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

runtime/bin/eventhandler_macos.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_MACOS)
 
 #include "bin/eventhandler.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 161 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);
     } 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 148 matching lines @@
         TimerUtils::GetCurrentTimeMilliseconds();
     if (millis <= 0) {
       DartUtils::PostNull(timeout_queue_.CurrentPort());
       timeout_queue_.RemoveCurrent();
     }
   }
 }
 
 
 void EventHandlerImplementation::EventHandlerEntry(uword args) {
+  ThreadSignalBlocker signal_blocker(SIGPROF);
   static const intptr_t kMaxEvents = 16;
   struct kevent events[kMaxEvents];
   EventHandler* handler = reinterpret_cast<EventHandler*>(args);
   EventHandlerImplementation* handler_impl = &handler->delegate_;
   ASSERT(handler_impl != NULL);
   while (!handler_impl->shutdown_) {
     int64_t millis = handler_impl->GetTimeout();
     ASSERT(millis == kInfinityTimeout || millis >= 0);
     if (millis > kMaxInt32) millis = kMaxInt32;
     // NULL pointer timespec for infinite timeout.
     ASSERT(kInfinityTimeout < 0);
     struct timespec* timeout = NULL;
     struct timespec ts;
     if (millis >= 0) {
       int32_t millis32 = static_cast<int32_t>(millis);
       int32_t secs = millis32 / 1000;
       ts.tv_sec = secs;
       ts.tv_nsec = (millis32 - (secs * 1000)) * 1000000;
       timeout = &ts;
     }
-    intptr_t result = TEMP_FAILURE_RETRY(kevent(handler_impl->kqueue_fd_,
-                                                NULL,
-                                                0,
-                                                events,
-                                                kMaxEvents,
-                                                timeout));
+    intptr_t result = TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
+        kevent(handler_impl->kqueue_fd_, NULL, 0, events, kMaxEvents, timeout));
     if (result == -1) {
       const int kBufferSize = 1024;
       char error_message[kBufferSize];
       strerror_r(errno, error_message, kBufferSize);
       FATAL1("kevent failed %s\n", error_message);
     } else {
       handler_impl->HandleTimeout();
       handler_impl->HandleEvents(events, result);
     }
   }
@@ skipping 31 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_MACOS)