1 /*
2 *
3 * Copyright 2015 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #ifndef GRPC_IMPL_CODEGEN_ATM_GCC_SYNC_H
20 #define GRPC_IMPL_CODEGEN_ATM_GCC_SYNC_H
21
22 /* variant of atm_platform.h for gcc and gcc-like compiers with __sync_*
23 interface */
24 #include <grpc/impl/codegen/port_platform.h>
25
26 typedef intptr_t gpr_atm;
27 #define GPR_ATM_MAX INTPTR_MAX
28 #define GPR_ATM_MIN INTPTR_MIN
29
30 #define GPR_ATM_COMPILE_BARRIER_() __asm__ __volatile__("" : : : "memory")
31
32 #if defined(__i386) || defined(__x86_64__)
33 /* All loads are acquire loads and all stores are release stores. */
34 #define GPR_ATM_LS_BARRIER_() GPR_ATM_COMPILE_BARRIER_()
35 #else
36 #define GPR_ATM_LS_BARRIER_() gpr_atm_full_barrier()
37 #endif
38
39 #define gpr_atm_full_barrier() (__sync_synchronize())
40
gpr_atm_acq_load(const gpr_atm * p)41 static __inline gpr_atm gpr_atm_acq_load(const gpr_atm* p) {
42 gpr_atm value = *p;
43 GPR_ATM_LS_BARRIER_();
44 return value;
45 }
46
gpr_atm_no_barrier_load(const gpr_atm * p)47 static __inline gpr_atm gpr_atm_no_barrier_load(const gpr_atm* p) {
48 gpr_atm value = *p;
49 GPR_ATM_COMPILE_BARRIER_();
50 return value;
51 }
52
gpr_atm_rel_store(gpr_atm * p,gpr_atm value)53 static __inline void gpr_atm_rel_store(gpr_atm* p, gpr_atm value) {
54 GPR_ATM_LS_BARRIER_();
55 *p = value;
56 }
57
gpr_atm_no_barrier_store(gpr_atm * p,gpr_atm value)58 static __inline void gpr_atm_no_barrier_store(gpr_atm* p, gpr_atm value) {
59 GPR_ATM_COMPILE_BARRIER_();
60 *p = value;
61 }
62
63 #undef GPR_ATM_LS_BARRIER_
64 #undef GPR_ATM_COMPILE_BARRIER_
65
66 #define gpr_atm_no_barrier_fetch_add(p, delta) \
67 gpr_atm_full_fetch_add((p), (delta))
68 #define gpr_atm_full_fetch_add(p, delta) (__sync_fetch_and_add((p), (delta)))
69
70 #define gpr_atm_no_barrier_cas(p, o, n) gpr_atm_acq_cas((p), (o), (n))
71 #define gpr_atm_acq_cas(p, o, n) (__sync_bool_compare_and_swap((p), (o), (n)))
72 #define gpr_atm_rel_cas(p, o, n) gpr_atm_acq_cas((p), (o), (n))
73 #define gpr_atm_full_cas(p, o, n) gpr_atm_acq_cas((p), (o), (n))
74
gpr_atm_full_xchg(gpr_atm * p,gpr_atm n)75 static __inline gpr_atm gpr_atm_full_xchg(gpr_atm* p, gpr_atm n) {
76 gpr_atm cur;
77 do {
78 cur = gpr_atm_acq_load(p);
79 } while (!gpr_atm_rel_cas(p, cur, n));
80 return cur;
81 }
82
83 #endif /* GRPC_IMPL_CODEGEN_ATM_GCC_SYNC_H */
84