1 /*
2 * Copyright (c) 2016, Salvatore Sanfilippo <antirez at gmail dot com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * * Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * * Neither the name of Redis nor the names of its contributors may be used
14 * to endorse or promote products derived from this software without
15 * specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include "server.h"
31 #include <unistd.h>
32
33 /* Open a child-parent channel used in order to move information about the
34 * RDB / AOF saving process from the child to the parent (for instance
35 * the amount of copy on write memory used) */
openChildInfoPipe(void)36 void openChildInfoPipe(void) {
37 if (pipe(server.child_info_pipe) == -1) {
38 /* On error our two file descriptors should be still set to -1,
39 * but we call anyway cloesChildInfoPipe() since can't hurt. */
40 closeChildInfoPipe();
41 } else if (anetNonBlock(NULL,server.child_info_pipe[0]) != ANET_OK) {
42 closeChildInfoPipe();
43 } else {
44 memset(&server.child_info_data,0,sizeof(server.child_info_data));
45 }
46 }
47
48 /* Close the pipes opened with openChildInfoPipe(). */
closeChildInfoPipe(void)49 void closeChildInfoPipe(void) {
50 if (server.child_info_pipe[0] != -1 ||
51 server.child_info_pipe[1] != -1)
52 {
53 close(server.child_info_pipe[0]);
54 close(server.child_info_pipe[1]);
55 server.child_info_pipe[0] = -1;
56 server.child_info_pipe[1] = -1;
57 }
58 }
59
60 /* Send COW data to parent. The child should call this function after populating
61 * the corresponding fields it want to sent (according to the process type). */
sendChildInfo(int ptype)62 void sendChildInfo(int ptype) {
63 if (server.child_info_pipe[1] == -1) return;
64 server.child_info_data.magic = CHILD_INFO_MAGIC;
65 server.child_info_data.process_type = ptype;
66 ssize_t wlen = sizeof(server.child_info_data);
67 if (write(server.child_info_pipe[1],&server.child_info_data,wlen) != wlen) {
68 /* Nothing to do on error, this will be detected by the other side. */
69 }
70 }
71
72 /* Receive COW data from parent. */
receiveChildInfo(void)73 void receiveChildInfo(void) {
74 if (server.child_info_pipe[0] == -1) return;
75 ssize_t wlen = sizeof(server.child_info_data);
76 if (read(server.child_info_pipe[0],&server.child_info_data,wlen) == wlen &&
77 server.child_info_data.magic == CHILD_INFO_MAGIC)
78 {
79 if (server.child_info_data.process_type == CHILD_INFO_TYPE_RDB) {
80 server.stat_rdb_cow_bytes = server.child_info_data.cow_size;
81 } else if (server.child_info_data.process_type == CHILD_INFO_TYPE_AOF) {
82 server.stat_aof_cow_bytes = server.child_info_data.cow_size;
83 }
84 }
85 }
86