mojo/system/constants.h

   1 // Copyright 2013 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 MOJO_SYSTEM_CONSTANTS_H_
   6 #define MOJO_SYSTEM_CONSTANTS_H_
   7
   8 #include <stddef.h>
   9
  10 namespace mojo {
  11 namespace system {
  12
  13 // Maximum of open (Mojo) handles.
  14 // TODO(vtl): This doesn't count "live" handles, some of which may live in
  15 // messages.
  16 const size_t kMaxHandleTableSize = 1000000;
  17
  18 const size_t kMaxWaitManyNumHandles = kMaxHandleTableSize;
  19
  20 const size_t kMaxMessageNumBytes = 4 * 1024 * 1024;
  21
  22 const size_t kMaxMessageNumHandles = 10000;
  23
  24 // Maximum capacity of a data pipe, in bytes. This value must fit into a
  25 // |uint32_t|.
  26 // WARNING: If you bump it closer to 2^32, you must audit all the code to check
  27 // that we don't overflow (2^31 would definitely be risky; up to 2^30 is
  28 // probably okay).
  29 const size_t kMaxDataPipeCapacityBytes = 256 * 1024 * 1024;  // 256 MB.
  30
  31 const size_t kDefaultDataPipeCapacityBytes = 1024 * 1024;  // 1 MB.
  32
  33 // Alignment for the "start" of the data buffer used by data pipes. (The
  34 // alignment of elements will depend on this and the element size.)
  35 const size_t kDataPipeBufferAlignmentBytes = 16;
  36
  37 }  // namespace system
  38 }  // namespace mojo
  39
  40 #endif  // MOJO_SYSTEM_CONSTANTS_H_