1 //! Atomic intrinsics are implemented using a global lock for now, as Cranelift doesn't support
2 //! atomic operations yet.
4 // FIXME implement atomic instructions in Cranelift.
8 #[cfg(all(feature = "jit", unix))]
10 static mut __cg_clif_global_atomic_mutex: libc::pthread_mutex_t = libc::PTHREAD_MUTEX_INITIALIZER;
12 pub(crate) fn init_global_lock(
13 module: &mut impl Module,
14 bcx: &mut FunctionBuilder<'_>,
18 // When using JIT, dylibs won't find the __cg_clif_global_atomic_mutex data object defined here,
19 // so instead we define it in the cg_clif dylib.
24 let mut data_ctx = DataContext::new();
25 data_ctx.define_zeroinit(1024); // 1024 bytes should be big enough on all platforms.
26 data_ctx.set_align(16);
27 let atomic_mutex = module
29 "__cg_clif_global_atomic_mutex",
35 module.define_data(atomic_mutex, &data_ctx).unwrap();
37 let pthread_mutex_init = module
41 &cranelift_codegen::ir::Signature {
42 call_conv: module.target_config().default_call_conv,
45 module.target_config().pointer_type(), /* *mut pthread_mutex_t */
48 module.target_config().pointer_type(), /* *const pthread_mutex_attr_t */
51 returns: vec![AbiParam::new(types::I32 /* c_int */)],
56 let pthread_mutex_init = module.declare_func_in_func(pthread_mutex_init, bcx.func);
58 let atomic_mutex = module.declare_data_in_func(atomic_mutex, bcx.func);
59 let atomic_mutex = bcx
61 .global_value(module.target_config().pointer_type(), atomic_mutex);
63 let nullptr = bcx.ins().iconst(module.target_config().pointer_type(), 0);
65 bcx.ins().call(pthread_mutex_init, &[atomic_mutex, nullptr]);
68 pub(crate) fn init_global_lock_constructor(
69 module: &mut impl Module,
70 constructor_name: &str,
72 let sig = Signature::new(CallConv::SystemV);
73 let init_func_id = module
74 .declare_function(constructor_name, Linkage::Export, &sig)
77 let mut ctx = Context::new();
78 ctx.func = Function::with_name_signature(ExternalName::user(0, 0), sig);
80 let mut func_ctx = FunctionBuilderContext::new();
81 let mut bcx = FunctionBuilder::new(&mut ctx.func, &mut func_ctx);
83 let block = bcx.create_block();
84 bcx.switch_to_block(block);
86 crate::atomic_shim::init_global_lock(module, &mut bcx, false);
88 bcx.ins().return_(&[]);
89 bcx.seal_all_blocks();
96 &mut cranelift_codegen::binemit::NullTrapSink {},
103 pub(crate) fn lock_global_lock(fx: &mut FunctionCx<'_, '_, impl Module>) {
104 let atomic_mutex = fx
108 "__cg_clif_global_atomic_mutex",
115 let pthread_mutex_lock = fx
119 "pthread_mutex_lock",
121 &cranelift_codegen::ir::Signature {
122 call_conv: fx.cx.module.target_config().default_call_conv,
123 params: vec![AbiParam::new(
124 fx.cx.module.target_config().pointer_type(), /* *mut pthread_mutex_t */
126 returns: vec![AbiParam::new(types::I32 /* c_int */)],
131 let pthread_mutex_lock = fx
134 .declare_func_in_func(pthread_mutex_lock, fx.bcx.func);
136 let atomic_mutex = fx.cx.module.declare_data_in_func(atomic_mutex, fx.bcx.func);
137 let atomic_mutex = fx
140 .global_value(fx.cx.module.target_config().pointer_type(), atomic_mutex);
142 fx.bcx.ins().call(pthread_mutex_lock, &[atomic_mutex]);
145 pub(crate) fn unlock_global_lock(fx: &mut FunctionCx<'_, '_, impl Module>) {
146 let atomic_mutex = fx
150 "__cg_clif_global_atomic_mutex",
157 let pthread_mutex_unlock = fx
161 "pthread_mutex_unlock",
163 &cranelift_codegen::ir::Signature {
164 call_conv: fx.cx.module.target_config().default_call_conv,
165 params: vec![AbiParam::new(
166 fx.cx.module.target_config().pointer_type(), /* *mut pthread_mutex_t */
168 returns: vec![AbiParam::new(types::I32 /* c_int */)],
173 let pthread_mutex_unlock = fx
176 .declare_func_in_func(pthread_mutex_unlock, fx.bcx.func);
178 let atomic_mutex = fx.cx.module.declare_data_in_func(atomic_mutex, fx.bcx.func);
179 let atomic_mutex = fx
182 .global_value(fx.cx.module.target_config().pointer_type(), atomic_mutex);
184 fx.bcx.ins().call(pthread_mutex_unlock, &[atomic_mutex]);