xref: /aosp_15_r20/external/grpc-grpc/include/grpc/support/atm_windows.h (revision cc02d7e222339f7a4f6ba5f422e6413f4bd931f2)
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_SUPPORT_ATM_WINDOWS_H
20 #define GRPC_SUPPORT_ATM_WINDOWS_H
21 
22 /** Win32 variant of atm_platform.h */
23 #include <grpc/support/port_platform.h>
24 
25 #ifdef GPR_WINDOWS
26 
27 typedef intptr_t gpr_atm;
28 #define GPR_ATM_MAX INTPTR_MAX
29 #define GPR_ATM_MIN INTPTR_MIN
30 
31 #define gpr_atm_full_barrier MemoryBarrier
32 
gpr_atm_acq_load(const gpr_atm * p)33 static __inline gpr_atm gpr_atm_acq_load(const gpr_atm* p) {
34   gpr_atm result = *p;
35   gpr_atm_full_barrier();
36   return result;
37 }
38 
gpr_atm_no_barrier_load(const gpr_atm * p)39 static __inline gpr_atm gpr_atm_no_barrier_load(const gpr_atm* p) {
40   /* TODO(dklempner): Can we implement something better here? */
41   return gpr_atm_acq_load(p);
42 }
43 
gpr_atm_rel_store(gpr_atm * p,gpr_atm value)44 static __inline void gpr_atm_rel_store(gpr_atm* p, gpr_atm value) {
45   gpr_atm_full_barrier();
46   *p = value;
47 }
48 
gpr_atm_no_barrier_store(gpr_atm * p,gpr_atm value)49 static __inline void gpr_atm_no_barrier_store(gpr_atm* p, gpr_atm value) {
50   /* TODO(ctiller): Can we implement something better here? */
51   gpr_atm_rel_store(p, value);
52 }
53 
gpr_atm_no_barrier_cas(gpr_atm * p,gpr_atm o,gpr_atm n)54 static __inline int gpr_atm_no_barrier_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
55 /** InterlockedCompareExchangePointerNoFence() not available on vista or
56    windows7 */
57 #ifdef GPR_ARCH_64
58   return o == (gpr_atm)InterlockedCompareExchangeAcquire64(
59                   (volatile LONGLONG*)p, (LONGLONG)n, (LONGLONG)o);
60 #else
61   return o == (gpr_atm)InterlockedCompareExchangeAcquire((volatile LONG*)p,
62                                                          (LONG)n, (LONG)o);
63 #endif
64 }
65 
gpr_atm_acq_cas(gpr_atm * p,gpr_atm o,gpr_atm n)66 static __inline int gpr_atm_acq_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
67 #ifdef GPR_ARCH_64
68   return o == (gpr_atm)InterlockedCompareExchangeAcquire64(
69                   (volatile LONGLONG*)p, (LONGLONG)n, (LONGLONG)o);
70 #else
71   return o == (gpr_atm)InterlockedCompareExchangeAcquire((volatile LONG*)p,
72                                                          (LONG)n, (LONG)o);
73 #endif
74 }
75 
gpr_atm_rel_cas(gpr_atm * p,gpr_atm o,gpr_atm n)76 static __inline int gpr_atm_rel_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
77 #ifdef GPR_ARCH_64
78   return o == (gpr_atm)InterlockedCompareExchangeRelease64(
79                   (volatile LONGLONG*)p, (LONGLONG)n, (LONGLONG)o);
80 #else
81   return o == (gpr_atm)InterlockedCompareExchangeRelease((volatile LONG*)p,
82                                                          (LONG)n, (LONG)o);
83 #endif
84 }
85 
gpr_atm_full_cas(gpr_atm * p,gpr_atm o,gpr_atm n)86 static __inline int gpr_atm_full_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
87 #ifdef GPR_ARCH_64
88   return o == (gpr_atm)InterlockedCompareExchange64((volatile LONGLONG*)p,
89                                                     (LONGLONG)n, (LONGLONG)o);
90 #else
91   return o == (gpr_atm)InterlockedCompareExchange((volatile LONG*)p, (LONG)n,
92                                                   (LONG)o);
93 #endif
94 }
95 
gpr_atm_no_barrier_fetch_add(gpr_atm * p,gpr_atm delta)96 static __inline gpr_atm gpr_atm_no_barrier_fetch_add(gpr_atm* p,
97                                                      gpr_atm delta) {
98   /** Use the CAS operation to get pointer-sized fetch and add */
99   gpr_atm old;
100   do {
101     old = *p;
102   } while (!gpr_atm_no_barrier_cas(p, old, old + delta));
103   return old;
104 }
105 
gpr_atm_full_fetch_add(gpr_atm * p,gpr_atm delta)106 static __inline gpr_atm gpr_atm_full_fetch_add(gpr_atm* p, gpr_atm delta) {
107   /** Use a CAS operation to get pointer-sized fetch and add */
108   gpr_atm old;
109 #ifdef GPR_ARCH_64
110   do {
111     old = *p;
112   } while (old != (gpr_atm)InterlockedCompareExchange64((volatile LONGLONG*)p,
113                                                         (LONGLONG)old + delta,
114                                                         (LONGLONG)old));
115 #else
116   do {
117     old = *p;
118   } while (old != (gpr_atm)InterlockedCompareExchange(
119                       (volatile LONG*)p, (LONG)old + delta, (LONG)old));
120 #endif
121   return old;
122 }
123 
gpr_atm_full_xchg(gpr_atm * p,gpr_atm n)124 static __inline gpr_atm gpr_atm_full_xchg(gpr_atm* p, gpr_atm n) {
125   return (gpr_atm)InterlockedExchangePointer((PVOID*)p, (PVOID)n);
126 }
127 
128 #endif /* GPR_WINDOWS */
129 
130 #endif /* GRPC_SUPPORT_ATM_WINDOWS_H */
131