Speed up GetRandomBytes by only entering signal-blocking scope once.

runtime/bin/eventhandler_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "bin/eventhandler.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 154 matching lines @@
       perror("Interrupt message failure:");
     }
     FATAL1("Interrupt message failure. Wrote %" Pd " bytes.", result);
   }
 }
 
 
 void EventHandlerImplementation::HandleInterruptFd() {
   const intptr_t MAX_MESSAGES = kInterruptMessageSize;
   InterruptMessage msg[MAX_MESSAGES];
-  ssize_t bytes = TEMP_FAILURE_RETRY(
+  ssize_t bytes = TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
       read(interrupt_fds_[0], msg, MAX_MESSAGES * kInterruptMessageSize));
   for (ssize_t i = 0; i < bytes / kInterruptMessageSize; i++) {
     if (msg[i].id == kTimerId) {
       timeout_queue_.UpdateTimeout(msg[i].dart_port, msg[i].data);
       struct itimerspec it;
       memset(&it, 0, sizeof(it));
       if (timeout_queue_.HasTimeout()) {
         int64_t millis = timeout_queue_.CurrentTimeout();
         it.it_value.tv_sec = millis / 1000;
         it.it_value.tv_nsec = (millis % 1000) * 1000000;
@@ skipping 73 matching lines @@
 
 
 void EventHandlerImplementation::HandleEvents(struct epoll_event* events,
                                               int size) {
   bool interrupt_seen = false;
   for (int i = 0; i < size; i++) {
     if (events[i].data.ptr == NULL) {
       interrupt_seen = true;
     } else if (events[i].data.fd == timer_fd_) {
       int64_t val;
-      VOID_TEMP_FAILURE_RETRY(read(timer_fd_, &val, sizeof(val)));
+      VOID_TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
+          read(timer_fd_, &val, sizeof(val)));
       if (timeout_queue_.HasTimeout()) {
         DartUtils::PostNull(timeout_queue_.CurrentPort());
         timeout_queue_.RemoveCurrent();
       }
     } else {
       SocketData* sd = reinterpret_cast<SocketData*>(events[i].data.ptr);
       intptr_t event_mask = GetPollEvents(events[i].events, sd);
       if (event_mask != 0) {
         if (sd->TakeToken()) {
           // Took last token, remove from epoll.
           RemoveFromEpollInstance(epoll_fd_, sd);
         }
         Dart_Port port = sd->port();
         ASSERT(port != 0);
         DartUtils::PostInt32(port, event_mask);
       }
     }
   }
   if (interrupt_seen) {
     // Handle after socket events, so we avoid closing a socket before we handle
     // the current events.
     HandleInterruptFd();
   }
 }
 
 
 void EventHandlerImplementation::Poll(uword args) {
+  ThreadSignalBlocker signal_blocker(SIGPROF);
   static const intptr_t kMaxEvents = 16;
   struct epoll_event events[kMaxEvents];
   EventHandler* handler = reinterpret_cast<EventHandler*>(args);
   EventHandlerImplementation* handler_impl = &handler->delegate_;
   ASSERT(handler_impl != NULL);
   while (!handler_impl->shutdown_) {
-    intptr_t result = TEMP_FAILURE_RETRY(epoll_wait(handler_impl->epoll_fd_,
-                                                    events,
-                                                    kMaxEvents,
-                                                    -1));
+    intptr_t result = TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
+        epoll_wait(handler_impl->epoll_fd_, events, kMaxEvents, -1));
     ASSERT(EAGAIN == EWOULDBLOCK);
     if (result <= 0) {
       if (errno != EWOULDBLOCK) {
         perror("Poll failed");
       }
     } else {
       handler_impl->HandleEvents(events, result);
     }
   }
   delete handler;
@@ skipping 29 matching lines @@
 
 uint32_t EventHandlerImplementation::GetHashmapHashFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return dart::Utils::WordHash(fd + 1);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)