TipcMsgAppendInt2ArrayPtr

Name

TipcMsgAppendInt2ArrayPtr — use a pointer to append a field containing an array of INT2 fields to a message

Synopsis

T_BOOL TipcMsgAppendInt2ArrayPtr(msg, int2_array_data, array_size, field_return) 
T_IPC_MSG msg; 
T_INT2 *int2_array_data; 
T_INT4 array_size; 
T_IPC_MSG_FIELD *field_return; 

Arguments

msg — message to append field to

int2_array_data — data for new message field

array_size — number of elements in int2_array_data

field_return — optional location to return field (use NULL if not needed)

Return Values

TRUE if the field was successfully appended to the message, FALSE otherwise.

Diagnostics

If TipcMsgAppendInt2ArrayPtr fails, it returns FALSE and sets the global SmartSockets error number to one of:

Description

TipcMsgAppendInt2ArrayPtr appends a two-byte integer array (INT2_ARRAY) field containing int2_array_data to the end of a message’s data. This function does not make a copy of the array. Instead, the supplied pointer to the array is entered directly into the new message field’s internal data structure. The caller is responsible for making sure that the pointer remains valid for the lifetime of the message field, and for freeing it, if necessary, when the message field has been destroyed.

One advantage of TipcMsgAppendInt2ArrayPtr over TipcMsgAppendInt2Array is that the array data can be modified after the field is appended, but before the message is sent. Another advantage is that the overhead of one copy operation is avoided. The data is still copied into the connection write buffer when the message is sent.

To update the pointer to point to a new memory location, use the TipcMsgFieldUpdateInt2ArrayPtr function.

See Also

TipcMsgAppendInt2Array, TipcMsgNextInt2Array, TipcMsgFieldSetSize, TipcMsgFieldUpdateInt2ArrayPtr

Examples

This example creates a message and appends a pointer to an INT2_ARRAY field:

T_IPC_MT mt; 
T_IPC_MSG msg; 
T_INT2 data[10]; 
T_IPC_MSG_FIELD field; 
 
#define USER_MT_INT2_ARRAY_TEST 100 
mt = TipcMtCreate("int2_array_test", USER_MT_INT2_ARRAY_TEST, 
                  "int2_array"); 
if (mt == NULL) { 
  return;  /* error */ 
} 
 
msg = TipcMsgCreate(mt) 
if (msg == NULL) { 
  return;  /* error */ 
} 
 
/* An RTclient would typically set the destination of */ 
/* a message at this point by calling TipcMsgSetDest. */ 
 
if (!TipcMsgAppendInt2ArrayPtr(msg, data, 0, &field)) { 
  return;  /* error */ 
} 
 
data[0] = 56; 
data[1] = 57; 
if (!TipcMsgFieldSetSize(field, 2)) { 
  return;  /* error */ 
} 
 
/* A process would typically send a message at this point by */ 
/* calling TipcConnMsgSend or TipcSrvMsgSend. */ 
 
/* A process would typically destroy a message at this point by */ 
/* calling TipcMsgDestroy. */