1 | /* Copyright (c) 2009-2020, Salvatore Sanfilippo <antirez at gmail dot com> |
2 | * All rights reserved. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions are met: |
6 | * |
7 | * * Redistributions of source code must retain the above copyright notice, |
8 | * this list of conditions and the following disclaimer. |
9 | * * Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * * Neither the name of Redis nor the names of its contributors may be used |
13 | * to endorse or promote products derived from this software without |
14 | * specific prior written permission. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
17 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
20 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 | * POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
28 | |
29 | #include "server.h" |
30 | #include "cluster.h" |
31 | |
32 | /* ========================== Clients timeouts ============================= */ |
33 | |
34 | /* Check if this blocked client timedout (does nothing if the client is |
35 | * not blocked right now). If so send a reply, unblock it, and return 1. |
36 | * Otherwise 0 is returned and no operation is performed. */ |
37 | int checkBlockedClientTimeout(client *c, mstime_t now) { |
38 | if (c->flags & CLIENT_BLOCKED && |
39 | c->bpop.timeout != 0 |
40 | && c->bpop.timeout < now) |
41 | { |
42 | /* Handle blocking operation specific timeout. */ |
43 | replyToBlockedClientTimedOut(c); |
44 | unblockClient(c); |
45 | return 1; |
46 | } else { |
47 | return 0; |
48 | } |
49 | } |
50 | |
51 | /* Check for timeouts. Returns non-zero if the client was terminated. |
52 | * The function gets the current time in milliseconds as argument since |
53 | * it gets called multiple times in a loop, so calling gettimeofday() for |
54 | * each iteration would be costly without any actual gain. */ |
55 | int clientsCronHandleTimeout(client *c, mstime_t now_ms) { |
56 | time_t now = now_ms/1000; |
57 | |
58 | if (server.maxidletime && |
59 | /* This handles the idle clients connection timeout if set. */ |
60 | !(c->flags & CLIENT_SLAVE) && /* No timeout for slaves and monitors */ |
61 | !mustObeyClient(c) && /* No timeout for masters and AOF */ |
62 | !(c->flags & CLIENT_BLOCKED) && /* No timeout for BLPOP */ |
63 | !(c->flags & CLIENT_PUBSUB) && /* No timeout for Pub/Sub clients */ |
64 | (now - c->lastinteraction > server.maxidletime)) |
65 | { |
66 | serverLog(LL_VERBOSE,"Closing idle client" ); |
67 | freeClient(c); |
68 | return 1; |
69 | } else if (c->flags & CLIENT_BLOCKED) { |
70 | /* Cluster: handle unblock & redirect of clients blocked |
71 | * into keys no longer served by this server. */ |
72 | if (server.cluster_enabled) { |
73 | if (clusterRedirectBlockedClientIfNeeded(c)) |
74 | unblockClient(c); |
75 | } |
76 | } |
77 | return 0; |
78 | } |
79 | |
80 | /* For blocked clients timeouts we populate a radix tree of 128 bit keys |
81 | * composed as such: |
82 | * |
83 | * [8 byte big endian expire time]+[8 byte client ID] |
84 | * |
85 | * We don't do any cleanup in the Radix tree: when we run the clients that |
86 | * reached the timeout already, if they are no longer existing or no longer |
87 | * blocked with such timeout, we just go forward. |
88 | * |
89 | * Every time a client blocks with a timeout, we add the client in |
90 | * the tree. In beforeSleep() we call handleBlockedClientsTimeout() to run |
91 | * the tree and unblock the clients. */ |
92 | |
93 | #define CLIENT_ST_KEYLEN 16 /* 8 bytes mstime + 8 bytes client ID. */ |
94 | |
95 | /* Given client ID and timeout, write the resulting radix tree key in buf. */ |
96 | void encodeTimeoutKey(unsigned char *buf, uint64_t timeout, client *c) { |
97 | timeout = htonu64(timeout); |
98 | memcpy(buf,&timeout,sizeof(timeout)); |
99 | memcpy(buf+8,&c,sizeof(c)); |
100 | if (sizeof(c) == 4) memset(buf+12,0,4); /* Zero padding for 32bit target. */ |
101 | } |
102 | |
103 | /* Given a key encoded with encodeTimeoutKey(), resolve the fields and write |
104 | * the timeout into *toptr and the client pointer into *cptr. */ |
105 | void decodeTimeoutKey(unsigned char *buf, uint64_t *toptr, client **cptr) { |
106 | memcpy(toptr,buf,sizeof(*toptr)); |
107 | *toptr = ntohu64(*toptr); |
108 | memcpy(cptr,buf+8,sizeof(*cptr)); |
109 | } |
110 | |
111 | /* Add the specified client id / timeout as a key in the radix tree we use |
112 | * to handle blocked clients timeouts. The client is not added to the list |
113 | * if its timeout is zero (block forever). */ |
114 | void addClientToTimeoutTable(client *c) { |
115 | if (c->bpop.timeout == 0) return; |
116 | uint64_t timeout = c->bpop.timeout; |
117 | unsigned char buf[CLIENT_ST_KEYLEN]; |
118 | encodeTimeoutKey(buf,timeout,c); |
119 | if (raxTryInsert(server.clients_timeout_table,buf,sizeof(buf),NULL,NULL)) |
120 | c->flags |= CLIENT_IN_TO_TABLE; |
121 | } |
122 | |
123 | /* Remove the client from the table when it is unblocked for reasons |
124 | * different than timing out. */ |
125 | void removeClientFromTimeoutTable(client *c) { |
126 | if (!(c->flags & CLIENT_IN_TO_TABLE)) return; |
127 | c->flags &= ~CLIENT_IN_TO_TABLE; |
128 | uint64_t timeout = c->bpop.timeout; |
129 | unsigned char buf[CLIENT_ST_KEYLEN]; |
130 | encodeTimeoutKey(buf,timeout,c); |
131 | raxRemove(server.clients_timeout_table,buf,sizeof(buf),NULL); |
132 | } |
133 | |
134 | /* This function is called in beforeSleep() in order to unblock clients |
135 | * that are waiting in blocking operations with a timeout set. */ |
136 | void handleBlockedClientsTimeout(void) { |
137 | if (raxSize(server.clients_timeout_table) == 0) return; |
138 | uint64_t now = mstime(); |
139 | raxIterator ri; |
140 | raxStart(&ri,server.clients_timeout_table); |
141 | raxSeek(&ri,"^" ,NULL,0); |
142 | |
143 | while(raxNext(&ri)) { |
144 | uint64_t timeout; |
145 | client *c; |
146 | decodeTimeoutKey(ri.key,&timeout,&c); |
147 | if (timeout >= now) break; /* All the timeouts are in the future. */ |
148 | c->flags &= ~CLIENT_IN_TO_TABLE; |
149 | checkBlockedClientTimeout(c,now); |
150 | raxRemove(server.clients_timeout_table,ri.key,ri.key_len,NULL); |
151 | raxSeek(&ri,"^" ,NULL,0); |
152 | } |
153 | raxStop(&ri); |
154 | } |
155 | |
156 | /* Get a timeout value from an object and store it into 'timeout'. |
157 | * The final timeout is always stored as milliseconds as a time where the |
158 | * timeout will expire, however the parsing is performed according to |
159 | * the 'unit' that can be seconds or milliseconds. |
160 | * |
161 | * Note that if the timeout is zero (usually from the point of view of |
162 | * commands API this means no timeout) the value stored into 'timeout' |
163 | * is zero. */ |
164 | int getTimeoutFromObjectOrReply(client *c, robj *object, mstime_t *timeout, int unit) { |
165 | long long tval; |
166 | long double ftval; |
167 | |
168 | if (unit == UNIT_SECONDS) { |
169 | if (getLongDoubleFromObjectOrReply(c,object,&ftval, |
170 | "timeout is not a float or out of range" ) != C_OK) |
171 | return C_ERR; |
172 | tval = (long long) (ftval * 1000.0); |
173 | } else { |
174 | if (getLongLongFromObjectOrReply(c,object,&tval, |
175 | "timeout is not an integer or out of range" ) != C_OK) |
176 | return C_ERR; |
177 | } |
178 | |
179 | if (tval < 0) { |
180 | addReplyError(c,"timeout is negative" ); |
181 | return C_ERR; |
182 | } |
183 | |
184 | if (tval > 0) { |
185 | tval += mstime(); |
186 | } |
187 | *timeout = tval; |
188 | |
189 | return C_OK; |
190 | } |
191 | |