sysdeps/managarm: store cancelEvent in shared memory page

Author: Geertiebear

sysdeps/managarm/generic/entry.cpp

@@ -31,6 +31,7 @@ namespace {
 	thread_local unsigned __mlibc_gsf_nesting;
 	thread_local void *__mlibc_cached_thread_page;
 	thread_local HelHandle *cachedFileTable;
+	thread_local HelHandle *cancelEvent;
 
 	// This construction is a bit weird: Even though the variables above
 	// are thread_local we still protect their initialization with a pthread_once_t
@@ -46,6 +47,7 @@ namespace {
 		__mlibc_cached_thread_page = data.threadPage;
 		cachedFileTable = data.fileTable;
 		__mlibc_clk_tracker_page = data.clockTrackerPage;
+		cancelEvent = data.cancelRequestEvent;
 	}
 }
 
@@ -103,6 +105,11 @@ HelHandle getHandleForFd(int fd) {
 	return cacheFileTable()[fd];
 }
 
+void setCurrentRequestEvent(HelHandle event) {
+	pthread_once(&has_cached_infos, &actuallyCacheInfos);
+	__atomic_store_n(cancelEvent, event, __ATOMIC_RELEASE);
+}
+
 void clearCachedInfos() {
 	has_cached_infos = PTHREAD_ONCE_INIT;
 }

sysdeps/managarm/include/mlibc/posix-pipe.hpp

@@ -292,6 +292,7 @@ inline HelHandleResult *parseHandle(ElementHandle &element) {
 HelHandle getPosixLane();
 HelHandle *cacheFileTable();
 HelHandle getHandleForFd(int fd);
+void setCurrentRequestEvent(HelHandle event);
 void clearCachedInfos();
 
 extern thread_local Queue globalQueue;
@@ -324,12 +325,12 @@ auto exchangeMsgsSyncCancellable(HelHandle descriptor, HelHandle event,
 	auto results = helix_ng::createResultsTuple(args...);
 	auto actions = helix_ng::chainActionArrays(args...);
 
+	setCurrentRequestEvent(event);
 	HEL_CHECK(helSubmitAsync(descriptor, actions.data(),
 		actions.size(), globalQueue.getQueue(), 0, 0));
 
 	auto element = globalQueue.dequeueSingle(false);
 	if (!element) {
-		HEL_CHECK(helRaiseEvent(event));
 		element = globalQueue.dequeueSingle();
 		__ensure(element);
 	}
@@ -339,6 +340,8 @@ auto exchangeMsgsSyncCancellable(HelHandle descriptor, HelHandle event,
 		(results.template get<p>().parse(ptr, *element), ...);
 	} (std::make_index_sequence<std::tuple_size_v<decltype(results)>>{});
 
+	setCurrentRequestEvent(kHelNullHandle);
+
 	return results;
 }