Fix io_uring backend tests

Summary: Fix io_uring backend tests

Reviewed By: yfeldblum, danobi

Differential Revision: D19023775

fbshipit-source-id: d696064d26b37f52529c84601f6797ef82b0ddb5

folly/experimental/io/IoUringBackend.cpp

@@ -124,11 +124,12 @@ int IoUringBackend::cancelOne(IoCb* ioCb) {
   return ret;
 }
 
-int IoUringBackend::getActiveEvents(bool waitForEvents) {
+int IoUringBackend::getActiveEvents(WaitForEventsMode waitForEvents) {
   size_t i = 0;
   struct io_uring_cqe* cqe = nullptr;
   // we can be called from the submitList() method
-  if (FOLLY_LIKELY(waitForEvents)) {
+  // or with non blocking flags
+  if (FOLLY_LIKELY(waitForEvents == WaitForEventsMode::WAIT)) {
     ::io_uring_wait_cqe(&ioRing_, &cqe);
   } else {
     ::io_uring_peek_cqe(&ioRing_, &cqe);
@@ -154,7 +155,7 @@ int IoUringBackend::submitBusyCheck() {
   int num;
   while ((num = ::io_uring_submit(&ioRing_)) == -EBUSY) {
     // if we get EBUSY, try to consume some CQ entries
-    getActiveEvents(false);
+    getActiveEvents(WaitForEventsMode::DONT_WAIT);
   };
   return num;
 }
@@ -163,12 +164,14 @@ int IoUringBackend::submitBusyCheckAndWait() {
   int num;
   while ((num = ::io_uring_submit_and_wait(&ioRing_, 1)) == -EBUSY) {
     // if we get EBUSY, try to consume some CQ entries
-    getActiveEvents(false);
+    getActiveEvents(WaitForEventsMode::DONT_WAIT);
   };
   return num;
 }
 
-size_t IoUringBackend::submitList(IoCbList& ioCbs) {
+size_t IoUringBackend::submitList(
+    IoCbList& ioCbs,
+    WaitForEventsMode waitForEvents) {
   int i = 0;
   size_t ret = 0;
 
@@ -182,7 +185,9 @@ size_t IoUringBackend::submitList(IoCbList& ioCbs) {
     entry->prepPollAdd(sqe, ev->ev_fd, getPollFlags(ev->ev_events));
     i++;
     if (ioCbs.empty()) {
-      int num = submitBusyCheckAndWait();
+      int num = (waitForEvents == WaitForEventsMode::WAIT)
+          ? submitBusyCheckAndWait()
+          : submitBusyCheck();
       CHECK_EQ(num, i);
       ret += i;
     } else {

folly/experimental/io/IoUringBackend.h

@@ -46,8 +46,8 @@ class IoUringBackend : public PollIoBackend {
  protected:
   // from PollIoBackend
   void* allocSubmissionEntry() override;
-  int getActiveEvents(bool waitForEvents = true) override;
-  size_t submitList(IoCbList& ioCbs) override;
+  int getActiveEvents(WaitForEventsMode waitForEvents) override;
+  size_t submitList(IoCbList& ioCbs, WaitForEventsMode waitForEvents) override;
   int submitOne(IoCb* ioCb) override;
   int cancelOne(IoCb* ioCb) override;
 

folly/experimental/io/PollIoBackend.cpp

@@ -225,7 +225,7 @@ size_t PollIoBackend::processActiveEvents() {
   size_t ret = 0;
   IoCb* ioCb;
 
-  while (!activeEvents_.empty()) {
+  while (!activeEvents_.empty() && !loopBreak_) {
     bool release = true;
     ioCb = &activeEvents_.front();
     activeEvents_.pop_front();
@@ -261,15 +261,18 @@ size_t PollIoBackend::processActiveEvents() {
 int PollIoBackend::eb_event_base_loop(int flags) {
   // schedule the timers
   bool done = false;
+  auto waitForEvents = (flags & EVLOOP_NONBLOCK) ? WaitForEventsMode::DONT_WAIT
+                                                 : WaitForEventsMode::WAIT;
   while (!done) {
     scheduleTimeout();
-    submitList(submitList_);
     // check if we need to break here
     if (loopBreak_) {
       loopBreak_ = false;
       break;
     }
 
+    submitList(submitList_, waitForEvents);
+
     if (!numInsertedEvents_ && timers_.empty()) {
       return 1;
     }
@@ -279,7 +282,8 @@ int PollIoBackend::eb_event_base_loop(int flags) {
       eb_poll_loop_pre_hook(&call_time);
     }
 
-    int ret = getActiveEvents();
+    // do not wait for events if EVLOOP_NONBLOCK is set
+    int ret = getActiveEvents(waitForEvents);
 
     if (eb_poll_loop_post_hook) {
       eb_poll_loop_post_hook(call_time, ret);
@@ -287,12 +291,12 @@ int PollIoBackend::eb_event_base_loop(int flags) {
 
     size_t numProcessedTimers = 0;
 
-    if (processTimers_) {
+    if (processTimers_ && !loopBreak_) {
       numProcessedTimers = processTimers();
       processTimers_ = false;
     }
 
-    if (!activeEvents_.empty()) {
+    if (!activeEvents_.empty() && !loopBreak_) {
       processActiveEvents();
       if (flags & EVLOOP_ONCE) {
         done = true;

folly/experimental/io/PollIoBackend.h

@@ -48,6 +48,8 @@ class PollIoBackend : public EventBaseBackendBase {
   int eb_event_del(Event& event) override;
 
  protected:
+  enum class WaitForEventsMode { WAIT, DONT_WAIT };
+
   struct IoCb
       : public boost::intrusive::list_base_hook<
             boost::intrusive::link_mode<boost::intrusive::auto_unlink>> {
@@ -161,8 +163,10 @@ class PollIoBackend : public EventBaseBackendBase {
   virtual IoCb* allocNewIoCb() = 0;
 
   virtual void* allocSubmissionEntry() = 0;
-  virtual int getActiveEvents(bool waitForEvents = true) = 0;
-  virtual size_t submitList(IoCbList& ioCbs) = 0;
+  virtual int getActiveEvents(WaitForEventsMode waitForEvents) = 0;
+  virtual size_t submitList(
+      IoCbList& ioCbs,
+      WaitForEventsMode waitForEvents) = 0;
   virtual int submitOne(IoCb* ioCb) = 0;
   virtual int cancelOne(IoCb* ioCb) = 0;