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_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_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 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 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: PetscErrorCode PetscCommSynchronizeTags(MPI_Comm comm)
163: {
164: PetscMPIInt *tagvalp = 0, tag;
165: PetscTruth flg;
169: MPI_Attr_get(comm, Petsc_Tag_keyval, (void **) &tagvalp, (PetscMPIInt *) &flg);
170: if (!flg) {
171: MPI_Comm innerComm;
172: void *ptr;
174: /* check if this communicator has a PETSc communicator imbedded in it */
175: MPI_Attr_get(comm, Petsc_InnerComm_keyval, &ptr, (PetscMPIInt*) &flg);
176: if (!flg) {
177: SETERRQ(PETSC_ERR_ARG_CORRUPT,"Bad MPI communicator supplied; must be a PETSc communicator");
178: } else {
179: /* We use PetscMemcpy() because casting from pointer to integer of different size is not allowed with some compilers */
180: PetscMemcpy(&innerComm, &ptr, sizeof(MPI_Comm));
181: MPI_Attr_get(innerComm, Petsc_Tag_keyval, (void **) &tagvalp, (PetscMPIInt *) &flg);
182: if (!flg) {
183: SETERRQ(PETSC_ERR_PLIB,"Inner PETSc communicator does not have its tagvalp attribute set");
184: }
185: }
186: }
187: MPI_Allreduce(tagvalp, &tag, 1, MPI_INT, MPI_MIN, comm);
188: tagvalp[0] = tag;
189: PetscInfo2(0, "Reset tag for comm %ld to \n", (long) comm, tagvalp[0]);
190: return(0);
191: }
195: /*@C
196: PetscCommDuplicate - Duplicates the communicator only if it is not already a PETSc
197: communicator.
199: Collective on MPI_Comm
201: Input Parameters:
202: . comm_in - Input communicator
204: Output Parameters:
205: + comm_out - Output communicator. May be comm_in.
206: - first_tag - Tag available that has not already been used with this communicator (you may
207: pass in PETSC_NULL if you do not need a tag)
209: PETSc communicators are just regular MPI communicators that keep track of which
210: tags have been used to prevent tag conflict. If you pass a non-PETSc communicator into
211: a PETSc creation routine it will attach a private communicator for use in the objects communications.
213: Level: developer
215: Concepts: communicator^duplicate
217: .seealso: PetscObjectGetNewTag(), PetscCommGetNewTag()
218: @*/
219: PetscErrorCode PetscCommDuplicate(MPI_Comm comm_in,MPI_Comm *comm_out,PetscMPIInt* first_tag)
220: {
222: PetscMPIInt *tagvalp,*maxval;
223: PetscTruth flg;
226: if (Petsc_Tag_keyval == MPI_KEYVAL_INVALID) {
227: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelTag,&Petsc_Tag_keyval,(void*)0);
228: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_InnerComm_keyval,(void*)0);
229: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_OuterComm_keyval,(void*)0);
230: }
231: MPI_Attr_get(comm_in,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
233: if (!flg) {
234: void *ptr;
235: /* check if this communicator has a PETSc communicator imbedded in it */
236: MPI_Attr_get(comm_in,Petsc_InnerComm_keyval,&ptr,(PetscMPIInt*)&flg);
237: if (!flg) {
238: /* This communicator is not yet known to this system, so we duplicate it and set its value */
239: MPI_Comm_dup(comm_in,comm_out);
240: MPI_Attr_get(MPI_COMM_WORLD,MPI_TAG_UB,(void**)&maxval,(PetscMPIInt*)&flg);
241: if (!flg) {
242: SETERRQ(PETSC_ERR_LIB,"MPI error: MPI_Attr_get() is not returning a MPI_TAG_UB");
243: }
244: PetscMalloc(2*sizeof(PetscMPIInt),&tagvalp);
245: tagvalp[0] = *maxval;
246: tagvalp[1] = 0;
247: MPI_Attr_put(*comm_out,Petsc_Tag_keyval,tagvalp);
248: PetscInfo3(0,"Duplicating a communicator %ld %ld max tags = %d\n",(long)comm_in,(long)*comm_out,*maxval);
250: /* save PETSc communicator inside user communicator, so we can get it next time */
251: PetscMemcpy(&ptr,comm_out,sizeof(MPI_Comm));
252: MPI_Attr_put(comm_in,Petsc_InnerComm_keyval,ptr);
253: PetscMemcpy(&ptr,&comm_in,sizeof(MPI_Comm));
254: MPI_Attr_put(*comm_out,Petsc_OuterComm_keyval,ptr);
255: } else {
256: /*
257: We use PetscMemcpy() because casting from pointer to integer of different size is not allowed with some compilers
258: */
259: PetscMemcpy(comm_out,&ptr,sizeof(MPI_Comm));
260: MPI_Attr_get(*comm_out,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
261: if (!flg) {
262: SETERRQ(PETSC_ERR_PLIB,"Inner PETSc communicator does not have its tagvalp attribute set");
263: }
264: PetscInfo2(0,"Using internal PETSc communicator %ld %ld\n",(long)comm_in,(long)*comm_out);
265: }
266: } else {
267: #if defined(PETSC_USE_DEBUG)
268: PetscMPIInt tag;
269: MPI_Allreduce(tagvalp,&tag,1,MPI_INT,MPI_BOR,comm_in);
270: if (tag != tagvalp[0]) {
271: SETERRQ(PETSC_ERR_ARG_CORRUPT,"Communicator was used on subset of processors.");
272: }
273: #endif
274: *comm_out = comm_in;
275: }
277: if (tagvalp[0] < 1) {
278: PetscInfo1(0,"Out of tags for object, starting to recycle. Comm reference count %d\n",tagvalp[1]);
279: MPI_Attr_get(MPI_COMM_WORLD,MPI_TAG_UB,(void**)&maxval,(PetscMPIInt*)&flg);
280: if (!flg) {
281: SETERRQ(PETSC_ERR_LIB,"MPI error: MPI_Attr_get() is not returning a MPI_TAG_UB");
282: }
283: tagvalp[0] = *maxval - 128; /* hope that any still active tags were issued right at the beginning of the run */
284: }
286: if (first_tag) {
287: *first_tag = tagvalp[0]--;
288: }
289: tagvalp[1]++; /* number of references to this comm */
290: return(0);
291: }
295: /*@C
296: PetscCommDestroy - Frees communicator. Use in conjunction with PetscCommDuplicate().
298: Collective on MPI_Comm
300: Input Parameter:
301: . comm - the communicator to free
303: Level: developer
305: Concepts: communicator^destroy
307: @*/
308: PetscErrorCode PetscCommDestroy(MPI_Comm *comm)
309: {
311: PetscMPIInt *tagvalp;
312: PetscTruth flg;
313: MPI_Comm icomm = *comm,ocomm;
314: void *ptr;
317: if (Petsc_Tag_keyval == MPI_KEYVAL_INVALID) {
318: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelTag,&Petsc_Tag_keyval,(void*)0);
319: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_InnerComm_keyval,(void*)0);
320: MPI_Keyval_create(MPI_NULL_COPY_FN,Petsc_DelComm,&Petsc_OuterComm_keyval,(void*)0);
321: }
322: MPI_Attr_get(icomm,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
323: if (!flg) {
324: MPI_Attr_get(icomm,Petsc_InnerComm_keyval,&ptr,(PetscMPIInt*)&flg);
325: /*
326: We use PetscMemcpy() because casting from pointer to integer of different size is not allowed with some compilers
327: */
328: PetscMemcpy(&icomm,&ptr,sizeof(MPI_Comm));
329: if (!flg) {
330: return(0);
331: }
332: MPI_Attr_get(icomm,Petsc_Tag_keyval,(void**)&tagvalp,(PetscMPIInt*)&flg);
333: if (!flg) {
334: SETERRQ(PETSC_ERR_ARG_CORRUPT,"Error freeing MPI_Comm, problem with corrupted memory");
335: }
336: }
337: tagvalp[1]--;
338: if (!tagvalp[1]) {
340: MPI_Attr_get(icomm,Petsc_OuterComm_keyval,&ptr,(PetscMPIInt*)&flg);
341: PetscMemcpy(&ocomm,&ptr,sizeof(MPI_Comm));
343: if (flg) {
344: MPI_Attr_delete(ocomm,Petsc_InnerComm_keyval);
345: }
347: PetscInfo1(0,"Deleting MPI_Comm %ld\n",(long)icomm);
348: MPI_Comm_free(&icomm);
349: }
350: return(0);
351: }