NAME

MPI_Testall - Test an array of requests in a non-blocking way to see if they all have completed

SYNOPSIS

#include <mpi.h> 
int MPI_Testall(int count , MPI_Request *request_array , int *flag , MPI_Status *status_array ); 
#include <pmpi.h> 
int PMPI_Testall(int count , MPI_Request *request_array , int *flag , MPI_Status *status_array ); 
#include <mpi.h> 
static bool MPI::Request::Testall(int count , MPI::Request *request_array ,
	 MPI::Status *status_array ); 
static bool MPI::Status::Testall(int count , MPI::Request *request_array ); 
INCLUDE 'mpif.h' 
MPI_TESTALL(count , request_array , flag , status_array , ierr ) 
INTEGER  count ,  request_array (*),  flag ,  status_array (MPI_STATUS_SIZE, *),  ierr 

INPUT PARAMETERS

count - number of requests in array (integer)

request_array - array of requests to test (array of handles)

OUTPUT PARAMETERS

flag - is any request complete (boolean)

status_array - status information about each request (array of structures)

DESCRIPTION

The MPI_Testall() function is used to test if an array of requests are all completed. This check is done in a non-blocking manner. If all requests are done, then flag is set to one. Otherwise it will be set to zero, and MPI_SUCCESS will be returned. Neither the request or status arrays will be modified in this case.

Otherwise, on completion, the original tag and source of a recieved message are stored in the MPI_TAG and MPI_SOURCE fields of the corresponding index of status_array respectively. If the received message has been truncated then MPI_ERROR will be set to be MPI_ERR_TRUNCATE. One additional field holds the total size of the message in bytes. If either a send or receive is successfully cancelled, then MPI_ERROR will contain MPI_ERR_CANCEL. Otherwise, it will be set to MPI_ERR_SUCCESS. If any MPI_ERROR field is not MPI_SUCCESS then this function will return MPI_ERR_IN_STATUS. This will not invoke an error handler. If status_array is MPI_STATUSES_IGNORE then this information will not be stored.

If a request is invalid, then its corresponding status is filled with MPI_ANY_TAG MPI_PROC_NULL MPI_SUCCESS and zero size in bytes. PMPI_Testall() is the profiling version of this function.

The C++ version of this function passes the flag output as the return value.

ERRORS

All MPI routines except for MPI_Wtime and MPI_Wtick return an error code. The the current MPI error handler is invoked if the return value is not MPI_SUCCESS. The default error handler aborts, but this may be changed with by using the MPI_Errhandler_set() function. The predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned instead. Note that MPI does not guarentee that an MPI program can continue past an error. In this implementation, all errors except MPI_ERR_INTERN or MPI_ERR_OTHER should always be recoverable.

In C, the error code is passed as the return value. In FORTRAN, all functions have an parameter ierr which returns the error code. MPI C++ functions do not directly return an error code. However, C++ users may want to use the MPI::ERRORS_THROW_EXCEPTIONS handler. This will throw an MPI::Exception with the corresponding error code. To prevent exceptions from being raised from within C and Fortran code, they will see all error return values as MPI_ERR_PENDING when this handler is chosen. In this implementation, call MPI::throw_exception() to throw the correct exception if this occurs.

MPI_SUCCESS - No error;

MPI_ERR_PENDING - Pending exception;

MPI_COUNT - Invalid array size;

MPI_ERR_ARG - Invalid pointer;

MPI_ERR_REQUEST - Invalid request array;

MPI_ERR_IN_STATUS - MPI_ERROR is set in a status structure. An error handler is not called.

SEE ALSO

MPI_Probe (3) MPI_Isend (3) MPI_Irecv (3) MPI_Test (3) MPI_Testany (3) MPI_Testsome (3) MPI_Wait (3)

• Lockless
• MPI Documentation
• MPI_Testall