test_shmem.c File Reference

#include "postgres.h"
#include "fmgr.h"
#include "miscadmin.h"
#include "storage/shmem.h"

Include dependency graph for test_shmem.c:

Go to the source code of this file.

Data Structures
struct	TestShmemData

Typedefs
typedef struct TestShmemData	TestShmemData

Functions
static void	test_shmem_request (void *arg)
static void	test_shmem_init (void *arg)
static void	test_shmem_attach (void *arg)
void	_PG_init (void)
	PG_FUNCTION_INFO_V1 (get_test_shmem_attach_count)
Datum	get_test_shmem_attach_count (PG_FUNCTION_ARGS)

Variables
	PG_MODULE_MAGIC
static TestShmemData *	TestShmem
static bool	attached_or_initialized = false
static const ShmemCallbacks	TestShmemCallbacks

Typedef Documentation

TestShmemData

typedef struct TestShmemData TestShmemData

Function Documentation

_PG_init()

void _PG_init

(

void

)

Definition at line 86 of file test_shmem.c.

{
    elog(LOG, "test_shmem module's _PG_init called");
    RegisterShmemCallbacks(&TestShmemCallbacks);
}

References elog, LOG, RegisterShmemCallbacks(), and TestShmemCallbacks.

get_test_shmem_attach_count()

Datum get_test_shmem_attach_count

(

PG_FUNCTION_ARGS

)

Definition at line 94 of file test_shmem.c.

{
    if (!attached_or_initialized)
        elog(ERROR, "shmem area not attached or initialized in this process");
    if (!TestShmem->initialized)
        elog(ERROR, "shmem area not yet initialized");
    PG_RETURN_INT32(TestShmem->attach_count);
}

References TestShmemData::attach_count, attached_or_initialized, elog, ERROR, TestShmemData::initialized, PG_RETURN_INT32, and TestShmem.

PG_FUNCTION_INFO_V1()

PG_FUNCTION_INFO_V1

(

get_test_shmem_attach_count

)

test_shmem_attach()

static void test_shmem_attach ( void *  arg )

static

Definition at line 73 of file test_shmem.c.

{
    elog(LOG, "test_shmem_attach callback called");
    if (!TestShmem->initialized)
        elog(ERROR, "shmem area not yet initialized");
    TestShmem->attach_count++;
 
    if (attached_or_initialized)
        elog(ERROR, "attach or initialize already called in this process");
    attached_or_initialized = true;
}

References TestShmemData::attach_count, attached_or_initialized, elog, ERROR, TestShmemData::initialized, LOG, and TestShmem.

test_shmem_init()

static void test_shmem_init ( void *  arg )

static

Definition at line 60 of file test_shmem.c.

{
    elog(LOG, "init callback called");
    if (TestShmem->initialized)
        elog(ERROR, "shmem area already initialized");
    TestShmem->initialized = true;
 
    if (attached_or_initialized)
        elog(ERROR, "attach or initialize already called in this process");
    attached_or_initialized = true;
}

References attached_or_initialized, elog, ERROR, TestShmemData::initialized, LOG, and TestShmem.

test_shmem_request()

static void test_shmem_request ( void *  arg )

static

Definition at line 50 of file test_shmem.c.

{
    elog(LOG, "test_shmem_request callback called");
 
    ShmemRequestStruct(.name = "test_shmem area",
                       .size = sizeof(TestShmemData),
                       .ptr = (void **) &TestShmem);
}

References elog, LOG, name, ShmemRequestStruct, and TestShmem.

Variable Documentation

attached_or_initialized

bool attached_or_initialized = false

static

Definition at line 36 of file test_shmem.c.

Referenced by get_test_shmem_attach_count(), test_shmem_attach(), and test_shmem_init().

PG_MODULE_MAGIC

PG_MODULE_MAGIC

Definition at line 25 of file test_shmem.c.

TestShmem

TestShmemData* TestShmem

static

Definition at line 34 of file test_shmem.c.

Referenced by get_test_shmem_attach_count(), test_shmem_attach(), test_shmem_init(), and test_shmem_request().

TestShmemCallbacks

const ShmemCallbacks TestShmemCallbacks

static

Initial value:

= {
    .flags = SHMEM_CALLBACKS_ALLOW_AFTER_STARTUP,
    .request_fn = test_shmem_request,
    .init_fn = test_shmem_init,
    .attach_fn = test_shmem_attach,
}

Definition at line 42 of file test_shmem.c.

                                                 {
    .flags = SHMEM_CALLBACKS_ALLOW_AFTER_STARTUP,
    .request_fn = test_shmem_request,
    .init_fn = test_shmem_init,
    .attach_fn = test_shmem_attach,
};

Referenced by _PG_init().