The counted send/receive methods attempt to transfer a specified number of bytes even if they must block and retry the operation in order to transfer the entire amount. The time spent blocking for the entire transfer can be limited by a specified ACE_Time_Value object which is a relative time (i.e., a fixed amount of time, not an absolute time of day). These methods return the count of transferred bytes, or -1 if an error occurs or the operation times out before the entire requested amount of data has been transferred. In error or timeout situations it's possible that some data was transferred before the error or timeout. The bytes_transferred
parameter is used to obtain the count of bytes transferred before the error or timeout occurred. If the total specified number of bytes is transferred without error, the method return value should equal the value of bytes_transferred
.
- Parameters:
-
buf | The buffer to write from or receive into. |
iov | An I/O vector containing a specified number of count/pointer pairs directing the data to be transferred. |
iovcnt | The number of I/O vectors to be used from iov. |
len | The number of bytes to transfer. |
flags | Flags that will be passed through to the recv() system call. |
timeout | Indicates how long to blocking trying to transfer data. If no timeout is supplied (timeout == 0) the method will wait indefinitely or until an error occurs for the specified number of bytes to be transferred. To avoid any waiting, specify a timeout value with 0 seconds. Note that the timeout period restarts on each retried operation issued; therefore, an operation that requires multiples retries may take longer than the specified timeout to complete. |
bytes_transferred | If non-0, points to a location which receives the total number of bytes transferred before the method returns, even if it's less than the number requested. |
- Return values:
-
len,the | complete number of bytes transferred. |
0 | EOF, i.e., the peer closed the connection. |
-1 | an error occurred before the entire amount was transferred. Check errno for more information. If the timeout period is reached, errno is ETIME. |
On partial transfers, i.e., if any data is transferred before timeout/error/EOF, *bytes_transferred will contain the number of bytes transferred.