add test wayland server

* implement epoll_create
* implement fstat dupfd
* implement eventfd
* update mlibc patches accordingly

Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>

Author: Andy-Python-Programmer

base-files/server.exe

@@ -1,4 +1,4 @@
-From c30a142fe0afaa4c4de66ab950be5dab1e931461 Mon Sep 17 00:00:00 2001
+From c11445241f6016b07ed89c0be2617488cfb79265 Mon Sep 17 00:00:00 2001
 From: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
 Date: Thu, 10 Feb 2022 19:12:25 +1100
 Subject: [PATCH] yes
@@ -7,11 +7,11 @@ Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>
 ---
  .gitignore                          |  3 ++
  options/rtdl/generic/linker.cpp     |  2 +-
- sysdeps/aero/generic/aero.cpp       | 12 ++++++--
- sysdeps/aero/generic/filesystem.cpp | 46 ++++++++++++++++++++++++-----
- sysdeps/aero/generic/signals.cpp    |  8 +++--
- sysdeps/aero/include/aero/syscall.h |  7 +++++
- 6 files changed, 65 insertions(+), 13 deletions(-)
+ sysdeps/aero/generic/aero.cpp       | 12 ++++-
+ sysdeps/aero/generic/filesystem.cpp | 68 +++++++++++++++++++++++++----
+ sysdeps/aero/generic/signals.cpp    |  8 +++-
+ sysdeps/aero/include/aero/syscall.h | 12 +++++
+ 6 files changed, 92 insertions(+), 13 deletions(-)
 
 diff --git a/.gitignore b/.gitignore
 index dbb35e8b..20c8d4c3 100644
@@ -68,7 +68,7 @@ index 7de909f5..4281beb9 100644
  #endif
  } // namespace mlibc
 diff --git a/sysdeps/aero/generic/filesystem.cpp b/sysdeps/aero/generic/filesystem.cpp
-index 6a13f19c..53223dc6 100644
+index 6a13f19c..8679b28a 100644
 --- a/sysdeps/aero/generic/filesystem.cpp
 +++ b/sysdeps/aero/generic/filesystem.cpp
 @@ -1,3 +1,4 @@
@@ -150,6 +150,33 @@ index 6a13f19c..53223dc6 100644
      return 0;
  }
 
+@@ -267,4 +297,26 @@ int sys_pipe(int *fds, int flags) {
+ 
+     return 0;
+ }
++
++int sys_epoll_create(int flags, int *fd) { 
++    auto result = syscall(SYS_EPOLL_CREATE, flags);
++
++    if (result < 0) {
++        return -result;
++    }
++
++    *fd = result;
++    return 0;
++}
++
++int sys_eventfd_create(unsigned int initval, int flags, int *fd) {
++    auto result = syscall(SYS_EVENT_FD, initval, flags);
++
++    if (result < 0) {
++        return -result;
++    }
++
++    *fd = result;
++    return 0;
++}
+ } // namespace mlibc
 diff --git a/sysdeps/aero/generic/signals.cpp b/sysdeps/aero/generic/signals.cpp
 index 3527370c..a6f69fff 100644
 --- a/sysdeps/aero/generic/signals.cpp
@@ -171,10 +198,10 @@ index 3527370c..a6f69fff 100644
  } // namespace mlibc
 \ No newline at end of file
 diff --git a/sysdeps/aero/include/aero/syscall.h b/sysdeps/aero/include/aero/syscall.h
-index 07b1b51b..bd4d348d 100644
+index 07b1b51b..ef797e40 100644
 --- a/sysdeps/aero/include/aero/syscall.h
 +++ b/sysdeps/aero/include/aero/syscall.h
-@@ -49,6 +49,13 @@
+@@ -49,6 +49,18 @@
  #define SYS_DUP 42
  #define SYS_FCNTL 43
  #define SYS_DUP2 44
@@ -185,6 +212,11 @@ index 07b1b51b..bd4d348d 100644
 +#define SYS_STAT 49
 +#define SYS_FSTAT 50
 +#define SYS_READ_LINK 51
++#define SYS_EPOLL_CREATE 52
++#define SYS_EPOLL_PWAIT 53
++#define SYS_EPOLL_CTL 54
++#define SYS_EPOLL_WAIT 55
++#define SYS_EVENT_FD 56
 
  // Invalid syscall used to trigger a log error in the kernel (as a hint)
  // so, that we can implement the syscall in the kernel.

patches/mlibc/mlibc.patch

@@ -0,0 +1,28 @@
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <wayland-server.h>
+
+void bail(char *msg) {
+  fprintf(stderr, "%s (error=%s)\n", msg, strerror(errno));
+}
+
+int main() {
+  struct wl_display *display = wl_display_create();
+  if (!display) {
+    bail("server: unable to create Wayland display");
+    return 1;
+  }
+
+  const char *socket = wl_display_add_socket_auto(display);
+  if (!socket) {
+    bail("server: unable to add socket to Wayland display");
+    return 1;
+  }
+
+  fprintf(stderr, "running Wayland display on %s\n", socket);
+  wl_display_run(display);
+
+  wl_display_destroy(display);
+  return 0;
+}

server.c

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2021-2022 The Aero Project Developers.
+ *
+ * This file is part of The Aero Project.
+ *
+ * Aero is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Aero is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Aero. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+use alloc::sync::Arc;
+
+use super::inode::INodeInterface;
+
+pub struct EPoll {}
+
+impl EPoll {
+    pub fn new() -> Arc<Self> {
+        Arc::new(Self {})
+    }
+}
+
+impl INodeInterface for EPoll {}

src/aero_kernel/src/fs/epoll.rs

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2021-2022 The Aero Project Developers.
+ *
+ * This file is part of The Aero Project.
+ *
+ * Aero is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Aero is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Aero. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+use alloc::sync::Arc;
+
+use super::inode::INodeInterface;
+
+pub struct EventFd {}
+
+impl EventFd {
+    pub fn new() -> Arc<Self> {
+        Arc::new(Self {})
+    }
+}
+
+impl INodeInterface for EventFd {
+    fn read_at(&self, _offset: usize, _buffer: &mut [u8]) -> super::Result<usize> {
+        unimplemented!()
+    }
+
+    fn write_at(&self, _offset: usize, _buffer: &[u8]) -> super::Result<usize> {
+        unimplemented!()
+    }
+}

src/aero_kernel/src/fs/eventfd.rs

@@ -33,6 +33,12 @@ use super::cache::{DirCacheItem, INodeCacheItem};
 use super::inode::FileType;
 use super::FileSystemError;
 
+pub enum DuplicateHint {
+    Exact(usize),
+    Any,
+    GreatorOrEqual(usize),
+}
+
 pub struct FileHandle {
     pub fd: usize,
     pub inode: DirCacheItem,
@@ -215,51 +221,67 @@ impl FileTable {
         }
     }
 
-    pub fn duplicate_at(
-        &self,
-        fd: usize,
-        new_fd: usize,
-        flags: OpenFlags,
-    ) -> Result<usize, aero_syscall::AeroSyscallError> {
-        let handle = self
-            .get_handle(fd)
-            .ok_or(aero_syscall::AeroSyscallError::EINVAL)?;
-
-        let mut files = self.0.write();
-
-        if files[new_fd].is_none() {
-            files[new_fd] = Some(handle.duplicate(flags)?);
-            Ok(0x00)
-        } else {
-            let handle = handle.duplicate(flags)?;
-            let old = files[new_fd]
-                .take()
-                .expect("duplicate_at: failed to take the value at new_fd");
-
-            old.inode.inode().close(old.flags);
-            files[new_fd] = Some(handle);
-
-            Ok(0x00)
-        }
-    }
-
+    /// Duplicates the provided file descriptor based on the provided duplicate
+    /// descriptor hint. Check out the documentation for [`DuplicateHint`] for more
+    /// information.
     pub fn duplicate(
         &self,
         fd: usize,
+        hint: DuplicateHint,
         flags: OpenFlags,
     ) -> Result<usize, aero_syscall::AeroSyscallError> {
         let handle = self
             .get_handle(fd)
             .ok_or(aero_syscall::AeroSyscallError::EINVAL)?;
 
-        let mut files = self.0.write();
+        let find_from = |files: &mut Vec<Option<Arc<FileHandle>>>, start: usize| {
+            let array = &mut files[start..];
 
-        if let Some((index, f)) = files.iter_mut().enumerate().find(|e| e.1.is_none()) {
-            *f = Some(handle.duplicate(flags)?);
-            Ok(index)
-        } else {
+            // Loop over the current file descriptor table and find the first
+            // avaliable file descriptor.
+            for (i, file) in array.iter_mut().enumerate() {
+                if file.is_none() {
+                    *file = Some(handle.duplicate(flags)?);
+                    return Ok(i);
+                }
+            }
+
+            // We ran out of file descriptors. Grow the table and add the
+            // file descriptor.
             files.push(Some(handle.duplicate(flags)?));
             Ok(files.len() - 1)
+        };
+
+        match hint {
+            DuplicateHint::Exact(new_fd) => {
+                let mut files = self.0.write();
+
+                // Ensure the file descriptor is available.
+                if files[new_fd].is_none() {
+                    files[new_fd] = Some(handle.duplicate(flags)?);
+                    Ok(0x00)
+                } else {
+                    // If the file descriptor is not available, then we close the
+                    // old one and set its handle to the new duplicate handle.
+                    let handle = handle.duplicate(flags)?;
+                    let old = files[new_fd].take().unwrap();
+
+                    old.inode.inode().close(old.flags);
+                    files[new_fd] = Some(handle);
+
+                    Ok(0x00)
+                }
+            }
+
+            DuplicateHint::Any => {
+                let mut files = self.0.write();
+                find_from(&mut files, 0)
+            }
+
+            DuplicateHint::GreatorOrEqual(hint_fd) => {
+                let mut files = self.0.write();
+                find_from(&mut files, hint_fd)
+            }
         }
     }
 

src/aero_kernel/src/fs/file_table.rs

@@ -36,6 +36,8 @@ use self::{cache::DirCacheItem, ramfs::RamFs};
 pub mod block;
 pub mod cache;
 pub mod devfs;
+pub mod epoll;
+pub mod eventfd;
 pub mod file_table;
 pub mod initramfs;
 pub mod inode;