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select.h
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1/*
2 * Copyright (C) 2019 Freie Universität Berlin
3 *
4 * This file is subject to the terms and conditions of the GNU Lesser
5 * General Public License v2.1. See the file LICENSE in the top level
6 * directory for more details.
7 */
8
9#pragma once
10
30
31#ifdef CPU_NATIVE
32/* On native, system headers may depend on system's <sys/select.h>. Hence,
33 * include the real sys/select.h here. */
34__extension__
35#include_next <sys/select.h>
36#endif
37
38#include <string.h>
39/* prevent cyclic dependency with newlib/picolibc's `sys/types.h` */
40#if (defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)) && !defined(CPU_ESP8266)
41#include <sys/_timeval.h>
42#else
43#include <sys/time.h>
44#endif
45
46#include "bitfield.h"
47
48#ifdef __cplusplus
49extern "C" {
50#endif
51
55#define POSIX_SELECT_THREAD_FLAG (1U << 3)
56
57#ifndef CPU_NATIVE
58
70#ifndef CONFIG_POSIX_FD_SET_SIZE
71#define CONFIG_POSIX_FD_SET_SIZE (16)
72#endif
74
75/* ESP's newlib has this already defined in `sys/types.h` */
76#if !defined(CPU_ESP8266)
82#define FD_SETSIZE (CONFIG_POSIX_FD_SET_SIZE)
83
87typedef struct {
90} fd_set;
91
98static inline void FD_CLR(int fd, fd_set *fdsetp)
99{
100 bf_unset(fdsetp->fds, fd);
101}
102
112static inline int FD_ISSET(int fd, fd_set *fdsetp)
113{
114 return (int)bf_isset(fdsetp->fds, fd);
115}
116
124static inline void FD_SET(int fd, fd_set *fdsetp)
125{
126 bf_set(fdsetp->fds, fd);
127}
128
134static inline void FD_ZERO(fd_set *fdsetp)
135{
136 memset(fdsetp->fds, 0, sizeof(fdsetp->fds));
137}
138#endif /* !defined(CPU_ESP32) && !defined(CPU_ESP8266) */
139
172int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds,
173 struct timeval *timeout);
174
175#endif /* CPU_NATIVE */
176
177#ifdef __cplusplus
178}
179#endif
180
bitfields operations on bitfields of arbitrary length
static void bf_set(uint8_t field[], size_t idx)
Set the bit to 1.
Definition bitfield.h:55
static void bf_unset(uint8_t field[], size_t idx)
Clear the bit.
Definition bitfield.h:79
static bool bf_isset(const uint8_t field[], size_t idx)
Check if the bet is set.
Definition bitfield.h:127
static int FD_ISSET(int fd, fd_set *fdsetp)
Checks if a file descriptor is a member of an fd_set
Definition select.h:112
static void FD_SET(int fd, fd_set *fdsetp)
Adds a file descriptor from an fd_set if it is not already a member.
Definition select.h:124
static void FD_ZERO(fd_set *fdsetp)
Initializes the descriptor set as an empty set.
Definition select.h:134
int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *timeout)
Examines the given file descriptor sets if they are ready for their respective operation.
#define FD_SETSIZE
Maximum number of file descriptors in an fd_set structure.
Definition select.h:82
static void FD_CLR(int fd, fd_set *fdsetp)
Removes a file descriptor from an fd_set if it is a member.
Definition select.h:98
The fd_set structure.
Definition select.h:87
BITFIELD(fds, FD_SETSIZE)
Bit-field to represent the set of file descriptors.
Definition of struct timeval for the atmega.
Definition time.h:22