bleh

Cargo.lock

@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "anyhow"
+version = "1.0.93"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c95c10ba0b00a02636238b814946408b1322d5ac4760326e6fb8ec956d85775"
+
 [[package]]
 name = "autocfg"
 version = "1.4.0"
@@ -41,6 +47,12 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "cfg_aliases"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
+
 [[package]]
 name = "dlib"
 version = "0.5.2"
@@ -76,8 +88,10 @@ checksum = "486f806e73c5707928240ddc295403b1b93c96a02038563881c4a2fd84b81ac4"
 name = "fbcserver"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "cc",
  "minifb",
+ "nix 0.29.0",
 ]
 
 [[package]]
@@ -288,6 +302,18 @@ dependencies = [
  "memoffset",
 ]
 
+[[package]]
+name = "nix"
+version = "0.29.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
+dependencies = [
+ "bitflags 2.6.0",
+ "cfg-if",
+ "cfg_aliases",
+ "libc",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.20.2"
@@ -552,7 +578,7 @@ dependencies = [
  "bitflags 1.3.2",
  "downcast-rs",
  "libc",
- "nix",
+ "nix 0.24.3",
  "scoped-tls",
  "wayland-commons",
  "wayland-scanner",
@@ -565,7 +591,7 @@ version = "0.29.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8691f134d584a33a6606d9d717b95c4fa20065605f798a3f350d78dced02a902"
 dependencies = [
- "nix",
+ "nix 0.24.3",
  "once_cell",
  "smallvec",
  "wayland-sys",
@@ -577,7 +603,7 @@ version = "0.29.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6865c6b66f13d6257bef1cd40cbfe8ef2f150fb8ebbdb1e8e873455931377661"
 dependencies = [
- "nix",
+ "nix 0.24.3",
  "wayland-client",
  "xcursor",
 ]

Cargo.toml

@@ -4,7 +4,9 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+anyhow = "1.0.93"
 minifb = "0.27.0"
+nix = { version = "0.29.0", features = [ "fs" ] }
 
 [build-dependencies]
 cc = "1.0.99"

agent/src/capture.hpp

@@ -6,6 +6,7 @@ namespace hazelnut {
 
 	enum class DisplayCaptureResult {
 		Ok,
+		OkUnchanged, // OK but nothing changed
 		OkButResized, // OK, but grab the buffer information again. It's different due to a resize
 		Fail,		  // epic fail
 	};

agent/src/capture_nvfbc.cpp

@@ -169,7 +169,7 @@ namespace hazelnut {
 			return true;
 		}
 
-		void PaintWithTileOptimization(u32* pBufferData) {
+		DisplayCaptureResult PaintWithTileOptimization(u32* pBufferData) {
 			bool copiedTiles = false;
 
 			for(u32 dy = 0; dy < diffmapHeight; ++dy) {
@@ -198,6 +198,11 @@ namespace hazelnut {
 					}
 				}
 			}
+
+			if(!copiedTiles)
+				return DisplayCaptureResult::OkUnchanged;
+
+			return DisplayCaptureResult::Ok;
 		}
 
 		void PaintFull(u32* pBufferData) {
@@ -259,7 +264,7 @@ namespace hazelnut {
 			}
 
 			if(useTilePainting) [[likely]] {
-				PaintWithTileOptimization(&pOut[0]);
+				result = PaintWithTileOptimization(&pOut[0]);
 			} else {
 				PaintFull(&pOut[0]);
 			}

agent/src/main.cpp

@@ -51,22 +51,35 @@ int main(int argc, char** argv) {
 	while(true) {
 		{
 			auto guard = pHeader->lock.lock();
-			auto result = pCaptureInterface->CaptureFrameTemp(pFrameHeader->bits());
 
-			if(result == hazelnut::DisplayCaptureResult::Ok) {
-				// Do nothing.
-			} else if(result == hazelnut::DisplayCaptureResult::OkButResized) {
-				// We resized. Notify of that
-				framebuffer = pCaptureInterface->GetFramebufferInformation();
-				diff = pCaptureInterface->GetDiffInformation();
-			} else {
-				printf("Failed to capture\n");
-				break;
+
+
+			auto result = pCaptureInterface->CaptureFrameTemp(pFrameHeader->bits(
+				pFrameHeader->serial.load() % hazelnut::kNrFramesQueued,
+				framebuffer.width,
+				framebuffer.height
+			));
+
+			switch(result) {
+				case hazelnut::DisplayCaptureResult::Ok:
+				case hazelnut::DisplayCaptureResult::OkButResized:
+					if(result == hazelnut::DisplayCaptureResult::OkButResized) {
+						framebuffer = pCaptureInterface->GetFramebufferInformation();
+						diff = pCaptureInterface->GetDiffInformation();
+					}
+
+					pFrameHeader->serial.fetch_add(1);
+					pFrameHeader->width.store(framebuffer.width);
+					pFrameHeader->height.store(framebuffer.height);
+					break;
+
+				case hazelnut::DisplayCaptureResult::OkUnchanged: continue; break;
+
+				default:
+					printf("Failed to capture");
+					return 1;
+					break;
 			}
-
-			pFrameHeader->serial.fetch_add(1);
-			pFrameHeader->width.store(framebuffer.width);
-			pFrameHeader->height.store(framebuffer.height);
 		}
 	}
 

build.rs

@@ -3,6 +3,10 @@ use cc;
 fn main() {
 	let mut build = cc::Build::new();
 
+	// HACK: cc sucks
+	println!("cargo:rerun-if-changed=src");
+	println!("cargo:rerun-if-changed=shared/src");
+
 	build
 		.emit_rerun_if_env_changed(true)
 		.cpp(true)

shared/src/ivshmem.cpp

@@ -21,8 +21,8 @@ namespace hazelnut {
 		delete pImpl;
 	}
 
-	bool IvshmemDevice::Open(const char* devName) {
-		return pImpl->Open(devName);
+	bool IvshmemDevice::Open(int fd) {
+		return pImpl->Open(fd);
 	}
 
 	void IvshmemDevice::Close() {

shared/src/ivshmem.hpp

@@ -14,8 +14,8 @@ namespace hazelnut {
 
 		~IvshmemDevice();
 
-		/// Opens the device. On Linux [devName] MUST point to a SHMEM file.
-		bool Open(const char* devName = nullptr);
+		/// Opens the device. On Linux [fd] MUST be a valid file descriptor for a SHMEM file.
+		bool Open(int fd = -1);
 
 		void Close();
 

shared/src/ivshmem_linux.cpp

@@ -15,17 +15,12 @@ namespace hazelnut {
 		void* pMap = nullptr;
 		usize size = 0;
 
-		bool OpenDevice(const char* devName) {
-			// devName is not optional on Linux.
-			if(devName == nullptr)
+		bool OpenDevice(int fd) {
+			// fd is not optional on Linux.
+			if(fd == -1)
 				return false;
 
-			int devFd = open(devName, O_RDWR, static_cast<mode_t>(0600));
-
-			if(devFd == -1)
-				return false;
-
-			fd = devFd;
+			this->fd = fd;
 			return true;
 		}
 
@@ -41,7 +36,6 @@ namespace hazelnut {
 
 			void* map = mmap(0, devSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 			if(map == MAP_FAILED) {
-                printf("map failed\n");
 				return false;
 			}
 
@@ -56,8 +50,8 @@ namespace hazelnut {
 				munmap(pMap, size);
 		}
 
-		bool Open(const char* pDevName) {
-			if(!OpenDevice(pDevName))
+		bool Open(int fd) {
+			if(!OpenDevice(fd))
 				return false;
 
 			if(!MapMemory()) {

shared/src/ivshmem_windows.cpp

@@ -138,7 +138,7 @@ namespace hazelnut {
 			memset(&ivshmemMmapStruct, 0, sizeof(IVSHMEM_MMAP));
 		}
 
-		bool Open(const char* pDevName) {
+		bool Open(int fd) {
 			if(!OpenDevice())
 				return false;
 

shared/src/test.cpp

@@ -1,4 +1,8 @@
 
+#include <fcntl.h>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 #include <thread>
 
 #include "atomic_spinlock.hpp"
@@ -11,7 +15,13 @@ int main(int argc, char** argv) {
 
 	hazelnut::IvshmemDevice dev;
 
-	if(!dev.Open("/dev/shm/lg-win7")) {
+	int fd = open("/dev/shm/lg-win7", O_RDWR, (mode_t)0600);
+
+	if(fd == -1) {
+		printf("Failed to open ivshmem device file\n");
+	}
+
+	if(!dev.Open(fd)) {
 		printf("Failed to open ivshmem device\n");
 		return 1;
 	}
@@ -21,6 +31,11 @@ int main(int argc, char** argv) {
 
 	printf("opened a %zu MB large ivshmem\n", (size / (1024 * 1024)));
 
+	memset(ptr, 0, size);
+
+	printf("zeroed :)\n");
+
+#if 0
 	auto* pHeader = (hazelnut::IvshHeader*)&ptr[0];;
 	auto* pFrameHeader = (hazelnut::FrameHeader*)&ptr[0x1000];
 
@@ -59,6 +74,6 @@ int main(int argc, char** argv) {
         // allow the vm some time to do whatever it is it wants to do
         std::this_thread::sleep_for(std::chrono::milliseconds(5));
 	}
-
+#endif
 	return 0;
 }

src/hzclient.rs

@@ -1,5 +1,5 @@
 //! Hazelnut C++ client bindings.
-use std::ffi;
+use nix::{fcntl::OFlag, sys::stat::Mode};
 
 pub(crate) mod sys {
     use std::ffi;
@@ -21,10 +21,7 @@ pub(crate) mod sys {
         pub(crate) fn rust_new_hazelnut_client() -> *mut ffi::c_void;
         pub(crate) fn rust_destroy_hazelnut_client(client: *mut ffi::c_void);
 
-        pub(crate) fn rust_hazelnut_client_open(
-            client: *mut ffi::c_void,
-            url: *const ffi::c_char,
-        ) -> bool;
+        pub(crate) fn rust_hazelnut_client_open(client: *mut ffi::c_void, fd: ffi::c_int) -> bool;
 
         pub(crate) fn rust_hazelnut_client_tick(client: *mut ffi::c_void) -> ResultCode;
 
@@ -62,14 +59,19 @@ impl HazelnutClient {
     }
 
     /// Opens the given IVSHMEM shmem file.
-    pub fn open(&mut self, path: &String) -> bool {
-        let cstr = ffi::CString::new(path.clone()).expect("dumbass");
+    pub fn open(&mut self, path: &String) -> anyhow::Result<()> {
+        // NOTE: `fd` is owned by the hazelnut client once it is provided to it, so we do not close it ourselves.
+        let fd = nix::fcntl::open(path.as_str(), OFlag::O_RDWR, Mode::S_IRUSR | Mode::S_IWUSR)?;
 
         // FIXME: this really should work by FD so we can just return io::Result<> or something, but bleh
         // for now it's "fine", also it's a path in the shared sources currently.
         unsafe {
-            return sys::rust_hazelnut_client_open(self.0, cstr.as_ptr());
+            if !sys::rust_hazelnut_client_open(self.0, fd) {
+                return Err(anyhow::anyhow!("Failed to open Hazelnut client"));
+            }
         }
+
+        Ok(())
     }
 
     /// Ticks this client.

src/main.rs

@@ -2,7 +2,7 @@ use minifb::{Window, WindowOptions};
 
 mod hzclient;
 
-fn main() {
+fn main() -> anyhow::Result<()> {
     let mut screen_width: u32 = 320;
     let mut screen_height: u32 = 200;
     let mut window: Option<Window> = None;
@@ -11,12 +11,9 @@ fn main() {
 
     let socket_path: String = "/dev/shm/lg-win7".into();
 
-    if !client.open(&socket_path) {
-        println!("Could not open IVSHMEM.");
-        return ();
-    } else {
-        println!("Opened IVSHMEM device.");
-    }
+    client.open(&socket_path)?;
+
+    println!("Opened IVSHMEM device.");
 
     loop {
         match window.as_mut() {
@@ -62,10 +59,14 @@ fn main() {
             }
             hzclient::ResultCode::Unchanged => match window.as_mut() {
                 Some(window) => {
+                    client.unlock();
+
                     window.update();
                 }
                 _ => {}
             },
         }
     }
+
+    Ok(())
 }

src/rust_wrapper.cpp

@@ -5,8 +5,8 @@
 enum class ResultCode : u32 { Unchanged, Changed, Fail };
 
 struct HazelnutIvshmemClient {
-	bool Open(const char* path) {
-		if(!ivshmemDevice.Open(path))
+	bool Open(int fd) {
+		if(!ivshmemDevice.Open(fd))
 			return false;
 
 		auto* ptr = (u8*)ivshmemDevice.GetPointer();
@@ -14,17 +14,17 @@ struct HazelnutIvshmemClient {
 		pHeader = (hazelnut::IvshHeader*)&ptr[0];
 		pFrameHeader = (hazelnut::FrameHeader*)&ptr[0x1000];
 
-		serial = pHeader->serverSessionId.load();
+		sessionId = pHeader->serverSessionId.load();
 		lastFrameSerial = 0;
 		return true;
 	}
 
-	// THIS LEAVES THE LOCK HELD SO YOU CAN READ ON CHANGE!!!!
+	// NOTE: This function leaves the lock held on successful returns.
 	ResultCode TickOne() {
 		if(!pHeader)
 			return ResultCode::Fail;
 
-		if(serial != pHeader->serverSessionId.load())
+		if(sessionId != pHeader->serverSessionId.load())
 			return ResultCode::Fail;
 
 		if(pHeader->lock.try_lock_manually()) {
@@ -33,15 +33,11 @@ struct HazelnutIvshmemClient {
 		}
 
 		auto current = pFrameHeader->serial.load();
-
 		if(current == lastFrameSerial) {
-			pHeader->lock.unlock();
 			return ResultCode::Unchanged;
 		}
 
 		lastFrameSerial = current;
-		// printf("Frame with serial %u. Width %ux%u\n", lastSerial, pFrameHeader->width.load(), pFrameHeader->height.load());
-		// pHeader->lock.unlock();
 		return ResultCode::Changed;
 	}
 
@@ -51,6 +47,8 @@ struct HazelnutIvshmemClient {
 
 	u32* Framebuffer() {
 		if(pFrameHeader) {
+			auto width = pFrameHeader->width.load();
+			auto height = pFrameHeader->height.load();
 			return pFrameHeader->bits();
 		}
 
@@ -63,7 +61,7 @@ struct HazelnutIvshmemClient {
 	hazelnut::IvshHeader* pHeader;
 	hazelnut::FrameHeader* pFrameHeader;
 
-	u32 serial {};
+	u32 sessionId {};
 
 	u32 lastFrameSerial {};
 };
@@ -80,9 +78,9 @@ void rust_destroy_hazelnut_client(void* pClient) {
 		delete(HazelnutIvshmemClient*)pClient;
 }
 
-bool rust_hazelnut_client_open(void* pClient, const char* pszPath) {
+bool rust_hazelnut_client_open(void* pClient, int fd) {
 	if(pClient) {
-		return ((HazelnutIvshmemClient*)pClient)->Open(pszPath);
+		return ((HazelnutIvshmemClient*)pClient)->Open(fd);
 	}
 
 	return false;