Index: base/mac/mach_port_broker.h |
diff --git a/base/mac/mach_port_broker.h b/base/mac/mach_port_broker.h |
new file mode 100644 |
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+++ b/base/mac/mach_port_broker.h |
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+// Copyright 2016 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 BASE_MAC_MACH_PORT_BROKER_H_ |
+#define BASE_MAC_MACH_PORT_BROKER_H_ |
+ |
+#include <mach/mach.h> |
+ |
+#include <map> |
+#include <string> |
+ |
+#include "base/base_export.h" |
+#include "base/mac/dispatch_source_mach.h" |
+#include "base/mac/scoped_mach_port.h" |
+#include "base/macros.h" |
+#include "base/memory/scoped_ptr.h" |
+#include "base/process/port_provider_mac.h" |
+#include "base/process/process_handle.h" |
+#include "base/synchronization/lock.h" |
+ |
+namespace base { |
+ |
+// On OS X, the task port of a process is required to collect metrics about the |
+// process, and to insert Mach ports into the process. Running |task_for_pid()| |
+// is only allowed for privileged code. However, a process has port rights to |
+// all its subprocesses, so let the child processes send their Mach port to the |
+// parent over IPC. |
+// |
+// Mach ports can only be sent over Mach IPC, not over the |socketpair()| that |
+// the regular IPC system uses. Hence, the child processes opens a Mach |
+// connection shortly after launching and ipc their mach data to the parent |
+// process. A single |MachPortBroker| with a given name is expected to exist in |
+// the parent process. |
+// |
+// Since this data arrives over a separate channel, it is not available |
+// immediately after a child process has been started. |
+class BASE_EXPORT MachPortBroker : public base::PortProvider { |
+ public: |
+ // For use in child processes. This will send the task port of the current |
+ // process over Mach IPC to the port registered by name (via this class) in |
+ // the parent process. Returns true if the message was sent successfully |
+ // and false if otherwise. |
+ static bool ChildSendTaskPortToParent(const std::string& name); |
+ |
+ // Returns the Mach port name to use when sending or receiving messages. |
+ // Does the Right Thing in the browser and in child processes. |
+ static std::string GetMachPortName(const std::string& name, bool is_child); |
+ |
+ MachPortBroker(const std::string& name); |
+ ~MachPortBroker() override; |
+ |
+ // Performs any initialization work. |
+ bool Init(); |
+ |
+ // Adds a placeholder to the map for the given pid with MACH_PORT_NULL. |
+ // Callers are expected to later update the port with FinalizePid(). Callers |
+ // MUST acquire the lock given by GetLock() before calling this method (and |
+ // release the lock afterwards). |
+ void AddPlaceholderForPid(base::ProcessHandle pid); |
+ |
+ // Removes |pid| from the task port map. Callers MUST acquire the lock given |
+ // by GetLock() before calling this method (and release the lock afterwards). |
+ void InvalidatePid(base::ProcessHandle pid); |
+ |
+ // The lock that protects this MachPortBroker object. Callers MUST acquire |
+ // and release this lock around calls to AddPlaceholderForPid(), |
+ // InvalidatePid(), and FinalizePid(); |
+ base::Lock& GetLock() { return lock_; } |
+ |
+ // Implement |base::PortProvider|. |
+ mach_port_t TaskForPid(base::ProcessHandle process) const override; |
+ |
+ private: |
+ friend class MachPortBrokerTest; |
+ |
+ // Message handler that is invoked on |dispatch_source_| when an |
+ // incoming message needs to be received. |
+ void HandleRequest(); |
+ |
+ // Updates the mapping for |pid| to include the given |mach_info|. Does |
+ // nothing if PlaceholderForPid() has not already been called for the given |
+ // |pid|. Callers MUST acquire the lock given by GetLock() before calling |
+ // this method (and release the lock afterwards). |
+ void FinalizePid(base::ProcessHandle pid, mach_port_t task_port); |
+ |
+ // Name used to identify a particular port broker. |
+ const std::string name_; |
+ |
+ // The Mach port on which the server listens. |
+ base::mac::ScopedMachReceiveRight server_port_; |
+ |
+ // The dispatch source and queue on which Mach messages will be received. |
+ scoped_ptr<base::DispatchSourceMach> dispatch_source_; |
+ |
+ // Stores mach info for every process in the broker. |
+ typedef std::map<base::ProcessHandle, mach_port_t> MachMap; |
+ MachMap mach_map_; |
+ |
+ // Mutex that guards |mach_map_|. |
+ mutable base::Lock lock_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(MachPortBroker); |
+}; |
+ |
+} // namespace base |
+ |
+#endif // BASE_MAC_MACH_PORT_BROKER_H_ |