X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=ecd87cdccb555bafea525c3a5ded0063f2b63438;hp=83c6cd5b4d39c77f723aef5f67553b60d6653a31;hb=d9f939fe8a68267a62b68546b17e1ec9a34aab0b;hpb=97f53e18953fc2013c0b14f0261ac385e45b0284;ds=sidebyside

diff --git a/fd.c b/fd.c
index 83c6cd5b..ecd87cdc 100644
--- a/fd.c
+++ b/fd.c
@@ -281,11 +281,17 @@ 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.
+ *
+ * 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 Positive on success, negative on errors. Possible errors include: \p
  * E_FSTAT, any errors returned by para_open(), \p E_EMPTY, \p E_MMAP.
@@ -332,3 +338,47 @@ 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;
+}