src/ev_epoll.c - haproxy - Gitiles

 /*
  * FD polling functions for Linux epoll
  *
  * Copyright 2000-2014 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */

 #include <unistd.h>
 #include <sys/time.h>
 #include <sys/types.h>

 #include <common/compat.h>
 #include <common/config.h>
 #include <common/debug.h>
 #include <common/epoll.h>
 #include <common/standard.h>
 #include <common/ticks.h>
 #include <common/time.h>
 #include <common/tools.h>

 #include <types/global.h>

 #include <proto/fd.h>


 /* private data */
 static THREAD_LOCAL struct epoll_event *epoll_events = NULL;
 static int epoll_fd;

 /* This structure may be used for any purpose. Warning! do not use it in
  * recursive functions !
  */
 static THREAD_LOCAL struct epoll_event ev;

 #ifndef EPOLLRDHUP
 /* EPOLLRDHUP was defined late in libc, and it appeared in kernel 2.6.17 */
 #define EPOLLRDHUP 0x2000
 #endif

 /*
  * Immediately remove file descriptor from epoll set upon close.
  * Since we forked, some fds share inodes with the other process, and epoll may
  * send us events even though this process closed the fd (see man 7 epoll,
  * "Questions and answers", Q 6).
  */
 REGPRM1 static void __fd_clo(int fd)
 {
 	if (unlikely(fdtab[fd].cloned))
 		epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, &ev);
 }

 /*
  * Linux epoll() poller
  */
 REGPRM2 static void _do_poll(struct poller *p, int exp)
 {
 	int status, eo, en;
 	int fd, opcode;
 	int count;
 	int updt_idx;
 	int wait_time;

 	/* first, scan the update list to find polling changes */
 	for (updt_idx = 0; updt_idx < fd_nbupdt; updt_idx++) {
 		fd = fd_updt[updt_idx];

 		if (!fdtab[fd].owner)
 			continue;

 		SPIN_LOCK(FD_LOCK, &fdtab[fd].lock);
 		fdtab[fd].updated = 0;
 		fdtab[fd].new = 0;

 		eo = fdtab[fd].state;
 		en = fd_compute_new_polled_status(eo);
 		fdtab[fd].state = en;
 		SPIN_UNLOCK(FD_LOCK, &fdtab[fd].lock);

 		if ((eo ^ en) & FD_EV_POLLED_RW) {
 			/* poll status changed */

 			if ((en & FD_EV_POLLED_RW) == 0) {
 				/* fd removed from poll list */
 				opcode = EPOLL_CTL_DEL;
 			}
 			else if ((eo & FD_EV_POLLED_RW) == 0) {
 				/* new fd in the poll list */
 				opcode = EPOLL_CTL_ADD;
 			}
 			else {
 				/* fd status changed */
 				opcode = EPOLL_CTL_MOD;
 			}

 			/* construct the epoll events based on new state */
 			ev.events = 0;
 			if (en & FD_EV_POLLED_R)
 				ev.events |= EPOLLIN | EPOLLRDHUP;

 			if (en & FD_EV_POLLED_W)
 				ev.events |= EPOLLOUT;

 			ev.data.fd = fd;

 			epoll_ctl(epoll_fd, opcode, fd, &ev);
 		}
 	}
 	fd_nbupdt = 0;

 	/* compute the epoll_wait() timeout */
 	if (!exp)
 		wait_time = MAX_DELAY_MS;
 	else if (tick_is_expired(exp, now_ms))
 		wait_time = 0;
 	else {
 		wait_time = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
 		if (wait_time > MAX_DELAY_MS)
 			wait_time = MAX_DELAY_MS;
 	}

 	/* now let's wait for polled events */

 	gettimeofday(&before_poll, NULL);
 	status = epoll_wait(epoll_fd, epoll_events, global.tune.maxpollevents, wait_time);
 	tv_update_date(wait_time, status);
 	measure_idle();

 	/* process polled events */

 	for (count = 0; count < status; count++) {
 		unsigned int n;
 		unsigned int e = epoll_events[count].events;
 		fd = epoll_events[count].data.fd;

 		if (!fdtab[fd].owner || !(fdtab[fd].thread_mask & tid_bit))
 			continue;

 		/* it looks complicated but gcc can optimize it away when constants
 		 * have same values... In fact it depends on gcc :-(
 		 */
 		if (EPOLLIN == FD_POLL_IN && EPOLLOUT == FD_POLL_OUT &&
 		    EPOLLPRI == FD_POLL_PRI && EPOLLERR == FD_POLL_ERR &&
 		    EPOLLHUP == FD_POLL_HUP) {
 			n = e & (EPOLLIN|EPOLLOUT|EPOLLPRI|EPOLLERR|EPOLLHUP);
 		}
 		else {
 			n =	((e & EPOLLIN ) ? FD_POLL_IN  : 0) |
 				((e & EPOLLPRI) ? FD_POLL_PRI : 0) |
 				((e & EPOLLOUT) ? FD_POLL_OUT : 0) |
 				((e & EPOLLERR) ? FD_POLL_ERR : 0) |
 				((e & EPOLLHUP) ? FD_POLL_HUP : 0);
 		}

 		/* always remap RDHUP to HUP as they're used similarly */
 		if (e & EPOLLRDHUP) {
 			HA_ATOMIC_OR(&cur_poller.flags, HAP_POLL_F_RDHUP);
 			n |= FD_POLL_HUP;
 		}
 		fd_update_events(fd, n);
 	}
 	/* the caller will take care of cached events */
 }

 static int init_epoll_per_thread()
 {
 	epoll_events = calloc(1, sizeof(struct epoll_event) * global.tune.maxpollevents);
 	if (epoll_events == NULL)
 		return 0;
 	return 1;
 }

 static void deinit_epoll_per_thread()
 {
 	free(epoll_events);
 	epoll_events = NULL;
 }

 /*
  * Initialization of the epoll() poller.
  * Returns 0 in case of failure, non-zero in case of success. If it fails, it
  * disables the poller by setting its pref to 0.
  */
 REGPRM1 static int _do_init(struct poller *p)
 {
 	p->private = NULL;

 	epoll_fd = epoll_create(global.maxsock + 1);
 	if (epoll_fd < 0)
 		goto fail_fd;

 	hap_register_per_thread_init(init_epoll_per_thread);
 	hap_register_per_thread_deinit(deinit_epoll_per_thread);

 	return 1;

  fail_fd:
 	p->pref = 0;
 	return 0;
 }

 /*
  * Termination of the epoll() poller.
  * Memory is released and the poller is marked as unselectable.
  */
 REGPRM1 static void _do_term(struct poller *p)
 {
 	if (epoll_fd >= 0) {
 		close(epoll_fd);
 		epoll_fd = -1;
 	}

 	p->private = NULL;
 	p->pref = 0;
 }

 /*
  * Check that the poller works.
  * Returns 1 if OK, otherwise 0.
  */
 REGPRM1 static int _do_test(struct poller *p)
 {
 	int fd;

 	fd = epoll_create(global.maxsock + 1);
 	if (fd < 0)
 		return 0;
 	close(fd);
 	return 1;
 }

 /*
  * Recreate the epoll file descriptor after a fork(). Returns 1 if OK,
  * otherwise 0. It will ensure that all processes will not share their
  * epoll_fd. Some side effects were encountered because of this, such
  * as epoll_wait() returning an FD which was previously deleted.
  */
 REGPRM1 static int _do_fork(struct poller *p)
 {
 	if (epoll_fd >= 0)
 		close(epoll_fd);
 	epoll_fd = epoll_create(global.maxsock + 1);
 	if (epoll_fd < 0)
 		return 0;
 	return 1;
 }

 /*
  * It is a constructor, which means that it will automatically be called before
  * main(). This is GCC-specific but it works at least since 2.95.
  * Special care must be taken so that it does not need any uninitialized data.
  */
 __attribute__((constructor))
 static void _do_register(void)
 {
 	struct poller *p;

 	if (nbpollers >= MAX_POLLERS)
 		return;

 	epoll_fd = -1;
 	p = &pollers[nbpollers++];

 	p->name = "epoll";
 	p->pref = 300;
 	p->flags = 0;
 	p->private = NULL;

 	p->clo  = __fd_clo;
 	p->test = _do_test;
 	p->init = _do_init;
 	p->term = _do_term;
 	p->poll = _do_poll;
 	p->fork = _do_fork;
 }


 /*
  * Local variables:
  *  c-indent-level: 8
  *  c-basic-offset: 8
  * End:
  */
	/*
	* FD polling functions for Linux epoll
	*
	* Copyright 2000-2014 Willy Tarreau <w@1wt.eu>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*/

	#include <unistd.h>
	#include <sys/time.h>
	#include <sys/types.h>

	#include <common/compat.h>
	#include <common/config.h>
	#include <common/debug.h>
	#include <common/epoll.h>
	#include <common/standard.h>
	#include <common/ticks.h>
	#include <common/time.h>
	#include <common/tools.h>

	#include <types/global.h>

	#include <proto/fd.h>


	/* private data */
	static THREAD_LOCAL struct epoll_event *epoll_events = NULL;
	static int epoll_fd;

	/* This structure may be used for any purpose. Warning! do not use it in
	* recursive functions !
	*/
	static THREAD_LOCAL struct epoll_event ev;

	#ifndef EPOLLRDHUP
	/* EPOLLRDHUP was defined late in libc, and it appeared in kernel 2.6.17 */
	#define EPOLLRDHUP 0x2000
	#endif

	/*
	* Immediately remove file descriptor from epoll set upon close.
	* Since we forked, some fds share inodes with the other process, and epoll may
	* send us events even though this process closed the fd (see man 7 epoll,
	* "Questions and answers", Q 6).
	*/
	REGPRM1 static void __fd_clo(int fd)
	{
	if (unlikely(fdtab[fd].cloned))
	epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, &ev);
	}

	/*
	* Linux epoll() poller
	*/
	REGPRM2 static void _do_poll(struct poller *p, int exp)
	{
	int status, eo, en;
	int fd, opcode;
	int count;
	int updt_idx;
	int wait_time;

	/* first, scan the update list to find polling changes */
	for (updt_idx = 0; updt_idx < fd_nbupdt; updt_idx++) {
	fd = fd_updt[updt_idx];

	if (!fdtab[fd].owner)
	continue;

	SPIN_LOCK(FD_LOCK, &fdtab[fd].lock);
	fdtab[fd].updated = 0;
	fdtab[fd].new = 0;

	eo = fdtab[fd].state;
	en = fd_compute_new_polled_status(eo);
	fdtab[fd].state = en;
	SPIN_UNLOCK(FD_LOCK, &fdtab[fd].lock);

	if ((eo ^ en) & FD_EV_POLLED_RW) {
	/* poll status changed */

	if ((en & FD_EV_POLLED_RW) == 0) {
	/* fd removed from poll list */
	opcode = EPOLL_CTL_DEL;
	}
	else if ((eo & FD_EV_POLLED_RW) == 0) {
	/* new fd in the poll list */
	opcode = EPOLL_CTL_ADD;
	}
	else {
	/* fd status changed */
	opcode = EPOLL_CTL_MOD;
	}

	/* construct the epoll events based on new state */
	ev.events = 0;
	if (en & FD_EV_POLLED_R)
	ev.events \|= EPOLLIN \| EPOLLRDHUP;

	if (en & FD_EV_POLLED_W)
	ev.events \|= EPOLLOUT;

	ev.data.fd = fd;

	epoll_ctl(epoll_fd, opcode, fd, &ev);
	}
	}
	fd_nbupdt = 0;

	/* compute the epoll_wait() timeout */
	if (!exp)
	wait_time = MAX_DELAY_MS;
	else if (tick_is_expired(exp, now_ms))
	wait_time = 0;
	else {
	wait_time = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
	if (wait_time > MAX_DELAY_MS)
	wait_time = MAX_DELAY_MS;
	}

	/* now let's wait for polled events */

	gettimeofday(&before_poll, NULL);
	status = epoll_wait(epoll_fd, epoll_events, global.tune.maxpollevents, wait_time);
	tv_update_date(wait_time, status);
	measure_idle();

	/* process polled events */

	for (count = 0; count < status; count++) {
	unsigned int n;
	unsigned int e = epoll_events[count].events;
	fd = epoll_events[count].data.fd;

	if (!fdtab[fd].owner \|\| !(fdtab[fd].thread_mask & tid_bit))
	continue;

	/* it looks complicated but gcc can optimize it away when constants
	* have same values... In fact it depends on gcc :-(
	*/
	if (EPOLLIN == FD_POLL_IN && EPOLLOUT == FD_POLL_OUT &&
	EPOLLPRI == FD_POLL_PRI && EPOLLERR == FD_POLL_ERR &&
	EPOLLHUP == FD_POLL_HUP) {
	n = e & (EPOLLIN\|EPOLLOUT\|EPOLLPRI\|EPOLLERR\|EPOLLHUP);
	}
	else {
	n = ((e & EPOLLIN ) ? FD_POLL_IN : 0) \|
	((e & EPOLLPRI) ? FD_POLL_PRI : 0) \|
	((e & EPOLLOUT) ? FD_POLL_OUT : 0) \|
	((e & EPOLLERR) ? FD_POLL_ERR : 0) \|
	((e & EPOLLHUP) ? FD_POLL_HUP : 0);
	}

	/* always remap RDHUP to HUP as they're used similarly */
	if (e & EPOLLRDHUP) {
	HA_ATOMIC_OR(&cur_poller.flags, HAP_POLL_F_RDHUP);
	n \|= FD_POLL_HUP;
	}
	fd_update_events(fd, n);
	}
	/* the caller will take care of cached events */
	}

	static int init_epoll_per_thread()
	{
	epoll_events = calloc(1, sizeof(struct epoll_event) * global.tune.maxpollevents);
	if (epoll_events == NULL)
	return 0;
	return 1;
	}

	static void deinit_epoll_per_thread()
	{
	free(epoll_events);
	epoll_events = NULL;
	}

	/*
	* Initialization of the epoll() poller.
	* Returns 0 in case of failure, non-zero in case of success. If it fails, it
	* disables the poller by setting its pref to 0.
	*/
	REGPRM1 static int _do_init(struct poller *p)
	{
	p->private = NULL;

	epoll_fd = epoll_create(global.maxsock + 1);
	if (epoll_fd < 0)
	goto fail_fd;

	hap_register_per_thread_init(init_epoll_per_thread);
	hap_register_per_thread_deinit(deinit_epoll_per_thread);

	return 1;

	fail_fd:
	p->pref = 0;
	return 0;
	}

	/*
	* Termination of the epoll() poller.
	* Memory is released and the poller is marked as unselectable.
	*/
	REGPRM1 static void _do_term(struct poller *p)
	{
	if (epoll_fd >= 0) {
	close(epoll_fd);
	epoll_fd = -1;
	}

	p->private = NULL;
	p->pref = 0;
	}

	/*
	* Check that the poller works.
	* Returns 1 if OK, otherwise 0.
	*/
	REGPRM1 static int _do_test(struct poller *p)
	{
	int fd;

	fd = epoll_create(global.maxsock + 1);
	if (fd < 0)
	return 0;
	close(fd);
	return 1;
	}

	/*
	* Recreate the epoll file descriptor after a fork(). Returns 1 if OK,
	* otherwise 0. It will ensure that all processes will not share their
	* epoll_fd. Some side effects were encountered because of this, such
	* as epoll_wait() returning an FD which was previously deleted.
	*/
	REGPRM1 static int _do_fork(struct poller *p)
	{
	if (epoll_fd >= 0)
	close(epoll_fd);
	epoll_fd = epoll_create(global.maxsock + 1);
	if (epoll_fd < 0)
	return 0;
	return 1;
	}

	/*
	* It is a constructor, which means that it will automatically be called before
	* main(). This is GCC-specific but it works at least since 2.95.
	* Special care must be taken so that it does not need any uninitialized data.
	*/
	__attribute__((constructor))
	static void _do_register(void)
	{
	struct poller *p;

	if (nbpollers >= MAX_POLLERS)
	return;

	epoll_fd = -1;
	p = &pollers[nbpollers++];

	p->name = "epoll";
	p->pref = 300;
	p->flags = 0;
	p->private = NULL;

	p->clo = __fd_clo;
	p->test = _do_test;
	p->init = _do_init;
	p->term = _do_term;
	p->poll = _do_poll;
	p->fork = _do_fork;
	}


	/*
	* Local variables:
	* c-indent-level: 8
	* c-basic-offset: 8
	* End:
	*/