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calebwin
Example panics at runtime (`COPY_DST` flag)
Hello, running the compute example:
View full code
use emu_core::prelude::*;
use emu_glsl::*;
use zerocopy::*;
#[repr(C)]
#[derive(AsBytes, FromBytes, Copy, Clone, Default, Debug, GlslStruct)]
struct Shape {
x: u32,
y: u32,
w: i32,
h: i32,
r: [i32; 2],
}
fn main() -> Result<(), Box<dyn std::error::Error>> {
// ensure that a device pool has been initialized
// this should be called before every time when you assume you have devices to use
// that goes for both library users and application users
futures::executor::block_on(assert_device_pool_initialized());
println!("{:?}", take()?.lock().unwrap().info.as_ref().unwrap());
// create some data on GPU
// even mutate it once loaded to GPU
let mut shapes: DeviceBox<[Shape]> = vec![Default::default(); 1024].as_device_boxed_mut()?;
let mut x: DeviceBox<[i32]> = vec![0; 1024].as_device_boxed_mut()?;
shapes.set(vec![
Shape {
x: 0,
y: 0,
w: 100,
h: 100,
r: [2, 9]
};
1024
])?;
// compile GslKernel to SPIR-V
// then, we can either inspect the SPIR-V or finish the compilation by generating a DeviceFnMut
// then, run the DeviceFnMut
let c = compile::<GlslKernel, GlslKernelCompile, Vec<u32>, GlobalCache>(
GlslKernel::new()
.spawn(64)
.share("float stuff[64]")
.param_mut::<[Shape], _>("Shape[] shapes")
.param_mut::<[i32], _>("int[] x")
.param::<i32, _>("int scalar")
.with_struct::<Shape>()
.with_const("int c", "7")
.with_helper_code(
r#"
Shape flip(Shape s) {
s.x = s.x + s.w;
s.y = s.y + s.h;
s.w *= -1;
s.h *= -1;
s.r = ivec2(5, 3);
return s;
}
"#,
)
.with_kernel_code(
"shapes[gl_GlobalInvocationID.x] = flip(shapes[gl_GlobalInvocationID.x]); x[gl_GlobalInvocationID.x] = scalar + c + int(gl_WorkGroupID.x);",
),
)?.finish()?;
unsafe {
spawn(16).launch(call!(c, &mut shapes, &mut x, &DeviceBox::new(10)?))?;
}
// download from GPU and print out
println!("{:?}", futures::executor::block_on(shapes.get())?);
println!("{:?}", futures::executor::block_on(x.get())?);
Ok(())
}
$ cargo run
yields
Finished dev [unoptimized + debuginfo] target(s) in 0.44s
Running `target/debug/emu_test`
Limits {
max_bind_groups: 4,
max_dynamic_uniform_buffers_per_pipeline_layout: 8,
max_dynamic_storage_buffers_per_pipeline_layout: 4,
max_sampled_textures_per_shader_stage: 16,
max_samplers_per_shader_stage: 16,
max_storage_buffers_per_shader_stage: 4,
max_storage_textures_per_shader_stage: 4,
max_uniform_buffers_per_shader_stage: 12,
max_uniform_buffer_binding_size: 16384,
max_push_constant_size: 0,
}
{ name: "Intel(R) Iris(TM) Plus Graphics 655", vendor_id: 0, device_id: 0, device_type: IntegratedGpu }
wgpu error: Validation Error
Caused by:
In CommandEncoder::copy_buffer_to_buffer
Copy error
destination buffer/texture is missing the `COPY_DST` usage flag
note: destination = `<Buffer-(4, 1, Metal)>`
thread 'main' panicked at 'Handling wgpu errors as fatal by default', /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.7.0/src/backend/direct.rs:1896:5
stack backtrace:
0: std::panicking::begin_panic
at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/std/src/panicking.rs:616:12
1: wgpu::backend::direct::default_error_handler
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.7.0/src/backend/direct.rs:1896:5
2: core::ops::function::Fn::call
at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/ops/function.rs:70:5
3: <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call
at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/alloc/src/boxed.rs:1875:9
4: wgpu::backend::direct::ErrorSinkRaw::handle_error
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.7.0/src/backend/direct.rs:1883:9
5: wgpu::backend::direct::Context::handle_error
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.7.0/src/backend/direct.rs:109:9
6: wgpu::backend::direct::Context::handle_error_nolabel
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.7.0/src/backend/direct.rs:121:9
7: <wgpu::backend::direct::Context as wgpu::Context>::command_encoder_copy_buffer_to_buffer
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.7.0/src/backend/direct.rs:1542:13
8: wgpu::CommandEncoder::copy_buffer_to_buffer
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.7.0/src/lib.rs:1954:9
9: emu_core::device::Device::get::{{closure}}
at /Users/wbrickner/.cargo/git/checkouts/emu-7973979264d9dc07/9fe3db3/emu_core/src/device.rs:391:9
10: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/future/mod.rs:91:19
11: emu_core::boxed::<impl emu_core::device::DeviceBox<[T]>>::get::{{closure}}
at /Users/wbrickner/.cargo/git/checkouts/emu-7973979264d9dc07/9fe3db3/emu_core/src/boxed.rs:298:23
12: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/future/mod.rs:91:19
13: futures_executor::local_pool::block_on::{{closure}}
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-executor-0.3.21/src/local_pool.rs:315:23
14: futures_executor::local_pool::run_executor::{{closure}}
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-executor-0.3.21/src/local_pool.rs:90:37
15: std::thread::local::LocalKey<T>::try_with
at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/std/src/thread/local.rs:442:16
16: std::thread::local::LocalKey<T>::with
at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/std/src/thread/local.rs:418:9
17: futures_executor::local_pool::run_executor
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-executor-0.3.21/src/local_pool.rs:86:5
18: futures_executor::local_pool::block_on
at /Users/wbrickner/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-executor-0.3.21/src/local_pool.rs:315:5
19: emu_test::main
at ./src/main.rs:71:22
20: core::ops::function::FnOnce::call_once
at /rustc/fe5b13d681f25ee6474be29d748c65adcd91f69e/library/core/src/ops/function.rs:227:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
my understanding is that buffers must have their usage declared correctly (with some amount of detail) at construction time through wgpu.
Weird! I see that you are setting the copy destination flag correctly. Following the execution from .as_device_boxed_mut() above:
https://github.com/calebwin/emu/blob/9fe3db33b1e19063e227e753c5c48677cd37439d/emu_core/src/device.rs#L260-L302
Any idea what the issue is?
Update: removing the
shapes.set(vec![
Shape {
x: 0,
y: 0,
w: 100,
h: 100,
r: [2, 9]
};
1024
])?;
eliminates the error, and things always complete successfully.
Alternatively, leaving the .set call and removing the final .get call also prevents the panic.
Are usage flags being corrupted by .set?
Ok, here's the problem:
https://github.com/calebwin/emu/commit/80a28e78e651c7c02410238dcb654000ad9772ba#diff-c42b8503ace5f383ffbc7c9f91463d31dc54fc36b2d3974c49a3e2fc434024e9R331-R337
when setting, the existing staging buffer is discarded and replaced with a new staging buffer, which is created with the usage flag COPY_SRC.
Adding to the end of the function the construction of a new staging buffer with MAP_READ | COPY_DST (as it usually has, from the DeviceBox construction pathway) solves the issue, when it comes time to read the correct usage is there.
I would like to not do it this way, it seems quite wasteful to prepare a new allocation and immediately discard it etc. Mixing
COPY_SRC and COPY_DST and MAP_READ permissions is not allowed evidently. The usage flag paradigm is the problem here, unsure how fundamentally important it really is. Perhaps two staging buffers could be lazily prepared, one for copies to/from the GPU device.
@wbrickner Thanks for doing this investigation in this issue. I see how the staging buffer creation is problematic...
If anyone has a PR that fixes this, I can review/edit/merge.
