v/thirdparty/picoev/src/picoev.h

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2020-01-23 03:26:30 +01:00
/*
* Copyright (c) 2009, Cybozu Labs, Inc.
* 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.
* * Neither the name of the <ORGANIZATION> nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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 HOLDER 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.
*/
#ifndef picoev_h
#define picoev_h
#ifdef __cplusplus
extern "C" {
# define PICOEV_INLINE inline
#else
# define PICOEV_INLINE static __inline__
#endif
#include <assert.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#define PICOEV_IS_INITED (picoev.max_fd != 0)
#define PICOEV_IS_INITED_AND_FD_IN_RANGE(fd) \
(((unsigned)fd) < (unsigned)picoev.max_fd)
#define PICOEV_TOO_MANY_LOOPS (picoev.num_loops != 0) /* use after ++ */
#define PICOEV_FD_BELONGS_TO_LOOP(loop, fd) \
((loop)->loop_id == picoev.fds[fd].loop_id)
#define PICOEV_TIMEOUT_VEC_OF(loop, idx) \
((loop)->timeout.vec + (idx) * picoev.timeout_vec_size)
#define PICOEV_TIMEOUT_VEC_OF_VEC_OF(loop, idx) \
((loop)->timeout.vec_of_vec + (idx) * picoev.timeout_vec_of_vec_size)
#define PICOEV_RND_UP(v, d) (((v) + (d) - 1) / (d) * (d))
#define PICOEV_PAGE_SIZE 4096
#define PICOEV_CACHE_LINE_SIZE 32 /* in bytes, ok if greater than the actual */
#define PICOEV_SIMD_BITS 128
#define PICOEV_TIMEOUT_VEC_SIZE 128
#define PICOEV_SHORT_BITS (sizeof(short) * 8)
#define PICOEV_READ 1
#define PICOEV_WRITE 2
#define PICOEV_TIMEOUT 4
#define PICOEV_ADD 0x40000000
#define PICOEV_DEL 0x20000000
#define PICOEV_READWRITE (PICOEV_READ | PICOEV_WRITE)
#define PICOEV_TIMEOUT_IDX_UNUSED (UCHAR_MAX)
typedef unsigned short picoev_loop_id_t;
typedef struct picoev_loop_st picoev_loop;
typedef void picoev_handler(picoev_loop* loop, int fd, int revents,
void* cb_arg);
typedef struct picoev_fd_st {
/* use accessors! */
/* TODO adjust the size to match that of a cache line */
picoev_handler* callback;
void* cb_arg;
picoev_loop_id_t loop_id;
char events;
unsigned char timeout_idx; /* PICOEV_TIMEOUT_IDX_UNUSED if not used */
int _backend; /* can be used by backends (never modified by core) */
} picoev_fd;
struct picoev_loop_st {
/* read only */
picoev_loop_id_t loop_id;
struct {
short* vec;
short* vec_of_vec;
size_t base_idx;
time_t base_time;
int resolution;
void* _free_addr;
} timeout;
time_t now;
};
typedef struct picoev_globals_st {
/* read only */
picoev_fd* fds;
void* _fds_free_addr;
int max_fd;
int num_loops;
size_t timeout_vec_size; /* # of elements in picoev_loop.timeout.vec[0] */
size_t timeout_vec_of_vec_size; /* ... in timeout.vec_of_vec[0] */
} picoev_globals;
extern picoev_globals picoev;
/* creates a new event loop (defined by each backend) */
picoev_loop* picoev_create_loop(int max_timeout);
/* destroys a loop (defined by each backend) */
int picoev_destroy_loop(picoev_loop* loop);
/* internal: updates events to be watched (defined by each backend) */
int picoev_update_events_internal(picoev_loop* loop, int fd, int events);
/* internal: poll once and call the handlers (defined by each backend) */
int picoev_poll_once_internal(picoev_loop* loop, int max_wait);
/* internal, aligned allocator with address scrambling to avoid cache
line contention */
PICOEV_INLINE
void* picoev_memalign(size_t sz, void** orig_addr, int clear) {
sz = sz + PICOEV_PAGE_SIZE + PICOEV_CACHE_LINE_SIZE;
if ((*orig_addr = malloc(sz)) == NULL) {
return NULL;
}
if (clear != 0) {
memset(*orig_addr, 0, sz);
}
return
(void*)PICOEV_RND_UP((unsigned long)*orig_addr
+ (rand() % PICOEV_PAGE_SIZE),
PICOEV_CACHE_LINE_SIZE);
}
/* initializes picoev */
PICOEV_INLINE
int picoev_init(int max_fd) {
assert(! PICOEV_IS_INITED);
assert(max_fd > 0);
if ((picoev.fds = (picoev_fd*)picoev_memalign(sizeof(picoev_fd) * max_fd,
&picoev._fds_free_addr, 1))
== NULL) {
return -1;
}
picoev.max_fd = max_fd;
picoev.num_loops = 0;
picoev.timeout_vec_size
= PICOEV_RND_UP(picoev.max_fd, PICOEV_SIMD_BITS) / PICOEV_SHORT_BITS;
picoev.timeout_vec_of_vec_size
= PICOEV_RND_UP(picoev.timeout_vec_size, PICOEV_SIMD_BITS)
/ PICOEV_SHORT_BITS;
return 0;
}
/* deinitializes picoev */
PICOEV_INLINE
int picoev_deinit(void) {
assert(PICOEV_IS_INITED);
free(picoev._fds_free_addr);
picoev.fds = NULL;
picoev._fds_free_addr = NULL;
picoev.max_fd = 0;
picoev.num_loops = 0;
return 0;
}
/* updates timeout */
PICOEV_INLINE
void picoev_set_timeout(picoev_loop* loop, int fd, int secs) {
picoev_fd* target;
short* vec, * vec_of_vec;
size_t vi = fd / PICOEV_SHORT_BITS, delta;
assert(PICOEV_IS_INITED_AND_FD_IN_RANGE(fd));
assert(PICOEV_FD_BELONGS_TO_LOOP(loop, fd));
target = picoev.fds + fd;
/* clear timeout */
if (target->timeout_idx != PICOEV_TIMEOUT_IDX_UNUSED) {
vec = PICOEV_TIMEOUT_VEC_OF(loop, target->timeout_idx);
if ((vec[vi] &= ~((unsigned short)SHRT_MIN >> (fd % PICOEV_SHORT_BITS)))
== 0) {
vec_of_vec = PICOEV_TIMEOUT_VEC_OF_VEC_OF(loop, target->timeout_idx);
vec_of_vec[vi / PICOEV_SHORT_BITS]
&= ~((unsigned short)SHRT_MIN >> (vi % PICOEV_SHORT_BITS));
}
target->timeout_idx = PICOEV_TIMEOUT_IDX_UNUSED;
}
if (secs != 0) {
delta = (loop->now + secs - loop->timeout.base_time)
/ loop->timeout.resolution;
if (delta >= PICOEV_TIMEOUT_VEC_SIZE) {
delta = PICOEV_TIMEOUT_VEC_SIZE - 1;
}
target->timeout_idx =
(loop->timeout.base_idx + delta) % PICOEV_TIMEOUT_VEC_SIZE;
vec = PICOEV_TIMEOUT_VEC_OF(loop, target->timeout_idx);
vec[vi] |= (unsigned short)SHRT_MIN >> (fd % PICOEV_SHORT_BITS);
vec_of_vec = PICOEV_TIMEOUT_VEC_OF_VEC_OF(loop, target->timeout_idx);
vec_of_vec[vi / PICOEV_SHORT_BITS]
|= (unsigned short)SHRT_MIN >> (vi % PICOEV_SHORT_BITS);
}
}
/* registers a file descriptor and callback argument to a event loop */
PICOEV_INLINE
int picoev_add(picoev_loop* loop, int fd, int events, int timeout_in_secs,
picoev_handler* callback, void* cb_arg) {
picoev_fd* target;
if (!PICOEV_IS_INITED_AND_FD_IN_RANGE(fd)) { return -1; }
target = picoev.fds + fd;
assert(target->loop_id == 0);
target->callback = callback;
target->cb_arg = cb_arg;
target->loop_id = loop->loop_id;
target->events = 0;
target->timeout_idx = PICOEV_TIMEOUT_IDX_UNUSED;
if (picoev_update_events_internal(loop, fd, events | PICOEV_ADD) != 0) {
target->loop_id = 0;
return -1;
}
picoev_set_timeout(loop, fd, timeout_in_secs);
return 0;
}
/* unregisters a file descriptor from event loop */
PICOEV_INLINE
int picoev_del(picoev_loop* loop, int fd) {
picoev_fd* target;
assert(PICOEV_IS_INITED_AND_FD_IN_RANGE(fd));
target = picoev.fds + fd;
if (picoev_update_events_internal(loop, fd, PICOEV_DEL) != 0) {
return -1;
}
picoev_set_timeout(loop, fd, 0);
target->loop_id = 0;
return 0;
}
/* check if fd is registered (checks all loops if loop == NULL) */
PICOEV_INLINE
int picoev_is_active(picoev_loop* loop, int fd) {
assert(PICOEV_IS_INITED_AND_FD_IN_RANGE(fd));
return loop != NULL
? picoev.fds[fd].loop_id == loop->loop_id
: picoev.fds[fd].loop_id != 0;
}
/* returns events being watched for given descriptor */
PICOEV_INLINE
int picoev_get_events(picoev_loop* loop __attribute__((unused)), int fd) {
assert(PICOEV_IS_INITED_AND_FD_IN_RANGE(fd));
return picoev.fds[fd].events & PICOEV_READWRITE;
}
/* sets events to be watched for given desriptor */
PICOEV_INLINE
int picoev_set_events(picoev_loop* loop, int fd, int events) {
assert(PICOEV_IS_INITED_AND_FD_IN_RANGE(fd));
if (picoev.fds[fd].events != events
&& picoev_update_events_internal(loop, fd, events) != 0) {
return -1;
}
return 0;
}
/* returns callback for given descriptor */
PICOEV_INLINE
picoev_handler* picoev_get_callback(picoev_loop* loop __attribute__((unused)),
int fd, void** cb_arg) {
assert(PICOEV_IS_INITED_AND_FD_IN_RANGE(fd));
if (cb_arg != NULL) {
*cb_arg = picoev.fds[fd].cb_arg;
}
return picoev.fds[fd].callback;
}
/* sets callback for given descriptor */
PICOEV_INLINE
void picoev_set_callback(picoev_loop* loop __attribute__((unused)), int fd,
picoev_handler* callback, void** cb_arg) {
assert(PICOEV_IS_INITED_AND_FD_IN_RANGE(fd));
if (cb_arg != NULL) {
picoev.fds[fd].cb_arg = *cb_arg;
}
picoev.fds[fd].callback = callback;
}
/* function to iterate registered information. To start iteration, set curfd
to -1 and call the function until -1 is returned */
PICOEV_INLINE
int picoev_next_fd(picoev_loop* loop, int curfd) {
if (curfd != -1) {
assert(PICOEV_IS_INITED_AND_FD_IN_RANGE(curfd));
}
while (++curfd < picoev.max_fd) {
if (loop->loop_id == picoev.fds[curfd].loop_id) {
return curfd;
}
}
return -1;
}
/* internal function */
PICOEV_INLINE
int picoev_init_loop_internal(picoev_loop* loop, int max_timeout) {
loop->loop_id = ++picoev.num_loops;
assert(PICOEV_TOO_MANY_LOOPS);
if ((loop->timeout.vec_of_vec
= (short*)picoev_memalign((picoev.timeout_vec_of_vec_size
+ picoev.timeout_vec_size)
* sizeof(short) * PICOEV_TIMEOUT_VEC_SIZE,
&loop->timeout._free_addr, 1))
== NULL) {
--picoev.num_loops;
return -1;
}
loop->timeout.vec = loop->timeout.vec_of_vec
+ picoev.timeout_vec_of_vec_size * PICOEV_TIMEOUT_VEC_SIZE;
loop->timeout.base_idx = 0;
loop->timeout.base_time = time(NULL);
loop->timeout.resolution
= PICOEV_RND_UP(max_timeout, PICOEV_TIMEOUT_VEC_SIZE)
/ PICOEV_TIMEOUT_VEC_SIZE;
return 0;
}
/* internal function */
PICOEV_INLINE
void picoev_deinit_loop_internal(picoev_loop* loop) {
free(loop->timeout._free_addr);
}
/* internal function */
PICOEV_INLINE
void picoev_handle_timeout_internal(picoev_loop* loop) {
size_t i, j, k;
for (;
loop->timeout.base_time <= loop->now - loop->timeout.resolution;
loop->timeout.base_idx
= (loop->timeout.base_idx + 1) % PICOEV_TIMEOUT_VEC_SIZE,
loop->timeout.base_time += loop->timeout.resolution) {
/* TODO use SIMD instructions */
short* vec = PICOEV_TIMEOUT_VEC_OF(loop, loop->timeout.base_idx);
short* vec_of_vec
= PICOEV_TIMEOUT_VEC_OF_VEC_OF(loop, loop->timeout.base_idx);
for (i = 0; i < picoev.timeout_vec_of_vec_size; ++i) {
short vv = vec_of_vec[i];
if (vv != 0) {
for (j = i * PICOEV_SHORT_BITS; vv != 0; j++, vv <<= 1) {
if (vv < 0) {
short v = vec[j];
assert(v != 0);
for (k = j * PICOEV_SHORT_BITS; v != 0; k++, v <<= 1) {
if (v < 0) {
picoev_fd* fd = picoev.fds + k;
assert(fd->loop_id == loop->loop_id);
fd->timeout_idx = PICOEV_TIMEOUT_IDX_UNUSED;
(*fd->callback)(loop, k, PICOEV_TIMEOUT, fd->cb_arg);
}
}
vec[j] = 0;
}
}
vec_of_vec[i] = 0;
}
}
}
}
/* loop once */
PICOEV_INLINE
int picoev_loop_once(picoev_loop* loop, int max_wait) {
loop->now = time(NULL);
if (max_wait > loop->timeout.resolution) {
max_wait = loop->timeout.resolution;
}
if (picoev_poll_once_internal(loop, max_wait) != 0) {
return -1;
}
if (max_wait != 0) {
loop->now = time(NULL);
}
picoev_handle_timeout_internal(loop);
return 0;
}
#undef PICOEV_INLINE
#ifdef __cplusplus
}
#endif
#endif