platform_bionic/libc/include/sched.h
Elliott Hughes 655e430b28 Remove the always-true __INTRODUCED_IN() annotations.
The NDK no longer supports API levels earlier than 21.

This *doesn't* include <ctype.h> because I have a separate change
rewriting that (that's blocked on the upcoming libc++ update).

Test: treehugger
Change-Id: I53e915f27011dfc0513e0c78d8799377e183ceca
2023-06-16 12:39:33 -07:00

389 lines
13 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#pragma once
/**
* @file sched.h
* @brief Thread execution scheduling.
*/
#include <bits/timespec.h>
#include <linux/sched.h>
#include <sys/cdefs.h>
__BEGIN_DECLS
/*
* @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* _Nonnull __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* _Nonnull __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* _Nonnull __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* _Nonnull __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 (* __BIONIC_COMPLICATED_NULLNESS __fn)(void* __BIONIC_COMPLICATED_NULLNESS ), void* __BIONIC_COMPLICATED_NULLNESS __child_stack, int __flags, void* _Nullable __arg, ...);
/**
* [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.
*/
int unshare(int __flags);
/**
* [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.
*/
int setns(int __fd, int __ns_type);
/**
* [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
#define CPU_SETSIZE 32
#endif
#define __CPU_BITTYPE unsigned long int /* mandated by the kernel */
#define __CPU_BITS (8 * sizeof(__CPU_BITTYPE))
#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* _Nonnull __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* _Nonnull __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)
/**
* [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); \
if (__cpu < 8 * (setsize)) \
(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); \
if (__cpu < 8 * (setsize)) \
(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); \
(__cpu < 8 * (setsize)) \
? ((set)->__bits[__CPU_ELT(__cpu)] & __CPU_MASK(__cpu)) != 0 \
: 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* _Nonnull __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); \
const __CPU_BITTYPE* __src1 = (srcset1)->__bits; \
const __CPU_BITTYPE* __src2 = (srcset2)->__bits; \
size_t __nn = 0, __nn_max = (setsize)/sizeof(__CPU_BITTYPE); \
for (; __nn < __nn_max; __nn++) \
(__dst)->__bits[__nn] = __src1[__nn] op __src2[__nn]; \
} while (0)
/**
* [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)
/**
* [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* _Nullable __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* _Nonnull __set);
#endif /* __USE_GNU */
__END_DECLS