Enforce handle ownership in base::Process

base/process/process_linux.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/process/process.h"
 
 #include <errno.h>
 #include <sys/resource.h>
 
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/strings/string_split.h"
 #include "base/strings/stringprintf.h"
 #include "base/synchronization/lock.h"
 
 namespace base {
 
 namespace {
+
 const int kForegroundPriority = 0;
 
 #if defined(OS_CHROMEOS)
 // We are more aggressive in our lowering of background process priority
 // for chromeos as we have much more control over other processes running
 // on the machine.
 //
 // TODO(davemoore) Refactor this by adding support for higher levels to set
 // the foregrounding / backgrounding process so we don't have to keep
 // chrome / chromeos specific logic here.
@@ skipping 25 matching lines @@
         base::GetFileSystemType(background_file, &background_type) &&
         foreground_type == FILE_SYSTEM_CGROUP &&
         background_type == FILE_SYSTEM_CGROUP;
   }
 };
 
 base::LazyInstance<CGroups> cgroups = LAZY_INSTANCE_INITIALIZER;
 #else
 const int kBackgroundPriority = 5;
 #endif
+
+struct CheckForNicePermission {
+  CheckForNicePermission() : can_reraise_priority(false) {
+    // We won't be able to raise the priority if we don't have the right rlimit.
+    // The limit may be adjusted in /etc/security/limits.conf for PAM systems.
+    struct rlimit rlim;
+    if ((getrlimit(RLIMIT_NICE, &rlim) == 0) &&
+        (20 - kForegroundPriority) <= static_cast<int>(rlim.rlim_cur)) {
+        can_reraise_priority = true;
+    }
+  };
+
+  bool can_reraise_priority;
+};
+
+}  // namespace
+
+// static
+bool Process::CanBackgroundProcesses() {
+#if defined(OS_CHROMEOS)
+  if (cgroups.Get().enabled)
+    return true;
+#endif
+
+  static LazyInstance<CheckForNicePermission> check_for_nice_permission =
+      LAZY_INSTANCE_INITIALIZER;
+  return check_for_nice_permission.Get().can_reraise_priority;
 }
 
 bool Process::IsProcessBackgrounded() const {
-  DCHECK(process_);
+  DCHECK(IsValid());
 
 #if defined(OS_CHROMEOS)
   if (cgroups.Get().enabled) {
     std::string proc;
     if (base::ReadFileToString(
             base::FilePath(StringPrintf(kProcPath, process_)),
             &proc)) {
       std::vector<std::string> proc_parts;
       base::SplitString(proc, ':', &proc_parts);
       DCHECK(proc_parts.size() == 3);
       bool ret = proc_parts[2] == std::string(kBackground);
       return ret;
     } else {
       return false;
     }
   }
 #endif
   return GetPriority() == kBackgroundPriority;
 }
 
 bool Process::SetProcessBackgrounded(bool background) {
-  DCHECK(process_);
+  DCHECK(IsValid());
 
 #if defined(OS_CHROMEOS)
   if (cgroups.Get().enabled) {
     std::string pid = StringPrintf("%d", process_);
     const base::FilePath file =
         background ?
             cgroups.Get().background_file : cgroups.Get().foreground_file;
     return base::WriteFile(file, pid.c_str(), pid.size()) > 0;
   }
 #endif // OS_CHROMEOS
 
   if (!CanBackgroundProcesses())
     return false;
 
   int priority = background ? kBackgroundPriority : kForegroundPriority;
   int result = setpriority(PRIO_PROCESS, process_, priority);
   DPCHECK(result == 0);
   return result == 0;
 }
 
-struct CheckForNicePermission {
-  CheckForNicePermission() : can_reraise_priority(false) {
-    // We won't be able to raise the priority if we don't have the right rlimit.
-    // The limit may be adjusted in /etc/security/limits.conf for PAM systems.
-    struct rlimit rlim;
-    if ((getrlimit(RLIMIT_NICE, &rlim) == 0) &&
-        (20 - kForegroundPriority) <= static_cast<int>(rlim.rlim_cur)) {
-        can_reraise_priority = true;
-    }
-  };
-
-  bool can_reraise_priority;
-};
-
-// static
-bool Process::CanBackgroundProcesses() {
-#if defined(OS_CHROMEOS)
-  if (cgroups.Get().enabled)
-    return true;
-#endif
-
-  static LazyInstance<CheckForNicePermission> check_for_nice_permission =
-      LAZY_INSTANCE_INITIALIZER;
-  return check_for_nice_permission.Get().can_reraise_priority;
-}
-
 }  // namespace base