Profiler Take 2

runtime/vm/os_macos.cc

Index: runtime/vm/os_macos.cc
diff --git a/runtime/vm/os_macos.cc b/runtime/vm/os_macos.cc
index 76d9fb68379dc5caa1e6658cd2fae223744db58f..302ff8af73774a6ceb67ff0f5afeb6f1ff5c52c7 100644
--- a/runtime/vm/os_macos.cc
+++ b/runtime/vm/os_macos.cc
@@ -131,8 +131,22 @@ int OS::NumberOfAvailableProcessors() {
 
 
 void OS::Sleep(int64_t millis) {
-  // TODO(5411554):  For now just use usleep we may have to revisit this.
-  usleep(millis * 1000);
+  int64_t micros = millis * kMicrosecondsPerMillisecond;
+  SleepMicros(micros);
+}
+
+
+void OS::SleepMicros(int64_t micros) {
+  // We must loop here because SIGPROF will interrupt usleep.
+  int64_t start = GetCurrentTimeMicros();
+  while (micros > 0) {
+    usleep(micros);
+    int64_t now = GetCurrentTimeMicros();
+    int64_t delta = now - start;
+    ASSERT(delta >= 0);
+    start = now;
+    micros -= delta;
+  }
 }