diff options
Diffstat (limited to 'libbuild2/scheduler.hxx')
| -rw-r--r-- | libbuild2/scheduler.hxx | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/libbuild2/scheduler.hxx b/libbuild2/scheduler.hxx index d3b8ceb..3cc206e 100644 --- a/libbuild2/scheduler.hxx +++ b/libbuild2/scheduler.hxx @@ -192,13 +192,15 @@ namespace build2 // // The external flag indicates whether the wait is for an event external // to the scheduler, that is, triggered by something other than one of the - // threads managed by the scheduler. + // threads managed by the scheduler. This is used to suspend deadlock + // detection (which is progress-based and which cannot be measured for + // external events). // void deactivate (bool external); void - activate (bool external, bool = false); + activate (bool external); // Sleep for the specified duration, deactivating the thread before going // to sleep and re-activating it after waking up (which means this @@ -217,7 +219,7 @@ namespace build2 // Allocate additional active thread count to the current active thread, // for example, to be "passed" to an external program: // - // scheduler::alloc_guard ag (ctx.sched, ctx.sched.max_active () / 2); + // scheduler::alloc_guard ag (*ctx.sched, ctx.sched->max_active () / 2); // args.push_back ("-flto=" + to_string (1 + ag.n)); // run (args); // ag.deallocate (); @@ -242,6 +244,22 @@ namespace build2 void deallocate (size_t); + // Similar to allocate() but reserve all the available threads blocking + // until this becomes possible. Call unlock() on the specified lock before + // deactivating and lock() after activating (can be used to unlock the + // phase). Typical usage: + // + // scheduler::alloc_guard ag (*ctx.sched, + // phase_unlock (ctx, true /* delay */)); + // + // Or, without unlocking the phase: + // + // scheduler::alloc_guard ag (*ctx.sched, phase_unlock (nullptr)); + // + template <typename L> + size_t + serialize (L& lock); + struct alloc_guard { size_t n; @@ -249,6 +267,10 @@ namespace build2 alloc_guard (): n (0), s_ (nullptr) {} alloc_guard (scheduler& s, size_t m): n (s.allocate (m)), s_ (&s) {} + template <typename L, + typename std::enable_if<!std::is_integral<L>::value, int>::type = 0> + alloc_guard (scheduler& s, L&& l): n (s.serialize (l)), s_ (&s) {} + alloc_guard (alloc_guard&& x) noexcept : n (x.n), s_ (x.s_) {x.s_ = nullptr;} @@ -939,6 +961,12 @@ namespace build2 private: optional<size_t> wait_impl (size_t, const atomic_count&, work_queue); + + void + deactivate_impl (bool, lock&&); + + lock + activate_impl (bool, bool); }; } |