diff options
Diffstat (limited to 'build2/target')
| -rw-r--r-- | build2/target | 42 |
1 files changed, 20 insertions, 22 deletions
diff --git a/build2/target b/build2/target index 48c80e7..90aaeec 100644 --- a/build2/target +++ b/build2/target @@ -410,40 +410,35 @@ namespace build2 // subset of the target's state as well as the number of its sub-tasks // (execution of prerequisites). // - // The task starts unexecuted and can then transition to postponed or + // The count starts unexecuted and can then transition to postponed or // executing. Postponed can transition to executing. And executing // transitions (via a decrement) to executed. Once it is executed, then // state_ becomes immutable. // + // The target is said to be synchronized (in this thread) if we have + // either observed the task count to reach count_executed or we have + // successfully changed it (via compare_exchange) to count_executing. + // If the target is synchronized, then we can access and modify (second + // case) its state, mtime, etc. + // static const size_t count_unexecuted = 0; static const size_t count_postponed = 1; static const size_t count_executed = 2; static const size_t count_executing = 3; - atomic_count task_count; + mutable atomic_count task_count; - // @@ MT TODO: when can be called. + // Return the "stapshot" of the target state. That is, unless the target + // has been executed, its state can change asynchronously. // target_state - state () const - { - // We go an extra step and short-circuit to the target state even if the - // raw state is not group provided the recipe is group_recipe. - - if (state_ == target_state::group) - return group->state_; + atomic_state () const; - if (group == nullptr) - return state_; - - if (recipe_function* const* f = recipe_.target<recipe_function*> ()) - { - if (*f == &group_action) - return group->state_; - } - - return state_; - } + // During execution this function can only be called if we have observed + // (synchronization-wise) that this target has been executed. + // + target_state + synchronized_state () const; // Number of direct targets that depend on this target in the current // action. It is incremented during the match phase and then decremented @@ -1176,6 +1171,8 @@ namespace build2 // Return true if this target is newer than the specified timestamp. // + // Note: can only be called on a synchronized target. + // bool newer (timestamp mt) const { @@ -1186,7 +1183,8 @@ namespace build2 // much we can do here except detect the case where the target was // changed on this run. // - return mt < mp || (mt == mp && state () == target_state::changed); + return mt < mp || (mt == mp && + synchronized_state () == target_state::changed); } protected: |