Tornado

5
Shell
Table 5-17
Interpreting: dir = opendir ("/myDev/myFile")
Tornado Shell
(on host)
Parse the string
"/myDev/myFile".
Target Server & Symbol Table
(on host)
Agent
(on target)
Allocate memory for the
string; return address A.
5
Write "/myDev/myFile";
return address A.
Parse the name
opendir.
Look up opendir;
return address B.
Parse the function call
B(A); wait for the result.
Spawn a task to run opendir( )
and signal result C when done.
Receive C from target agent
and pass it to host shell.
Parse the symbol dir.
Look up dir (fails).
Request a new symbol
table entry dir.
Define dir; return symbol D.
Parse the assignment
D=C.
Allocate agent-pool memory
for the value of dir.
Write the value of dir.
(notably opendir( )in this case) have access to it. There is a pool of target memory
reserved for host interactions. Because this pool is reserved, it can be managed
from the host system. The server allocates the required memory, and informs the
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