wind: Handle ftruncate() and mmap() errors properly

Classic "keeping a pointer to an element inside a vector after the vector is updated" bug, ah yes.

wind/Client.h

@@ -8,4 +8,11 @@ struct Client
     Vector<Window*> windows;
     bool rpc_in_progress { false };
     u8 rpc_id { 0 };
+
+    Client(os::LocalServer::Client&& client)
+#ifdef CLIENT_IMPLEMENTATION
+        : conn(move(client)), windows() {}
+#else
+        ;
+#endif
 };

wind/IPC.cpp

@@ -26,29 +26,32 @@ static Result<u32*> create_shm_region(const char* path, int* outfd, ui::Rect rec
     int fd = shm_open(path, O_RDWR | O_CREAT | O_EXCL, 0600);
     if (fd < 0)
     {
-        os::eprintln("wind: could not create shared memory region: shm_open failed (%s) - %s", path, strerror(errno));
-        return err(errno);
+        int olderr = errno;
+        os::eprintln("wind: could not create shared memory region: shm_open failed (%s) - %s", path, strerror(olderr));
+        return err(olderr);
     }
 
     usize size = align_up<PAGE_SIZE>(rect.width * rect.height * 4); // 4 bytes per pixel
 
     if (ftruncate(fd, size) < 0)
     {
+        int olderr = errno;
         os::eprintln("wind: could not create shared memory region: ftruncate failed (%d, %zu) - %s", fd, size,
-                     strerror(errno));
+                     strerror(olderr));
         shm_unlink(path);
         close(fd);
-        return 0;
+        return err(olderr);
     }
 
     void* p = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
     if (p == MAP_FAILED)
     {
+        int olderr = errno;
         os::eprintln("wind: could not create shared memory region: mmap failed (%zu, %d) - %s", size, fd,
-                     strerror(errno));
+                     strerror(olderr));
         shm_unlink(path);
         close(fd);
-        return 0;
+        return err(olderr);
     }
 
     if (outfd) *outfd = fd;

wind/main.cpp

@@ -1,3 +1,4 @@
+#define CLIENT_IMPLEMENTATION
 #include "Client.h"
 #include "IPC.h"
 #include "Mouse.h"
@@ -18,7 +19,7 @@
 #include <time.h>
 #include <unistd.h>
 
-static void debug(const Vector<Client>& clients)
+static void debug(const Vector<OwnedPtr<Client>>& clients)
 {
     os::println("--- wind: DEBUG OUTPUT ---");
 
@@ -26,7 +27,7 @@ static void debug(const Vector<Client>& clients)
 
     for (const auto& client : clients)
     {
-        os::println("Client with fd %d, owns %zu windows", client.conn.fd(), client.windows.size());
+        os::println("Client with fd %d, owns %zu windows", client->conn.fd(), client->windows.size());
     }
 
     os::println("-- wind: Listing windows --");
@@ -113,7 +114,7 @@ Result<int> luna_main(int argc, char** argv)
 
     ui::Color background = ui::BLACK;
 
-    Vector<Client> clients;
+    Vector<OwnedPtr<Client>> clients;
     Vector<struct pollfd> fds;
     TRY(fds.try_append({ .fd = mouse->fd(), .events = POLLIN, .revents = 0 }));
     TRY(fds.try_append({ .fd = keyboard->fd(), .events = POLLIN, .revents = 0 }));
@@ -149,14 +150,14 @@ Result<int> luna_main(int argc, char** argv)
         }
         for (usize i = 0; i < clients.size(); i++)
         {
-            if (fds[i + 3].revents & POLLIN) wind::handle_ipc(clients[i]);
+            if (fds[i + 3].revents & POLLIN) wind::handle_ipc(*clients[i]);
             if (fds[i + 3].revents & POLLHUP)
             {
                 os::println("wind: Client %d disconnected", i);
                 fds.remove_at(i + 3);
                 auto client = clients.remove_at(i);
-                client.conn.disconnect();
-                for (auto& window : client.windows)
+                client->conn.disconnect();
+                for (auto& window : client->windows)
                 {
                     if (window)
                     {
@@ -171,7 +172,7 @@ Result<int> luna_main(int argc, char** argv)
             auto client = TRY(server->accept());
             os::println("wind: New client connected!");
             TRY(fds.try_append({ .fd = client.fd(), .events = POLLIN, .revents = 0 }));
-            Client c { move(client), {} };
+            OwnedPtr<Client> c = TRY(adopt_owned_if_nonnull(new Client(move(client))));
             TRY(clients.try_append(move(c)));
         }
     }