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.
5 #ifndef LIBRARIES_NACL_IO_KERNEL_OBJECT_H_
6 #define LIBRARIES_NACL_IO_KERNEL_OBJECT_H_
14 #include "nacl_io/error.h"
15 #include "nacl_io/filesystem.h"
16 #include "nacl_io/kernel_handle.h"
17 #include "nacl_io/node.h"
18 #include "nacl_io/path.h"
20 #include "sdk_util/macros.h"
21 #include "sdk_util/simple_lock.h"
25 // KernelObject provides basic functionality for threadsafe access to kernel
26 // objects such as the CWD, mount points, file descriptors and file handles.
27 // All Kernel locks are private to ensure the lock order.
29 // All calls are assumed to be a relative path.
33 Descriptor_t() : flags(0) {}
34 explicit Descriptor_t(const ScopedKernelHandle& h,
35 const std::string& open_path)
36 : handle(h), flags(0), path(open_path) {}
38 ScopedKernelHandle handle;
42 typedef std::vector<Descriptor_t> HandleMap_t;
43 typedef std::map<std::string, ScopedFilesystem> FsMap_t;
46 virtual ~KernelObject();
48 // Attach the given Filesystem object at the specified path.
49 Error AttachFsAtPath(const ScopedFilesystem& fs, const std::string& path);
51 // Unmap the Filesystem object from the specified path and release it.
52 Error DetachFsAtPath(const std::string& path, ScopedFilesystem* out_fs);
54 // Find the filesystem for the given path, and acquires it and return a
55 // path relative to the filesystem.
56 // Assumes |out_fs| and |rel_path| are non-NULL.
57 Error AcquireFsAndRelPath(const std::string& path,
58 ScopedFilesystem* out_fs,
61 // Find the filesystem and node for the given path, acquiring/creating it as
62 // specified by the |oflags|.
63 // Assumes |out_fs| and |out_node| are non-NULL.
64 Error AcquireFsAndNode(const std::string& path,
65 int oflags, mode_t mflags,
66 ScopedFilesystem* out_fs,
67 ScopedNode* out_node);
69 // Get FD-specific flags (currently only FD_CLOEXEC is supported).
70 Error GetFDFlags(int fd, int* out_flags);
71 // Set FD-specific flags (currently only FD_CLOEXEC is supported).
72 Error SetFDFlags(int fd, int flags);
74 // Convert from FD to KernelHandle, and acquire the handle.
75 // Assumes |out_handle| is non-NULL.
76 Error AcquireHandle(int fd, ScopedKernelHandle* out_handle);
77 Error AcquireHandleAndPath(int fd,
78 ScopedKernelHandle* out_handle,
79 std::string* out_path);
81 // Allocate a new fd and assign the handle to it, while
82 // ref counting the handle and associated filesystem.
83 // Assumes |handle| is non-NULL;
84 int AllocateFD(const ScopedKernelHandle& handle,
85 const std::string& path = std::string());
87 // Assumes |handle| is non-NULL;
88 void FreeAndReassignFD(int fd,
89 const ScopedKernelHandle& handle,
90 const std::string& path);
93 // Returns or sets CWD
95 Error SetCWD(const std::string& path);
98 // Also returns current umask (like POSIX's umask(2))
99 mode_t SetUmask(mode_t);
101 // Returns parts of the absolute path for the given relative path
102 Path GetAbsParts(const std::string& path);
107 std::vector<int> free_fds_;
108 HandleMap_t handle_map_;
109 FsMap_t filesystems_;
111 // Lock to protect free_fds_ and handle_map_.
112 sdk_util::SimpleLock handle_lock_;
114 // Lock to protect filesystems_.
115 sdk_util::SimpleLock fs_lock_;
117 // Lock to protect cwd_.
118 sdk_util::SimpleLock cwd_lock_;
119 // Lock to protect umask_.
120 sdk_util::SimpleLock umask_lock_;
122 DISALLOW_COPY_AND_ASSIGN(KernelObject);
125 } // namespace nacl_io
127 #endif // LIBRARIES_NACL_IO_KERNEL_OBJECT_H_