memory.c

来自「postgresql8.3.4源码,开源数据库」· C语言 代码 · 共 154 行

/* $PostgreSQL: pgsql/src/interfaces/ecpg/ecpglib/memory.c,v 1.12 2007/11/15 21:14:45 momjian Exp $ */

#define POSTGRES_ECPG_INTERNAL
#include "postgres_fe.h"

#include "ecpg-pthread-win32.h"
#include "ecpgtype.h"
#include "ecpglib.h"
#include "ecpgerrno.h"
#include "extern.h"

void
ecpg_free(void *ptr)
{
	free(ptr);
}

char *
ecpg_alloc(long size, int lineno)
{
	char	   *new = (char *) calloc(1L, size);

	if (!new)
	{
		ecpg_raise(lineno, ECPG_OUT_OF_MEMORY, ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
		return NULL;
	}

	return (new);
}

char *
ecpg_realloc(void *ptr, long size, int lineno)
{
	char	   *new = (char *) realloc(ptr, size);

	if (!new)
	{
		ecpg_raise(lineno, ECPG_OUT_OF_MEMORY, ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
		return NULL;
	}

	return (new);
}

char *
ecpg_strdup(const char *string, int lineno)
{
	char	   *new;

	if (string == NULL)
		return NULL;

	new = strdup(string);
	if (!new)
	{
		ecpg_raise(lineno, ECPG_OUT_OF_MEMORY, ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
		return NULL;
	}

	return (new);
}

/* keep a list of memory we allocated for the user */
struct auto_mem
{
	void	   *pointer;
	struct auto_mem *next;
};

#ifdef ENABLE_THREAD_SAFETY
static pthread_key_t auto_mem_key;
static pthread_once_t auto_mem_once = PTHREAD_ONCE_INIT;

static void
auto_mem_destructor(void *arg)
{
	ECPGfree_auto_mem();
}

static void
auto_mem_key_init(void)
{
	pthread_key_create(&auto_mem_key, auto_mem_destructor);
}

static struct auto_mem *
get_auto_allocs(void)
{
	pthread_once(&auto_mem_once, auto_mem_key_init);
	return (struct auto_mem *) pthread_getspecific(auto_mem_key);
}

static void
set_auto_allocs(struct auto_mem * am)
{
	pthread_setspecific(auto_mem_key, am);
}
#else
static struct auto_mem *auto_allocs = NULL;

#define get_auto_allocs()		(auto_allocs)
#define set_auto_allocs(am)		do { auto_allocs = (am); } while(0)
#endif

void
ecpg_add_mem(void *ptr, int lineno)
{
	struct auto_mem *am = (struct auto_mem *) ecpg_alloc(sizeof(struct auto_mem), lineno);

	am->pointer = ptr;
	am->next = get_auto_allocs();
	set_auto_allocs(am);
}

void
ECPGfree_auto_mem(void)
{
	struct auto_mem *am = get_auto_allocs();

	/* free all memory we have allocated for the user */
	if (am)
	{
		do
		{
			struct auto_mem *act = am;

			am = am->next;
			ecpg_free(act->pointer);
			ecpg_free(act);
		} while (am);
		set_auto_allocs(NULL);
	}
}

void
ecpg_clear_auto_mem(void)
{
	struct auto_mem *am = get_auto_allocs();

	/* only free our own structure */
	if (am)
	{
		do
		{
			struct auto_mem *act = am;

			am = am->next;
			ecpg_free(act);
		} while (am);
		set_auto_allocs(NULL);
	}
}