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

runtime/bin/eventhandler_android.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_ANDROID)
 
 #include "bin/eventhandler.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 144 matching lines @@
       perror("Interrupt message failure:");
     }
     FATAL1("Interrupt message failure. Wrote %d 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);
     } else if (msg[i].id == kShutdownId) {
       shutdown_ = true;
     } else {
       SocketData* sd = GetSocketData(msg[i].id);
       if ((msg[i].data & (1 << kShutdownReadCommand)) != 0) {
         ASSERT(msg[i].data == (1 << kShutdownReadCommand));
@@ skipping 107 matching lines @@
         TimerUtils::GetCurrentTimeMilliseconds();
     if (millis <= 0) {
       DartUtils::PostNull(timeout_queue_.CurrentPort());
       timeout_queue_.RemoveCurrent();
     }
   }
 }
 
 
 void EventHandlerImplementation::Poll(uword args) {
+  ThreadSignalBlocker signal_blocker(SIGPROF);
   static const intptr_t kMaxEvents = 16;
   struct epoll_event events[kMaxEvents];
   EventHandlerImplementation* handler =
       reinterpret_cast<EventHandlerImplementation*>(args);
   ASSERT(handler != NULL);
   while (!handler->shutdown_) {
     int64_t millis = handler->GetTimeout();
     ASSERT(millis == kInfinityTimeout || millis >= 0);
     if (millis > kMaxInt32) millis = kMaxInt32;
-    intptr_t result = TEMP_FAILURE_RETRY(epoll_wait(handler->epoll_fd_,
-                                                    events,
-                                                    kMaxEvents,
-                                                    millis));
+    intptr_t result = TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
+        epoll_wait(handler->epoll_fd_, events, kMaxEvents, millis));
     ASSERT(EAGAIN == EWOULDBLOCK);
     if (result == -1) {
       if (errno != EWOULDBLOCK) {
         perror("Poll failed");
       }
     } else {
       handler->HandleTimeout();
       handler->HandleEvents(events, result);
     }
   }
@@ 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_ANDROID)