X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=556f3e96c073b12de38496c595042616a96bafa0;hp=c48f1fef175708331706594f51d54e6d69d0662f;hb=5f25c580aed568f05dd8ec285c2990ad1906b83d;hpb=e57d2b9211bb734b71838142a7936fe6dfdc449c

diff --git a/fd.c b/fd.c
index c48f1fef..556f3e96 100644
--- a/fd.c
+++ b/fd.c
@@ -1,4 +1,16 @@
+/*
+ * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
+ *
+ * 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
@@ -14,19 +26,44 @@ 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_tv 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)
+		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 && errno == EINTR);
+	} 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;
 }
 
+/**
+ * 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 +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);
+}
+