From 9e47b1fdea6fe589c531c5c649a9f1c22bc3a029 Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Mon, 27 Jan 2020 09:42:19 +0200 Subject: Protect cc guess cache with mutex --- libbuild2/cc/guess.cxx | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/libbuild2/cc/guess.cxx b/libbuild2/cc/guess.cxx index d5fc884..182a997 100644 --- a/libbuild2/cc/guess.cxx +++ b/libbuild2/cc/guess.cxx @@ -2770,6 +2770,7 @@ namespace build2 // several times) so we cache the result. // static map cache; + static mutex cache_mutex; const compiler_info& guess (const char* xm, @@ -2800,6 +2801,8 @@ namespace build2 if (x_lo != nullptr) append_options (cs, *x_lo); key = cs.string (); + mlock l (cache_mutex); + auto i (cache.find (key)); if (i != cache.end ()) return i->second; @@ -2949,7 +2952,15 @@ namespace build2 r.bin_pattern = p.directory ().representation (); // Trailing slash. } - return (cache[key] = move (r)); + // It's possible the cache entry already exists, in which case we + // ignore our value. + // + // But what if the compiler information it contains is different? Well, + // we don't generally deal with toolchain changes during the build so we + // ignore this special case as well. + // + mlock l (cache_mutex); + return cache.insert (make_pair (move (key), move (r))).first->second; } strings -- cgit v1.1