/**
- * Check whether a file exists.
- *
- * \param fn The file name.
- *
- * \return Non-zero iff file exists.
- */
-int file_exists(const char *fn)
-{
- struct stat statbuf;
-
- return !stat(fn, &statbuf);
-}
-
-/**
- * Paraslash's wrapper for select(2).
- *
- * It calls select(2) (with no exceptfds) and starts over if select() was
- * interrupted by a signal.
- *
- * \param n The highest-numbered descriptor in any of the two sets, plus 1.
- * \param readfds fds that should be checked for readability.
- * \param writefds fds that should be checked for writablility.
- * \param timeout_tv upper bound on the amount of time elapsed before select()
- * returns.
- *
- * \return The return value of the underlying select() call on success, the
- * negative system error code on errors.
- *
- * All arguments are passed verbatim to select(2).
- * \sa select(2) select_tut(2).
- */
-int para_select(int n, fd_set *readfds, fd_set *writefds,
- struct timeval *timeout_tv)
-{
- int ret, err;
- do {
- ret = select(n, readfds, writefds, NULL, timeout_tv);
- err = errno;
- } while (ret < 0 && err == EINTR);
- if (ret < 0)
- return -ERRNO_TO_ERROR(errno);
- return ret;
-}
-
-/**
- * Set a file descriptor to blocking mode.
- *
- * \param fd The file descriptor.
- *
- * \return Standard.
- */
-__must_check int mark_fd_blocking(int fd)
-{
- int flags = fcntl(fd, F_GETFL);
- if (flags < 0)
- return -ERRNO_TO_ERROR(errno);
- flags = fcntl(fd, F_SETFL, ((long)flags) & ~O_NONBLOCK);
- if (flags < 0)
- return -ERRNO_TO_ERROR(errno);
- return 1;
-}
-
-/**
- * Set a file descriptor to non-blocking mode.
- *
- * \param fd The file descriptor.
- *
- * \return Standard.
- */
-__must_check int mark_fd_nonblocking(int fd)
-{
- int flags = fcntl(fd, F_GETFL);
- if (flags < 0)
- return -ERRNO_TO_ERROR(errno);
- flags = fcntl(fd, F_SETFL, ((long)flags) | O_NONBLOCK);
- if (flags < 0)
- return -ERRNO_TO_ERROR(errno);
- return 1;
-}
-
-/**
- * Set a file descriptor in a fd_set.
- *
- * \param fd The file descriptor to be set.
- * \param fds The file descriptor set.
- * \param max_fileno Highest-numbered file descriptor.
- *
- * This wrapper for FD_SET() passes its first two arguments to \p FD_SET. Upon
- * return, \a max_fileno contains the maximum of the old_value and \a fd.
- *
- * \sa para_select.
-*/
-void para_fd_set(int fd, fd_set *fds, int *max_fileno)
-{
-
- if (fd < 0 || fd >= FD_SETSIZE) {
- EMERG_LOG("fatal: tried to add invalid fd %d\n", fd);
- exit(EXIT_FAILURE);
- }
-#if 0
- {
- int flags = fcntl(fd, F_GETFL);
- if (!(flags & O_NONBLOCK)) {
- EMERG_LOG("fd %d is a blocking file descriptor\n", fd);
- exit(EXIT_FAILURE);
- }
- }
-#endif
- FD_SET(fd, fds);
- *max_fileno = MAX(*max_fileno, fd);
-}
-
-/**
- * Paraslash's wrapper for mmap.
- *
- * \param length Number of bytes to mmap.
- * \param prot Either PROT_NONE or the bitwise OR of one or more of
- * PROT_EXEC PROT_READ PROT_WRITE.
- * \param flags Exactly one of MAP_SHARED and MAP_PRIVATE.
- * \param fd The file to mmap from.
- * \param offset Mmap start.
- *
- * \return This function either returns a valid pointer to the mapped area
- * or calls exit() on errors.
- */
-void *para_mmap(size_t length, int prot, int flags, int fd, off_t offset)
-{
- void *ret = mmap(NULL, length, prot, flags, fd, offset);
- if (ret != MAP_FAILED)
- return ret;
- EMERG_LOG("mmap failed: %s\n", strerror(errno));
- EMERG_LOG("length: %zu, flags: %d, fd: %d, offset: %zu\n",
- length, flags, fd, (size_t)offset);
- exit(EXIT_FAILURE);
-}
-