Add libtask channels

channel code borrowed from libtask, modified to match the names of
libcoio.
This commit is contained in:
Moritz Bitsch 2018-08-06 07:47:19 +02:00
parent 3af6983505
commit 16e396efc3
3 changed files with 452 additions and 0 deletions

View file

@ -4,6 +4,7 @@ project(coio)
add_library(${PROJECT_NAME}
coro.c
coio.c
channel.c
coio_glib.c)
add_custom_target(${PROJECT_NAME}_files SOURCES coioimpl.h)

393
channel.c Normal file
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@ -0,0 +1,393 @@
/* Copyright (c) 2005 Russ Cox, MIT; see COPYRIGHT */
/* Copyright (c) 2019 Moritz Bitsch */
#include "coioimpl.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
CoioChannel* coio_chancreate(int elemsize, int bufsize)
{
CoioChannel* c;
c = malloc(sizeof *c+bufsize*elemsize);
if (c == NULL)
{
perror("chancreate malloc");
exit(1);
}
memset(c, 0, sizeof *c);
c->elemsize = elemsize;
c->bufsize = bufsize;
c->nbuf = 0;
c->buf = (unsigned char*)(c+1);
return c;
}
/* bug - work out races */
void coio_chanfree(CoioChannel* c)
{
if (c == NULL)
return;
free(c->name);
free(c->arecv.a);
free(c->asend.a);
free(c);
}
static void addarray(Altarray* a, CoioAlt* alt)
{
if (a->n == a->m)
{
a->m += 16;
a->a = realloc(a->a, a->m*sizeof a->a[0]);
}
a->a[a->n++] = alt;
}
static void delarray(Altarray* a, int i)
{
--a->n;
a->a[i] = a->a[a->n];
}
/*
* doesn't really work for things other than CHANSND and CHANRCV
* but is only used as arg to chanarray, which can handle it
*/
#define otherop(op) (COIO_CHANSND+COIO_CHANRCV-(op))
static Altarray* chanarray(CoioChannel* c, uint op)
{
switch (op)
{
default:
return NULL;
case COIO_CHANSND:
return &c->asend;
case COIO_CHANRCV:
return &c->arecv;
}
}
static int altcanexec(CoioAlt* a)
{
Altarray* ar;
CoioChannel* c;
if (a->op == COIO_CHANNOP)
return 0;
c = a->c;
if (c->bufsize == 0)
{
ar = chanarray(c, otherop(a->op));
return ar && ar->n;
}
else
{
switch (a->op)
{
default:
return 0;
case COIO_CHANSND:
return c->nbuf < c->bufsize;
case COIO_CHANRCV:
return c->nbuf > 0;
}
}
}
static void altqueue(CoioAlt* a)
{
Altarray* ar;
ar = chanarray(a->c, a->op);
addarray(ar, a);
}
static void altdequeue(CoioAlt* a)
{
unsigned int i;
Altarray* ar;
ar = chanarray(a->c, a->op);
if (ar == NULL)
{
fprintf(stderr, "bad use of altdequeue op=%d\n", a->op);
abort();
}
for (i=0; i<ar->n; i++)
if (ar->a[i] == a)
{
delarray(ar, i);
return;
}
fprintf(stderr, "cannot find self in altdq\n");
abort();
}
static void altalldequeue(CoioAlt* a)
{
int i;
for (i=0; a[i].op!=COIO_CHANEND && a[i].op!=COIO_CHANNOBLK; i++)
if (a[i].op != COIO_CHANNOP)
altdequeue(&a[i]);
}
static void amove(void* dst, void* src, uint n)
{
if (dst)
{
if (src == NULL)
memset(dst, 0, n);
else
memmove(dst, src, n);
}
}
/*
* Actually move the data around. There are up to three
* players: the sender, the receiver, and the channel itself.
* If the channel is unbuffered or the buffer is empty,
* data goes from sender to receiver. If the channel is full,
* the receiver removes some from the channel and the sender
* gets to put some in.
*/
static void altcopy(CoioAlt* s, CoioAlt* r)
{
CoioAlt* t;
CoioChannel* c;
unsigned char* cp;
/*
* Work out who is sender and who is receiver
*/
if (s == NULL && r == NULL)
return;
assert(s != NULL);
c = s->c;
if (s->op == COIO_CHANRCV)
{
t = s;
s = r;
r = t;
}
assert(s==NULL || s->op == COIO_CHANSND);
assert(r==NULL || r->op == COIO_CHANRCV);
/*
* Channel is empty (or unbuffered) - copy directly.
*/
if (s && r && c->nbuf == 0)
{
amove(r->v, s->v, c->elemsize);
return;
}
/*
* Otherwise it's always okay to receive and then send.
*/
if (r)
{
cp = c->buf + c->off*c->elemsize;
amove(r->v, cp, c->elemsize);
--c->nbuf;
if (++c->off == c->bufsize)
c->off = 0;
}
if (s)
{
cp = c->buf + (c->off+c->nbuf)%c->bufsize*c->elemsize;
amove(cp, s->v, c->elemsize);
++c->nbuf;
}
}
static void altexec(CoioAlt* a)
{
int i;
Altarray* ar;
CoioAlt* other;
CoioChannel* c;
c = a->c;
ar = chanarray(c, otherop(a->op));
if (ar && ar->n)
{
i = rand()%ar->n;
other = ar->a[i];
altcopy(a, other);
altalldequeue(other->xalt);
other->xalt[0].xalt = other;
coio_ready(other->task);
}
else
altcopy(a, NULL);
}
#define dbgalt 0
int coio_chanalt(CoioAlt* a)
{
int i, j, ncan, n, canblock;
CoioChannel* c;
CoioTask* t;
//needstack(512);
for (i=0; a[i].op != COIO_CHANEND && a[i].op != COIO_CHANNOBLK; i++)
;
n = i;
canblock = a[i].op == COIO_CHANEND;
t = coio_current;
for (i=0; i<n; i++)
{
a[i].task = t;
a[i].xalt = a;
}
if (dbgalt) printf("alt ");
ncan = 0;
for (i=0; i<n; i++)
{
c = a[i].c;
if (dbgalt) printf(" %c:", "esrnb"[a[i].op]);
if (dbgalt)
{
if (c->name) printf("%s", c->name);
else printf("%p", c);
}
if (altcanexec(&a[i]))
{
if (dbgalt) printf("*");
ncan++;
}
}
if (ncan)
{
j = rand()%ncan;
for (i=0; i<n; i++)
{
if (altcanexec(&a[i]))
{
if (j-- == 0)
{
if (dbgalt)
{
c = a[i].c;
printf(" => %c:", "esrnb"[a[i].op]);
if (c->name) printf("%s", c->name);
else printf("%p", c);
printf("\n");
}
altexec(&a[i]);
return i;
}
}
}
}
if (dbgalt)printf("\n");
if (!canblock)
return -1;
for (i=0; i<n; i++)
{
if (a[i].op != COIO_CHANNOP)
altqueue(&a[i]);
}
coio_transfer();
/*
* the guy who ran the op took care of dequeueing us
* and then set a[0].alt to the one that was executed.
*/
return a[0].xalt - a;
}
static int _chanop(CoioChannel* c, int op, void* p, int canblock)
{
CoioAlt a[2];
a[0].c = c;
a[0].op = op;
a[0].v = p;
a[1].op = canblock ? COIO_CHANEND : COIO_CHANNOBLK;
if (coio_chanalt(a) < 0)
return -1;
return 1;
}
int coio_chansend(CoioChannel* c, void* v)
{
return _chanop(c, COIO_CHANSND, v, 1);
}
int coio_channbsend(CoioChannel* c, void* v)
{
return _chanop(c, COIO_CHANSND, v, 0);
}
int coio_chanrecv(CoioChannel* c, void* v)
{
return _chanop(c, COIO_CHANRCV, v, 1);
}
int coio_channbrecv(CoioChannel* c, void* v)
{
return _chanop(c, COIO_CHANRCV, v, 0);
}
int coio_chansendp(CoioChannel* c, void* v)
{
return _chanop(c, COIO_CHANSND, (void*)&v, 1);
}
void* coio_chanrecvp(CoioChannel* c)
{
void* v;
_chanop(c, COIO_CHANRCV, (void*)&v, 1);
return v;
}
int coio_channbsendp(CoioChannel* c, void* v)
{
return _chanop(c, COIO_CHANSND, (void*)&v, 0);
}
void* coio_channbrecvp(CoioChannel* c)
{
void* v;
_chanop(c, COIO_CHANRCV, (void*)&v, 0);
return v;
}
int coio_chansendul(CoioChannel* c, ulong val)
{
return _chanop(c, COIO_CHANSND, &val, 1);
}
ulong coio_chanrecvul(CoioChannel* c)
{
ulong val;
_chanop(c, COIO_CHANRCV, &val, 1);
return val;
}
int coio_channbsendul(CoioChannel* c, ulong val)
{
return _chanop(c, COIO_CHANSND, &val, 0);
}
ulong coio_channbrecvul(CoioChannel* c)
{
ulong val;
_chanop(c, COIO_CHANRCV, &val, 0);
return val;
}

58
coio.h
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@ -33,6 +33,64 @@ uvlong coio_now();
int coio_delay(int ms);
void coio_ready(CoioTask* task);
/* channel communication from libtask */
typedef struct CoioAlt CoioAlt;
typedef struct Altarray Altarray;
typedef struct CoioChannel CoioChannel;
enum
{
COIO_CHANEND,
COIO_CHANSND,
COIO_CHANRCV,
COIO_CHANNOP,
COIO_CHANNOBLK,
};
struct CoioAlt
{
CoioChannel* c;
void* v;
unsigned int op;
CoioTask* task;
CoioAlt* xalt;
};
struct Altarray
{
CoioAlt** a;
unsigned int n;
unsigned int m;
};
struct CoioChannel
{
unsigned int bufsize;
unsigned int elemsize;
unsigned char* buf;
unsigned int nbuf;
unsigned int off;
Altarray asend;
Altarray arecv;
char* name;
};
int coio_chanalt(CoioAlt* alts);
CoioChannel* coio_chancreate(int elemsize, int elemcnt);
void coio_chanfree(CoioChannel* c);
int coio_channbrecv(CoioChannel* c, void* v);
void* coio_channbrecvp(CoioChannel* c);
unsigned long coio_channbrecvul(CoioChannel* c);
int coio_channbsend(CoioChannel* c, void* v);
int coio_channbsendp(CoioChannel* c, void* v);
int coio_channbsendul(CoioChannel* c, unsigned long v);
int coio_chanrecv(CoioChannel* c, void* v);
void* coio_chanrecvp(CoioChannel* c);
unsigned long coio_chanrecvul(CoioChannel* c);
int coio_chansend(CoioChannel* c, void* v);
int coio_chansendp(CoioChannel* c, void* v);
int coio_chansendul(CoioChannel* c, unsigned long v);
#ifdef __cplusplus
}
#endif