Ensure index cache entry written in test

Now that index cache files are written in the background, one test in
index-cache.exp is racy -- it assumes that the cache file will have
been written during startup.

This patch fixes the problem by introducing a new maintenance command
to wait for all pending writes to the index cache.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
Reviewed-By: Eli Zaretskii <eliz@gnu.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index bfda7ed..954f148 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -41374,6 +41374,12 @@ give an error.
 For platforms that do support creating the backtrace this feature is
 @code{on} by default.
 
+@kindex maint wait-for-index-cache
+@item maint wait-for-index-cache
+Wait until all pending writes to the index cache have completed.  This
+is used by the test suite to avoid races when the index cache is being
+updated by a worker thread.
+
 @kindex maint with
 @item maint with @var{setting} [@var{value}] [-- @var{command}]
 Like the @code{with} command, but works with @code{maintenance set}