Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * test_shmem.c
4 : : * Helpers to test shmem allocation routines
5 : : *
6 : : * Test basic memory allocation in an extension module. One notable feature
7 : : * that is not exercised by any other module in the repository is the
8 : : * allocating (non-DSM) shared memory after postmaster startup.
9 : : *
10 : : * Copyright (c) 2020-2026, PostgreSQL Global Development Group
11 : : *
12 : : * IDENTIFICATION
13 : : * src/test/modules/test_shmem/test_shmem.c
14 : : *
15 : : *-------------------------------------------------------------------------
16 : : */
17 : :
18 : : #include "postgres.h"
19 : :
20 : : #include "fmgr.h"
21 : : #include "miscadmin.h"
22 : : #include "storage/shmem.h"
23 : :
24 : :
29 heikki.linnakangas@i 25 :GNC 4 : PG_MODULE_MAGIC;
26 : :
27 : : typedef struct TestShmemData
28 : : {
29 : : int value;
30 : : bool initialized;
31 : : int attach_count;
32 : : } TestShmemData;
33 : :
34 : : static TestShmemData *TestShmem;
35 : :
36 : : static bool attached_or_initialized = false;
37 : :
38 : : static void test_shmem_request(void *arg);
39 : : static void test_shmem_init(void *arg);
40 : : static void test_shmem_attach(void *arg);
41 : :
42 : : static const ShmemCallbacks TestShmemCallbacks = {
43 : : .flags = SHMEM_CALLBACKS_ALLOW_AFTER_STARTUP,
44 : : .request_fn = test_shmem_request,
45 : : .init_fn = test_shmem_init,
46 : : .attach_fn = test_shmem_attach,
47 : : };
48 : :
49 : : static void
50 : 4 : test_shmem_request(void *arg)
51 : : {
52 [ + - ]: 4 : elog(LOG, "test_shmem_request callback called");
53 : :
54 : 4 : ShmemRequestStruct(.name = "test_shmem area",
55 : : .size = sizeof(TestShmemData),
56 : : .ptr = (void **) &TestShmem);
57 : 4 : }
58 : :
59 : : static void
60 : 2 : test_shmem_init(void *arg)
61 : : {
62 [ + - ]: 2 : elog(LOG, "init callback called");
63 [ - + ]: 2 : if (TestShmem->initialized)
29 heikki.linnakangas@i 64 [ # # ]:UNC 0 : elog(ERROR, "shmem area already initialized");
29 heikki.linnakangas@i 65 :GNC 2 : TestShmem->initialized = true;
66 : :
67 [ - + ]: 2 : if (attached_or_initialized)
29 heikki.linnakangas@i 68 [ # # ]:UNC 0 : elog(ERROR, "attach or initialize already called in this process");
29 heikki.linnakangas@i 69 :GNC 2 : attached_or_initialized = true;
70 : 2 : }
71 : :
72 : : static void
73 : 2 : test_shmem_attach(void *arg)
74 : : {
75 [ + - ]: 2 : elog(LOG, "test_shmem_attach callback called");
76 [ - + ]: 2 : if (!TestShmem->initialized)
29 heikki.linnakangas@i 77 [ # # ]:UNC 0 : elog(ERROR, "shmem area not yet initialized");
29 heikki.linnakangas@i 78 :GNC 2 : TestShmem->attach_count++;
79 : :
80 [ - + ]: 2 : if (attached_or_initialized)
29 heikki.linnakangas@i 81 [ # # ]:UNC 0 : elog(ERROR, "attach or initialize already called in this process");
29 heikki.linnakangas@i 82 :GNC 2 : attached_or_initialized = true;
83 : 2 : }
84 : :
85 : : void
86 : 4 : _PG_init(void)
87 : : {
88 [ + - ]: 4 : elog(LOG, "test_shmem module's _PG_init called");
89 : 4 : RegisterShmemCallbacks(&TestShmemCallbacks);
90 : 4 : }
91 : :
92 : 5 : PG_FUNCTION_INFO_V1(get_test_shmem_attach_count);
93 : : Datum
94 : 4 : get_test_shmem_attach_count(PG_FUNCTION_ARGS)
95 : : {
96 [ - + ]: 4 : if (!attached_or_initialized)
29 heikki.linnakangas@i 97 [ # # ]:UNC 0 : elog(ERROR, "shmem area not attached or initialized in this process");
29 heikki.linnakangas@i 98 [ - + ]:GNC 4 : if (!TestShmem->initialized)
29 heikki.linnakangas@i 99 [ # # ]:UNC 0 : elog(ERROR, "shmem area not yet initialized");
29 heikki.linnakangas@i 100 :GNC 4 : PG_RETURN_INT32(TestShmem->attach_count);
101 : : }
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