Profiler Take 2

runtime/bin/utils_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 <errno.h>  // NOLINT
 #include <netdb.h>  // NOLINT
 #include <sys/time.h>  // NOLINT
+#include <time.h>  // NOLINT
 
 #include "bin/utils.h"
 #include "platform/assert.h"
 
 
 namespace dart {
 namespace bin {
 
 OSError::OSError() : sub_system_(kSystem), code_(0), message_(NULL) {
   set_sub_system(kSystem);
@@ skipping 68 matching lines @@
 int64_t TimerUtils::GetCurrentTimeMicros() {
   struct timeval tv;
   if (gettimeofday(&tv, NULL) < 0) {
     UNREACHABLE();
     return 0;
   }
   return (static_cast<int64_t>(tv.tv_sec) * 1000000) + tv.tv_usec;
 }
 
 void TimerUtils::Sleep(int64_t millis) {
-  // We must loop here because SIGPROF will interrupt usleep.
-  int64_t micros = millis * 1000;
-  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;
+  struct timespec req;  // requested.
+  struct timespec rem;  // remainder.
+  int64_t micros = millis * kMicrosecondsPerMillisecond;
+  int64_t seconds = micros / kMicrosecondsPerSecond;
+  micros = micros - seconds * kMicrosecondsPerSecond;
+  int64_t nanos = micros * kNanosecondsPerMicrosecond;
+  req.tv_sec = seconds;
+  req.tv_nsec = nanos;
+  while (true) {
+    int r = nanosleep(&req, &rem);
+    if (r == 0) {
+      break;
+    }
+    // We should only ever see an interrupt error.
+    ASSERT(errno == EINTR);
+    // Copy remainder into requested and repeat.
+    req = rem;
   }
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)