Changeset e0f93e0 for libcfa/src
- Timestamp:
- Jul 30, 2020, 2:57:36 PM (4 years ago)
- Branches:
- ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum
- Children:
- f00b26d4
- Parents:
- 22ddade
- File:
-
- 1 edited
Legend:
- Unmodified
- Added
- Removed
-
libcfa/src/bits/locks.hfa
r22ddade re0f93e0 164 164 165 165 #undef CHECKED 166 167 struct $thread; 168 extern void park( __cfaabi_dbg_ctx_param ); 169 extern void unpark( struct $thread * this __cfaabi_dbg_ctx_param2 ); 170 static inline struct $thread * active_thread (); 171 172 // Semaphore which only supports a single thread 173 struct single_sem { 174 struct $thread * volatile ptr; 175 }; 176 177 static inline { 178 void ?{}(single_sem & this) { 179 this.ptr = 0p; 180 } 181 182 void ^?{}(single_sem & this) {} 183 184 bool wait(single_sem & this) { 185 for() { 186 struct $thread * expected = this.ptr; 187 if(expected == 1p) { 188 if(__atomic_compare_exchange_n(&this.ptr, &expected, 0p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) { 189 return false; 190 } 191 } 192 else { 193 /* paranoid */ verify( expected == 0p ); 194 if(__atomic_compare_exchange_n(&this.ptr, &expected, active_thread(), false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) { 195 park( __cfaabi_dbg_ctx ); 196 return true; 197 } 198 } 199 200 } 201 } 202 203 bool post(single_sem & this) { 204 for() { 205 struct $thread * expected = this.ptr; 206 if(expected == 1p) return false; 207 if(expected == 0p) { 208 if(__atomic_compare_exchange_n(&this.ptr, &expected, 1p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) { 209 return false; 210 } 211 } 212 else { 213 if(__atomic_compare_exchange_n(&this.ptr, &expected, 0p, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) { 214 unpark( expected __cfaabi_dbg_ctx2 ); 215 return true; 216 } 217 } 218 } 219 } 220 } 166 221 #endif
Note: See TracChangeset
for help on using the changeset viewer.