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openmpi/ompi/mpi/cxx/request.h
Jeff Squyres 0a28212392 This is a workaround to bug in the Intel C++ compiler, version 9.1
(all versions up to and including 20060925).  The issue has been
reported to Intel, along with a small [non-MPI] test program that
reproduces the problem (the test program and the OMPI C++ bindings
work fine with Intel C++ 9.0 and many other C++ compilers).

In short, a static initializer for a global variable (i.e., its
constructor is fired before main()) that takes as an argument a
reference to a typedef'd type will simply get the wrong value in the
argument.  Specifically:

{{{
namespace MPI {
    Intracomm COMM_WORLD(MPI_COMM_WORLD);
}
}}}

The constructor for MPI::Intracomm should get the value of
&ompi_mpi_comm_world.  It does not; it seems to get a random value.

As mandated by MPI-2, annex B.13.4, for C/C++ interoperability, the
prototype for this constructor is:

{{{
class Intracomm {
public:
    Intracomm(const MPI_Comm& data);
};
}}}

Experiments with icpc 9.1/20060925 have shown that removing the
reference from the prototype makes it work (!).  After lots of
discussions about this issue with a C++ expert (Doug Gregor from IU),
we decided the following (cut-n-paste from an e-mail):

-----
> So here's my question: given that OMPI's MPI_<CLASS> types are all
> pointers, is there any legal MPI program that adheres to the above
> bindings that would fail to compile or work properly if we simply
> removed the "&" from the second binding, above?

I don't know of any way that a program could detect this change. FWIW,
the C++ committee has agreed that implementation of the C++ standard
library are allowed to decide arbitrarily between const& and by-value.
If they don't care, MPI users won't care.

When you remove the '&', I suggest also removing the "const". It is
redundant, but can trigger some strange name mangling in Sun's C++
compiler.
-----

So with this change:

 * we now work again with the Intel 9.1 compiler
 * our C++ bindings do not exactly conform to the MPI-2 spec, but
   valid/legal MPI C++ apps cannot tell the difference (i.e., the
   functionality is the same)

This commit was SVN r12514.
2006-11-09 17:34:12 +00:00

236 строки
6.1 KiB
C++

// -*- c++ -*-
//
// Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
// University Research and Technology
// Corporation. All rights reserved.
// Copyright (c) 2004-2005 The University of Tennessee and The University
// of Tennessee Research Foundation. All rights
// reserved.
// Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
// University of Stuttgart. All rights reserved.
// Copyright (c) 2004-2005 The Regents of the University of California.
// All rights reserved.
// Copyright (c) 2006 Cisco Systems, Inc. All rights reserved.
// $COPYRIGHT$
//
// Additional copyrights may follow
//
// $HEADER$
//
class Request {
#if 0 /* OMPI_ENABLE_MPI_PROFILING */
// friend class PMPI::Request;
#endif
public:
#if 0 /* OMPI_ENABLE_MPI_PROFILING */
// construction
Request() { }
Request(MPI_Request i) : pmpi_request(i) { }
// copy / assignment
Request(const Request& r) : pmpi_request(r.pmpi_request) { }
Request(const PMPI::Request& r) : pmpi_request(r) { }
virtual ~Request() {}
Request& operator=(const Request& r) {
pmpi_request = r.pmpi_request; return *this; }
// comparison
bool operator== (const Request &a)
{ return (bool)(pmpi_request == a.pmpi_request); }
bool operator!= (const Request &a)
{ return (bool)!(*this == a); }
// inter-language operability
Request& operator= (const MPI_Request &i) {
pmpi_request = i; return *this; }
operator MPI_Request () const { return pmpi_request; }
// operator MPI_Request* () const { return pmpi_request; }
operator const PMPI::Request&() const { return pmpi_request; }
#else
// construction / destruction
Request() { mpi_request = MPI_REQUEST_NULL; }
virtual ~Request() {}
Request(MPI_Request i) : mpi_request(i) { }
// copy / assignment
Request(const Request& r) : mpi_request(r.mpi_request) { }
Request& operator=(const Request& r) {
mpi_request = r.mpi_request; return *this; }
// comparison
bool operator== (const Request &a)
{ return (bool)(mpi_request == a.mpi_request); }
bool operator!= (const Request &a)
{ return (bool)!(*this == a); }
// inter-language operability
Request& operator= (const MPI_Request &i) {
mpi_request = i; return *this; }
operator MPI_Request () const { return mpi_request; }
// operator MPI_Request* () const { return (MPI_Request*)&mpi_request; }
#endif
//
// Point-to-Point Communication
//
virtual void Wait(Status &status);
virtual void Wait();
virtual bool Test(Status &status);
virtual bool Test();
virtual void Free(void);
static int Waitany(int count, Request array[], Status& status);
static int Waitany(int count, Request array[]);
static bool Testany(int count, Request array[], int& index, Status& status);
static bool Testany(int count, Request array[], int& index);
static void Waitall(int count, Request req_array[], Status stat_array[]);
static void Waitall(int count, Request req_array[]);
static bool Testall(int count, Request req_array[], Status stat_array[]);
static bool Testall(int count, Request req_array[]);
static int Waitsome(int incount, Request req_array[],
int array_of_indices[], Status stat_array[]) ;
static int Waitsome(int incount, Request req_array[],
int array_of_indices[]);
static int Testsome(int incount, Request req_array[],
int array_of_indices[], Status stat_array[]);
static int Testsome(int incount, Request req_array[],
int array_of_indices[]);
virtual void Cancel(void) const;
virtual bool Get_status(Status& status) const;
virtual bool Get_status() const;
protected:
#if ! 0 /* OMPI_ENABLE_MPI_PROFILING */
MPI_Request mpi_request;
#endif
private:
#if 0 /* OMPI_ENABLE_MPI_PROFILING */
PMPI::Request pmpi_request;
#endif
};
class Prequest : public Request {
#if 0 /* OMPI_ENABLE_MPI_PROFILING */
// friend class PMPI::Prequest;
#endif
public:
Prequest() { }
#if 0 /* OMPI_ENABLE_MPI_PROFILING */
Prequest(const Request& p) : Request(p), pmpi_request(p) { }
Prequest(const PMPI::Prequest& r) :
Request((const PMPI::Request&)r),
pmpi_request(r) { }
Prequest(const MPI_Request &i) : Request(i), pmpi_request(i) { }
virtual ~Prequest() { }
Prequest& operator=(const Request& r) {
Request::operator=(r);
pmpi_request = (PMPI::Prequest)r; return *this; }
Prequest& operator=(const Prequest& r) {
Request::operator=(r);
pmpi_request = r.pmpi_request; return *this; }
#else
Prequest(const Request& p) : Request(p) { }
Prequest(const MPI_Request &i) : Request(i) { }
virtual ~Prequest() { }
Prequest& operator=(const Request& r) {
mpi_request = r; return *this; }
Prequest& operator=(const Prequest& r) {
mpi_request = r.mpi_request; return *this; }
#endif
virtual void Start();
static void Startall(int count, Prequest array_of_requests[]);
#if 0 /* OMPI_ENABLE_MPI_PROFILING */
private:
PMPI::Prequest pmpi_request;
#endif
};
//
// Generalized requests
//
class Grequest : public MPI::Request {
public:
typedef int Query_function(void *, Status&);
typedef int Free_function(void *);
typedef int Cancel_function(void *, bool);
Grequest() {}
Grequest(const Request& req) : Request(req) {}
Grequest(const MPI_Request &req) : Request(req) {}
virtual ~Grequest() {}
Grequest& operator=(const Request& req) {
mpi_request = req; return(*this);
}
Grequest& operator=(const Grequest& req) {
mpi_request = req.mpi_request; return(*this);
}
static Grequest Start(Query_function *, Free_function *,
Cancel_function *, void *);
virtual void Complete();
};
//
// Type used for intercepting Generalized requests in the C++ layer so
// that the type can be converted to C++ types before invoking the
// user-specified C++ callbacks.
//
struct Grequest_intercept_t {
void *git_extra;
Grequest::Query_function *git_cxx_query_fn;
Grequest::Free_function *git_cxx_free_fn;
Grequest::Cancel_function *git_cxx_cancel_fn;
};