diff options
Diffstat (limited to 'libbuild2/target.hxx')
| -rw-r--r-- | libbuild2/target.hxx | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/libbuild2/target.hxx b/libbuild2/target.hxx index 3f73e63..c7b1131 100644 --- a/libbuild2/target.hxx +++ b/libbuild2/target.hxx @@ -380,9 +380,12 @@ namespace build2 // // Note that the group-member link-up can happen anywhere between the // member creation and rule matching so reading the group before the - // member has been matched can be racy. + // member has been matched can be racy. However, once the member is linked + // up to the group, this relationship is immutable. As a result, one can + // atomically query the current value to see if already linked up (can be + // used as an optimization, to avoid deadlocks, etc). // - const target* group = nullptr; + relaxed_atomic<const target*> group = nullptr; // What has been described above is an "explicit" group. That is, there is // a dedicated target type that explicitly serves as a group and there is |