1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
#ifndef IOLOOPER_H
#define IOLOOPER_H
#include <stdint.h>
/* An IOLooper is an abstraction for select() */
typedef struct IoLooper IoLooper;
IoLooper* iolooper_new(void);
void iolooper_free( IoLooper* iol );
void iolooper_reset( IoLooper* iol );
void iolooper_add_read( IoLooper* iol, int fd );
void iolooper_add_write( IoLooper* iol, int fd );
void iolooper_del_read( IoLooper* iol, int fd );
void iolooper_del_write( IoLooper* iol, int fd );
enum {
IOLOOPER_READ = (1<<0),
IOLOOPER_WRITE = (1<<1),
};
void iolooper_modify( IoLooper* iol, int fd, int oldflags, int newflags);
int iolooper_poll( IoLooper* iol );
/* Wrapper around select()
* Return:
* > 0 in case an I/O has occurred, or < 0 on error, or 0 on timeout with
* errno set to ETIMEDOUT.
*/
int iolooper_wait( IoLooper* iol, int64_t duration );
int iolooper_is_read( IoLooper* iol, int fd );
int iolooper_is_write( IoLooper* iol, int fd );
/* Returns 1 if this IoLooper has one or more file descriptor to interact with */
int iolooper_has_operations( IoLooper* iol );
/* Gets current time in milliseconds.
* Return:
* Number of milliseconds corresponded to the current time on success, or -1
* on failure.
*/
int64_t iolooper_now(void);
/* Waits for an I/O to occur before specific absolute time.
* This routine should be used (instead of iolooper_wait) in cases when multiple
* sequential I/O should be completed within given time interval. For instance,
* consider the scenario, when "server" does two sequential writes, and "client"
* now has to read data transferred with these two distinct writes. It might be
* wasteful to do two reads, each with the same (large) timeout. Instead, it
* would be better to assign a deadline for both reads before the first read,
* and call iolooper_wait_absoulte with the same deadline value:
* int64_t deadline = iolooper_now() + TIMEOUT;
* if (iolooper_wait_absoulte(iol, deadline)) {
* // Process first buffer.
* (iolooper_wait_absoulte(iol, deadline)) {
* // Process second read
* }
* }
* Param:
* iol IoLooper instance for an I/O.
* deadline Deadline (absoulte time in milliseconds) before which an I/O should
* occur.
* Return:
* Number of I/O descriptors set in iol, if an I/O has occurred, 0 if no I/O
* occurred before the deadline, or -1 on error.
*/
int iolooper_wait_absolute(IoLooper* iol, int64_t deadline);
#endif /* IOLOOPER_H */
|
