Actual source code: tagm.c
1: #define PETSC_DLL
2: /*
3: Some PETSc utilites
4: */
5: #include petscsys.h
6: #if defined(PETSC_HAVE_STDLIB_H)
7: #include <stdlib.h>
8: #endif
10: /* ---------------------------------------------------------------- */
11: /*
12: A simple way to manage tags inside a communicator.
14: It uses the attributes to determine if a new communicator
15: is needed and to store the available tags.
17: Notes on the implementation
19: The tagvalues to use are stored in a two element array. The first element
20: is the first free tag value. The second is used to indicate how
21: many "copies" of the communicator there are used in destroying.
23:
24: */
26: static PetscMPIInt Petsc_Tag_keyval = MPI_KEYVAL_INVALID;
27: static PetscMPIInt Petsc_InnerComm_keyval = MPI_KEYVAL_INVALID;
28: static PetscMPIInt Petsc_OuterComm_keyval = MPI_KEYVAL_INVALID;
32: /*
33: Private routine to delete internal storage when a communicator is freed.
34: This is called by MPI, not by users.
38: */
39: PetscMPIInt PETSC_DLLEXPORT Petsc_DelTag(MPI_Comm comm,PetscMPIInt keyval,void* attr_val,void* extra_state)
40: {
44: PetscInfo1(0,"Deleting tag data in an MPI_Comm %ld\n",(long)comm);if (ierr) PetscFunctionReturn((PetscMPIInt)ierr);
45: PetscFree(attr_val);if (ierr) PetscFunctionReturn((PetscMPIInt)ierr);
46: PetscFunctionReturn(MPI_SUCCESS);
47: }
53: /*
54: Private routine to delete internal storage when a communicator is freed.
55: This is called by MPI, not by users.
59: */
60: PetscMPIInt PETSC_DLLEXPORT Petsc_DelComm(MPI_Comm comm,PetscMPIInt keyval,void* attr_val,void* extra_state)
61: {
65: PetscInfo1(0,"Deleting PETSc communicator imbedded in a user MPI_Comm %ld\n",(long)comm);if (ierr) PetscFunctionReturn((PetscMPIInt)ierr);
66: /* actually don't delete anything because we cannot increase the reference count of the communicator anyways */
67: PetscFunctionReturn(MPI_SUCCESS);
68: }
73: /*@C
74: PetscObjectGetNewTag - Gets a unique new tag from a PETSc object. All
75: processors that share the object MUST call this routine EXACTLY the same
76: number of times. This tag should only be used with the current objects
77: communicator; do NOT use it with any other MPI communicator.
79: Collective on PetscObject
81: Input Parameter:
82: . obj - the PETSc object; this must be cast with a (PetscObject), for example,
83: PetscObjectGetNewTag((PetscObject)mat,&tag);
85: Output Parameter:
86: . tag - the new tag
88: Level: developer
90: Concepts: tag^getting
91: Concepts: message tag^getting
92: Concepts: MPI message tag^getting
94: .seealso: PetscCommGetNewTag()
95: @*/
96: PetscErrorCode PETSC_DLLEXPORT PetscObjectGetNewTag(PetscObject obj,PetscMPIInt *tag)
97: {
101: PetscCommGetNewTag(obj->comm,tag);
102: return(0);
103: }
107: /*@
108: PetscCommGetNewTag - Gets a unique new tag from a PETSc communicator. All
109: processors that share the communicator MUST call this routine EXACTLY the same
110: number of times. This tag should only be used with the current objects
111: communicator; do NOT use it with any other MPI communicator.
113: Collective on comm
115: Input Parameter:
116: . comm - the PETSc communicator
118: Output Parameter:
119: . tag - the new tag
121: Level: developer
123: Concepts: tag^getting
124: Concepts: message tag^getting
125: Concepts: MPI message tag^getting
127: .seealso: PetscObjectGetNewTag(), PetscCommDuplicate()
128: @*/
129: PetscErrorCode PETSC_DLLEXPORT PetscCommGetNewTag(MPI_Comm comm,PetscMPIInt *tag)
130: {
132: PetscMPIInt *tagvalp=0,*maxval;
133: PetscTruth flg;
138: if (Petsc_Tag_keyval == MPI_KEYVAL_INVALID) {
139: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelTag,&Petsc_Tag_keyval,(void*)0);
140: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_InnerComm_keyval,(void*)0);
141: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_OuterComm_keyval,(void*)0);
142: }
144: MPI_Attr_get(comm,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
145: if (!flg) SETERRQ(PETSC_ERR_ARG_CORRUPT,"Bad MPI communicator supplied; must be a PETSc communicator");
147: if (tagvalp[0] < 1) {
148: PetscInfo1(0,"Out of tags for object, starting to recycle. Comm reference count %d\n",tagvalp[1]);
149: MPI_Attr_get(MPI_COMM_WORLD,MPI_TAG_UB,(void**)&maxval,(PetscMPIInt*)&flg);
150: if (!flg) {
151: SETERRQ(PETSC_ERR_LIB,"MPI error: MPI_Attr_get() is not returning a MPI_TAG_UB");
152: }
153: tagvalp[0] = *maxval - 128; /* hope that any still active tags were issued right at the beginning of the run */
154: }
156: *tag = tagvalp[0]--;
157: return(0);
158: }
162: /*@C
163: PetscCommDuplicate - Duplicates the communicator only if it is not already a PETSc
164: communicator.
166: Collective on MPI_Comm
168: Input Parameters:
169: . comm_in - Input communicator
171: Output Parameters:
172: + comm_out - Output communicator. May be comm_in.
173: - first_tag - Tag available that has not already been used with this communicator (you may
174: pass in PETSC_NULL if you do not need a tag)
176: PETSc communicators are just regular MPI communicators that keep track of which
177: tags have been used to prevent tag conflict. If you pass a non-PETSc communicator into
178: a PETSc creation routine it will attach a private communicator for use in the objects communications.
180: Level: developer
182: Concepts: communicator^duplicate
184: .seealso: PetscObjectGetNewTag(), PetscCommGetNewTag()
185: @*/
186: PetscErrorCode PETSC_DLLEXPORT PetscCommDuplicate(MPI_Comm comm_in,MPI_Comm *comm_out,PetscMPIInt* first_tag)
187: {
189: PetscMPIInt *tagvalp,*maxval;
190: PetscTruth flg;
193: if (Petsc_Tag_keyval == MPI_KEYVAL_INVALID) {
194: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelTag,&Petsc_Tag_keyval,(void*)0);
195: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_InnerComm_keyval,(void*)0);
196: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_OuterComm_keyval,(void*)0);
197: }
198: MPI_Attr_get(comm_in,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
200: if (!flg) {
201: void *ptr;
202: /* check if this communicator has a PETSc communicator imbedded in it */
203: MPI_Attr_get(comm_in,Petsc_InnerComm_keyval,&ptr,(PetscMPIInt*)&flg);
204: if (!flg) {
205: /* This communicator is not yet known to this system, so we duplicate it and set its value */
206: MPI_Comm_dup(comm_in,comm_out);
207: MPI_Attr_get(MPI_COMM_WORLD,MPI_TAG_UB,(void**)&maxval,(PetscMPIInt*)&flg);
208: if (!flg) {
209: SETERRQ(PETSC_ERR_LIB,"MPI error: MPI_Attr_get() is not returning a MPI_TAG_UB");
210: }
211: PetscMalloc(2*sizeof(PetscMPIInt),&tagvalp);
212: tagvalp[0] = *maxval;
213: tagvalp[1] = 0;
214: MPI_Attr_put(*comm_out,Petsc_Tag_keyval,tagvalp);
215: PetscInfo3(0,"Duplicating a communicator %ld %ld max tags = %d\n",(long)comm_in,(long)*comm_out,*maxval);
217: /* save PETSc communicator inside user communicator, so we can get it next time */
218: PetscMemcpy(&ptr,comm_out,sizeof(MPI_Comm));
219: MPI_Attr_put(comm_in,Petsc_InnerComm_keyval,ptr);
220: PetscMemcpy(&ptr,&comm_in,sizeof(MPI_Comm));
221: MPI_Attr_put(*comm_out,Petsc_OuterComm_keyval,ptr);
222: } else {
223: /*
224: We use PetscMemcpy() because casting from pointer to integer of different size is not allowed with some compilers
225: */
226: PetscMemcpy(comm_out,&ptr,sizeof(MPI_Comm));
227: MPI_Attr_get(*comm_out,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
228: if (!flg) {
229: SETERRQ(PETSC_ERR_PLIB,"Inner PETSc communicator does not have its tagvalp attribute set");
230: }
231: PetscInfo2(0,"Using internal PETSc communicator %ld %ld\n",(long)comm_in,(long)*comm_out);
232: }
233: } else {
234: #if defined(PETSC_USE_DEBUG)
235: PetscMPIInt tag;
236: MPI_Allreduce(tagvalp,&tag,1,MPI_INT,MPI_BOR,comm_in);
237: if (tag != tagvalp[0]) {
238: SETERRQ(PETSC_ERR_ARG_CORRUPT,"Communicator was used on subset of processors.");
239: }
240: #endif
241: *comm_out = comm_in;
242: }
244: if (tagvalp[0] < 1) {
245: PetscInfo1(0,"Out of tags for object, starting to recycle. Comm reference count %d\n",tagvalp[1]);
246: MPI_Attr_get(MPI_COMM_WORLD,MPI_TAG_UB,(void**)&maxval,(PetscMPIInt*)&flg);
247: if (!flg) {
248: SETERRQ(PETSC_ERR_LIB,"MPI error: MPI_Attr_get() is not returning a MPI_TAG_UB");
249: }
250: tagvalp[0] = *maxval - 128; /* hope that any still active tags were issued right at the beginning of the run */
251: }
253: if (first_tag) {
254: *first_tag = tagvalp[0]--;
255: }
256: tagvalp[1]++; /* number of references to this comm */
257: return(0);
258: }
262: /*@C
263: PetscCommDestroy - Frees communicator. Use in conjunction with PetscCommDuplicate().
265: Collective on MPI_Comm
267: Input Parameter:
268: . comm - the communicator to free
270: Level: developer
272: Concepts: communicator^destroy
274: @*/
275: PetscErrorCode PETSC_DLLEXPORT PetscCommDestroy(MPI_Comm *comm)
276: {
278: PetscMPIInt *tagvalp;
279: PetscTruth flg;
280: MPI_Comm icomm = *comm,ocomm;
281: void *ptr;
284: if (Petsc_Tag_keyval == MPI_KEYVAL_INVALID) {
285: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelTag,&Petsc_Tag_keyval,(void*)0);
286: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_InnerComm_keyval,(void*)0);
287: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_OuterComm_keyval,(void*)0);
288: }
289: MPI_Attr_get(icomm,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
290: if (!flg) {
291: MPI_Attr_get(icomm,Petsc_InnerComm_keyval,&ptr,(PetscMPIInt*)&flg);
292: /*
293: We use PetscMemcpy() because casting from pointer to integer of different size is not allowed with some compilers
294: */
295: PetscMemcpy(&icomm,&ptr,sizeof(MPI_Comm));
296: if (!flg) {
297: return(0);
298: }
299: MPI_Attr_get(icomm,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
300: if (!flg) {
301: SETERRQ(PETSC_ERR_ARG_CORRUPT,"Error freeing MPI_Comm, problem with corrupted memory");
302: }
303: }
304: tagvalp[1]--;
305: if (!tagvalp[1]) {
307: MPI_Attr_get(icomm,Petsc_OuterComm_keyval,&ptr,(PetscMPIInt*)&flg);
308: PetscMemcpy(&ocomm,&ptr,sizeof(MPI_Comm));
310: if (flg) {
311: MPI_Attr_delete(ocomm,Petsc_InnerComm_keyval);
312: }
314: PetscInfo1(0,"Deleting MPI_Comm %ld\n",(long)icomm);
315: MPI_Comm_free(&icomm);
316: }
317: return(0);
318: }