[dart:io] Adds ProcessInfo.{max,current}Rss. Adds OS::MaxRSS on Fuchsia.

runtime/bin/process_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.
 
 #if !defined(DART_IO_DISABLED)
 
 #include "platform/globals.h"
 #if defined(HOST_OS_ANDROID)
 
 #include "bin/process.h"
@@ skipping 869 matching lines @@
 void Process::TerminateExitCodeHandler() {
   ExitCodeHandler::TerminateExitCodeThread();
 }
 
 
 intptr_t Process::CurrentProcessId() {
   return static_cast<intptr_t>(getpid());
 }
 
 
+intptr_t Process::CurrentRSS() {
+  // The second value in /proc/self/statm is the current RSS in pages.
+  File* statm = File::Open("/proc/self/statm", File::kRead);
+  if (statm == NULL) {
+    return -1;
+  }
+  RefCntReleaseScope<File> releaser(statm);
+  const intptr_t statm_length = 1 * KB;
+  void* buffer = reinterpret_cast<void*>(Dart_ScopeAllocate(statm_length));
+  const intptr_t statm_read = statm->Read(buffer, statm_length);
+  if (statm_read <= 0) {
+    return -1;
+  }
+  intptr_t current_rss_pages = 0;
+  int matches =
+      sscanf(reinterpret_cast<char*>(buffer), "%*s%" Pu "", &current_rss_pages);
+  if (matches != 1) {
+    return -1;
+  }
+  return current_rss_pages * getpagesize();
+}
+
+
+intptr_t Process::MaxRSS() {
+  struct rusage usage;
+  usage.ru_maxrss = 0;
+  int r = getrusage(RUSAGE_SELF, &usage);
+  if (r < 0) {
+    return -1;
+  }
+  return usage.ru_maxrss * KB;
+}
+
+
 static Mutex* signal_mutex = new Mutex();
 static SignalInfo* signal_handlers = NULL;
 static const int kSignalsCount = 7;
 static const int kSignals[kSignalsCount] = {
     SIGHUP, SIGINT, SIGTERM, SIGUSR1, SIGUSR2, SIGWINCH,
     SIGQUIT  // Allow VMService to listen on SIGQUIT.
 };
 
 
 SignalInfo::~SignalInfo() {
@@ skipping 96 matching lines @@
     VOID_NO_RETRY_EXPECTED(sigaction(signal, &act, NULL));
   }
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(HOST_OS_ANDROID)
 
 #endif  // !defined(DART_IO_DISABLED)