diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/httpserver.cpp | 86 |
1 files changed, 70 insertions, 16 deletions
diff --git a/src/httpserver.cpp b/src/httpserver.cpp index a83f4421d7..3ad329a669 100644 --- a/src/httpserver.cpp +++ b/src/httpserver.cpp @@ -17,6 +17,7 @@ #include <rpc/protocol.h> // For HTTP status codes #include <shutdown.h> #include <sync.h> +#include <util/check.h> #include <util/strencodings.h> #include <util/threadnames.h> #include <util/translation.h> @@ -26,9 +27,10 @@ #include <cstdlib> #include <deque> #include <memory> +#include <numeric> #include <optional> #include <string> -#include <unordered_set> +#include <unordered_map> #include <sys/types.h> #include <sys/stat.h> @@ -149,10 +151,68 @@ static GlobalMutex g_httppathhandlers_mutex; static std::vector<HTTPPathHandler> pathHandlers GUARDED_BY(g_httppathhandlers_mutex); //! Bound listening sockets static std::vector<evhttp_bound_socket *> boundSockets; + +/** + * @brief Helps keep track of open `evhttp_connection`s with active `evhttp_requests` + * + */ +class HTTPRequestTracker +{ +private: + mutable Mutex m_mutex; + mutable std::condition_variable m_cv; + //! For each connection, keep a counter of how many requests are open + std::unordered_map<const evhttp_connection*, size_t> m_tracker GUARDED_BY(m_mutex); + + void RemoveConnectionInternal(const decltype(m_tracker)::iterator it) EXCLUSIVE_LOCKS_REQUIRED(m_mutex) + { + m_tracker.erase(it); + if (m_tracker.empty()) m_cv.notify_all(); + } +public: + //! Increase request counter for the associated connection by 1 + void AddRequest(evhttp_request* req) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex) + { + const evhttp_connection* conn{Assert(evhttp_request_get_connection(Assert(req)))}; + WITH_LOCK(m_mutex, ++m_tracker[conn]); + } + //! Decrease request counter for the associated connection by 1, remove connection if counter is 0 + void RemoveRequest(evhttp_request* req) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex) + { + const evhttp_connection* conn{Assert(evhttp_request_get_connection(Assert(req)))}; + LOCK(m_mutex); + auto it{m_tracker.find(conn)}; + if (it != m_tracker.end() && it->second > 0) { + if (--(it->second) == 0) RemoveConnectionInternal(it); + } + } + //! Remove a connection entirely + void RemoveConnection(const evhttp_connection* conn) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex) + { + LOCK(m_mutex); + auto it{m_tracker.find(Assert(conn))}; + if (it != m_tracker.end()) RemoveConnectionInternal(it); + } + + size_t CountActiveRequests() const EXCLUSIVE_LOCKS_REQUIRED(!m_mutex) + { + LOCK(m_mutex); + return std::accumulate(m_tracker.begin(), m_tracker.end(), size_t(0), + [](size_t acc_count, const auto& pair) { return acc_count + pair.second; }); + } + size_t CountActiveConnections() const EXCLUSIVE_LOCKS_REQUIRED(!m_mutex) + { + return WITH_LOCK(m_mutex, return m_tracker.size()); + } + //! Wait until there are no more connections with active requests in the tracker + void WaitUntilEmpty() const EXCLUSIVE_LOCKS_REQUIRED(!m_mutex) + { + WAIT_LOCK(m_mutex, lock); + m_cv.wait(lock, [this]() EXCLUSIVE_LOCKS_REQUIRED(m_mutex) { return m_tracker.empty(); }); + } +}; //! Track active requests -static GlobalMutex g_requests_mutex; -static std::condition_variable g_requests_cv; -static std::unordered_set<evhttp_request*> g_requests GUARDED_BY(g_requests_mutex); +static HTTPRequestTracker g_requests; /** Check if a network address is allowed to access the HTTP server */ static bool ClientAllowed(const CNetAddr& netaddr) @@ -210,14 +270,11 @@ std::string RequestMethodString(HTTPRequest::RequestMethod m) /** HTTP request callback */ static void http_request_cb(struct evhttp_request* req, void* arg) { - // Track requests and notify when a request is completed. + // Track active requests { - WITH_LOCK(g_requests_mutex, g_requests.insert(req)); - g_requests_cv.notify_all(); + g_requests.AddRequest(req); evhttp_request_set_on_complete_cb(req, [](struct evhttp_request* req, void*) { - auto n{WITH_LOCK(g_requests_mutex, return g_requests.erase(req))}; - assert(n == 1); - g_requests_cv.notify_all(); + g_requests.RemoveRequest(req); }, nullptr); } @@ -473,13 +530,10 @@ void StopHTTPServer() } boundSockets.clear(); { - WAIT_LOCK(g_requests_mutex, lock); - if (!g_requests.empty()) { - LogPrint(BCLog::HTTP, "Waiting for %d requests to stop HTTP server\n", g_requests.size()); + if (g_requests.CountActiveConnections() != 0) { + LogPrint(BCLog::HTTP, "Waiting for %d requests to stop HTTP server\n", g_requests.CountActiveRequests()); } - g_requests_cv.wait(lock, []() EXCLUSIVE_LOCKS_REQUIRED(g_requests_mutex) { - return g_requests.empty(); - }); + g_requests.WaitUntilEmpty(); } if (eventHTTP) { // Schedule a callback to call evhttp_free in the event base thread, so |