1: #include <petsc/private/petscimpl.h>
  2: #include <petscviewersaws.h>
  3: #include <petscsys.h>

  5: /*@C
  6:   PetscObjectSAWsTakeAccess - Take access of the data fields that have been published to SAWs
  7:   by a `PetscObject` so their values may  be changed in the computation

  9:   Collective

 11:   Input Parameter:
 12: . obj - the `PetscObject` variable. This must be cast with a (`PetscObject`), for example, `PetscObjectSAWSTakeAccess`((`PetscObject`)mat);

 14:   Level: advanced

 16:   Developer Notes:
 17:   The naming should perhaps be changed to `PetscObjectSAWsGetAccess()` and
 18:   `PetscObjectSAWsRestoreAccess()`

 20: .seealso: `PetscObjectSetName()`, `PetscObjectSAWsViewOff()`, `PetscObjectSAWsGrantAccess()`
 21: @*/
 22: PetscErrorCode PetscObjectSAWsTakeAccess(PetscObject obj)
 23: {
 24:   if (obj->amsmem) {
 25:     /* cannot wrap with PetscPushStack() because that also deals with the locks */
 26:     SAWs_Lock();
 27:   }
 28:   return PETSC_SUCCESS;
 29: }

 31: /*@C
 32:   PetscObjectSAWsGrantAccess - Grants access of the data fields that have been published to
 33:   SAWs called when the changes made during `PetscObjectSAWsTakeAccess()` are complete.

 35:   Collective

 37:   Input Parameter:
 38: . obj - the `PetscObject` variable. This must be cast with a (`PetscObject`), for example, `PetscObjectSAWSRestoreAccess`((`PetscObject`)mat);

 40:   Level: advanced

 42:   Notes:
 43:   This allows the webserve to change the published values.

 45: .seealso: `PetscObjectSetName()`, `PetscObjectSAWsViewOff()`, `PetscObjectSAWsTakeAccess()`
 46: @*/
 47: PetscErrorCode PetscObjectSAWsGrantAccess(PetscObject obj)
 48: {
 49:   if (obj->amsmem) {
 50:     /* cannot wrap with PetscPushStack() because that also deals with the locks */
 51:     SAWs_Unlock();
 52:   }
 53:   return PETSC_SUCCESS;
 54: }

 56: /*@C
 57:   PetscSAWsBlock - Blocks on SAWs until a client (person using the web browser) unblocks it

 59:   Not Collective

 61:   Level: advanced

 63: .seealso: `PetscObjectSetName()`, `PetscObjectSAWsViewOff()`, `PetscObjectSAWsSetBlock()`, `PetscObjectSAWsBlock()`
 64: @*/
 65: PetscErrorCode PetscSAWsBlock(void)
 66: {
 67:   volatile PetscBool block = PETSC_TRUE;

 69:   PetscFunctionBegin;
 70:   PetscCallSAWs(SAWs_Register, ("__Block", (PetscBool *)&block, 1, SAWs_WRITE, SAWs_BOOLEAN));
 71:   SAWs_Lock();
 72:   while (block) {
 73:     SAWs_Unlock();
 74:     PetscCall(PetscInfo(NULL, "Blocking on SAWs\n"));
 75:     PetscCall(PetscSleep(.3));
 76:     SAWs_Lock();
 77:   }
 78:   SAWs_Unlock();
 79:   PetscCallSAWs(SAWs_Delete, ("__Block"));
 80:   PetscCall(PetscInfo(NULL, "Out of SAWs block\n"));
 81:   PetscFunctionReturn(PETSC_SUCCESS);
 82: }

 84: /*@C
 85:   PetscObjectSAWsBlock - Blocks the object if `PetscObjectSAWsSetBlock()` has been called

 87:   Collective

 89:   Input Parameter:
 90: . obj - the PETSc variable

 92:   Level: advanced

 94: .seealso: `PetscObjectSetName()`, `PetscObjectSAWsViewOff()`, `PetscObjectSAWsSetBlock()`, `PetscSAWsBlock()`
 95: @*/
 96: PetscErrorCode PetscObjectSAWsBlock(PetscObject obj)
 97: {
 98:   PetscFunctionBegin;

101:   if (!obj->amspublishblock || !obj->amsmem) PetscFunctionReturn(PETSC_SUCCESS);
102:   PetscCall(PetscSAWsBlock());
103:   PetscFunctionReturn(PETSC_SUCCESS);
104: }

106: /*@C
107:   PetscObjectSAWsSetBlock - Sets whether an object will block at `PetscObjectSAWsBlock()`

109:   Collective

111:   Input Parameters:
112: + obj - the PETSc variable
113: - flg - whether it should block

115:   Level: advanced

117: .seealso: `PetscObjectSetName()`, `PetscObjectSAWsViewOff()`, `PetscObjectSAWsBlock()`, `PetscSAWsBlock()`
118: @*/
119: PetscErrorCode PetscObjectSAWsSetBlock(PetscObject obj, PetscBool flg)
120: {
121:   PetscFunctionBegin;
123:   obj->amspublishblock = flg;
124:   PetscFunctionReturn(PETSC_SUCCESS);
125: }

127: PetscErrorCode PetscObjectSAWsViewOff(PetscObject obj)
128: {
129:   char dir[PETSC_MAX_PATH_LEN];

131:   PetscFunctionBegin;
132:   if (obj->classid == PETSC_VIEWER_CLASSID) PetscFunctionReturn(PETSC_SUCCESS);
133:   if (!obj->amsmem) PetscFunctionReturn(PETSC_SUCCESS);
134:   PetscCall(PetscSNPrintf(dir, sizeof(dir), "/PETSc/Objects/%s", obj->name));
135:   PetscCallSAWs(SAWs_Delete, (dir));
136:   PetscFunctionReturn(PETSC_SUCCESS);
137: }