:@spawnat

@spawnat

Accepts two arguments, p and an expression. A closure is created around the expression and run asynchronously on process p. Returns a RemoteRef to the result.

Examples

Asynchronously execute an expression on a specific process:
```
julia> p = 2;  # Process number
julia> result = @spawnat p begin
           a = 10
           b = 20
           a + b
       end
RemoteRef{Channel{Any}}(2, 1, 3, nothing)

julia> fetch(result)
30
```
In this example, the expression a + b is executed asynchronously on process 2 using @spawnat. The result is stored in a RemoteRef object, which can be fetched later using fetch.
Use variables from the calling scope inside the expression:
```
julia> p = 3;  # Process number
julia> x = 5;
julia> y = 2;
julia> result = @spawnat p x * y
RemoteRef{Channel{Any}}(3, 1, 4, nothing)

julia> fetch(result)
10
```
Here, the variables x and y from the calling scope are used inside the expression x * y. The result is fetched from the RemoteRef object and returned.

Handle complex expressions with multiple lines:

julia> p = 1;  # Process number
julia> result = @spawnat p begin
           sum = 0
           for i in 1:5
               sum += i
           end
           sum
       end
RemoteRef{Channel{Any}}(1, 1, 2, nothing)

julia> fetch(result)
15

In this example, a multi-line expression is executed asynchronously on process 1. The loop calculates the sum of numbers from 1 to 5, and the final result is fetched from the RemoteRef.

Common mistake example:

julia> p = 4;  # Process number
julia> result = @spawnat p a + b
ERROR: UndefVarError: a not defined

In this example, the variables a and b used inside the expression are not defined in the calling scope. Make sure to define and assign values to the variables before using them in @spawnat.

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:@spawnat

Examples

See Also

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