1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #pragma once 30 31 /** 32 * @file sched.h 33 * @brief Thread execution scheduling. 34 */ 35 36 #include <bits/timespec.h> 37 #include <linux/sched.h> 38 #include <sys/cdefs.h> 39 40 __BEGIN_DECLS 41 42 /* 43 * @def SCHED_NORMAL 44 * The standard (as opposed to real-time) round-robin scheduling policy. 45 * 46 * (Linux's name for POSIX's SCHED_OTHER.) 47 * 48 * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) 49 */ 50 51 /* 52 * @def SCHED_FIFO 53 * The real-time first-in/first-out scheduling policy. 54 * 55 * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) 56 */ 57 58 /* 59 * @def SCHED_RR 60 * The real-time round-robin policy. (See also SCHED_NORMAL/SCHED_OTHER.) 61 * 62 * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) 63 */ 64 65 /* 66 * @def SCHED_BATCH 67 * The batch scheduling policy. 68 * 69 * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) 70 */ 71 72 /* 73 * @def SCHED_IDLE 74 * The low priority "only when otherwise idle" scheduling priority. 75 * 76 * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) 77 */ 78 79 /* 80 * @def SCHED_DEADLINE 81 * The deadline scheduling policy. 82 * 83 * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) 84 */ 85 86 /* 87 * The standard (as opposed to real-time) round-robin scheduling policy. 88 * 89 * (POSIX's name for Linux's SCHED_NORMAL.) 90 */ 91 #define SCHED_OTHER SCHED_NORMAL 92 93 /** 94 * See sched_getparam()/sched_setparam() and 95 * sched_getscheduler()/sched_setscheduler(). 96 */ 97 struct sched_param { 98 int sched_priority; 99 }; 100 101 /** 102 * [sched_setscheduler(2)](https://man7.org/linux/man-pages/man2/sched_setscheduler.2.html) 103 * sets the scheduling policy and associated parameters for the given thread. 104 * 105 * Returns 0 on success and returns -1 and sets `errno` on failure. 106 */ 107 int sched_setscheduler(pid_t __pid, int __policy, const struct sched_param* _Nonnull __param); 108 109 /** 110 * [sched_getscheduler(2)](https://man7.org/linux/man-pages/man2/sched_getscheduler.2) 111 * gets the scheduling policy for the given thread. 112 * 113 * Returns a non-negative thread policy on success and returns -1 and sets 114 * `errno` on failure. 115 */ 116 int sched_getscheduler(pid_t __pid); 117 118 /** 119 * [sched_yield(2)](http://man7.org/linux/man-pages/man2/sched_yield.2.html) 120 * voluntarily gives up using the CPU so that another thread can run. 121 * 122 * Returns 0 on success and returns -1 and sets `errno` on failure. 123 */ 124 int sched_yield(void); 125 126 /** 127 * [sched_get_priority_max(2)](http://man7.org/linux/man-pages/man2/sched_get_priority_max.2.html) 128 * gets the maximum priority value allowed for the given scheduling policy. 129 * 130 * Returns a priority on success and returns -1 and sets `errno` on failure. 131 */ 132 int sched_get_priority_max(int __policy); 133 134 /** 135 * [sched_get_priority_min(2)](http://man7.org/linux/man-pages/man2/sched_get_priority_min.2.html) 136 * gets the minimum priority value allowed for the given scheduling policy. 137 * 138 * Returns a priority on success and returns -1 and sets `errno` on failure. 139 */ 140 int sched_get_priority_min(int __policy); 141 142 /** 143 * [sched_setparam(2)](http://man7.org/linux/man-pages/man2/sched_setparam.2.html) 144 * sets the scheduling parameters for the given thread. 145 * 146 * Returns 0 on success and returns -1 and sets `errno` on failure. 147 */ 148 int sched_setparam(pid_t __pid, const struct sched_param* _Nonnull __param); 149 150 /** 151 * [sched_getparam(2)](http://man7.org/linux/man-pages/man2/sched_getparam.2.html) 152 * gets the scheduling parameters for the given thread. 153 * 154 * Returns 0 on success and returns -1 and sets `errno` on failure. 155 */ 156 int sched_getparam(pid_t __pid, struct sched_param* _Nonnull __param); 157 158 /** 159 * [sched_rr_get_interval(2)](http://man7.org/linux/man-pages/man2/sched_rr_get_interval.2.html) 160 * queries the round-robin time quantum for the given thread. 161 * 162 * Returns 0 on success and returns -1 and sets `errno` on failure. 163 */ 164 int sched_rr_get_interval(pid_t __pid, struct timespec* _Nonnull __quantum); 165 166 #if defined(__USE_GNU) 167 168 /** 169 * [clone(2)](http://man7.org/linux/man-pages/man2/clone.2.html) 170 * creates a new child process. 171 * 172 * Returns the pid of the child to the caller on success and 173 * returns -1 and sets `errno` on failure. 174 */ 175 int clone(int (* __BIONIC_COMPLICATED_NULLNESS __fn)(void* __BIONIC_COMPLICATED_NULLNESS ), void* __BIONIC_COMPLICATED_NULLNESS __child_stack, int __flags, void* _Nullable __arg, ...); 176 177 /** 178 * [unshare(2)](http://man7.org/linux/man-pages/man2/unshare.2.html) 179 * disassociates part of the caller's execution context. 180 * 181 * Returns 0 on success and returns -1 and sets `errno` on failure. 182 */ 183 int unshare(int __flags); 184 185 /** 186 * [setns(2)](http://man7.org/linux/man-pages/man2/setns.2.html) 187 * reassociates a thread with a different namespace. 188 * 189 * Returns 0 on success and returns -1 and sets `errno` on failure. 190 */ 191 int setns(int __fd, int __ns_type); 192 193 /** 194 * [sched_getcpu(3)](http://man7.org/linux/man-pages/man3/sched_getcpu.3.html) 195 * reports which CPU the caller is running on. 196 * 197 * Returns a non-negative CPU number on success and returns -1 and sets 198 * `errno` on failure. 199 */ 200 int sched_getcpu(void); 201 202 #ifdef __LP64__ 203 #define CPU_SETSIZE 1024 204 #else 205 #define CPU_SETSIZE 32 206 #endif 207 208 #define __CPU_BITTYPE unsigned long int /* mandated by the kernel */ 209 #define __CPU_BITS (8 * sizeof(__CPU_BITTYPE)) 210 #define __CPU_ELT(x) ((x) / __CPU_BITS) 211 #define __CPU_MASK(x) ((__CPU_BITTYPE)1 << ((x) & (__CPU_BITS - 1))) 212 213 /** 214 * [cpu_set_t](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) is a 215 * statically-sized CPU set. See `CPU_ALLOC` for dynamically-sized CPU sets. 216 */ 217 typedef struct { 218 __CPU_BITTYPE __bits[ CPU_SETSIZE / __CPU_BITS ]; 219 } cpu_set_t; 220 221 /** 222 * [sched_setaffinity(2)](http://man7.org/linux/man-pages/man2/sched_setaffinity.2.html) 223 * sets the CPU affinity mask for the given thread. 224 * 225 * Returns 0 on success and returns -1 and sets `errno` on failure. 226 */ 227 int sched_setaffinity(pid_t __pid, size_t __set_size, const cpu_set_t* _Nonnull __set); 228 229 /** 230 * [sched_getaffinity(2)](http://man7.org/linux/man-pages/man2/sched_getaffinity.2.html) 231 * gets the CPU affinity mask for the given thread. 232 * 233 * Returns 0 on success and returns -1 and sets `errno` on failure. 234 */ 235 int sched_getaffinity(pid_t __pid, size_t __set_size, cpu_set_t* _Nonnull __set); 236 237 /** 238 * [CPU_ZERO](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) clears all 239 * bits in a static CPU set. 240 */ 241 #define CPU_ZERO(set) CPU_ZERO_S(sizeof(cpu_set_t), set) 242 /** 243 * [CPU_ZERO_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) clears all 244 * bits in a dynamic CPU set allocated by `CPU_ALLOC`. 245 */ 246 #define CPU_ZERO_S(setsize, set) __builtin_memset(set, 0, setsize) 247 248 /** 249 * [CPU_SET](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) sets one 250 * bit in a static CPU set. 251 */ 252 #define CPU_SET(cpu, set) CPU_SET_S(cpu, sizeof(cpu_set_t), set) 253 /** 254 * [CPU_SET_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) sets one 255 * bit in a dynamic CPU set allocated by `CPU_ALLOC`. 256 */ 257 #define CPU_SET_S(cpu, setsize, set) \ 258 do { \ 259 size_t __cpu = (cpu); \ 260 if (__cpu < 8 * (setsize)) \ 261 (set)->__bits[__CPU_ELT(__cpu)] |= __CPU_MASK(__cpu); \ 262 } while (0) 263 264 /** 265 * [CPU_CLR](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) clears one 266 * bit in a static CPU set. 267 */ 268 #define CPU_CLR(cpu, set) CPU_CLR_S(cpu, sizeof(cpu_set_t), set) 269 /** 270 * [CPU_CLR_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) clears one 271 * bit in a dynamic CPU set allocated by `CPU_ALLOC`. 272 */ 273 #define CPU_CLR_S(cpu, setsize, set) \ 274 do { \ 275 size_t __cpu = (cpu); \ 276 if (__cpu < 8 * (setsize)) \ 277 (set)->__bits[__CPU_ELT(__cpu)] &= ~__CPU_MASK(__cpu); \ 278 } while (0) 279 280 /** 281 * [CPU_ISSET](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) tests 282 * whether the given bit is set in a static CPU set. 283 */ 284 #define CPU_ISSET(cpu, set) CPU_ISSET_S(cpu, sizeof(cpu_set_t), set) 285 /** 286 * [CPU_ISSET_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) tests 287 * whether the given bit is set in a dynamic CPU set allocated by `CPU_ALLOC`. 288 */ 289 #define CPU_ISSET_S(cpu, setsize, set) \ 290 (__extension__ ({ \ 291 size_t __cpu = (cpu); \ 292 (__cpu < 8 * (setsize)) \ 293 ? ((set)->__bits[__CPU_ELT(__cpu)] & __CPU_MASK(__cpu)) != 0 \ 294 : 0; \ 295 })) 296 297 /** 298 * [CPU_COUNT](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) counts 299 * how many bits are set in a static CPU set. 300 */ 301 #define CPU_COUNT(set) CPU_COUNT_S(sizeof(cpu_set_t), set) 302 /** 303 * [CPU_COUNT_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) counts 304 * how many bits are set in a dynamic CPU set allocated by `CPU_ALLOC`. 305 */ 306 #define CPU_COUNT_S(setsize, set) __sched_cpucount((setsize), (set)) 307 int __sched_cpucount(size_t __set_size, const cpu_set_t* _Nonnull __set); 308 309 /** 310 * [CPU_EQUAL](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) tests 311 * whether two static CPU sets have the same bits set and cleared as each other. 312 */ 313 #define CPU_EQUAL(set1, set2) CPU_EQUAL_S(sizeof(cpu_set_t), set1, set2) 314 /** 315 * [CPU_EQUAL_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) tests 316 * whether two dynamic CPU sets allocated by `CPU_ALLOC` have the same bits 317 * set and cleared as each other. 318 */ 319 #define CPU_EQUAL_S(setsize, set1, set2) (__builtin_memcmp(set1, set2, setsize) == 0) 320 321 /** 322 * [CPU_AND](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) ands two 323 * static CPU sets. 324 */ 325 #define CPU_AND(dst, set1, set2) __CPU_OP(dst, set1, set2, &) 326 /** 327 * [CPU_AND_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) ands two 328 * dynamic CPU sets allocated by `CPU_ALLOC`. 329 */ 330 #define CPU_AND_S(setsize, dst, set1, set2) __CPU_OP_S(setsize, dst, set1, set2, &) 331 332 /** 333 * [CPU_OR](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) ors two 334 * static CPU sets. 335 */ 336 #define CPU_OR(dst, set1, set2) __CPU_OP(dst, set1, set2, |) 337 /** 338 * [CPU_OR_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) ors two 339 * dynamic CPU sets allocated by `CPU_ALLOC`. 340 */ 341 #define CPU_OR_S(setsize, dst, set1, set2) __CPU_OP_S(setsize, dst, set1, set2, |) 342 343 /** 344 * [CPU_XOR](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) 345 * exclusive-ors two static CPU sets. 346 */ 347 #define CPU_XOR(dst, set1, set2) __CPU_OP(dst, set1, set2, ^) 348 /** 349 * [CPU_XOR_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) 350 * exclusive-ors two dynamic CPU sets allocated by `CPU_ALLOC`. 351 */ 352 #define CPU_XOR_S(setsize, dst, set1, set2) __CPU_OP_S(setsize, dst, set1, set2, ^) 353 354 #define __CPU_OP(dst, set1, set2, op) __CPU_OP_S(sizeof(cpu_set_t), dst, set1, set2, op) 355 356 #define __CPU_OP_S(setsize, dstset, srcset1, srcset2, op) \ 357 do { \ 358 cpu_set_t* __dst = (dstset); \ 359 const __CPU_BITTYPE* __src1 = (srcset1)->__bits; \ 360 const __CPU_BITTYPE* __src2 = (srcset2)->__bits; \ 361 size_t __nn = 0, __nn_max = (setsize)/sizeof(__CPU_BITTYPE); \ 362 for (; __nn < __nn_max; __nn++) \ 363 (__dst)->__bits[__nn] = __src1[__nn] op __src2[__nn]; \ 364 } while (0) 365 366 /** 367 * [CPU_ALLOC_SIZE](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) 368 * returns the size of a CPU set large enough for CPUs in the range 0..count-1. 369 */ 370 #define CPU_ALLOC_SIZE(count) \ 371 __CPU_ELT((count) + (__CPU_BITS - 1)) * sizeof(__CPU_BITTYPE) 372 373 /** 374 * [CPU_ALLOC](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) 375 * allocates a CPU set large enough for CPUs in the range 0..count-1. 376 */ 377 #define CPU_ALLOC(count) __sched_cpualloc((count)) 378 cpu_set_t* _Nullable __sched_cpualloc(size_t __count); 379 380 /** 381 * [CPU_FREE](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) 382 * deallocates a CPU set allocated by `CPU_ALLOC`. 383 */ 384 #define CPU_FREE(set) __sched_cpufree((set)) 385 void __sched_cpufree(cpu_set_t* _Nonnull __set); 386 387 #endif /* __USE_GNU */ 388 389 __END_DECLS 390