X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=ef2c64caced7aaef2751d6fa0233e0b33346dfae;hp=c48f1fef175708331706594f51d54e6d69d0662f;hb=c04ac3f234670c8ba990c15605e1f3f6f2bf4780;hpb=e57d2b9211bb734b71838142a7936fe6dfdc449c

diff --git a/fd.c b/fd.c
index c48f1fef..ef2c64ca 100644
--- a/fd.c
+++ b/fd.c
@@ -1,4 +1,28 @@
+/*
+ * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
+ *
+ *     This program is free software; you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation; either version 2 of the License, or
+ *     (at your option) any later version.
+ *
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program; if not, write to the Free Software
+ *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ */
+
+/** \file fd.c helper functions for file descriptor handling */
+
 #include "para.h"
+
+#include <fcntl.h>
+#include <sys/select.h>
+
 #include "error.h"
 /**
  * check whether a file exists
@@ -14,6 +38,23 @@ int file_exists(const char *fn)
 	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 upper bound on the amount of time elapsed before select()
+ *  returns
+ *
+ * \return The return value of the underlying select() call.
+ *
+ * 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)
 {
@@ -21,12 +62,19 @@ int para_select(int n, fd_set *readfds, fd_set *writefds,
 	do {
 		ret = select(n, readfds, writefds, NULL, timeout);
 		err = errno;
-	} while (ret < 0 && errno == EINTR);
+	} while (ret < 0 && err == EINTR);
 	if (ret < 0)
 		PARA_CRIT_LOG("select error (%s)\n", strerror(err));
 	return ret;
 }
 
+/**
+ * set a file descriptor to non-blocking mode
+ *
+ * \param fd The file descriptor
+ *
+ * \returns 1 on success, -E_F_GETFL, -E_F_SETFL, on errors.
+ */
 int mark_fd_nonblock(int fd)
 {
 	int flags = fcntl(fd, F_GETFL);
@@ -37,3 +85,43 @@ int mark_fd_nonblock(int fd)
 	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)
+{
+	FD_SET(fd, fds);
+	*max_fileno = PARA_MAX(*max_fileno, fd);
+}
+
+/**
+ * paraslash's wrapper for fread(3)
+ *
+ * \param dest destination pointer
+ * \param nbytes size of one element
+ * \param nmemb number of elements to write
+ * \param stream the input stream
+ *
+ * \return negative on errors, zero on end of file, and the number of bytes
+ * (not elements) read on success.
+ *
+ * \sa fread(3)
+ */
+__must_check int para_fread(void *dest, size_t nbytes, size_t nmemb, FILE *stream)
+{
+	size_t res = fread(dest, nbytes, nmemb, stream);
+	if (res == nmemb)
+		return nbytes * nmemb;
+	if (feof(stream))
+		return 0;
+	return -E_FREAD;
+}