summaryrefslogtreecommitdiff
path: root/source3/lib/pthreadpool/pthreadpool_sync.c
blob: 0c2d12fef30fdf03210f94210d8174d37bc7921c (plain)
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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/*
 * Unix SMB/CIFS implementation.
 * sync dummy implementation of the pthreadpool API
 * Copyright (C) Volker Lendecke 2009
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <assert.h>
#include <fcntl.h>
#include <sys/time.h>

#include "pthreadpool.h"

struct pthreadpool {
	/*
	 * pipe for signalling
	 */
	int sig_pipe[2];

	/*
	 * Have we sent something into the pipe that has not been
	 * retrieved yet?
	 */
	int pipe_busy;

	/*
	 * Jobids that we have not sent into the pipe yet
	 */
	size_t num_ids;
	int *ids;
};

int pthreadpool_init(unsigned max_threads, struct pthreadpool **presult)
{
	struct pthreadpool *pool;
	int ret;

	pool = (struct pthreadpool *)calloc(1, sizeof(struct pthreadpool));
	if (pool == NULL) {
		return ENOMEM;
	}
	ret = pipe(pool->sig_pipe);
	if (ret == -1) {
		int err = errno;
		free(pool);
		return err;
	}
	*presult = pool;
	return 0;
}

int pthreadpool_signal_fd(struct pthreadpool *pool)
{
	return pool->sig_pipe[0];
}

static int pthreadpool_write_to_pipe(struct pthreadpool *pool)
{
	ssize_t written;

	if (pool->pipe_busy) {
		return 0;
	}
	if (pool->num_ids == 0) {
		return 0;
	}

	written = -1;
	errno = EINTR;

	while ((written == -1) && (errno == EINTR)) {
		written = write(pool->sig_pipe[1], &pool->ids[0], sizeof(int));
	}
	if (written == -1) {
		return errno;
	}
	if (written != sizeof(int)) {
		/*
		 * If a single int only partially fits into the pipe,
		 * we can assume ourselves pretty broken
		 */
		close(pool->sig_pipe[1]);
		pool->sig_pipe[1] = -1;
		return EIO;
	}

	if (pool->num_ids > 1) {
		memmove(pool->ids, pool->ids+1, sizeof(int) * (pool->num_ids-1));
	}
	pool->num_ids -= 1;
	pool->pipe_busy = 1;
	return 0;
}

int pthreadpool_add_job(struct pthreadpool *pool, int job_id,
			void (*fn)(void *private_data), void *private_data)
{
	int *tmp;

	if (pool->sig_pipe[1] == -1) {
		return EIO;
	}

	fn(private_data);

	tmp = realloc(pool->ids, sizeof(int) * (pool->num_ids+1));
	if (tmp == NULL) {
		return ENOMEM;
	}
	pool->ids = tmp;
	pool->ids[pool->num_ids] = job_id;
	pool->num_ids += 1;

	return pthreadpool_write_to_pipe(pool);

}

int pthreadpool_finished_job(struct pthreadpool *pool, int *jobid)
{
	int ret_jobid;
	ssize_t nread;

	nread = -1;
	errno = EINTR;

	while ((nread == -1) && (errno == EINTR)) {
		nread = read(pool->sig_pipe[0], &ret_jobid, sizeof(int));
	}
	if (nread == -1) {
		return errno;
	}
	if (nread != sizeof(int)) {
		return EINVAL;
	}
	*jobid = ret_jobid;

	pool->pipe_busy = 0;
	return pthreadpool_write_to_pipe(pool);
}

int pthreadpool_destroy(struct pthreadpool *pool)
{
	if (pool->sig_pipe[0] != -1) {
		close(pool->sig_pipe[0]);
		pool->sig_pipe[0] = -1;
	}

	if (pool->sig_pipe[1] != -1) {
		close(pool->sig_pipe[1]);
		pool->sig_pipe[1] = -1;
	}
	free(pool->ids);
	free(pool);
	return 0;
}