bsc_fd: Add a build option to be able to debug fd list corruption
bsc_register_fd on an already registered fd can corrupt the list
in a heavy way and make the select end in an infinite loop, this
code will workaround the issue and provide a way to set a breakpoint
at the right position in the code.
diff --git a/configure.in b/configure.in
index c3e0061..1684aaa 100644
--- a/configure.in
+++ b/configure.in
@@ -77,6 +77,17 @@
AC_DEFINE([PANIC_INFLOOP],[1],[Use infinite loop on panic rather than fprintf/abort])
fi
+AC_ARG_ENABLE(bsc_fd_check,
+ [AS_HELP_STRING(
+ [--enable-bsc-fd-check],
+ [Instrument bsc_register_fd to check that the fd is registered]
+ )],
+ [fd_check=1], [fd_check=0])
+if test "x$fd_check" = "x1"
+then
+ AC_DEFINE([BSC_FD_CHECK],[1],[Instrument the bsc_register_fd])
+fi
+
AC_OUTPUT(
libosmocore.pc
diff --git a/src/select.c b/src/select.c
index 2f6afa7..f52b0a0 100644
--- a/src/select.c
+++ b/src/select.c
@@ -19,6 +19,8 @@
*/
#include <fcntl.h>
+#include <stdio.h>
+
#include <osmocore/select.h>
#include <osmocore/linuxlist.h>
#include <osmocore/timer.h>
@@ -48,6 +50,16 @@
if (fd->fd > maxfd)
maxfd = fd->fd;
+#ifdef BSC_FD_CHECK
+ struct bsc_fd *entry;
+ llist_for_each_entry(entry, &bsc_fds, list) {
+ if (entry == fd) {
+ fprintf(stderr, "Adding a bsc_fd that is already in the list.\n");
+ return 0;
+ }
+ }
+#endif
+
llist_add_tail(&fd->list, &bsc_fds);
return 0;