OpenMPI  0.1.1
mca_base_component_repository.h
1 /*
2  * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
3  * University Research and Technology
4  * Corporation. All rights reserved.
5  * Copyright (c) 2004-2005 The University of Tennessee and The University
6  * of Tennessee Research Foundation. All rights
7  * reserved.
8  * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
9  * University of Stuttgart. All rights reserved.
10  * Copyright (c) 2004-2005 The Regents of the University of California.
11  * All rights reserved.
12  * $COPYRIGHT$
13  *
14  * Additional copyrights may follow
15  *
16  * $HEADER$
17  */
18 
19 #ifndef MCA_BASE_COMPONENT_REPOSITORY_H
20 #define MCA_BASE_COMPONENT_REPOSITORY_H
21 
22 #include "opal_config.h"
23 
24 BEGIN_C_DECLS
25 
26  OPAL_DECLSPEC int mca_base_component_repository_init(void);
27 
28 /* This file provide the external interface to our base component
29  * module. Most of the components that depend on it, will use the
30  * retain_component() function to increase the reference count on a
31  * particular component (as opposed to the retain() function, which is
32  * internal to the opal/mca/base). But it's convenient to have all
33  * the functions exported from one header file rather than to separate
34  * retain_component() and retain() into two separate header files
35  * (i.e., have a separate header file just for retain()).
36  *
37  * Note that internal to opal/mca/base, <ltdl.h> will *always* be
38  * included before this file, and <ltdl.h> is not included anywhere
39  * else in the OMPI tree. So checking for the LTDL_H preprocessor
40  * macro is a good indicator as to whether this file is being included
41  * from an opal/mca/base source file or not. If we are, then we need
42  * already have a real definition of lt_dlhandle. If we are being
43  * included from elsewhere, then <ltdl.h> will not previously have
44  * been included, LTDL_H will not be defined, and we need a fake
45  * definition of lt_dlhandle (or we'll get compile errors). So just
46  * typedef it to (void*).
47  *
48  * One more case that this handles is the --disable-dlopen case. In
49  * that case, even in opal/mca/base, we *won't* be including <ltdl.h>.
50  * Hence, LTDL_H won't be defined, so we'll end up typedefing
51  * lt_dlhandle to (void *). "But why does that matter?" you ask, "If
52  * we configure with --disable-dlopen, then lt_dlhandle shouldn't be
53  * used anywhere." Incorrect, Grasshopper. A small number of places
54  * (like the retain() function) are still prototyped, but have 99% of
55  * their innards #if'ed out -- i.e., they just return
56  * OPAL_ERR_NOT_SUPPORTED. Why was it coded up this way? I'm not
57  * entirely sure -- there may be a reason (and that reason may just be
58  * conservative coding), but I'm not really too inspired to look into
59  * it any further at this point. :-)
60  */
61 #if !defined(LTDL_H)
62  typedef void *lt_dlhandle;
63 #endif
64 
65  OPAL_DECLSPEC int mca_base_component_repository_retain(char *type,
66  lt_dlhandle component_handle,
67  const mca_base_component_t *component_struct);
68 
69  OPAL_DECLSPEC int mca_base_component_repository_retain_component(const char *type,
70  const char *name);
71  OPAL_DECLSPEC int mca_base_component_repository_link(const char *src_type,
72  const char *src_name,
73  const char *depend_type,
74  const char *depend_name);
75  OPAL_DECLSPEC void mca_base_component_repository_release(const mca_base_component_t *component);
76  OPAL_DECLSPEC void mca_base_component_repository_finalize(void);
77 
78 END_C_DECLS
79 
80 #endif /* MCA_BASE_COMPONENT_REPOSITORY_H */
Common type for all MCA components.
Definition: mca.h:250