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The function returns zero.

15.3. Waiting for completion of loading remote element buffer of non-regular access.

long waitib_ (long BufferHeader[]);

BufferHeader - header of the remote element buffer of non-regular access.

The function returns zero.

15.4. Deleting remote element buffer of non-regular access.

long delib_ (long BufferHeader[]);

BufferHeader - header of the remote element buffer to be deleted.

Non-static remote element buffer can be deleted by the function delib_ only if it was created in the current program block.

To delete remote element buffer the function delobj_ can also be used (see section 17.5).

The function returns zero.

15.5. Access to remote elements, allocated in the buffer.

At any processor the remote element buffer of non-regular access is similar to a local part of two-dimensional distributed array. Therefore its header may be declared, for example, as

long BufferHeader[3];

The access to allocated in the buffer remote element, is implemented by index variables of sampling rule of the array distributed dimension (by the index variables of the matrix of global indexes):

BasePtr[ BufferHeader[1]*V_k + J + BufferHeader[2] ] ,

where:

For C language the value of the base pointer can be specified equal to NULL in the function crtib_ call. Then the access to the allocated in the buffer remote element can be performed as follows:

((Type *)BufferHeader[2])[ BufferHeader[1]*V_k + J ] ,

where Type is the type of the distributed array elements.

The coefficient BufferHeader[1] and the address constant BufferHeader[2] are calculated by Run-Time Library when executing the function crtrb_ in the following way.

Let:

Then:

BufferHeader[1] = MAX( ME[V_k,0] );

V_k,нач  V_k  V_k,last

BufferHeader[2] = -BufferHeader[1]*V_k,init;

Note. To access to the remote elements, allocated in the buffer, the functions and macros, considered in section 13, can be used. When they are used

1. the buffer header is necessary to use instead of the distributed array header;

2. the array rank is equal to 2.

1. the vector of the index variables values (V_k and J) of the distributed dimension sampling rule is used as the index vector of the element.

15.6. Creating group of remote element buffers of non-regular access.

The function crtbg_ creates an empty buffer group (not containing buffers) and returns a pointer to the group.

If the flag *StaticSignPtr of static group is not equal to zero, then the created group will not be deleted, when the control exits the program block (see section 8). Such group can be deleted only explicitly using the function delig_, considered below.

If *DelBufSignPtr is not equal to zero, then all included in the group buffers will be deleted when the group is deleted. If deleting is explicit, all included buffers are deleted explicitly , and if deleting is implicit, the ones are deleted implicitly.

15.7. Including remote element buffer of non-regular access in the group.

The function returns zero.

15.8. Starting loading remote element buffers of specified group.

long loadig_ (IndirectAccessGroupRef *IndirectAccessGroupRefPtr);

*IndirectAccessGroupRefPtr - pointer to the buffer group.

The function returns zero.

15.9. Waiting for completion of loading remote element buffers of specified group.

long waitig_ (IndirectAccessGroupRef *IndirectAccessGroupRefPtr);

*IndirectAccessGroupRefPtr - pointer to the buffer group.

The function returns zero.

15.10. Deleting group of remote element buffers of non-regular access.

long delig_ (IndirectAccessGroupRef *IndirectAccessGroupRefPtr);

*IndirectAccessGroupRefPtr - pointer to the buffer group to be deleted.

Non-static buffer group can be deleted by the function delig_ only if it was created in the current program block.

To delete the buffer group the function delobj_ can also be used (see section 17.5).

The function returns zero.

16. Input/Output.

16.1. Analogies to functions of C language standard library.

All functions discussed below is intended for usage for input/output of the replicated variables (all copies of each variable are equal). The implementation of these functions is based on the execution of the standard C functions on the processor, called «I/O processor». The result (if one exists) of the functions is sent to all the processors. For example, the execution of the function dvm_prinf results in single printing from the I/O processor. The execution of the function printf results in multiple printing from each processor. It is possible to determine if the current processor is I/O processor with the help of the function tstio_ (see section 17.6).

Note, that it is possible to use in the user program the I/O functions of the standard C language library (ANSI), which have no corresponding functions in the list below and have no undesirable effect of multiple execution.

16.1.1. High level input/output functions.

ANSI:

TURBO-C & MICROSOFT-C:

TURBO-C:

In the functions above to specify standard streams the following pointers can be used:

Note1. The distinction (in the realization) between the functions dvm_void_printf, dvm_void_fprintf, dvm_void_vprintf, dvm_void_vfprintf are the functions dvm_printf, dvm_fprintf, dvm_vprintf, dvm_vfprintf is that the I/O processor does not send the return values of the functions printf, fprintf, vprintf and vfprintf to another processors, i.e. their is difference in the execution time. The full analogues of the standard functions printf, fprintf, vprintf and vfprintf are the functions dvm_printf, dvm_fprintf, dvm_vprintf and dvm_.

Note2. The functions dvm_fread and dvm_fwrite can be used to read/write the distributed array. In this case, the BufferPtr pointer has to point to the header of the distributed array. The size of the array element is assumed to be equal to *TypeSizePtr (that is value used at the array creation with the function crtda_), not Size. The number of the elements to read/write is assumed to be equal to the minimum of Count*Size/(*TypeSizePtr) and the number of the elements in the distributed array (also see the description of the functions dvm_dfread and dvm_dfwrite in sections 16.2 and 16.3).

16.1.2. Low lewel I/O functions.

TURBO-C & MICROSOFT-C & PORTLAND GROUP-C:

To access to standard I/O streams in low level I/O functions the following pointers may be used:

16.1.3. Operations with directories and files.

ANSI:

TURBO-C & MICROSOFT-C & PORTLAND GROUP-C:

Note. A user program can use low level I/O functions and the functions dvm_access and dvm_stat only in the case, if C compiler library contains corresponding functions.

16.2. Reading from file to sub-array of distributed array.

Характеристики

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