Changeset 0fc6b6c in mainline for uspace/lib/cpp/include/__bits/thread/promise.hpp

Timestamp:

2019-07-01T14:52:42Z (5 years ago)

Author:

Jaroslav Jindrak <dzejrou@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

a552044

Parents:

0d299c93

Message:

cpp: make sure that promise::get_future increments the refcount since the state is shared between the future and the promise

File:

• uspace/lib/cpp/include/__bits/thread/promise.hpp (modified) (3 diffs)

uspace/lib/cpp/include/__bits/thread/promise.hpp

@@ -162 +162 @@
             future<R> get_future()
             {
+                assert(this->state_);
+
+                /**
+                 * Note: Future constructor that takes a shared
+                 *       state as its argument does not call increment
+                 *       because a future can be created as the only
+                 *       owner of that state (e.g. when created by
+                 *       std::async), so we have to do it here.
+                 */
+                this->state_->increment();
+
                 return future<R>{this->state_};
             }
@@ -253 +264 @@
             future<R&> get_future()
             {
+                assert(this->state_);
+
+                /**
+                 * Note: Future constructor that takes a shared
+                 *       state as its argument does not call increment
+                 *       because a future can be created as the only
+                 *       owner of that state (e.g. when created by
+                 *       std::async), so we have to do it here.
+                 */
+                this->state_->increment();
+
                 return future<R&>{this->state_};
             }
@@ -315 +337 @@
             future<void> get_future()
             {
+                assert(this->state_);
+
+                /**
+                 * Note: Future constructor that takes a shared
+                 *       state as its argument does not call increment
+                 *       because a future can be created as the only
+                 *       owner of that state (e.g. when created by
+                 *       std::async), so we have to do it here.
+                 */
+                this->state_->increment();
+
                 return future<void>{this->state_};
             }