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/*
* Copyright (C) Max Romanov
* Copyright (C) NGINX, Inc.
*/
#ifndef NXT_CONFIGURE
#include "nxt_go_port_memory.h"
#include "nxt_go_process.h"
#include "nxt_go_array.h"
#include "nxt_go_log.h"
#include <nxt_go_gen.h>
#include <nxt_main.h>
#if (NXT_HAVE_MEMFD_CREATE)
#include <linux/memfd.h>
#include <unistd.h>
#include <sys/syscall.h>
#endif
static nxt_port_mmap_header_t *
nxt_go_new_port_mmap(nxt_go_process_t *process, nxt_port_id_t id)
{
int name_len, rc;
void *mem;
char name[64];
nxt_fd_t fd;
nxt_port_msg_t port_msg;
nxt_port_mmap_t *port_mmap;
nxt_port_mmap_header_t *hdr;
fd = -1;
union {
struct cmsghdr cm;
char space[CMSG_SPACE(sizeof(int))];
} cmsg;
port_mmap = nxt_go_array_zero_add(&process->outgoing);
if (nxt_slow_path(port_mmap == NULL)) {
nxt_go_warn("failed to add port mmap to outgoing array");
return NULL;
}
name_len = snprintf(name, sizeof(name) - 1, "/nginext.go.%p", name);
#if (NXT_HAVE_MEMFD_CREATE)
fd = syscall(SYS_memfd_create, name, MFD_CLOEXEC);
if (nxt_slow_path(fd == -1)) {
nxt_go_warn("memfd_create(%s) failed %d", name, errno);
goto remove_fail;
}
nxt_go_debug("memfd_create(%s): %d", name, fd);
#elif (NXT_HAVE_SHM_OPEN)
shm_unlink((char *) name); // just in case
fd = shm_open((char *) name, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
nxt_go_debug("shm_open(%s): %d", name, fd);
if (nxt_slow_path(fd == -1)) {
nxt_go_warn("shm_open(%s) failed %d", name, errno);
goto remove_fail;
}
if (nxt_slow_path(shm_unlink((char *) name) == -1)) {
nxt_go_warn("shm_unlink(%s) failed %d", name, errno);
}
#endif
if (nxt_slow_path(ftruncate(fd, PORT_MMAP_SIZE) == -1)) {
nxt_go_warn("ftruncate() failed %d", errno);
goto remove_fail;
}
mem = mmap(NULL, PORT_MMAP_SIZE,
PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (nxt_slow_path(mem == MAP_FAILED)) {
goto remove_fail;
}
port_mmap->hdr = mem;
/* Init segment header. */
hdr = port_mmap->hdr;
memset(hdr->free_map, 0xFFU, sizeof(hdr->free_map));
hdr->id = process->outgoing.nelts - 1;
hdr->pid = process->pid;
/* Mark first chunk as busy */
nxt_port_mmap_set_chunk_busy(hdr, 0);
/* Mark as busy chunk followed the last available chunk. */
nxt_port_mmap_set_chunk_busy(hdr, PORT_MMAP_CHUNK_COUNT);
port_msg.stream = 0;
port_msg.pid = getpid();
port_msg.reply_port = 0;
port_msg.type = _NXT_PORT_MSG_MMAP;
port_msg.last = 1;
port_msg.mmap = 0;
cmsg.cm.cmsg_len = CMSG_LEN(sizeof(int));
cmsg.cm.cmsg_level = SOL_SOCKET;
cmsg.cm.cmsg_type = SCM_RIGHTS;
/*
* nxt_memcpy() is used instead of simple
* *(int *) CMSG_DATA(&cmsg.cm) = fd;
* because GCC 4.4 with -O2/3/s optimization may issue a warning:
* dereferencing type-punned pointer will break strict-aliasing rules
*
* Fortunately, GCC with -O1 compiles this nxt_memcpy()
* in the same simple assignment as in the code above.
*/
memcpy(CMSG_DATA(&cmsg.cm), &fd, sizeof(int));
rc = nxt_go_port_send(hdr->pid, id, &port_msg, sizeof(port_msg),
&cmsg, sizeof(cmsg));
nxt_go_debug("new mmap #%d created for %d -> %d",
(int)hdr->id, (int)getpid(), (int)process->pid);
close(fd);
return hdr;
remove_fail:
if (fd != -1) {
close(fd);
}
process->outgoing.nelts--;
return NULL;
}
nxt_port_mmap_header_t *
nxt_go_port_mmap_get(nxt_go_process_t *process, nxt_port_id_t port_id,
nxt_chunk_id_t *c)
{
nxt_port_mmap_t *port_mmap;
nxt_port_mmap_t *end_port_mmap;
nxt_port_mmap_header_t *hdr;
port_mmap = NULL;
hdr = NULL;
nxt_go_mutex_lock(&process->outgoing_mutex);
port_mmap = process->outgoing.elts;
end_port_mmap = port_mmap + process->outgoing.nelts;
while (port_mmap < end_port_mmap) {
if (nxt_port_mmap_get_free_chunk(port_mmap->hdr, c)) {
hdr = port_mmap->hdr;
goto unlock_return;
}
port_mmap++;
}
hdr = nxt_go_new_port_mmap(process, port_id);
unlock_return:
nxt_go_mutex_unlock(&process->outgoing_mutex);
return hdr;
}
#endif /* NXT_CONFIGURE */
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