[Info-vax] Apache + mod_php performance

[Arne Vajhøj]

On 10/7/2024 11:52 AM, Dan Cross wrote:
> // Demonstration of a listener process that accepts
> // incoming TCP connections and passes them to a
> // worker process over Unix domain sockets.
> //
> // Dan Cross <cross at gajendra.net>
> 
> #include <sys/types.h>
> #include <sys/socket.h>
> #include <sys/uio.h>
> #include <netinet/in.h>
> 
> #include <stddef.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <unistd.h>
> #include <string.h>
> 
> // Sends a file descripter, `fd`, over a Unix domain socket `sd`
> // via the 4.4BSD access rights passing mechanism.
> //
> // Returns 1 on success, -1 on failure.
> int
> sendfd(int sd, int fd)
> {
> 	struct msghdr mh;
> 	struct iovec iv;
> 	struct cmsghdr *ptr;
> 	size_t len;
> 	int ret;
> 	char dummy;
> 
> 	// Construct the control message header.  Note this is
> 	// malloc'ed to ensure proper alignment.
> 	len = CMSG_SPACE(sizeof(int));
> 	ptr = malloc(len);
> 	if (ptr == NULL)
> 		return -1;
> 	memset(ptr, 0, len);
> 	ptr->cmsg_len = len;
> 	ptr->cmsg_level = SOL_SOCKET;
> 	ptr->cmsg_type = SCM_RIGHTS;
> 	memcpy(CMSG_DATA(ptr), &fd, sizeof(int));
> 
> 	// We send a single byte of dummy data in case the
> 	// implementation does not pass control data with an
> 	// otherwise empty data transfer.
> 	dummy = 0;
> 	memset(&iv, 0, sizeof(iv));
> 	iv.iov_base = &dummy;
> 	iv.iov_len = 1;
> 
> 	// Construct the message header.  Points to the dummy
> 	// data and the control message header.
> 	memset(&mh, 0, sizeof(mh));
> 	mh.msg_name = NULL;
> 	mh.msg_namelen = 0;
> 	mh.msg_iov = &iv;
> 	mh.msg_iovlen = 1;
> 	mh.msg_control = (caddr_t)ptr;
> 	mh.msg_controllen = len;
> 	mh.msg_flags = 0;
> 
> 	// Loop in case there's no room in the kernel buffer
> 	// to send.  Cf.Stevens et al.
> 	do {
> 		ret = sendmsg(sd, &mh, 0);
> 	} while (ret == 0);
> 	free(ptr);
> 
> 	return ret;
> }
> 
> // Receives a file descriptor over the Unix domain socket `sd`
> // and store it into `*fdp` on success.
> //
> // Returns 1 on success, 0 on EOF, -1 on error.
> int
> recvfd(int sd, int *fdp)
> {
> 	struct msghdr mh;
> 	struct iovec iv;
> 	struct cmsghdr *ptr;
> 	size_t len;
> 	int ret;
> 	char dummy;
> 
> 	if (fdp == NULL)
> 		return -1;
> 
> 	// Allocate space for the control message.
> 	len = CMSG_SPACE(sizeof(int));
> 	ptr = malloc(len);
> 	if (ptr == NULL)
> 		return -1;
> 
> 	// Fill in an iovec to receive one byte of dummy data.
> 	// Required on some systems that do not pass control
> 	// messages on empty data transfers.
> 	memset(&iv, 0, sizeof(iv));
> 	iv.iov_base = &dummy;
> 	iv.iov_len = 1;
> 
> 	// Fill in the msghdr structure.  `recvmsg(2)` will
> 	// update it.
> 	memset(&mh, 0, sizeof(mh));
> 	mh.msg_name = NULL;
> 	mh.msg_namelen = 0;
> 	mh.msg_iov = &iv;
> 	mh.msg_iovlen = 1;
> 	mh.msg_control = ptr;
> 	mh.msg_controllen = len;
> 	mh.msg_flags = 0;
> 
> 	ret = recvmsg(sd, &mh, 0);
> 	if (ret <= 0) {
> 		free(ptr);
> 		return ret;
> 	}
> 	if (mh.msg_flags != 0) {
> 		free(ptr);
> 		return -1;
> 	}
> 	memcpy(fdp, CMSG_DATA(ptr), sizeof(int));
> 	free(ptr);
> 
> 	return 1;
> }
> 
> void
> dispatcher(int sdworker, int port)
> {
> 	int sd, nsd;
> 	struct sockaddr_in sa;
> 	struct sockaddr_in client;
> 	socklen_t clientlen;
> 
> 	sd = socket(AF_INET, SOCK_STREAM, 0);
> 	if (sd < 0) {
> 		perror("socket");
> 		close(sdworker);
> 		exit(EXIT_FAILURE);
> 	}
> 	memset(&sa, 0, sizeof sa);
> 	sa.sin_family = AF_INET;
> 	sa.sin_port = htons((unsigned short)port);
> 	sa.sin_addr.s_addr = htonl(INADDR_ANY);
> 	if (bind(sd, (struct sockaddr *)&sa, sizeof sa) < 0) {
> 		perror("bind");
> 		close(sdworker);
> 		close(sd);
> 		exit(EXIT_FAILURE);
> 	}
> 	if (listen(sd, 255) < 0) {
> 		perror("listen");
> 		close(sdworker);
> 		close(sd);
> 		exit(EXIT_FAILURE);
> 	}
> 
> 	memset(&client, 0, sizeof client);
> 	clientlen = sizeof client;
> 	while ((nsd = accept(sd, (struct sockaddr *)&client, &clientlen)) >= 0) {
> 		if (sendfd(sdworker, nsd) < 0) {
> 			perror("sendfd");
> 			close(sdworker);
> 			close(nsd);
> 			close(sd);
> 			exit(EXIT_FAILURE);
> 		}
> 		close(nsd);
> 	}
> }
> 
> static void
> echo(int sd)
> {
> 	char *p;
> 	char buf[1024];
> 	ssize_t nb, wb;
> 
> 	for (;;) {
> 		nb = read(sd, buf, sizeof buf);
> 		if (nb < 0)
> 			perror("read");
> 		if (nb <= 0)
> 			return;
> 		p = buf;
> 		while (nb > 0) {
> 			wb = write(sd, p, nb);
> 			if (wb < 0)
> 				perror("write");
> 			if (wb <= 0)
> 				return;
> 			nb -= wb;
> 			p += wb;
> 		}
> 	}
> }
> 
> void
> worker(int sddispatcher)
> {
> 	int sd;
> 
> 	while (recvfd(sddispatcher, &sd) > 0) {
> 		echo(sd);
> 		close(sd);
> 	}
> }
> 
> int
> main(void)
> {
> 	int sds[2];
> 	pid_t pid;
> 
> 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sds) > 0) {
> 		perror("socketpair");
> 		exit(EXIT_FAILURE);
> 	}
> 
> 	for (int k = 0; k < 3; k++) {
> 		pid = fork();
> 		if (pid < 0) {
> 			perror("fork");
> 			exit(EXIT_FAILURE);
> 		}
> 		if (pid == 0) {	// Child
> 			close(sds[0]);
> 			worker(sds[1]);
> 			exit(EXIT_SUCCESS);
> 		}
> 	}
> 	close(sds[1]);
> 	dispatcher(sds[0], 8200);
> 
> 	return EXIT_SUCCESS;
> }

$ cc zz

    len = CMSG_SPACE(sizeof(int));
.........^
%CC-I-IMPLICITFUNC, In this statement, the identifier "CMSG_SPACE" is 
implicitly declared as a function.
at line number 33 in file DKA0:[arne]zz.c;1

    mh.msg_control = (caddr_t)ptr;
...^
%CC-E-NEEDMEMBER, In this statement, "msg_control" is not a member of "mh".
at line number 56 in file DKA0:[arne]zz.c;1

    mh.msg_controllen = len;
...^
%CC-E-NEEDMEMBER, In this statement, "msg_controllen" is not a member of 
"mh".
at line number 57 in file DKA0:[arne]zz.c;1

    mh.msg_flags = 0;
...^
%CC-E-NEEDMEMBER, In this statement, "msg_flags" is not a member of "mh".
at line number 58 in file DKA0:[arne]zz.c;1

    mh.msg_control = ptr;
...^
%CC-E-NEEDMEMBER, In this statement, "msg_control" is not a member of "mh".
at line number 100 in file DKA0:[arne]zz.c;1

    mh.msg_controllen = len;
...^
%CC-E-NEEDMEMBER, In this statement, "msg_controllen" is not a member of 
"mh".
at line number 101 in file DKA0:[arne]zz.c;1

    mh.msg_flags = 0;
...^
%CC-E-NEEDMEMBER, In this statement, "msg_flags" is not a member of "mh".
at line number 102 in file DKA0:[arne]zz.c;1

    if (mh.msg_flags != 0) {
.......^
%CC-E-NEEDMEMBER, In this statement, "msg_flags" is not a member of "mh".
at line number 108 in file DKA0:[arne]zz.c;1

       pid = fork();
............^
%CC-I-IMPLICITFUNC, In this statement, the identifier "fork" is 
implicitly declared as a function.
at line number 201 in file DKA0:[arne]zz.c;1

Arne