replace standard GPL header by a one-line pointer to COPYING

[paraslash.git] / fd.c

diff --git a/fd.c b/fd.c
index 81ba5cffb7e6919ec7eca5d4fdfd9d0aecc92f61..556f3e96c073b12de38496c595042616a96bafa0 100644 (file)
--- a/fd.c
+++ b/fd.c
@@ -1,24 +1,16 @@
 /*
- * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2007 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.
+ * Licensed under the GPL v2. For licencing details see COPYING.
  */
 
 /** \file fd.c helper functions for file descriptor handling */
 
 #include "para.h"
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <sys/select.h>
+
 #include "error.h"
 /**
  * check whether a file exists
@@ -43,8 +35,8 @@ int file_exists(const char *fn)
  * \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
+ * \param timeout_tv upper bound on the amount of time elapsed before select()
+ * returns
  *
  * \return The return value of the underlying select() call.
  *
@@ -52,15 +44,16 @@ int file_exists(const char *fn)
  * \sa select(2) select_tut(2)
  */
 int para_select(int n, fd_set *readfds, fd_set *writefds,
-               struct timeval *timeout)
+               struct timeval *timeout_tv)
 {
        int ret, err;
        do {
-               ret = select(n, readfds, writefds, NULL, timeout);
+               ret = select(n, readfds, writefds, NULL, timeout_tv);
                err = errno;
        } while (ret < 0 && err == EINTR);
        if (ret < 0)
-               PARA_CRIT_LOG("select error (%s)\n", strerror(err));
+               PARA_CRIT_LOG("select error: %s, max_fileno: %d\n",
+                       strerror(err), n);
        return ret;
 }
 
@@ -81,3 +74,86 @@ 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)
+{
+
+       if (fd < 0 || fd >= FD_SETSIZE) {
+               PARA_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)) {
+                       PARA_EMERG_LOG("fd %d is a blocking file descriptor\n", fd);
+                       exit(EXIT_FAILURE);
+               }
+       }
+#endif
+       FD_SET(fd, fds);
+       *max_fileno = PARA_MAX(*max_fileno, fd);
+}
+
+/**
+* paraslash's wrapper for fgets(3)
+* \param line pointer to the buffer to store the line
+* \param size the size of the buffer given by \a line
+* \param f the stream to read from
+*
+* \return Unlike the standard fgets() function, an integer value
+* is returned. On success, this function returns 1. On errors, -E_FGETS
+* is returned. A zero return value indicates an end of file condition.
+*/
+__must_check int para_fgets(char *line, int size, FILE *f)
+{
+again:
+       if (fgets(line, size, f))
+               return 1;
+       if (feof(f))
+               return 0;
+       if (!ferror(f))
+               return -E_FGETS;
+       if (errno != EINTR) {
+               PARA_ERROR_LOG("%s\n", strerror(errno));
+               return -E_FGETS;
+       }
+       clearerr(f);
+       goto again;
+}
+
+/**
+ * *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;
+       PARA_EMERG_LOG("mmap failed: %s\n", strerror(errno));
+       PARA_EMERG_LOG("length: %zu, flags: %d, fd: %d, offset: %zu\n",
+               length, flags, fd, (size_t)offset);
+       exit(EXIT_FAILURE);
+}
+