diff options
Diffstat (limited to 'libc/include/sched.h')
-rw-r--r-- | libc/include/sched.h | 304 |
1 files changed, 273 insertions, 31 deletions
diff --git a/libc/include/sched.h b/libc/include/sched.h index 3260231cf..364ca1065 100644 --- a/libc/include/sched.h +++ b/libc/include/sched.h @@ -26,8 +26,12 @@ * SUCH DAMAGE. */ -#ifndef _SCHED_H_ -#define _SCHED_H_ +#pragma once + +/** + * @file sched.h + * @brief Thread execution scheduling. + */ #include <bits/timespec.h> #include <linux/sched.h> @@ -35,29 +39,170 @@ __BEGIN_DECLS -/* This name is used by glibc, but not by the kernel. */ +/* + * @def SCHED_NORMAL + * The standard (as opposed to real-time) round-robin scheduling policy. + * + * (Linux's name for POSIX's SCHED_OTHER.) + * + * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) + */ + +/* + * @def SCHED_FIFO + * The real-time first-in/first-out scheduling policy. + * + * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) + */ + +/* + * @def SCHED_RR + * The real-time round-robin policy. (See also SCHED_NORMAL/SCHED_OTHER.) + * + * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) + */ + +/* + * @def SCHED_BATCH + * The batch scheduling policy. + * + * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) + */ + +/* + * @def SCHED_IDLE + * The low priority "only when otherwise idle" scheduling priority. + * + * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) + */ + +/* + * @def SCHED_DEADLINE + * The deadline scheduling policy. + * + * See [sched(7)](http://man7.org/linux/man-pages/man7/sched.7.html) + */ + +/* + * The standard (as opposed to real-time) round-robin scheduling policy. + * + * (POSIX's name for Linux's SCHED_NORMAL.) + */ #define SCHED_OTHER SCHED_NORMAL +/** + * See sched_getparam()/sched_setparam() and + * sched_getscheduler()/sched_setscheduler(). + */ struct sched_param { int sched_priority; }; +/** + * [sched_setscheduler(2)](http://man7.org/linux/man-pages/man2/sched_getcpu.2.html) + * sets the scheduling policy and associated parameters for the given thread. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + */ int sched_setscheduler(pid_t __pid, int __policy, const struct sched_param* __param); + +/** + * [sched_getscheduler(2)](http://man7.org/linux/man-pages/man2/sched_getcpu.2.html) + * gets the scheduling policy for the given thread. + * + * Returns a non-negative thread policy on success and returns -1 and sets + * `errno` on failure. + */ int sched_getscheduler(pid_t __pid); + +/** + * [sched_yield(2)](http://man7.org/linux/man-pages/man2/sched_yield.2.html) + * voluntarily gives up using the CPU so that another thread can run. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + */ int sched_yield(void); + +/** + * [sched_get_priority_max(2)](http://man7.org/linux/man-pages/man2/sched_get_priority_max.2.html) + * gets the maximum priority value allowed for the given scheduling policy. + * + * Returns a priority on success and returns -1 and sets `errno` on failure. + */ int sched_get_priority_max(int __policy); + +/** + * [sched_get_priority_min(2)](http://man7.org/linux/man-pages/man2/sched_get_priority_min.2.html) + * gets the minimum priority value allowed for the given scheduling policy. + * + * Returns a priority on success and returns -1 and sets `errno` on failure. + */ int sched_get_priority_min(int __policy); + +/** + * [sched_setparam(2)](http://man7.org/linux/man-pages/man2/sched_setparam.2.html) + * sets the scheduling parameters for the given thread. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + */ int sched_setparam(pid_t __pid, const struct sched_param* __param); + +/** + * [sched_getparam(2)](http://man7.org/linux/man-pages/man2/sched_getparam.2.html) + * gets the scheduling parameters for the given thread. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + */ int sched_getparam(pid_t __pid, struct sched_param* __param); + +/** + * [sched_rr_get_interval(2)](http://man7.org/linux/man-pages/man2/sched_rr_get_interval.2.html) + * queries the round-robin time quantum for the given thread. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + */ int sched_rr_get_interval(pid_t __pid, struct timespec* __quantum); #if defined(__USE_GNU) +/** + * [clone(2)](http://man7.org/linux/man-pages/man2/clone.2.html) + * creates a new child process. + * + * Returns the pid of the child to the caller on success and + * returns -1 and sets `errno` on failure. + */ int clone(int (*__fn)(void*), void* __child_stack, int __flags, void* __arg, ...) __INTRODUCED_IN_ARM(9) __INTRODUCED_IN_X86(17); + +/** + * [unshare(2)](http://man7.org/linux/man-pages/man2/unshare.2.html) + * disassociates part of the caller's execution context. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + * + * Available since API level 17. + */ int unshare(int __flags) __INTRODUCED_IN(17); -int sched_getcpu(void); + +/** + * [setns(2)](http://man7.org/linux/man-pages/man2/setns.2.html) + * reassociates a thread with a different namespace. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + * + * Available since API level 21. + */ int setns(int __fd, int __ns_type) __INTRODUCED_IN(21); +/** + * [sched_getcpu(3)](http://man7.org/linux/man-pages/man3/sched_getcpu.3.html) + * reports which CPU the caller is running on. + * + * Returns a non-negative CPU number on success and returns -1 and sets + * `errno` on failure. + */ +int sched_getcpu(void); + #ifdef __LP64__ #define CPU_SETSIZE 1024 #else @@ -69,39 +214,50 @@ int setns(int __fd, int __ns_type) __INTRODUCED_IN(21); #define __CPU_ELT(x) ((x) / __CPU_BITS) #define __CPU_MASK(x) ((__CPU_BITTYPE)1 << ((x) & (__CPU_BITS - 1))) +/** + * [cpu_set_t](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) is a + * statically-sized CPU set. See `CPU_ALLOC` for dynamically-sized CPU sets. + */ typedef struct { __CPU_BITTYPE __bits[ CPU_SETSIZE / __CPU_BITS ]; } cpu_set_t; +/** + * [sched_setaffinity(2)](http://man7.org/linux/man-pages/man2/sched_setaffinity.2.html) + * sets the CPU affinity mask for the given thread. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + */ int sched_setaffinity(pid_t __pid, size_t __set_size, const cpu_set_t* __set); + +/** + * [sched_getaffinity(2)](http://man7.org/linux/man-pages/man2/sched_getaffinity.2.html) + * gets the CPU affinity mask for the given thread. + * + * Returns 0 on success and returns -1 and sets `errno` on failure. + */ int sched_getaffinity(pid_t __pid, size_t __set_size, cpu_set_t* __set); +/** + * [CPU_ZERO](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) clears all + * bits in a static CPU set. + */ #define CPU_ZERO(set) CPU_ZERO_S(sizeof(cpu_set_t), set) -#define CPU_SET(cpu, set) CPU_SET_S(cpu, sizeof(cpu_set_t), set) -#define CPU_CLR(cpu, set) CPU_CLR_S(cpu, sizeof(cpu_set_t), set) -#define CPU_ISSET(cpu, set) CPU_ISSET_S(cpu, sizeof(cpu_set_t), set) -#define CPU_COUNT(set) CPU_COUNT_S(sizeof(cpu_set_t), set) -#define CPU_EQUAL(set1, set2) CPU_EQUAL_S(sizeof(cpu_set_t), set1, set2) - -#define CPU_AND(dst, set1, set2) __CPU_OP(dst, set1, set2, &) -#define CPU_OR(dst, set1, set2) __CPU_OP(dst, set1, set2, |) -#define CPU_XOR(dst, set1, set2) __CPU_OP(dst, set1, set2, ^) - -#define __CPU_OP(dst, set1, set2, op) __CPU_OP_S(sizeof(cpu_set_t), dst, set1, set2, op) - -/* Support for dynamically-allocated cpu_set_t */ - -#define CPU_ALLOC_SIZE(count) \ - __CPU_ELT((count) + (__CPU_BITS - 1)) * sizeof(__CPU_BITTYPE) - -#define CPU_ALLOC(count) __sched_cpualloc((count)) -#define CPU_FREE(set) __sched_cpufree((set)) - -cpu_set_t* __sched_cpualloc(size_t __count); -void __sched_cpufree(cpu_set_t* __set); - +/** + * [CPU_ZERO_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) clears all + * bits in a dynamic CPU set allocated by `CPU_ALLOC`. + */ #define CPU_ZERO_S(setsize, set) __builtin_memset(set, 0, setsize) +/** + * [CPU_SET](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) sets one + * bit in a static CPU set. + */ +#define CPU_SET(cpu, set) CPU_SET_S(cpu, sizeof(cpu_set_t), set) +/** + * [CPU_SET_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) sets one + * bit in a dynamic CPU set allocated by `CPU_ALLOC`. + */ #define CPU_SET_S(cpu, setsize, set) \ do { \ size_t __cpu = (cpu); \ @@ -109,6 +265,15 @@ void __sched_cpufree(cpu_set_t* __set); (set)->__bits[__CPU_ELT(__cpu)] |= __CPU_MASK(__cpu); \ } while (0) +/** + * [CPU_CLR](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) clears one + * bit in a static CPU set. + */ +#define CPU_CLR(cpu, set) CPU_CLR_S(cpu, sizeof(cpu_set_t), set) +/** + * [CPU_CLR_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) clears one + * bit in a dynamic CPU set allocated by `CPU_ALLOC`. + */ #define CPU_CLR_S(cpu, setsize, set) \ do { \ size_t __cpu = (cpu); \ @@ -116,6 +281,15 @@ void __sched_cpufree(cpu_set_t* __set); (set)->__bits[__CPU_ELT(__cpu)] &= ~__CPU_MASK(__cpu); \ } while (0) +/** + * [CPU_ISSET](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) tests + * whether the given bit is set in a static CPU set. + */ +#define CPU_ISSET(cpu, set) CPU_ISSET_S(cpu, sizeof(cpu_set_t), set) +/** + * [CPU_ISSET_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) tests + * whether the given bit is set in a dynamic CPU set allocated by `CPU_ALLOC`. + */ #define CPU_ISSET_S(cpu, setsize, set) \ (__extension__ ({ \ size_t __cpu = (cpu); \ @@ -124,12 +298,65 @@ void __sched_cpufree(cpu_set_t* __set); : 0; \ })) +/** + * [CPU_COUNT](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) counts + * how many bits are set in a static CPU set. + */ +#define CPU_COUNT(set) CPU_COUNT_S(sizeof(cpu_set_t), set) +/** + * [CPU_COUNT_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) counts + * how many bits are set in a dynamic CPU set allocated by `CPU_ALLOC`. + */ +#define CPU_COUNT_S(setsize, set) __sched_cpucount((setsize), (set)) +int __sched_cpucount(size_t __set_size, const cpu_set_t* __set); + +/** + * [CPU_EQUAL](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) tests + * whether two static CPU sets have the same bits set and cleared as each other. + */ +#define CPU_EQUAL(set1, set2) CPU_EQUAL_S(sizeof(cpu_set_t), set1, set2) +/** + * [CPU_EQUAL_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) tests + * whether two dynamic CPU sets allocated by `CPU_ALLOC` have the same bits + * set and cleared as each other. + */ #define CPU_EQUAL_S(setsize, set1, set2) (__builtin_memcmp(set1, set2, setsize) == 0) +/** + * [CPU_AND](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) ands two + * static CPU sets. + */ +#define CPU_AND(dst, set1, set2) __CPU_OP(dst, set1, set2, &) +/** + * [CPU_AND_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) ands two + * dynamic CPU sets allocated by `CPU_ALLOC`. + */ #define CPU_AND_S(setsize, dst, set1, set2) __CPU_OP_S(setsize, dst, set1, set2, &) + +/** + * [CPU_OR](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) ors two + * static CPU sets. + */ +#define CPU_OR(dst, set1, set2) __CPU_OP(dst, set1, set2, |) +/** + * [CPU_OR_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) ors two + * dynamic CPU sets allocated by `CPU_ALLOC`. + */ #define CPU_OR_S(setsize, dst, set1, set2) __CPU_OP_S(setsize, dst, set1, set2, |) + +/** + * [CPU_XOR](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) + * exclusive-ors two static CPU sets. + */ +#define CPU_XOR(dst, set1, set2) __CPU_OP(dst, set1, set2, ^) +/** + * [CPU_XOR_S](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) + * exclusive-ors two dynamic CPU sets allocated by `CPU_ALLOC`. + */ #define CPU_XOR_S(setsize, dst, set1, set2) __CPU_OP_S(setsize, dst, set1, set2, ^) +#define __CPU_OP(dst, set1, set2, op) __CPU_OP_S(sizeof(cpu_set_t), dst, set1, set2, op) + #define __CPU_OP_S(setsize, dstset, srcset1, srcset2, op) \ do { \ cpu_set_t* __dst = (dstset); \ @@ -140,12 +367,27 @@ void __sched_cpufree(cpu_set_t* __set); (__dst)->__bits[__nn] = __src1[__nn] op __src2[__nn]; \ } while (0) -#define CPU_COUNT_S(setsize, set) __sched_cpucount((setsize), (set)) +/** + * [CPU_ALLOC_SIZE](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) + * returns the size of a CPU set large enough for CPUs in the range 0..count-1. + */ +#define CPU_ALLOC_SIZE(count) \ + __CPU_ELT((count) + (__CPU_BITS - 1)) * sizeof(__CPU_BITTYPE) -int __sched_cpucount(size_t __set_size, const cpu_set_t* __set); +/** + * [CPU_ALLOC](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) + * allocates a CPU set large enough for CPUs in the range 0..count-1. + */ +#define CPU_ALLOC(count) __sched_cpualloc((count)) +cpu_set_t* __sched_cpualloc(size_t __count); + +/** + * [CPU_FREE](https://man7.org/linux/man-pages/man3/CPU_SET.3.html) + * deallocates a CPU set allocated by `CPU_ALLOC`. + */ +#define CPU_FREE(set) __sched_cpufree((set)) +void __sched_cpufree(cpu_set_t* __set); #endif /* __USE_GNU */ __END_DECLS - -#endif /* _SCHED_H_ */ |