content/browser/zygote_host/zygote_host_impl_linux.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_
   6 #define CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_
   7
   8 #include <set>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/pickle.h"
  13 #include "base/process/kill.h"
  14 #include "base/synchronization/lock.h"
  15 #include "content/public/browser/file_descriptor_info.h"
  16 #include "content/public/browser/zygote_host_linux.h"
  17
  18 template<typename Type>
  19 struct DefaultSingletonTraits;
  20
  21 namespace content {
  22
  23 class CONTENT_EXPORT ZygoteHostImpl : public ZygoteHost {
  24  public:
  25   // Returns the singleton instance.
  26   static ZygoteHostImpl* GetInstance();
  27
  28   void Init(const std::string& sandbox_cmd);
  29
  30   // After the last known Zygote child exits, notify the Zygote to exit.
  31   void TearDownAfterLastChild();
  32
  33   // Tries to start a process of type indicated by process_type.
  34   // Returns its pid on success, otherwise
  35   // base::kNullProcessHandle;
  36   pid_t ForkRequest(const std::vector<std::string>& command_line,
  37                     scoped_ptr<FileDescriptorInfo> mapping,
  38                     const std::string& process_type);
  39   void EnsureProcessTerminated(pid_t process);
  40
  41   // Get the termination status (and, optionally, the exit code) of
  42   // the process. |exit_code| is set to the exit code of the child
  43   // process. (|exit_code| may be NULL.)
  44   // Unfortunately the Zygote can not accurately figure out if a process
  45   // is already dead without waiting synchronously for it.
  46   // |known_dead| should be set to true when we already know that the process
  47   // is dead. When |known_dead| is false, processes could be seen as
  48   // still running, even when they're not. When |known_dead| is true, the
  49   // process will be SIGKILL-ed first (which should have no effect if it was
  50   // really dead). This is to prevent a waiting waitpid() from blocking in
  51   // a single-threaded Zygote. See crbug.com/157458.
  52   base::TerminationStatus GetTerminationStatus(base::ProcessHandle handle,
  53                                                bool known_dead,
  54                                                int* exit_code);
  55
  56   // ZygoteHost implementation:
  57   pid_t GetPid() const override;
  58   int GetSandboxStatus() const override;
  59   void AdjustRendererOOMScore(base::ProcessHandle process_handle,
  60                               int score) override;
  61
  62  private:
  63   friend struct DefaultSingletonTraits<ZygoteHostImpl>;
  64
  65   ZygoteHostImpl();
  66   ~ZygoteHostImpl() override;
  67
  68   // Notify the Zygote to exit immediately. This object should not be
  69   // used afterwards.
  70   void TearDown();
  71
  72   // Should be called every time a Zygote child is born.
  73   void ZygoteChildBorn(pid_t process);
  74
  75   // Should be called every time a Zygote child died.
  76   void ZygoteChildDied(pid_t process);
  77
  78   // Sends |data| to the zygote via |control_fd_|.  If |fds| is non-NULL, the
  79   // included file descriptors will also be passed.  The caller is responsible
  80   // for acquiring |control_lock_|.
  81   bool SendMessage(const Pickle& data, const std::vector<int>* fds);
  82
  83   ssize_t ReadReply(void* buf, size_t buflen);
  84
  85   // Whether we should use the namespace sandbox instead of the setuid sandbox.
  86   bool ShouldUseNamespaceSandbox();
  87
  88   int control_fd_;  // the socket to the zygote
  89   // A lock protecting all communication with the zygote. This lock must be
  90   // acquired before sending a command and released after the result has been
  91   // received.
  92   base::Lock control_lock_;
  93   pid_t pid_;
  94   bool init_;
  95   bool use_suid_sandbox_for_adj_oom_score_;
  96   std::string sandbox_binary_;
  97   bool have_read_sandbox_status_word_;
  98   int sandbox_status_;
  99   // A lock protecting list_of_running_zygote_children_ and
 100   // should_teardown_after_last_child_exits_.
 101   base::Lock child_tracking_lock_;
 102   std::set<pid_t> list_of_running_zygote_children_;
 103   bool should_teardown_after_last_child_exits_;
 104 };
 105
 106 }  // namespace content
 107
 108 #endif  // CONTENT_BROWSER_ZYGOTE_HOST_ZYGOTE_HOST_IMPL_LINUX_H_