Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * ipci.c
4 : * POSTGRES inter-process communication initialization code.
5 : *
6 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/backend/storage/ipc/ipci.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 : #include "postgres.h"
16 :
17 : #include "access/clog.h"
18 : #include "access/commit_ts.h"
19 : #include "access/multixact.h"
20 : #include "access/nbtree.h"
21 : #include "access/subtrans.h"
22 : #include "access/syncscan.h"
23 : #include "access/transam.h"
24 : #include "access/twophase.h"
25 : #include "access/xlogprefetcher.h"
26 : #include "access/xlogrecovery.h"
27 : #include "access/xlogwait.h"
28 : #include "commands/async.h"
29 : #include "miscadmin.h"
30 : #include "pgstat.h"
31 : #include "postmaster/autovacuum.h"
32 : #include "postmaster/bgworker_internals.h"
33 : #include "postmaster/bgwriter.h"
34 : #include "postmaster/walsummarizer.h"
35 : #include "replication/logicallauncher.h"
36 : #include "replication/origin.h"
37 : #include "replication/slot.h"
38 : #include "replication/slotsync.h"
39 : #include "replication/walreceiver.h"
40 : #include "replication/walsender.h"
41 : #include "storage/aio_subsys.h"
42 : #include "storage/bufmgr.h"
43 : #include "storage/dsm.h"
44 : #include "storage/dsm_registry.h"
45 : #include "storage/ipc.h"
46 : #include "storage/pg_shmem.h"
47 : #include "storage/pmsignal.h"
48 : #include "storage/predicate.h"
49 : #include "storage/proc.h"
50 : #include "storage/procarray.h"
51 : #include "storage/procsignal.h"
52 : #include "storage/sinvaladt.h"
53 : #include "utils/guc.h"
54 : #include "utils/injection_point.h"
55 :
56 : /* GUCs */
57 : int shared_memory_type = DEFAULT_SHARED_MEMORY_TYPE;
58 :
59 : shmem_startup_hook_type shmem_startup_hook = NULL;
60 :
61 : static Size total_addin_request = 0;
62 :
63 : static void CreateOrAttachShmemStructs(void);
64 :
65 : /*
66 : * RequestAddinShmemSpace
67 : * Request that extra shmem space be allocated for use by
68 : * a loadable module.
69 : *
70 : * This may only be called via the shmem_request_hook of a library that is
71 : * loaded into the postmaster via shared_preload_libraries. Calls from
72 : * elsewhere will fail.
73 : */
74 : void
75 32 : RequestAddinShmemSpace(Size size)
76 : {
77 32 : if (!process_shmem_requests_in_progress)
78 0 : elog(FATAL, "cannot request additional shared memory outside shmem_request_hook");
79 32 : total_addin_request = add_size(total_addin_request, size);
80 32 : }
81 :
82 : /*
83 : * CalculateShmemSize
84 : * Calculates the amount of shared memory needed.
85 : */
86 : Size
87 4108 : CalculateShmemSize(void)
88 : {
89 : Size size;
90 :
91 : /*
92 : * Size of the Postgres shared-memory block is estimated via moderately-
93 : * accurate estimates for the big hogs, plus 100K for the stuff that's too
94 : * small to bother with estimating.
95 : *
96 : * We take some care to ensure that the total size request doesn't
97 : * overflow size_t. If this gets through, we don't need to be so careful
98 : * during the actual allocation phase.
99 : */
100 4108 : size = 100000;
101 4108 : size = add_size(size, hash_estimate_size(SHMEM_INDEX_SIZE,
102 : sizeof(ShmemIndexEnt)));
103 4108 : size = add_size(size, dsm_estimate_size());
104 4108 : size = add_size(size, DSMRegistryShmemSize());
105 4108 : size = add_size(size, BufferManagerShmemSize());
106 4108 : size = add_size(size, LockManagerShmemSize());
107 4108 : size = add_size(size, PredicateLockShmemSize());
108 4108 : size = add_size(size, ProcGlobalShmemSize());
109 4108 : size = add_size(size, XLogPrefetchShmemSize());
110 4108 : size = add_size(size, VarsupShmemSize());
111 4108 : size = add_size(size, XLOGShmemSize());
112 4108 : size = add_size(size, XLogRecoveryShmemSize());
113 4108 : size = add_size(size, CLOGShmemSize());
114 4108 : size = add_size(size, CommitTsShmemSize());
115 4108 : size = add_size(size, SUBTRANSShmemSize());
116 4108 : size = add_size(size, TwoPhaseShmemSize());
117 4108 : size = add_size(size, BackgroundWorkerShmemSize());
118 4108 : size = add_size(size, MultiXactShmemSize());
119 4108 : size = add_size(size, LWLockShmemSize());
120 4108 : size = add_size(size, ProcArrayShmemSize());
121 4108 : size = add_size(size, BackendStatusShmemSize());
122 4108 : size = add_size(size, SharedInvalShmemSize());
123 4108 : size = add_size(size, PMSignalShmemSize());
124 4108 : size = add_size(size, ProcSignalShmemSize());
125 4108 : size = add_size(size, CheckpointerShmemSize());
126 4108 : size = add_size(size, AutoVacuumShmemSize());
127 4108 : size = add_size(size, ReplicationSlotsShmemSize());
128 4108 : size = add_size(size, ReplicationOriginShmemSize());
129 4108 : size = add_size(size, WalSndShmemSize());
130 4108 : size = add_size(size, WalRcvShmemSize());
131 4108 : size = add_size(size, WalSummarizerShmemSize());
132 4108 : size = add_size(size, PgArchShmemSize());
133 4108 : size = add_size(size, ApplyLauncherShmemSize());
134 4108 : size = add_size(size, BTreeShmemSize());
135 4108 : size = add_size(size, SyncScanShmemSize());
136 4108 : size = add_size(size, AsyncShmemSize());
137 4108 : size = add_size(size, StatsShmemSize());
138 4108 : size = add_size(size, WaitEventCustomShmemSize());
139 4108 : size = add_size(size, InjectionPointShmemSize());
140 4108 : size = add_size(size, SlotSyncShmemSize());
141 4108 : size = add_size(size, AioShmemSize());
142 4108 : size = add_size(size, WaitLSNShmemSize());
143 :
144 : /* include additional requested shmem from preload libraries */
145 4108 : size = add_size(size, total_addin_request);
146 :
147 : /* might as well round it off to a multiple of a typical page size */
148 4108 : size = add_size(size, 8192 - (size % 8192));
149 :
150 4108 : return size;
151 : }
152 :
153 : #ifdef EXEC_BACKEND
154 : /*
155 : * AttachSharedMemoryStructs
156 : * Initialize a postmaster child process's access to shared memory
157 : * structures.
158 : *
159 : * In !EXEC_BACKEND mode, we inherit everything through the fork, and this
160 : * isn't needed.
161 : */
162 : void
163 : AttachSharedMemoryStructs(void)
164 : {
165 : /* InitProcess must've been called already */
166 : Assert(MyProc != NULL);
167 : Assert(IsUnderPostmaster);
168 :
169 : /*
170 : * In EXEC_BACKEND mode, backends don't inherit the number of fast-path
171 : * groups we calculated before setting the shmem up, so recalculate it.
172 : */
173 : InitializeFastPathLocks();
174 :
175 : CreateOrAttachShmemStructs();
176 :
177 : /*
178 : * Now give loadable modules a chance to set up their shmem allocations
179 : */
180 : if (shmem_startup_hook)
181 : shmem_startup_hook();
182 : }
183 : #endif
184 :
185 : /*
186 : * CreateSharedMemoryAndSemaphores
187 : * Creates and initializes shared memory and semaphores.
188 : */
189 : void
190 2208 : CreateSharedMemoryAndSemaphores(void)
191 : {
192 : PGShmemHeader *shim;
193 : PGShmemHeader *seghdr;
194 : Size size;
195 :
196 : Assert(!IsUnderPostmaster);
197 :
198 : /* Compute the size of the shared-memory block */
199 2208 : size = CalculateShmemSize();
200 2208 : elog(DEBUG3, "invoking IpcMemoryCreate(size=%zu)", size);
201 :
202 : /*
203 : * Create the shmem segment
204 : */
205 2208 : seghdr = PGSharedMemoryCreate(size, &shim);
206 :
207 : /*
208 : * Make sure that huge pages are never reported as "unknown" while the
209 : * server is running.
210 : */
211 : Assert(strcmp("unknown",
212 : GetConfigOption("huge_pages_status", false, false)) != 0);
213 :
214 2204 : InitShmemAccess(seghdr);
215 :
216 : /*
217 : * Set up shared memory allocation mechanism
218 : */
219 2204 : InitShmemAllocation();
220 :
221 : /* Initialize subsystems */
222 2204 : CreateOrAttachShmemStructs();
223 :
224 : /* Initialize dynamic shared memory facilities. */
225 2204 : dsm_postmaster_startup(shim);
226 :
227 : /*
228 : * Now give loadable modules a chance to set up their shmem allocations
229 : */
230 2204 : if (shmem_startup_hook)
231 30 : shmem_startup_hook();
232 2204 : }
233 :
234 : /*
235 : * Initialize various subsystems, setting up their data structures in
236 : * shared memory.
237 : *
238 : * This is called by the postmaster or by a standalone backend.
239 : * It is also called by a backend forked from the postmaster in the
240 : * EXEC_BACKEND case. In the latter case, the shared memory segment
241 : * already exists and has been physically attached to, but we have to
242 : * initialize pointers in local memory that reference the shared structures,
243 : * because we didn't inherit the correct pointer values from the postmaster
244 : * as we do in the fork() scenario. The easiest way to do that is to run
245 : * through the same code as before. (Note that the called routines mostly
246 : * check IsUnderPostmaster, rather than EXEC_BACKEND, to detect this case.
247 : * This is a bit code-wasteful and could be cleaned up.)
248 : */
249 : static void
250 2204 : CreateOrAttachShmemStructs(void)
251 : {
252 : /*
253 : * Now initialize LWLocks, which do shared memory allocation and are
254 : * needed for InitShmemIndex.
255 : */
256 2204 : CreateLWLocks();
257 :
258 : /*
259 : * Set up shmem.c index hashtable
260 : */
261 2204 : InitShmemIndex();
262 :
263 2204 : dsm_shmem_init();
264 2204 : DSMRegistryShmemInit();
265 :
266 : /*
267 : * Set up xlog, clog, and buffers
268 : */
269 2204 : VarsupShmemInit();
270 2204 : XLOGShmemInit();
271 2204 : XLogPrefetchShmemInit();
272 2204 : XLogRecoveryShmemInit();
273 2204 : CLOGShmemInit();
274 2204 : CommitTsShmemInit();
275 2204 : SUBTRANSShmemInit();
276 2204 : MultiXactShmemInit();
277 2204 : BufferManagerShmemInit();
278 :
279 : /*
280 : * Set up lock manager
281 : */
282 2204 : LockManagerShmemInit();
283 :
284 : /*
285 : * Set up predicate lock manager
286 : */
287 2204 : PredicateLockShmemInit();
288 :
289 : /*
290 : * Set up process table
291 : */
292 2204 : if (!IsUnderPostmaster)
293 2204 : InitProcGlobal();
294 2204 : ProcArrayShmemInit();
295 2204 : BackendStatusShmemInit();
296 2204 : TwoPhaseShmemInit();
297 2204 : BackgroundWorkerShmemInit();
298 :
299 : /*
300 : * Set up shared-inval messaging
301 : */
302 2204 : SharedInvalShmemInit();
303 :
304 : /*
305 : * Set up interprocess signaling mechanisms
306 : */
307 2204 : PMSignalShmemInit();
308 2204 : ProcSignalShmemInit();
309 2204 : CheckpointerShmemInit();
310 2204 : AutoVacuumShmemInit();
311 2204 : ReplicationSlotsShmemInit();
312 2204 : ReplicationOriginShmemInit();
313 2204 : WalSndShmemInit();
314 2204 : WalRcvShmemInit();
315 2204 : WalSummarizerShmemInit();
316 2204 : PgArchShmemInit();
317 2204 : ApplyLauncherShmemInit();
318 2204 : SlotSyncShmemInit();
319 :
320 : /*
321 : * Set up other modules that need some shared memory space
322 : */
323 2204 : BTreeShmemInit();
324 2204 : SyncScanShmemInit();
325 2204 : AsyncShmemInit();
326 2204 : StatsShmemInit();
327 2204 : WaitEventCustomShmemInit();
328 2204 : InjectionPointShmemInit();
329 2204 : AioShmemInit();
330 2204 : WaitLSNShmemInit();
331 2204 : }
332 :
333 : /*
334 : * InitializeShmemGUCs
335 : *
336 : * This function initializes runtime-computed GUCs related to the amount of
337 : * shared memory required for the current configuration.
338 : */
339 : void
340 1900 : InitializeShmemGUCs(void)
341 : {
342 : char buf[64];
343 : Size size_b;
344 : Size size_mb;
345 : Size hp_size;
346 :
347 : /*
348 : * Calculate the shared memory size and round up to the nearest megabyte.
349 : */
350 1900 : size_b = CalculateShmemSize();
351 1900 : size_mb = add_size(size_b, (1024 * 1024) - 1) / (1024 * 1024);
352 1900 : sprintf(buf, "%zu", size_mb);
353 1900 : SetConfigOption("shared_memory_size", buf,
354 : PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
355 :
356 : /*
357 : * Calculate the number of huge pages required.
358 : */
359 1900 : GetHugePageSize(&hp_size, NULL);
360 1900 : if (hp_size != 0)
361 : {
362 : Size hp_required;
363 :
364 1900 : hp_required = add_size(size_b / hp_size, 1);
365 1900 : sprintf(buf, "%zu", hp_required);
366 1900 : SetConfigOption("shared_memory_size_in_huge_pages", buf,
367 : PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
368 : }
369 :
370 1900 : sprintf(buf, "%d", ProcGlobalSemas());
371 1900 : SetConfigOption("num_os_semaphores", buf, PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
372 1900 : }
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