wgpu_context.rs

  1#[cfg(not(target_family = "wasm"))]
  2use anyhow::Context as _;
  3#[cfg(not(target_family = "wasm"))]
  4use gpui_util::ResultExt;
  5use std::sync::Arc;
  6use std::sync::atomic::{AtomicBool, Ordering};
  7
  8pub struct WgpuContext {
  9    pub instance: wgpu::Instance,
 10    pub adapter: wgpu::Adapter,
 11    pub device: Arc<wgpu::Device>,
 12    pub queue: Arc<wgpu::Queue>,
 13    dual_source_blending: bool,
 14    device_lost: Arc<AtomicBool>,
 15}
 16
 17#[derive(Clone, Copy)]
 18pub struct CompositorGpuHint {
 19    pub vendor_id: u32,
 20    pub device_id: u32,
 21}
 22
 23impl WgpuContext {
 24    #[cfg(not(target_family = "wasm"))]
 25    pub fn new(
 26        instance: wgpu::Instance,
 27        surface: &wgpu::Surface<'_>,
 28        compositor_gpu: Option<CompositorGpuHint>,
 29    ) -> anyhow::Result<Self> {
 30        let device_id_filter = match std::env::var("ZED_DEVICE_ID") {
 31            Ok(val) => parse_pci_id(&val)
 32                .context("Failed to parse device ID from `ZED_DEVICE_ID` environment variable")
 33                .log_err(),
 34            Err(std::env::VarError::NotPresent) => None,
 35            err => {
 36                err.context("Failed to read value of `ZED_DEVICE_ID` environment variable")
 37                    .log_err();
 38                None
 39            }
 40        };
 41
 42        // Select an adapter by actually testing surface configuration with the real device.
 43        // This is the only reliable way to determine compatibility on hybrid GPU systems.
 44        let (adapter, device, queue, dual_source_blending) =
 45            pollster::block_on(Self::select_adapter_and_device(
 46                &instance,
 47                device_id_filter,
 48                surface,
 49                compositor_gpu.as_ref(),
 50            ))?;
 51
 52        let device_lost = Arc::new(AtomicBool::new(false));
 53        device.set_device_lost_callback({
 54            let device_lost = Arc::clone(&device_lost);
 55            move |reason, message| {
 56                log::error!("wgpu device lost: reason={reason:?}, message={message}");
 57                if reason != wgpu::DeviceLostReason::Destroyed {
 58                    device_lost.store(true, Ordering::Relaxed);
 59                }
 60            }
 61        });
 62
 63        log::info!(
 64            "Selected GPU adapter: {:?} ({:?})",
 65            adapter.get_info().name,
 66            adapter.get_info().backend
 67        );
 68
 69        Ok(Self {
 70            instance,
 71            adapter,
 72            device: Arc::new(device),
 73            queue: Arc::new(queue),
 74            dual_source_blending,
 75            device_lost,
 76        })
 77    }
 78
 79    #[cfg(target_family = "wasm")]
 80    pub async fn new_web() -> anyhow::Result<Self> {
 81        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
 82            backends: wgpu::Backends::BROWSER_WEBGPU | wgpu::Backends::GL,
 83            flags: wgpu::InstanceFlags::default(),
 84            backend_options: wgpu::BackendOptions::default(),
 85            memory_budget_thresholds: wgpu::MemoryBudgetThresholds::default(),
 86            display: None,
 87        });
 88
 89        let adapter = instance
 90            .request_adapter(&wgpu::RequestAdapterOptions {
 91                power_preference: wgpu::PowerPreference::HighPerformance,
 92                compatible_surface: None,
 93                force_fallback_adapter: false,
 94            })
 95            .await
 96            .map_err(|e| anyhow::anyhow!("Failed to request GPU adapter: {e}"))?;
 97
 98        log::info!(
 99            "Selected GPU adapter: {:?} ({:?})",
100            adapter.get_info().name,
101            adapter.get_info().backend
102        );
103
104        let device_lost = Arc::new(AtomicBool::new(false));
105        let (device, queue, dual_source_blending) = Self::create_device(&adapter).await?;
106
107        Ok(Self {
108            instance,
109            adapter,
110            device: Arc::new(device),
111            queue: Arc::new(queue),
112            dual_source_blending,
113            device_lost,
114        })
115    }
116
117    async fn create_device(
118        adapter: &wgpu::Adapter,
119    ) -> anyhow::Result<(wgpu::Device, wgpu::Queue, bool)> {
120        let dual_source_blending = adapter
121            .features()
122            .contains(wgpu::Features::DUAL_SOURCE_BLENDING);
123
124        let mut required_features = wgpu::Features::empty();
125        if dual_source_blending {
126            required_features |= wgpu::Features::DUAL_SOURCE_BLENDING;
127        } else {
128            log::warn!(
129                "Dual-source blending not available on this GPU. \
130                Subpixel text antialiasing will be disabled."
131            );
132        }
133
134        let (device, queue) = adapter
135            .request_device(&wgpu::DeviceDescriptor {
136                label: Some("gpui_device"),
137                required_features,
138                required_limits: wgpu::Limits::downlevel_defaults()
139                    .using_resolution(adapter.limits())
140                    .using_alignment(adapter.limits()),
141                memory_hints: wgpu::MemoryHints::MemoryUsage,
142                trace: wgpu::Trace::Off,
143                experimental_features: wgpu::ExperimentalFeatures::disabled(),
144            })
145            .await
146            .map_err(|e| anyhow::anyhow!("Failed to create wgpu device: {e}"))?;
147
148        Ok((device, queue, dual_source_blending))
149    }
150
151    #[cfg(not(target_family = "wasm"))]
152    pub fn instance(display: Box<dyn wgpu::wgt::WgpuHasDisplayHandle>) -> wgpu::Instance {
153        wgpu::Instance::new(wgpu::InstanceDescriptor {
154            backends: wgpu::Backends::VULKAN | wgpu::Backends::GL,
155            flags: wgpu::InstanceFlags::default(),
156            backend_options: wgpu::BackendOptions::default(),
157            memory_budget_thresholds: wgpu::MemoryBudgetThresholds::default(),
158            display: Some(display),
159        })
160    }
161
162    pub fn check_compatible_with_surface(&self, surface: &wgpu::Surface<'_>) -> anyhow::Result<()> {
163        let caps = surface.get_capabilities(&self.adapter);
164        if caps.formats.is_empty() {
165            let info = self.adapter.get_info();
166            anyhow::bail!(
167                "Adapter {:?} (backend={:?}, device={:#06x}) is not compatible with the \
168                 display surface for this window.",
169                info.name,
170                info.backend,
171                info.device,
172            );
173        }
174        Ok(())
175    }
176
177    /// Select an adapter and create a device, testing that the surface can actually be configured.
178    /// This is the only reliable way to determine compatibility on hybrid GPU systems, where
179    /// adapters may report surface compatibility via get_capabilities() but fail when actually
180    /// configuring (e.g., NVIDIA reporting Vulkan Wayland support but failing because the
181    /// Wayland compositor runs on the Intel GPU).
182    #[cfg(not(target_family = "wasm"))]
183    async fn select_adapter_and_device(
184        instance: &wgpu::Instance,
185        device_id_filter: Option<u32>,
186        surface: &wgpu::Surface<'_>,
187        compositor_gpu: Option<&CompositorGpuHint>,
188    ) -> anyhow::Result<(wgpu::Adapter, wgpu::Device, wgpu::Queue, bool)> {
189        let mut adapters: Vec<_> = instance.enumerate_adapters(wgpu::Backends::all()).await;
190
191        if adapters.is_empty() {
192            anyhow::bail!("No GPU adapters found");
193        }
194
195        if let Some(device_id) = device_id_filter {
196            log::info!("ZED_DEVICE_ID filter: {:#06x}", device_id);
197        }
198
199        // Sort adapters into a single priority order. Tiers (from highest to lowest):
200        //
201        // 1. ZED_DEVICE_ID match — explicit user override
202        // 2. Compositor GPU match — the GPU the display server is rendering on
203        // 3. Device type (Discrete > Integrated > Other > Virtual > Cpu).
204        //    "Other" ranks above "Virtual" because OpenGL seems to count as "Other".
205        // 4. Backend — prefer Vulkan/Metal/Dx12 over GL/etc.
206        adapters.sort_by_key(|adapter| {
207            let info = adapter.get_info();
208
209            // Backends like OpenGL report device=0 for all adapters, so
210            // device-based matching is only meaningful when non-zero.
211            let device_known = info.device != 0;
212
213            let user_override: u8 = match device_id_filter {
214                Some(id) if device_known && info.device == id => 0,
215                _ => 1,
216            };
217
218            let compositor_match: u8 = match compositor_gpu {
219                Some(hint)
220                    if device_known
221                        && info.vendor == hint.vendor_id
222                        && info.device == hint.device_id =>
223                {
224                    0
225                }
226                _ => 1,
227            };
228
229            let type_priority: u8 = match info.device_type {
230                wgpu::DeviceType::DiscreteGpu => 0,
231                wgpu::DeviceType::IntegratedGpu => 1,
232                wgpu::DeviceType::Other => 2,
233                wgpu::DeviceType::VirtualGpu => 3,
234                wgpu::DeviceType::Cpu => 4,
235            };
236
237            let backend_priority: u8 = match info.backend {
238                wgpu::Backend::Vulkan => 0,
239                wgpu::Backend::Metal => 0,
240                wgpu::Backend::Dx12 => 0,
241                _ => 1,
242            };
243
244            (
245                user_override,
246                compositor_match,
247                type_priority,
248                backend_priority,
249            )
250        });
251
252        // Log all available adapters (in sorted order)
253        log::info!("Found {} GPU adapter(s):", adapters.len());
254        for adapter in &adapters {
255            let info = adapter.get_info();
256            log::info!(
257                "  - {} (vendor={:#06x}, device={:#06x}, backend={:?}, type={:?})",
258                info.name,
259                info.vendor,
260                info.device,
261                info.backend,
262                info.device_type,
263            );
264        }
265
266        // Test each adapter by creating a device and configuring the surface
267        for adapter in adapters {
268            let info = adapter.get_info();
269            log::info!("Testing adapter: {} ({:?})...", info.name, info.backend);
270
271            match Self::try_adapter_with_surface(&adapter, surface).await {
272                Ok((device, queue, dual_source_blending)) => {
273                    log::info!(
274                        "Selected GPU (passed configuration test): {} ({:?})",
275                        info.name,
276                        info.backend
277                    );
278                    return Ok((adapter, device, queue, dual_source_blending));
279                }
280                Err(e) => {
281                    log::info!(
282                        "  Adapter {} ({:?}) failed: {}, trying next...",
283                        info.name,
284                        info.backend,
285                        e
286                    );
287                }
288            }
289        }
290
291        anyhow::bail!("No GPU adapter found that can configure the display surface")
292    }
293
294    /// Try to use an adapter with a surface by creating a device and testing configuration.
295    /// Returns the device and queue if successful, allowing them to be reused.
296    #[cfg(not(target_family = "wasm"))]
297    async fn try_adapter_with_surface(
298        adapter: &wgpu::Adapter,
299        surface: &wgpu::Surface<'_>,
300    ) -> anyhow::Result<(wgpu::Device, wgpu::Queue, bool)> {
301        let caps = surface.get_capabilities(adapter);
302        if caps.formats.is_empty() {
303            anyhow::bail!("no compatible surface formats");
304        }
305        if caps.alpha_modes.is_empty() {
306            anyhow::bail!("no compatible alpha modes");
307        }
308
309        let (device, queue, dual_source_blending) = Self::create_device(adapter).await?;
310        let error_scope = device.push_error_scope(wgpu::ErrorFilter::Validation);
311
312        let test_config = wgpu::SurfaceConfiguration {
313            usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
314            format: caps.formats[0],
315            width: 64,
316            height: 64,
317            present_mode: wgpu::PresentMode::Fifo,
318            desired_maximum_frame_latency: 2,
319            alpha_mode: caps.alpha_modes[0],
320            view_formats: vec![],
321        };
322
323        surface.configure(&device, &test_config);
324
325        let error = error_scope.pop().await;
326        if let Some(e) = error {
327            anyhow::bail!("surface configuration failed: {e}");
328        }
329
330        Ok((device, queue, dual_source_blending))
331    }
332
333    pub fn supports_dual_source_blending(&self) -> bool {
334        self.dual_source_blending
335    }
336
337    /// Returns true if the GPU device was lost (e.g., due to driver crash, suspend/resume).
338    /// When this returns true, the context should be recreated.
339    pub fn device_lost(&self) -> bool {
340        self.device_lost.load(Ordering::Relaxed)
341    }
342
343    /// Returns a clone of the device_lost flag for sharing with renderers.
344    pub(crate) fn device_lost_flag(&self) -> Arc<AtomicBool> {
345        Arc::clone(&self.device_lost)
346    }
347}
348
349#[cfg(not(target_family = "wasm"))]
350fn parse_pci_id(id: &str) -> anyhow::Result<u32> {
351    let mut id = id.trim();
352
353    if id.starts_with("0x") || id.starts_with("0X") {
354        id = &id[2..];
355    }
356    let is_hex_string = id.chars().all(|c| c.is_ascii_hexdigit());
357    let is_4_chars = id.len() == 4;
358    anyhow::ensure!(
359        is_4_chars && is_hex_string,
360        "Expected a 4 digit PCI ID in hexadecimal format"
361    );
362
363    u32::from_str_radix(id, 16).context("parsing PCI ID as hex")
364}
365
366#[cfg(test)]
367mod tests {
368    use super::parse_pci_id;
369
370    #[test]
371    fn test_parse_device_id() {
372        assert!(parse_pci_id("0xABCD").is_ok());
373        assert!(parse_pci_id("ABCD").is_ok());
374        assert!(parse_pci_id("abcd").is_ok());
375        assert!(parse_pci_id("1234").is_ok());
376        assert!(parse_pci_id("123").is_err());
377        assert_eq!(
378            parse_pci_id(&format!("{:x}", 0x1234)).unwrap(),
379            parse_pci_id(&format!("{:X}", 0x1234)).unwrap(),
380        );
381
382        assert_eq!(
383            parse_pci_id(&format!("{:#x}", 0x1234)).unwrap(),
384            parse_pci_id(&format!("{:#X}", 0x1234)).unwrap(),
385        );
386    }
387}