diff options
Diffstat (limited to 'libbuild2/context.cxx')
| -rw-r--r-- | libbuild2/context.cxx | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/libbuild2/context.cxx b/libbuild2/context.cxx index 8052716..7944294 100644 --- a/libbuild2/context.cxx +++ b/libbuild2/context.cxx @@ -848,7 +848,7 @@ namespace build2 } } - bool run_phase_mutex:: + optional<bool> run_phase_mutex:: relock (run_phase o, run_phase n) { // Pretty much a fused unlock/lock implementation except that we always @@ -857,6 +857,7 @@ namespace build2 assert (o != n); bool r; + bool s (true); // True switch. if (o == run_phase::load) lm_.unlock (); @@ -919,6 +920,13 @@ namespace build2 { if (!lm_.try_lock ()) { + // If we failed to acquire the load mutex, then we know there is (or + // was) someone before us in the load phase. And it's impossible to + // switch to a different phase between our calls to try_lock() above + // and lock() below because of our +1 in lc_. + // + s = false; + ctx_.sched.deactivate (false /* external */); lm_.lock (); ctx_.sched.activate (false /* external */); @@ -928,7 +936,7 @@ namespace build2 r = !fail_; // Re-query. } - return r; + return r ? optional<bool> (s) : nullopt; } // C++17 deprecated uncaught_exception() so use uncaught_exceptions() if @@ -1043,7 +1051,8 @@ namespace build2 phase_lock* pl (phase_lock_instance); assert (&pl->ctx == &ctx); - if (!ctx.phase_mutex.relock (old_phase, new_phase)) + optional<bool> r (ctx.phase_mutex.relock (old_phase, new_phase)); + if (!r) { ctx.phase_mutex.relock (new_phase, old_phase); throw failed (); @@ -1052,14 +1061,31 @@ namespace build2 pl->phase = new_phase; if (new_phase == run_phase::load) // Note: load lock is exclusive. + { ctx.load_generation++; + // Invalidate cached target base_scope values if we are switching from a + // non-load phase (we don't cache during load which means load->load + // switch doesn't have anything to invalidate). + // + // @@ This is still quite expensive on project like Boost with a large + // number of files (targets) and a large number of load phase + // switches (due to directory buildfiles). + // + if (*r) + { + for (const unique_ptr<target>& t: ctx.targets) + t->base_scope_.store (nullptr, memory_order_relaxed); + } + } + //text << this_thread::get_id () << " phase switch " // << old_phase << " " << new_phase; } #if 0 - // NOTE: see push/pop_phase() logic if trying to enable this. + // NOTE: see push/pop_phase() logic if trying to enable this. Also + // the load stuff above. // phase_switch:: phase_switch (phase_unlock&& u, phase_lock&& l) |