MFEM  v4.1.0
Finite element discretization library
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Pages
globals.hpp
Go to the documentation of this file.
1 // Copyright (c) 2010-2020, Lawrence Livermore National Security, LLC. Produced
2 // at the Lawrence Livermore National Laboratory. All Rights reserved. See files
3 // LICENSE and NOTICE for details. LLNL-CODE-806117.
4 //
5 // This file is part of the MFEM library. For more information and source code
6 // availability visit https://mfem.org.
7 //
8 // MFEM is free software; you can redistribute it and/or modify it under the
9 // terms of the BSD-3 license. We welcome feedback and contributions, see file
10 // CONTRIBUTING.md for details.
11 
12 #ifndef MFEM_GLOBALS_HPP
13 #define MFEM_GLOBALS_HPP
14 
15 #include "../config/config.hpp"
16 #include <iostream>
17 
18 #ifdef MFEM_USE_MPI
19 #include <mpi.h>
20 #endif
21 
22 namespace mfem
23 {
24 
25 /// Simple extension of std::ostream.
26 /** This class adds the ability to enable and disable the stream. The associated
27  std::streambuf and tied std::ostream can be replaced with that of any
28  std::ostream. */
29 class OutStream : public std::ostream
30 {
31 protected:
32  // Pointer that stores the associated streambuf when output is disabled.
33  std::streambuf *m_rdbuf;
34  // Pointer that stores the tied ostream when output is disabled.
35  std::ostream *m_tie;
36 
37  void Init();
38 
39 public:
40  /** @brief Construct an OutStream from the given stream @a out, by using its
41  `rdbuf()`. */
42  OutStream(std::ostream &out) : std::ostream(NULL) { SetStream(out); }
43 
44  /** @brief Replace the `rdbuf()` and `tie()` of the OutStream with that of
45  @a out, enabling output. */
46  void SetStream(std::ostream &out)
47  {
48  rdbuf(m_rdbuf = out.rdbuf()); tie(m_tie = out.tie()); Init();
49  }
50 
51  /// Enable output.
52  void Enable() { if (!IsEnabled()) { rdbuf(m_rdbuf); tie(m_tie); } }
53  /// Disable output.
54  void Disable()
55  {
56  if (IsEnabled()) { m_rdbuf = rdbuf(NULL); m_tie = tie(NULL); }
57  }
58  /// Check if output is enabled.
59  bool IsEnabled() const { return (rdbuf() != NULL); }
60 };
61 
62 
63 /** @brief Global stream used by the library for standard output. Initially it
64  uses the same std::streambuf as std::cout, however that can be changed.
65  @sa OutStream. */
66 extern OutStream out;
67 /** @brief Global stream used by the library for standard error output.
68  Initially it uses the same std::streambuf as std::cerr, however that can be
69  changed.
70  @sa OutStream. */
71 extern OutStream err;
72 
73 
74 /** @brief Construct a string of the form "<prefix><myid><suffix>" where the
75  integer @a myid is padded with leading zeros to be at least @a width digits
76  long. */
77 /** This is a convenience function, e.g. to redirect mfem::out to individual
78  files for each rank, one can use:
79  \code
80  std::ofstream out_file(MakeParFilename("app_out.", myid).c_str());
81  mfem::out.SetStream(out_file);
82  \endcode
83 */
84 std::string MakeParFilename(const std::string &prefix, const int myid,
85  const std::string suffix = "", const int width = 6);
86 
87 
88 #ifdef MFEM_USE_MPI
89 
90 /** @name MFEM "global" communicator functions.
91 
92  Functions for getting and setting the MPI communicator used by the library
93  as the "global" communicator.
94 
95  This "global" communicator is used for example in the function mfem_error(),
96  which is invoked when an error is detected - the "global" communicator is
97  used as a parameter to MPI_Abort() to terminate all "global" tasks. */
98 ///@{
99 
100 /// Get MFEM's "global" MPI communicator.
101 MPI_Comm GetGlobalMPI_Comm();
102 
103 /// Set MFEM's "global" MPI communicator.
104 void SetGlobalMPI_Comm(MPI_Comm comm);
105 
106 ///@}
107 
108 #endif
109 
110 } // namespace mfem
111 
112 
113 // Request a global object to be instantiated for each thread in its TLS.
114 #define MFEM_THREAD_LOCAL thread_local
115 
116 
117 #endif
std::ostream * m_tie
Definition: globals.hpp:35
std::string MakeParFilename(const std::string &prefix, const int myid, const std::string suffix, const int width)
Construct a string of the form &quot;&lt;prefix&gt;&lt;myid&gt;&lt;suffix&gt;&quot; where the integer myid is padded with leading...
Definition: globals.cpp:43
Simple extension of std::ostream.
Definition: globals.hpp:29
void SetStream(std::ostream &out)
Replace the rdbuf() and tie() of the OutStream with that of out, enabling output. ...
Definition: globals.hpp:46
std::streambuf * m_rdbuf
Definition: globals.hpp:33
bool IsEnabled() const
Check if output is enabled.
Definition: globals.hpp:59
OutStream err(std::cerr)
Global stream used by the library for standard error output. Initially it uses the same std::streambu...
Definition: globals.hpp:71
void Disable()
Disable output.
Definition: globals.hpp:54
void Enable()
Enable output.
Definition: globals.hpp:52
OutStream out(std::cout)
Global stream used by the library for standard output. Initially it uses the same std::streambuf as s...
Definition: globals.hpp:66
void SetGlobalMPI_Comm(MPI_Comm comm)
Set MFEM&#39;s &quot;global&quot; MPI communicator.
Definition: globals.cpp:67
OutStream(std::ostream &out)
Construct an OutStream from the given stream out, by using its rdbuf().
Definition: globals.hpp:42
MPI_Comm GetGlobalMPI_Comm()
Get MFEM&#39;s &quot;global&quot; MPI communicator.
Definition: globals.cpp:62