move allocator to global state

src/main.zig

@@ -3,6 +3,12 @@ const builtin = @import("builtin");
 const options = @import("build_options");
 const glfw = @import("glfw");
 const macos = @import("macos");
+const tracy = @import("tracy");
+const internal_os = @import("os/main.zig");
+const xev = @import("xev");
+const fontconfig = @import("fontconfig");
+const harfbuzz = @import("harfbuzz");
+const renderer = @import("renderer.zig");
 const xdg = @import("xdg.zig");
 
 const App = @import("App.zig");
@@ -10,9 +16,14 @@ const cli_args = @import("cli_args.zig");
 const Config = @import("config.zig").Config;
 const Ghostty = @import("main_c.zig").Ghostty;
 
+/// Global process state. This is initialized in main() for exe artifacts
+/// and by ghostty_init() for lib artifacts. This should ONLY be used by
+/// the C API. The Zig API should NOT use any global state and should
+/// rely on allocators being passed in as parameters.
+pub var state: GlobalState = undefined;
+
 pub fn main() !void {
-    var state: Ghostty = undefined;
-    Ghostty.init(&state);
+    state.init();
     defer state.deinit();
     const alloc = state.alloc;
 
@@ -153,6 +164,80 @@ fn glfwErrorCallback(code: glfw.ErrorCode, desc: [:0]const u8) void {
     }
 }
 
+/// This represents the global process state. There should only
+/// be one of these at any given moment. This is extracted into a dedicated
+/// struct because it is reused by main and the static C lib.
+pub const GlobalState = struct {
+    const GPA = std.heap.GeneralPurposeAllocator(.{});
+
+    gpa: ?GPA,
+    alloc: std.mem.Allocator,
+
+    pub fn init(self: *GlobalState) void {
+        // Output some debug information right away
+        std.log.info("dependency harfbuzz={s}", .{harfbuzz.versionString()});
+        if (options.fontconfig) {
+            std.log.info("dependency fontconfig={d}", .{fontconfig.version()});
+        }
+        std.log.info("renderer={}", .{renderer.Renderer});
+        std.log.info("libxev backend={}", .{xev.backend});
+
+        // First things first, we fix our file descriptors
+        internal_os.fixMaxFiles();
+
+        // We need to make sure the process locale is set properly. Locale
+        // affects a lot of behaviors in a shell.
+        internal_os.ensureLocale();
+
+        // Initialize ourself to nothing so we don't have any extra state.
+        self.* = .{
+            .gpa = null,
+            .alloc = undefined,
+        };
+        errdefer self.deinit();
+
+        self.gpa = gpa: {
+            // Use the libc allocator if it is available beacuse it is WAY
+            // faster than GPA. We only do this in release modes so that we
+            // can get easy memory leak detection in debug modes.
+            if (builtin.link_libc) {
+                if (switch (builtin.mode) {
+                    .ReleaseSafe, .ReleaseFast => true,
+
+                    // We also use it if we can detect we're running under
+                    // Valgrind since Valgrind only instruments the C allocator
+                    else => std.valgrind.runningOnValgrind() > 0,
+                }) break :gpa null;
+            }
+
+            break :gpa GPA{};
+        };
+
+        self.alloc = alloc: {
+            const base = if (self.gpa) |*value|
+                value.allocator()
+            else if (builtin.link_libc)
+                std.heap.c_allocator
+            else
+                unreachable;
+
+            // If we're tracing, wrap the allocator
+            if (!tracy.enabled) break :alloc base;
+            var tracy_alloc = tracy.allocator(base, null);
+            break :alloc tracy_alloc.allocator();
+        };
+    }
+
+    /// Cleans up the global state. This doesn't _need_ to be called but
+    /// doing so in dev modes will check for memory leaks.
+    pub fn deinit(self: *GlobalState) void {
+        if (self.gpa) |*value| {
+            // We want to ensure that we deinit the GPA because this is
+            // the point at which it will output if there were safety violations.
+            _ = value.deinit();
+        }
+    }
+};
 test {
     _ = @import("Pty.zig");
     _ = @import("Command.zig");