[lttng-ust.git] / libringbuffer / shm.c

/*
 * libringbuffer/shm.c
 *
 * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "shm.h"
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>	/* For mode constants */
#include <fcntl.h>	/* For O_* constants */
#include <assert.h>
#include <stdio.h>
#include <signal.h>
#include <dirent.h>
#include <lttng/align.h>
#include <helper.h>
#include <limits.h>
#include <helper.h>
/* FIXME: Include UUID the proper way, e.g. config.h... */
#include <uuid/uuid.h>

/*
 * Ensure we have the required amount of space available by writing 0
 * into the entire buffer. Not doing so can trigger SIGBUS when going
 * beyond the available shm space.
 */
static
int zero_file(int fd, size_t len)
{
	ssize_t retlen;
	size_t written = 0;
	char *zeropage;
	long pagelen;
	int ret;

	pagelen = sysconf(_SC_PAGESIZE);
	if (pagelen < 0)
		return (int) pagelen;
	zeropage = calloc(pagelen, 1);
	if (!zeropage)
		return -ENOMEM;

	while (len > written) {
		do {
			retlen = write(fd, zeropage,
				min_t(size_t, pagelen, len - written));
		} while (retlen == -1UL && errno == EINTR);
		if (retlen < 0) {
			ret = (int) retlen;
			goto error;
		}
		written += retlen;
	}
	ret = 0;
error:
	free(zeropage);
	return ret;
}

struct shm_object_table *shm_object_table_create(size_t max_nb_obj)
{
	struct shm_object_table *table;

	table = zmalloc(sizeof(struct shm_object_table) +
			max_nb_obj * sizeof(table->objects[0]));
	table->size = max_nb_obj;
	return table;
}

/*
 * Generate a unique name with the desired prefix.
 * Pattern is as follow: prefix-pid-uuid.
 * Caller is responsible of freeing the resulting string.
 */
static
char *gen_unique_name(const char *prefix)
{
	int written;
	pid_t pid;
	uuid_t uuid;
	char uuid_str[37];
	char tmp_name[NAME_MAX];
	char *name;

	if (!prefix)
		return NULL;

	pid = getpid();

	uuid_generate(uuid);
	uuid_unparse(uuid, uuid_str);

	written = snprintf(tmp_name, NAME_MAX,
			   "%s-%d-%s", prefix, pid, uuid_str);

	if (written < 0 || written >= NAME_MAX)
		return NULL;

	name = zmalloc(written + 1);

	if (!name)
		return NULL;

	return strncpy(name, tmp_name, written);
}

struct shm_object *shm_object_table_append(struct shm_object_table *table,
					   size_t memory_map_size)
{
	int shmfd, ret, sigblocked = 0;
	struct shm_object *obj;
	char *memory_map;

	const char *base_shm      = "/dev/shm/";
	const char *base_path     = "/tmp/lttng-fds/";
	const char *waitfd_prefix = "ust-wait";
	const char *shm_prefix    = "ust-shm";

	char *wait_pipe_path, *wait_pipe_file;
	char *shm_path, *shm_symlink_path, *shm_file;

	char tmp_name[NAME_MAX] = "ust-shm-tmp-XXXXXX";

	sigset_t all_sigs, orig_sigs;

	if (table->allocated_len >= table->size)
		return NULL;
	obj = &table->objects[table->allocated_len];

	wait_pipe_file = gen_unique_name(waitfd_prefix);

	if (!wait_pipe_file) {
		goto error_gen_unique_wait;
	}

	wait_pipe_path = zmalloc(strlen(base_path)
				 + strlen(wait_pipe_file) + 1);

	if (!wait_pipe_path) {
		free(wait_pipe_file);
		goto error_wait_alloc;
	}

	strncat(wait_pipe_path, base_path, strlen(base_path));
	strncat(wait_pipe_path, wait_pipe_file, strlen(wait_pipe_file));

	free(wait_pipe_file);

	/* wait_fd: create named pipe */
	ret = mkfifo(wait_pipe_path, 0777);
	if (ret < 0) {
		PERROR("mkfifo");
		goto error_mkfifo;
	}

	obj->wait_fd[0] = -1;
	obj->wait_fd[1] = -1;
	obj->wait_pipe_path = wait_pipe_path;

	/* shm_fd: create shm */

	/*
	 * Theoretically, we could leak a shm if the application crashes
	 * between open and unlink. Disable signals on this thread for
	 * increased safety against this scenario.
	 */
	sigfillset(&all_sigs);
	ret = pthread_sigmask(SIG_BLOCK, &all_sigs, &orig_sigs);
	if (ret == -1) {
		PERROR("pthread_sigmask");
		goto error_pthread_sigmask;
	}
	sigblocked = 1;

	/*
	 * We specifically do _not_ use the / at the beginning of the
	 * pathname so that some OS implementations can keep it local to
	 * the process (POSIX leaves this implementation-defined).
	 */
	do {
		/*
		 * Using mktemp filename with O_CREAT | O_EXCL open
		 * flags.
		 */
		mktemp(tmp_name);
		if (tmp_name[0] == '\0') {
			PERROR("mktemp");
			goto error_shm_open;
		}
		shmfd = shm_open(tmp_name,
				 O_CREAT | O_EXCL | O_RDWR, 0700);
	} while (shmfd < 0 && (errno == EEXIST || errno == EACCES));
	if (shmfd < 0) {
		PERROR("shm_open");
		goto error_shm_open;
	}

	sigblocked = 0;
	ret = pthread_sigmask(SIG_SETMASK, &orig_sigs, NULL);
	if (ret == -1) {
		PERROR("pthread_sigmask");
		goto error_sigmask_release;
	}

	/* Create unique symlink to shm */
	shm_path = zmalloc(strlen(base_shm) + strlen(tmp_name) + 1);

	if (!shm_path) {
		goto error_shm_alloc;
	}

	strncat(shm_path, base_shm, strlen(base_shm));
	strncat(shm_path, tmp_name, strlen(tmp_name));

	shm_file = gen_unique_name(shm_prefix);

	if (!shm_file) {
		free(shm_path);
		goto error_gen_unique_shm;
	}

	shm_symlink_path = zmalloc(strlen(base_path) + strlen(shm_file) + 1);

	if (!shm_symlink_path) {
		free(shm_path);
		free(shm_file);
		goto error_symlink_alloc;
	}

	strncat(shm_symlink_path, base_path, strlen(base_path));
	strncat(shm_symlink_path, shm_file, strlen(shm_file));

	free(shm_file);

	ret = symlink(shm_path, shm_symlink_path);
	if (ret < 0) {
		PERROR("symlink");
		free(shm_path);
		free(shm_symlink_path);
		goto error_symlink_shm;
	}

	free(shm_path);

	ret = zero_file(shmfd, memory_map_size);
	if (ret) {
		PERROR("zero_file");
		goto error_zero_file;
	}
	ret = ftruncate(shmfd, memory_map_size);
	if (ret) {
		PERROR("ftruncate");
		goto error_ftruncate;
	}
	obj->shm_fd = shmfd;
	obj->shm_path = shm_symlink_path;

	/* memory_map: mmap */
	memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE,
			  MAP_SHARED, shmfd, 0);
	if (memory_map == MAP_FAILED) {
		PERROR("mmap");
		goto error_mmap;
	}
	obj->memory_map = memory_map;
	obj->memory_map_size = memory_map_size;
	obj->allocated_len = 0;
	obj->index = table->allocated_len++;

	return obj;

error_mmap:
error_ftruncate:
error_zero_file:
	free(shm_symlink_path);
error_symlink_shm:
error_symlink_alloc:
error_gen_unique_shm:
error_shm_alloc:
error_sigmask_release:
	ret = close(shmfd);
	if (ret) {
		PERROR("close");
		assert(0);
	}
error_shm_open:
	if (sigblocked) {
		ret = pthread_sigmask(SIG_SETMASK, &orig_sigs, NULL);
		if (ret == -1) {
			PERROR("pthread_sigmask");
		}
	}
error_pthread_sigmask:
error_mkfifo:
	free(wait_pipe_path);
error_wait_alloc:
error_gen_unique_wait:
	return NULL;
}

struct shm_object *shm_object_table_append_shadow(struct shm_object_table *table,
			int shm_fd, int wait_fd, size_t memory_map_size)
{
	struct shm_object *obj;
	char *memory_map;

	if (table->allocated_len >= table->size)
		return NULL;
	obj = &table->objects[table->allocated_len];

	/* wait_fd: set read end of the pipe. */
	obj->wait_fd[0] = wait_fd;
	obj->wait_fd[1] = -1;	/* write end is unset. */
	obj->shm_fd = shm_fd;

	/* memory_map: mmap */
	memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE,
			  MAP_SHARED, shm_fd, 0);
	if (memory_map == MAP_FAILED) {
		PERROR("mmap");
		goto error_mmap;
	}
	obj->memory_map = memory_map;
	obj->memory_map_size = memory_map_size;
	obj->allocated_len = memory_map_size;
	obj->index = table->allocated_len++;

	return obj;

error_mmap:
	return NULL;
}

static
void shmp_object_destroy(struct shm_object *obj)
{
	int ret, i;

	if (!obj->is_shadow) {
		ret = munmap(obj->memory_map, obj->memory_map_size);
		if (ret) {
			PERROR("umnmap");
			assert(0);
		}
	}
	if (obj->shm_fd >= 0) {
		ret = close(obj->shm_fd);
		if (ret) {
			PERROR("close");
			assert(0);
		}
	}

	if (obj->shm_path) {
		free(obj->shm_path);
	}

	for (i = 0; i < 2; i++) {
		if (obj->wait_fd[i] < 0)
			continue;
		ret = close(obj->wait_fd[i]);
		if (ret) {
			PERROR("close");
			assert(0);
		}
	}

	if (obj->wait_pipe_path) {
		free(obj->wait_pipe_path);
	}
}

void shm_object_table_destroy(struct shm_object_table *table)
{
	int i;

	for (i = 0; i < table->allocated_len; i++)
		shmp_object_destroy(&table->objects[i]);
	free(table);
}

/*
 * zalloc_shm - allocate memory within a shm object.
 *
 * Shared memory is already zeroed by shmget.
 * *NOT* multithread-safe (should be protected by mutex).
 * Returns a -1, -1 tuple on error.
 */
struct shm_ref zalloc_shm(struct shm_object *obj, size_t len)
{
	struct shm_ref ref;
	struct shm_ref shm_ref_error = { -1, -1 };

	if (obj->memory_map_size - obj->allocated_len < len)
		return shm_ref_error;
	ref.index = obj->index;
	ref.offset =  obj->allocated_len;
	obj->allocated_len += len;
	return ref;
}

void align_shm(struct shm_object *obj, size_t align)
{
	size_t offset_len = offset_align(obj->allocated_len, align);
	obj->allocated_len += offset_len;
}
Commit	Line	Data
1d498196 MD	1	/*
	2	* libringbuffer/shm.c
	3	*
e92f3e28	4	* Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
1d498196	5	*
e92f3e28 MD	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Lesser General Public
	8	* License as published by the Free Software Foundation; only
	9	* version 2.1 of the License.
	10	*
	11	* This library is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* Lesser General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Lesser General Public
	17	* License along with this library; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
1d498196 MD	19	*/
	20
	21	#include "shm.h"
	22	#include <unistd.h>
bf5ff35e	23	#include <string.h>
1d498196 MD	24	#include <fcntl.h>
	25	#include <sys/mman.h>
	26	#include <sys/stat.h> /* For mode constants */
	27	#include <fcntl.h> /* For O_* constants */
	28	#include <assert.h>
8da6cd6d MD	29	#include <stdio.h>
	30	#include <signal.h>
	31	#include <dirent.h>
4318ae1b	32	#include <lttng/align.h>
35897f8b	33	#include <helper.h>
96e80018	34	#include <limits.h>
ac64486f	35	#include <helper.h>
bf5ff35e CB	36	/* FIXME: Include UUID the proper way, e.g. config.h... */
bf5ff35e CB	37	#include <uuid/uuid.h>
ac64486f MD	38
	39	/*
	40	* Ensure we have the required amount of space available by writing 0
	41	* into the entire buffer. Not doing so can trigger SIGBUS when going
	42	* beyond the available shm space.
	43	*/
	44	static
	45	int zero_file(int fd, size_t len)
	46	{
	47	ssize_t retlen;
	48	size_t written = 0;
	49	char *zeropage;
	50	long pagelen;
	51	int ret;
	52
	53	pagelen = sysconf(_SC_PAGESIZE);
	54	if (pagelen < 0)
	55	return (int) pagelen;
	56	zeropage = calloc(pagelen, 1);
	57	if (!zeropage)
	58	return -ENOMEM;
	59
	60	while (len > written) {
	61	do {
	62	retlen = write(fd, zeropage,
	63	min_t(size_t, pagelen, len - written));
	64	} while (retlen == -1UL && errno == EINTR);
	65	if (retlen < 0) {
	66	ret = (int) retlen;
	67	goto error;
	68	}
	69	written += retlen;
	70	}
	71	ret = 0;
	72	error:
	73	free(zeropage);
	74	return ret;
	75	}
1d498196 MD	76
	77	struct shm_object_table *shm_object_table_create(size_t max_nb_obj)
	78	{
	79	struct shm_object_table *table;
	80
	81	table = zmalloc(sizeof(struct shm_object_table) +
	82	max_nb_obj * sizeof(table->objects[0]));
	83	table->size = max_nb_obj;
	84	return table;
	85	}
	86
bf5ff35e CB	87	/*
	88	* Generate a unique name with the desired prefix.
	89	* Pattern is as follow: prefix-pid-uuid.
	90	* Caller is responsible of freeing the resulting string.
	91	*/
	92	static
	93	char gen_unique_name(const char prefix)
	94	{
	95	int written;
	96	pid_t pid;
	97	uuid_t uuid;
	98	char uuid_str[37];
	99	char tmp_name[NAME_MAX];
	100	char *name;
	101
	102	if (!prefix)
	103	return NULL;
	104
	105	pid = getpid();
	106
	107	uuid_generate(uuid);
	108	uuid_unparse(uuid, uuid_str);
	109
	110	written = snprintf(tmp_name, NAME_MAX,
	111	"%s-%d-%s", prefix, pid, uuid_str);
	112
	113	if (written < 0 \|\| written >= NAME_MAX)
	114	return NULL;
	115
	116	name = zmalloc(written + 1);
	117
	118	if (!name)
	119	return NULL;
	120
	121	return strncpy(name, tmp_name, written);
	122	}
	123
1d498196 MD	124	struct shm_object shm_object_table_append(struct shm_object_table table,
	125	size_t memory_map_size)
	126	{
bf5ff35e	127	int shmfd, ret, sigblocked = 0;
1d498196 MD	128	struct shm_object *obj;
1d498196 MD	129	char *memory_map;
bf5ff35e CB	130
	131	const char *base_shm = "/dev/shm/";
	132	const char *base_path = "/tmp/lttng-fds/";
	133	const char *waitfd_prefix = "ust-wait";
	134	const char *shm_prefix = "ust-shm";
	135
	136	char wait_pipe_path, wait_pipe_file;
	137	char shm_path, shm_symlink_path, *shm_file;
	138
8da6cd6d	139	char tmp_name[NAME_MAX] = "ust-shm-tmp-XXXXXX";
bf5ff35e	140
8da6cd6d	141	sigset_t all_sigs, orig_sigs;
1d498196 MD	142
	143	if (table->allocated_len >= table->size)
	144	return NULL;
7a9c21bd	145	obj = &table->objects[table->allocated_len];
1d498196	146
bf5ff35e CB	147	wait_pipe_file = gen_unique_name(waitfd_prefix);
	148
	149	if (!wait_pipe_file) {
	150	goto error_gen_unique_wait;
1d498196	151	}
bf5ff35e CB	152
	153	wait_pipe_path = zmalloc(strlen(base_path)
	154	+ strlen(wait_pipe_file) + 1);
	155
	156	if (!wait_pipe_path) {
	157	free(wait_pipe_file);
	158	goto error_wait_alloc;
1d498196	159	}
bf5ff35e CB	160
	161	strncat(wait_pipe_path, base_path, strlen(base_path));
	162	strncat(wait_pipe_path, wait_pipe_file, strlen(wait_pipe_file));
	163
	164	free(wait_pipe_file);
	165
	166	/* wait_fd: create named pipe */
	167	ret = mkfifo(wait_pipe_path, 0777);
5d61a504	168	if (ret < 0) {
bf5ff35e CB	169	PERROR("mkfifo");
bf5ff35e CB	170	goto error_mkfifo;
5d61a504	171	}
bf5ff35e CB	172
	173	obj->wait_fd[0] = -1;
	174	obj->wait_fd[1] = -1;
	175	obj->wait_pipe_path = wait_pipe_path;
1d498196 MD	176
	177	/* shm_fd: create shm */
	178
8da6cd6d MD	179	/*
	180	* Theoretically, we could leak a shm if the application crashes
	181	* between open and unlink. Disable signals on this thread for
	182	* increased safety against this scenario.
	183	*/
	184	sigfillset(&all_sigs);
	185	ret = pthread_sigmask(SIG_BLOCK, &all_sigs, &orig_sigs);
	186	if (ret == -1) {
	187	PERROR("pthread_sigmask");
	188	goto error_pthread_sigmask;
	189	}
5a61337d	190	sigblocked = 1;
8da6cd6d	191
1d498196	192	/*
1d498196 MD	193	* We specifically do _not_ use the / at the beginning of the
	194	* pathname so that some OS implementations can keep it local to
	195	* the process (POSIX leaves this implementation-defined).
	196	*/
	197	do {
8da6cd6d MD	198	/*
	199	* Using mktemp filename with O_CREAT \| O_EXCL open
	200	* flags.
	201	*/
	202	mktemp(tmp_name);
	203	if (tmp_name[0] == '\0') {
	204	PERROR("mktemp");
	205	goto error_shm_open;
a8803897	206	}
8da6cd6d	207	shmfd = shm_open(tmp_name,
1d498196	208	O_CREAT \| O_EXCL \| O_RDWR, 0700);
8da6cd6d	209	} while (shmfd < 0 && (errno == EEXIST \|\| errno == EACCES));
1d498196 MD	210	if (shmfd < 0) {
	211	PERROR("shm_open");
	212	goto error_shm_open;
	213	}
bf5ff35e	214
5a61337d	215	sigblocked = 0;
8da6cd6d MD	216	ret = pthread_sigmask(SIG_SETMASK, &orig_sigs, NULL);
	217	if (ret == -1) {
	218	PERROR("pthread_sigmask");
5a61337d	219	goto error_sigmask_release;
8da6cd6d	220	}
bf5ff35e CB	221
	222	/* Create unique symlink to shm */
	223	shm_path = zmalloc(strlen(base_shm) + strlen(tmp_name) + 1);
	224
	225	if (!shm_path) {
	226	goto error_shm_alloc;
	227	}
	228
	229	strncat(shm_path, base_shm, strlen(base_shm));
	230	strncat(shm_path, tmp_name, strlen(tmp_name));
	231
	232	shm_file = gen_unique_name(shm_prefix);
	233
	234	if (!shm_file) {
	235	free(shm_path);
	236	goto error_gen_unique_shm;
	237	}
	238
	239	shm_symlink_path = zmalloc(strlen(base_path) + strlen(shm_file) + 1);
	240
	241	if (!shm_symlink_path) {
	242	free(shm_path);
	243	free(shm_file);
	244	goto error_symlink_alloc;
	245	}
	246
	247	strncat(shm_symlink_path, base_path, strlen(base_path));
	248	strncat(shm_symlink_path, shm_file, strlen(shm_file));
	249
	250	free(shm_file);
	251
	252	ret = symlink(shm_path, shm_symlink_path);
	253	if (ret < 0) {
	254	PERROR("symlink");
	255	free(shm_path);
	256	free(shm_symlink_path);
	257	goto error_symlink_shm;
	258	}
	259
	260	free(shm_path);
	261
ac64486f MD	262	ret = zero_file(shmfd, memory_map_size);
	263	if (ret) {
	264	PERROR("zero_file");
	265	goto error_zero_file;
	266	}
1d498196 MD	267	ret = ftruncate(shmfd, memory_map_size);
	268	if (ret) {
	269	PERROR("ftruncate");
	270	goto error_ftruncate;
	271	}
	272	obj->shm_fd = shmfd;
bf5ff35e	273	obj->shm_path = shm_symlink_path;
1d498196 MD	274
	275	/* memory_map: mmap */
	276	memory_map = mmap(NULL, memory_map_size, PROT_READ \| PROT_WRITE,
	277	MAP_SHARED, shmfd, 0);
	278	if (memory_map == MAP_FAILED) {
	279	PERROR("mmap");
	280	goto error_mmap;
	281	}
	282	obj->memory_map = memory_map;
	283	obj->memory_map_size = memory_map_size;
	284	obj->allocated_len = 0;
dc613eb9	285	obj->index = table->allocated_len++;
7a9c21bd	286
1d498196 MD	287	return obj;
	288
	289	error_mmap:
	290	error_ftruncate:
ac64486f	291	error_zero_file:
bf5ff35e CB	292	free(shm_symlink_path);
	293	error_symlink_shm:
	294	error_symlink_alloc:
	295	error_gen_unique_shm:
	296	error_shm_alloc:
5a61337d	297	error_sigmask_release:
1d498196 MD	298	ret = close(shmfd);
	299	if (ret) {
	300	PERROR("close");
	301	assert(0);
	302	}
	303	error_shm_open:
5a61337d MD	304	if (sigblocked) {
	305	ret = pthread_sigmask(SIG_SETMASK, &orig_sigs, NULL);
	306	if (ret == -1) {
	307	PERROR("pthread_sigmask");
	308	}
	309	}
8da6cd6d	310	error_pthread_sigmask:
bf5ff35e CB	311	error_mkfifo:
	312	free(wait_pipe_path);
	313	error_wait_alloc:
	314	error_gen_unique_wait:
1d498196	315	return NULL;
1d498196 MD	316	}
1d498196 MD	317
193183fb MD	318	struct shm_object shm_object_table_append_shadow(struct shm_object_table table,
	319	int shm_fd, int wait_fd, size_t memory_map_size)
	320	{
	321	struct shm_object *obj;
	322	char *memory_map;
	323
	324	if (table->allocated_len >= table->size)
	325	return NULL;
	326	obj = &table->objects[table->allocated_len];
	327
	328	/* wait_fd: set read end of the pipe. */
	329	obj->wait_fd[0] = wait_fd;
	330	obj->wait_fd[1] = -1; /* write end is unset. */
	331	obj->shm_fd = shm_fd;
	332
	333	/* memory_map: mmap */
	334	memory_map = mmap(NULL, memory_map_size, PROT_READ \| PROT_WRITE,
	335	MAP_SHARED, shm_fd, 0);
	336	if (memory_map == MAP_FAILED) {
	337	PERROR("mmap");
	338	goto error_mmap;
	339	}
	340	obj->memory_map = memory_map;
	341	obj->memory_map_size = memory_map_size;
	342	obj->allocated_len = memory_map_size;
	343	obj->index = table->allocated_len++;
	344
	345	return obj;
	346
	347	error_mmap:
	348	return NULL;
	349	}
	350
1d498196 MD	351	static
	352	void shmp_object_destroy(struct shm_object *obj)
	353	{
	354	int ret, i;
	355
7a784989 MD	356	if (!obj->is_shadow) {
	357	ret = munmap(obj->memory_map, obj->memory_map_size);
	358	if (ret) {
	359	PERROR("umnmap");
	360	assert(0);
	361	}
	362	}
ef9ff354 MD	363	if (obj->shm_fd >= 0) {
	364	ret = close(obj->shm_fd);
	365	if (ret) {
	366	PERROR("close");
	367	assert(0);
	368	}
1d498196	369	}
bf5ff35e CB	370
	371	if (obj->shm_path) {
	372	free(obj->shm_path);
	373	}
	374
1d498196	375	for (i = 0; i < 2; i++) {
824f40b8 MD	376	if (obj->wait_fd[i] < 0)
824f40b8 MD	377	continue;
1d498196 MD	378	ret = close(obj->wait_fd[i]);
	379	if (ret) {
	380	PERROR("close");
	381	assert(0);
	382	}
	383	}
bf5ff35e CB	384
	385	if (obj->wait_pipe_path) {
	386	free(obj->wait_pipe_path);
	387	}
1d498196 MD	388	}
	389
	390	void shm_object_table_destroy(struct shm_object_table *table)
	391	{
	392	int i;
	393
	394	for (i = 0; i < table->allocated_len; i++)
	395	shmp_object_destroy(&table->objects[i]);
	396	free(table);
	397	}
	398
	399	/*
	400	* zalloc_shm - allocate memory within a shm object.
	401	*
	402	* Shared memory is already zeroed by shmget.
	403	* NOT multithread-safe (should be protected by mutex).
	404	* Returns a -1, -1 tuple on error.
	405	*/
	406	struct shm_ref zalloc_shm(struct shm_object *obj, size_t len)
	407	{
	408	struct shm_ref ref;
	409	struct shm_ref shm_ref_error = { -1, -1 };
	410
	411	if (obj->memory_map_size - obj->allocated_len < len)
	412	return shm_ref_error;
	413	ref.index = obj->index;
	414	ref.offset = obj->allocated_len;
	415	obj->allocated_len += len;
	416	return ref;
	417	}
	418
	419	void align_shm(struct shm_object *obj, size_t align)
	420	{
	421	size_t offset_len = offset_align(obj->allocated_len, align);
	422	obj->allocated_len += offset_len;
	423	}