return 1;
ret = -ERRNO_TO_PARA_ERROR(errno);
/* Ignore return value of fchdir() and close(). We're busted anyway. */
-change_to_orig_dir:
if (cwd)
fchdir(*cwd);
close_cwd:
return 1;
return -ERRNO_TO_PARA_ERROR(errno);
}
+
+/**
+ * Map a file 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.
+ *
+ * \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.
+ *
+ * \sa para_open(), mmap(2).
+ */
+int mmap_full_file(const char *path, int open_mode, void **map,
+ size_t *size, int *fd_ptr)
+{
+ int fd, ret, mmap_prot, mmap_flags;
+ struct stat file_status;
+
+ if (open_mode == O_RDONLY) {
+ mmap_prot = PROT_READ;
+ mmap_flags = MAP_PRIVATE;
+ } else {
+ mmap_prot = PROT_READ | PROT_WRITE;
+ mmap_flags = MAP_SHARED;
+ }
+ ret = para_open(path, open_mode, 0);
+ if (ret < 0)
+ return ret;
+ fd = ret;
+ if (fstat(fd, &file_status) < 0) {
+ ret = -ERRNO_TO_PARA_ERROR(errno);
+ goto out;
+ }
+ *size = file_status.st_size;
+ ret = -E_EMPTY;
+ PARA_DEBUG_LOG("%s: size %zu\n", path, *size);
+ if (!*size)
+ goto out;
+ *map = mmap(NULL, *size, mmap_prot, mmap_flags, fd, 0);
+ if (*map == MAP_FAILED) {
+ *map = NULL;
+ ret = -E_MMAP;
+ goto out;
+ }
+ ret = 1;
+out:
+ if (ret < 0 || !fd_ptr)
+ close(fd);
+ else
+ *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;
+}