X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=abad80a86ce368660c1ed3b88a1c0e088488a422;hp=83c6cd5b4d39c77f723aef5f67553b60d6653a31;hb=bf94a866ee741567b4cf8e35d8e6a0565cdfe9bb;hpb=97f53e18953fc2013c0b14f0261ac385e45b0284 diff --git a/fd.c b/fd.c index 83c6cd5b..abad80a8 100644 --- a/fd.c +++ b/fd.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2006-2007 Andre Noll + * Copyright (C) 2006-2008 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -60,6 +60,24 @@ int para_select(int n, fd_set *readfds, fd_set *writefds, 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_PARA_ERROR(errno); + flags = fcntl(fd, F_SETFL, ((long)flags) & ~O_NONBLOCK); + if (flags < 0) + return -ERRNO_TO_PARA_ERROR(errno); + return 1; +} + /** * Set a file descriptor to non-blocking mode. * @@ -67,7 +85,7 @@ int para_select(int n, fd_set *readfds, fd_set *writefds, * * \return Standard. */ -int mark_fd_nonblock(int fd) +__must_check int mark_fd_nonblocking(int fd) { int flags = fcntl(fd, F_GETFL); if (flags < 0) @@ -281,14 +299,19 @@ int para_mkdir(const char *path, mode_t mode) } /** - * Map a file into memory. + * Open a file and map it into memory. * * \param path Name of the regular file to map. * \param open_mode Either \p O_RDONLY or \p O_RDWR. - * \param obj On success, the mapping is returned here. + * \param map On success, the mapping is returned here. + * \param size size of the mapping. + * \param fd_ptr The file descriptor of the mapping. * - * \return Positive on success, negative on errors. Possible errors include: \p - * E_FSTAT, any errors returned by para_open(), \p E_EMPTY, \p E_MMAP. + * If \a fd_ptr is \p NULL, the file descriptor resulting from the underlying + * open call is closed after mmap(). Otherwise the file is kept open and the + * file descriptor is returned in \a fd_ptr. + * + * \return Standard. * * \sa para_open(), mmap(2). */ @@ -332,3 +355,47 @@ out: *fd_ptr = fd; return ret; } + +/** + * A wrapper for munmap(2). + * + * \param start The start address of the memory mapping. + * \param length The size of the mapping. + * + * \return Positive on success, \p -E_MUNMAP on errors. + * + * \sa munmap(2), mmap_full_file(). + */ +int para_munmap(void *start, size_t length) +{ + if (munmap(start, length) >= 0) + return 1; + PARA_ERROR_LOG("munmap (%p/%zu) failed: %s\n", start, length, + strerror(errno)); + return -E_MUNMAP; +} + +/** + * check a file descriptor for writability + * + * \param fd the file descriptor + * + * \return positive if fd is ready for writing, zero if it isn't, negative if + * an error occurred. + */ + +int write_ok(int fd) +{ + struct timeval tv = {0, 0}; + fd_set wfds; + int ret; +again: + FD_ZERO(&wfds); + FD_SET(fd, &wfds); + tv.tv_sec = 0; + tv.tv_usec = 0; + ret = select(fd + 1, NULL, &wfds, NULL, &tv); + if (ret < 0 && errno == EINTR) + goto again; + return ret; +}