Merge bitcoin/bitcoin#19033: http: Release work queue after event base finish

4e353cb618745cdb5d98e58e7dcd400ded01299a http: Release work queue after event base finish (João Barbosa)

Pull request description:

  This fixes a race between `http_request_cb` and `StopHTTPServer` where
  the work queue is used after release.

  Fixes #18856.

ACKs for top commit:
  fjahr:
    Code review ACK 4e353cb618745cdb5d98e58e7dcd400ded01299a
  achow101:
    ACK 4e353cb618745cdb5d98e58e7dcd400ded01299a
  LarryRuane:
    ACK 4e353cb618745cdb5d98e58e7dcd400ded01299a
  hebasto:
    ACK 4e353cb618745cdb5d98e58e7dcd400ded01299a, tested (rebased on top of master 9313c4e6aa4b707c06a86b33d5d2753cd8383340) on Linux Mint 20.1 (x86_64) using MarcoFalke's [patch](https://github.com/bitcoin/bitcoin/pull/19033#issuecomment-640106647), including different `-rpcthreads`/`-rpcworkqueue` cases. The bug is fixed. The code is correct.

Tree-SHA512: 185d2a9744d0d5134d782bf321ac9958ba17b11a5b3d70b4897c8243e6b146dfd3f23c57aef8e10ae9484374120b64389c1949a9cf0a21dccc47ffc934c20930
This commit is contained in:
W. J. van der Laan 2021-06-21 11:15:11 +02:00 committed by pasta
parent 8ebffdfa7c
commit d3f9a66580

View File

@ -94,7 +94,7 @@ public:
bool Enqueue(WorkItem* item) bool Enqueue(WorkItem* item)
{ {
LOCK(cs); LOCK(cs);
if (queue.size() >= maxDepth) { if (!running || queue.size() >= maxDepth) {
return false; return false;
} }
queue.emplace_back(std::unique_ptr<WorkItem>(item)); queue.emplace_back(std::unique_ptr<WorkItem>(item));
@ -110,7 +110,7 @@ public:
WAIT_LOCK(cs, lock); WAIT_LOCK(cs, lock);
while (running && queue.empty()) while (running && queue.empty())
cond.wait(lock); cond.wait(lock);
if (!running) if (!running && queue.empty())
break; break;
i = std::move(queue.front()); i = std::move(queue.front());
queue.pop_front(); queue.pop_front();
@ -468,8 +468,6 @@ void StopHTTPServer()
thread.join(); thread.join();
} }
g_thread_http_workers.clear(); g_thread_http_workers.clear();
delete workQueue;
workQueue = nullptr;
} }
// Unlisten sockets, these are what make the event loop running, which means // Unlisten sockets, these are what make the event loop running, which means
// that after this and all connections are closed the event loop will quit. // that after this and all connections are closed the event loop will quit.
@ -489,6 +487,10 @@ void StopHTTPServer()
event_base_free(eventBase); event_base_free(eventBase);
eventBase = nullptr; eventBase = nullptr;
} }
if (workQueue) {
delete workQueue;
workQueue = nullptr;
}
LogPrint(BCLog::HTTP, "Stopped HTTP server\n"); LogPrint(BCLog::HTTP, "Stopped HTTP server\n");
} }