diff options
| -rw-r--r-- | build2/algorithm.cxx | 135 |
1 files changed, 82 insertions, 53 deletions
diff --git a/build2/algorithm.cxx b/build2/algorithm.cxx index 51877b3..032d657 100644 --- a/build2/algorithm.cxx +++ b/build2/algorithm.cxx @@ -834,46 +834,65 @@ namespace build2 // Try to atomically change applied to busy. Note that we are in the // execution phase so the target shall not be spin-locked. // - size_t tc (target::count_applied ()); - if (t.task_count.compare_exchange_strong ( - tc, - target::count_busy (), - memory_order_acq_rel, // Synchronize on success. - memory_order_acquire)) // Synchronize on failure. + size_t matc (target::count_matched ()); + size_t exec (target::count_executed ()); + size_t busy (target::count_busy ()); + + for (size_t tc (target::count_applied ());;) { - if (t.state_ != target_state::unchanged) // Noop recipe. + if (t.task_count.compare_exchange_strong ( + tc, + busy, + memory_order_acq_rel, // Synchronize on success. + memory_order_acquire)) // Synchronize on failure. { - if (task_count == nullptr) - return execute_impl (a, t); - - // Pass our diagnostics stack (this is safe since we expect the caller - // to wait for completion before unwinding its diag stack). + // Overriden match-only or noop recipe. // - if (sched.async (start_count, - *task_count, - [a] (target& t, const diag_frame* ds) - { - diag_frame df (ds); - execute_impl (a, t); // Note: noexcept. - }, - ref (t), - diag_frame::stack)) - return target_state::unknown; // Queued. - - // Executed synchronously, fall through. + if (tc == matc || t.state_ == target_state::unchanged) + { + t.state_ = target_state::unchanged; + t.task_count.store (exec, memory_order_release); + sched.resume (t.task_count); + } + else + { + if (task_count == nullptr) + return execute_impl (a, t); + + // Pass our diagnostics stack (this is safe since we expect the + // caller to wait for completion before unwinding its diag stack). + // + if (sched.async (start_count, + *task_count, + [a] (target& t, const diag_frame* ds) + { + diag_frame df (ds); + execute_impl (a, t); // Note: noexcept. + }, + ref (t), + diag_frame::stack)) + return target_state::unknown; // Queued. + + // Executed synchronously, fall through. + } } else { - t.task_count.store (target::count_executed (), memory_order_release); - sched.resume (t.task_count); + // Normally either busy or already executed. + // + if (tc >= busy) return target_state::busy; + else if (tc != exec) + { + // This can happen is we matched (a noop) recipe which then got + // overridden as part of group resolution but not all the way to + // applied. In this case we treat it as noop. + // + assert (tc == matc && t.action > a); + continue; + } } - } - else - { - // Should be either busy or already executed. - // - if (tc >= target::count_busy ()) return target_state::busy; - else assert (tc == target::count_executed ()); + + break; } return t.executed_state (false); @@ -884,32 +903,42 @@ namespace build2 { target& t (const_cast<target&> (ct)); // MT-aware. - size_t busy (target::count_busy ()); + // Similar logic to match() above. + // + size_t matc (target::count_matched ()); size_t exec (target::count_executed ()); + size_t busy (target::count_busy ()); - size_t tc (target::count_applied ()); - if (t.task_count.compare_exchange_strong ( - tc, - busy, - memory_order_acq_rel, // Synchronize on success. - memory_order_acquire)) // Synchronize on failure. + for (size_t tc (target::count_applied ());;) { - if (t.state_ != target_state::unchanged) // Noop recipe. - execute_impl (a, t); - else + if (t.task_count.compare_exchange_strong ( + tc, + busy, + memory_order_acq_rel, // Synchronize on success. + memory_order_acquire)) // Synchronize on failure. { - t.task_count.store (exec, memory_order_release); - sched.resume (t.task_count); + if (tc == matc || t.state_ == target_state::unchanged) + { + t.state_ = target_state::unchanged; + t.task_count.store (exec, memory_order_release); + sched.resume (t.task_count); + } + else + execute_impl (a, t); } - } - else - { - // If the target is busy, wait for it. - // - if (tc >= busy) - sched.wait (exec, t.task_count, scheduler::work_none); else - assert (tc == exec); + { + // If the target is busy, wait for it. + // + if (tc >= busy) sched.wait (exec, t.task_count, scheduler::work_none); + else if (tc != exec) + { + assert (tc == matc && t.action > a); + continue; + } + } + + break; } return t.executed_state (); |