ipc

Inter process communicator.

Syntax

• O = ipc(pid, 'eval', cmd)
• B = ipc(pid, 'isvar', name, scope)
• V = ipc(pid, 'get', name)
• V = ipc(pid, 'get', name, scope)
• TF = ipc(pid, 'minimize')
• ipc(pid, 'post', cmd)
• ipc(pid, 'post', cmd, scope)
• ipc(pid, 'put', var, name)
• ipc(pid, 'put', var, name, scope)
• ipc(pid, 'minimize', tf)

Input argument

• 'post' - a string: post a command to evaluate to another nelson's process in base scope (not blocking).
• 'eval' - a string: post a command to evaluate to another nelson's process in base scope (blocking).
• 'isvar' - a string: check if a variable exists into another nelson's process.
• 'put' - a string: send a variable into another nelson's process.
• 'get' - a string: get a variable from another nelson's process.
• 'minimize' - a string: minimize main window from another nelson's process.

Output argument

• B - a logical: true if variable exists.
• V - a variable from another nelson.
• TF - a logical: true if destination process is minimized.
• O - a character array: output of evaluate string.

Description

ipc allows to execute, get, put variables between multiple nelson's process.

All serializable nelson's types are supported. Unsupported types will be replaced by an empty matrix and a warning.

LIMITATION:

The limit for the size of data transferred is 5000x5000 double. On 32 bits architecture, 1024x1024 double.

Current limitation to limit memory usage.

Examples

master_pid = getpid()
initial_pids = getpid('available')

% Creates 4 nelsons process
N = 4;
for i = 1:N
    cmd = sprintf('nelson-gui -e MASTER_PID=%d &', i);
    unix(cmd);
    sleep(5)
end
current_pids = getpid('available')

% wait clients ready
for p = current_pids
    if p ~= master_pid
        while(~ipc(p, 'isvar', 'MASTER_PID')), sleep(1), end
    end
end

% Creates random matrix in others Nelson
n = 0;
for p = current_pids
    if p ~= master_pid
        cmd = sprintf('rng(%d);M = rand(10, 10); disp(M)', n);
        ipc(p, 'post', cmd);
        n = n + 1;
    end
end

% Creates a matrix with matrix from others Nelson
C = [];
for p = current_pids
    if p ~= master_pid
        R = ipc(p, 'get', 'M');
        C = [C; R]
        n = n + 1;
    end
end

% close all clients
for p = current_pids
    if p ~= master_pid
        ipc(p, 'post', 'exit')
    end
end

ipc(getpid(), 'eval', 'dir')

ipc(getpid(), 'minimize', true)
ipc(getpid(), 'minimize')

See also

getpid, unix, eval.

History

Author

Allan CORNET