Mapping

OpenCL provides a feature on buffers (and other memory objects) named mapping. With this feature, a region of device memory is mapped to hast memory, where it can be more efficiently accessed. Blaze offers support for this feature through the use of the MapBufferGuard and MapBufferMutGuard, which act simillarly to a RwLockReadGuard and a RwLockWriteGuard.

Examples

use std::ops::Deref;
use blaze_rs::prelude::*;

#[global_context]
static CONTEXT : SimpleContext = SimpleContext::default();

fn main () -> Result<()> {
    let buffer = Buffer::new(&[1, 2, 3, 4, 5], MemAccess::default(), false)?;
    let map = buffer.map_blocking(.., None)?;

    assert_eq!(map.deref(), &[1, 2, 3, 4, 5]);
    Ok(())
}

use std::ops::Deref;
use blaze_rs::prelude::*;

#[global_context]
static CONTEXT : SimpleContext = SimpleContext::default();

fn main () -> Result<()> {
    let mut buffer = Buffer::new(&[1, 2, 3, 4, 5], MemAccess::default(), false)?;
    let map = buffer.map_blocking(.., None)?;
    let mut mut_map = buffer.map_mut_blocking(.., None)?; // compile error: cannot borrow `buffer` as mutable because it is also borrowed as immutable

    assert_eq!(map.deref(), &[1, 2, 3, 4, 5]);
    Ok(())
}

Note that when maping mutably, the OpenCL mapping is done as a read-write mapping, not a write-only map.