Linux: inform the Zygote when it's waiting on a dead process

content/browser/zygote_host/zygote_host_impl_linux.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_
 #define CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 19 matching lines @@
   // Returns its pid on success, otherwise
   // base::kNullProcessHandle;
   pid_t ForkRequest(const std::vector<std::string>& command_line,
                     const std::vector<FileDescriptorInfo>& mapping,
                     const std::string& process_type);
   void EnsureProcessTerminated(pid_t process);
 
   // Get the termination status (and, optionally, the exit code) of
   // the process. |exit_code| is set to the exit code of the child
   // process. (|exit_code| may be NULL.)
+  // Unfortunately the Zygote can not accurately figure out if a process
+  // is already dead without waiting synchronously for it.
+  // |known_dead| should be set to true when we already know that the process
+  // is dead.
   base::TerminationStatus GetTerminationStatus(base::ProcessHandle handle,
+                                               bool known_dead,
                                                int* exit_code);
 
   // ZygoteHost implementation:
   virtual pid_t GetPid() const OVERRIDE;
   virtual pid_t GetSandboxHelperPid() const OVERRIDE;
   virtual int GetSandboxStatus() const OVERRIDE;
   virtual void AdjustRendererOOMScore(base::ProcessHandle process_handle,
                                       int score) OVERRIDE;
   virtual void AdjustLowMemoryMargin(int64 margin_mb) OVERRIDE;
 
@@ skipping 19 matching lines @@
   bool init_;
   bool using_suid_sandbox_;
   std::string sandbox_binary_;
   bool have_read_sandbox_status_word_;
   int sandbox_status_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_