tango_init() is now exported by client crate only

It allows to get rid of dummy entrypoints in nontango executables
bazhenov · Dec 19, 2023 · 72bc08f · 72bc08f
1 parent d6d854a
commit 72bc08f
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Showing 3 changed files with 24 additions and 33 deletions.
diff --git a/examples/benches/criterion.rs b/examples/benches/criterion.rs
@@ -6,12 +6,6 @@ use test_funcs::{factorial, str_take, sum, RandomSubstring};
 
 mod test_funcs;
 
-/// Because benchmarks are builded with linker flag -rdynamic there should be dummy library entrypoint defined
-/// in all benchmarks. This is only needed when two benchmarks harnesses are used in a single crate.
-mod dummy_entrypoint {
-    tango_bench::tango_benchmarks!([]);
-}
-
 fn sum_benchmark(c: &mut Criterion) {
     let mut group = c.benchmark_group("arithmetic");
 

diff --git a/tango-bench/src/dylib.rs b/tango-bench/src/dylib.rs
@@ -86,9 +86,9 @@ impl<'l> Spi<'l> {
 
 /// State which holds the information about list of benchmarks and which one is selected.
 /// Used in FFI API (`tango_*` functions).
-struct State {
-    benchmarks: Vec<Box<dyn MeasureTarget>>,
-    selected_function: usize,
+pub struct State {
+    pub benchmarks: Vec<Box<dyn MeasureTarget>>,
+    pub selected_function: usize,
 }
 
 impl State {
@@ -107,12 +107,12 @@ impl State {
 /// Tango execution model implies simultaneous exectution of the code from two binaries. To achive that
 /// Tango benchmark is compiled in a way that executable is also a shared library (.dll, .so, .dylib). This
 /// way two executables can coexist in the single process at the same time.
-mod ffi {
+pub mod ffi {
     use super::*;
     use std::{os::raw::c_char, ptr::null, usize};
 
     /// Signature types of all FFI API functions
-    type InitFn = unsafe extern "C" fn();
+    pub type InitFn = unsafe extern "C" fn();
     type CountFn = unsafe extern "C" fn() -> usize;
     type GetTestNameFn = unsafe extern "C" fn(*mut *const c_char, *mut usize);
     type SelectFn = unsafe extern "C" fn(usize);
@@ -128,7 +128,6 @@ mod ffi {
     mod type_check {
         use super::*;
 
-        const TANGO_INIT: InitFn = tango_init;
         const TANGO_COUNT: CountFn = tango_count;
         const TANGO_SELECT: SelectFn = tango_select;
         const TANGO_GET_TEST_NAME: GetTestNameFn = tango_get_test_name;
@@ -138,23 +137,8 @@ mod ffi {
         const TANGO_FREE: FreeFn = tango_free;
     }
 
-    extern "Rust" {
-        /// Each benchmark executable should define this function for the harness to load all benchmarks
-        fn __tango_create_benchmarks() -> Vec<Box<dyn MeasureTarget>>;
-    }
-
     /// Global state of the benchmarking library
-    static mut STATE: Option<State> = None;
-
-    #[no_mangle]
-    unsafe extern "C" fn tango_init() {
-        if STATE.is_none() {
-            STATE = Some(State {
-                benchmarks: __tango_create_benchmarks(),
-                selected_function: 0,
-            });
-        }
-    }
+    pub static mut STATE: Option<State> = None;
 
     #[no_mangle]
     unsafe extern "C" fn tango_count() -> usize {
@@ -241,7 +225,7 @@ mod ffi {
 
     impl VTable for SelfVTable {
         fn init(&self) {
-            unsafe { tango_init() }
+            // In executable mode `tango_init` is already called by the main function
         }
 
         fn count(&self) -> usize {

diff --git a/tango-bench/src/lib.rs b/tango-bench/src/lib.rs
@@ -61,11 +61,22 @@ pub enum Error {
 #[macro_export]
 macro_rules! tango_benchmarks {
     ($($func_expr:expr),+) => {
+
+        /// Type checking tango_init() function
+        const TANGO_INIT: $crate::dylib::ffi::InitFn = tango_init;
+
+        /// Exported function for initializing the benchmark harness
         #[no_mangle]
-        pub fn __tango_create_benchmarks() -> Vec<Box<dyn $crate::MeasureTarget>> {
-            let mut benchmarks = vec![];
-            $(benchmarks.extend($crate::IntoBenchmarks::into_benchmarks($func_expr));)*
-            benchmarks
+        unsafe extern "C" fn tango_init() {
+            use $crate::dylib::{ffi::STATE, State};
+            if STATE.is_none() {
+                let mut benchmarks = vec![];
+                $(benchmarks.extend($crate::IntoBenchmarks::into_benchmarks($func_expr));)*
+                STATE = Some(State {
+                    benchmarks,
+                    selected_function: 0,
+                });
+            }
         }
     };
 }
@@ -88,6 +99,8 @@ macro_rules! tango_benchmarks {
 macro_rules! tango_main {
     ($settings:expr) => {
         fn main() -> $crate::cli::Result<std::process::ExitCode> {
+            // Initialize Tango for SelfVTable usage
+            unsafe { tango_init() };
             $crate::cli::run($settings)
         }
     };