[NaCl SDK] Map active fds to absolute paths.

native_client_sdk/src/libraries/nacl_io/kernel_object.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 LIBRARIES_NACL_IO_KERNEL_OBJECT_H_
 #define LIBRARIES_NACL_IO_KERNEL_OBJECT_H_
 
 #include <pthread.h>
 
 #include <map>
@@ skipping 19 matching lines @@
 class KernelObject {
  public:
   struct Descriptor_t {
     Descriptor_t() : flags(0) {}
     explicit Descriptor_t(const ScopedKernelHandle& h) : handle(h), flags(0) {}
 
     ScopedKernelHandle handle;
     int flags;
   };
   typedef std::vector<Descriptor_t> HandleMap_t;
+  typedef std::map<int, std::string> FdPathMap_t;

[Sam Clegg, 2014/01/07 23:56:39]

Actually, why not just add at std::string to Descriptor_t?  Avoid this extra map
completely?

   typedef std::map<std::string, ScopedFilesystem> FsMap_t;
 
   KernelObject();
   virtual ~KernelObject();
 
   // Attach the given Filesystem object at the specified path.
   Error AttachFsAtPath(const ScopedFilesystem& fs, const std::string& path);
 
   // Unmap the Filesystem object from the specified path and release it.
   Error DetachFsAtPath(const std::string& path);
 
   // Find the filesystem for the given path, and acquires it and return a
   // path relative to the filesystem.
   // Assumes |out_fs| and |rel_path| are non-NULL.
   Error AcquireFsAndRelPath(const std::string& path,
                             ScopedFilesystem* out_fs,
                             Path* rel_path);
 
   // Find the filesystem and node for the given path, acquiring/creating it as
   // specified by the |oflags|.
   // Assumes |out_fs| and |out_node| are non-NULL.
   Error AcquireFsAndNode(const std::string& path,
                          int oflags,
                          ScopedFilesystem* out_fs,
                          ScopedNode* out_node);
 
   // Get FD-specific flags (currently only FD_CLOEXEC is supported).
   Error GetFDFlags(int fd, int* out_flags);
+  // Get path at which FD was opened, if available.
+  std::string GetFDPath(int fd);
   // Set FD-specific flags (currently only FD_CLOEXEC is supported).
   Error SetFDFlags(int fd, int flags);
 
   // Convert from FD to KernelHandle, and acquire the handle.
   // Assumes |out_handle| is non-NULL.
   Error AcquireHandle(int fd, ScopedKernelHandle* out_handle);
+  Error AcquireHandleAndPath(int fd, ScopedKernelHandle *out_handle,
+                             std::string& path);
 
   // Allocate a new fd and assign the handle to it, while
   // ref counting the handle and associated filesystem.
   // Assumes |handle| is non-NULL;
-  int AllocateFD(const ScopedKernelHandle& handle);
+  int AllocateFD(const ScopedKernelHandle& handle,
+                 std::string path = std::string());
 
   // Assumes |handle| is non-NULL;
-  void FreeAndReassignFD(int fd, const ScopedKernelHandle& handle);
+  void FreeAndReassignFD(int fd, const ScopedKernelHandle& handle,
+                         const std::string &path);
   void FreeFD(int fd);
 
   // Returns or sets CWD
   std::string GetCWD();
   Error SetCWD(const std::string& path);
 
   // Returns parts of the absolute path for the given relative path
   Path GetAbsParts(const std::string& path);
 
  private:
   std::string cwd_;
   std::vector<int> free_fds_;
   HandleMap_t handle_map_;
+  FdPathMap_t fd_paths_;
   FsMap_t filesystems_;
 
   // Lock to protect free_fds_ and handle_map_.
   sdk_util::SimpleLock handle_lock_;
 
   // Lock to protect filesystems_.
   sdk_util::SimpleLock fs_lock_;
 
   // Lock to protect cwd_.
   sdk_util::SimpleLock cwd_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(KernelObject);
 };
 
 }  // namespace nacl_io
 
 #endif  // LIBRARIES_NACL_IO_KERNEL_OBJECT_H_