/* http://frotznet.googlecode.com/svn/trunk/utils/fdevent.c
**
** Copyright 2006, Brian Swetland <swetland@frotz.net>
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include <sys/ioctl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stddef.h>
#include "fdevent.h"
#include "transport.h"
#include "sysdeps.h"
/* !!! Do not enable DEBUG for the adb that will run as the server:
** both stdout and stderr are used to communicate between the client
** and server. Any extra output will cause failures.
*/
#define DEBUG 0 /* non-0 will break adb server */
// This socket is used when a subproc shell service exists.
// It wakes up the fdevent_loop() and cause the correct handling
// of the shell's pseudo-tty master. I.e. force close it.
int SHELL_EXIT_NOTIFY_FD = -1;
static void fatal(const char *fn, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fprintf(stderr, "%s:", fn);
vfprintf(stderr, fmt, ap);
va_end(ap);
abort();
}
#define FATAL(x...) fatal(__FUNCTION__, x)
#if DEBUG
#define D(...) \
do { \
adb_mutex_lock(&D_lock); \
int save_errno = errno; \
fprintf(stderr, "%s::%s():", __FILE__, __FUNCTION__); \
errno = save_errno; \
fprintf(stderr, __VA_ARGS__); \
adb_mutex_unlock(&D_lock); \
errno = save_errno; \
} while(0)
static void dump_fde(fdevent *fde, const char *info)
{
adb_mutex_lock(&D_lock);
fprintf(stderr,"FDE #%03d %c%c%c %s\n", fde->fd,
fde->state & FDE_READ ? 'R' : ' ',
fde->state & FDE_WRITE ? 'W' : ' ',
fde->state & FDE_ERROR ? 'E' : ' ',
info);
adb_mutex_unlock(&D_lock);
}
#else
#define D(...) ((void)0)
#define dump_fde(fde, info) do { } while(0)
#endif
#define FDE_EVENTMASK 0x00ff
#define FDE_STATEMASK 0xff00
#define FDE_ACTIVE 0x0100
#define FDE_PENDING 0x0200
#define FDE_CREATED 0x0400
static void fdevent_plist_enqueue(fdevent *node);
static void fdevent_plist_remove(fdevent *node);
static fdevent *fdevent_plist_dequeue(void);
static void fdevent_subproc_event_func(int fd, unsigned events, void *userdata);
static fdevent list_pending = {
.next = &list_pending,
.prev = &list_pending,
};
static fdevent **fd_table = 0;
static int fd_table_max = 0;
#ifdef __linux__
#include <sys/epoll.h>
static int epoll_fd = -1;
static void fdevent_init()
{
epoll_fd = epoll_create1(EPOLL_CLOEXEC);
if(epoll_fd == -1) {
perror("epoll_create() failed");
exit(1);
}
}
static void fdevent_connect(fdevent *fde)
{
// Nothing to do here. fdevent_update will handle the EPOLL_CTL_ADD.
}
static void fdevent_disconnect(fdevent *fde)
{
struct epoll_event ev;
memset(&ev, 0, sizeof(ev));
ev.events = 0;
ev.data.ptr = fde;
/* technically we only need to delete if we
** were actively monitoring events, but let's
** be aggressive and do it anyway, just in case
** something's out of sync
*/
epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fde->fd, &ev);
}
static void fdevent_update(fdevent *fde, unsigned events)
{
struct epoll_event ev;
int active;
active = (fde->state & FDE_EVENTMASK) != 0;
memset(&ev, 0, sizeof(ev));
ev.events = 0;
ev.data.ptr = fde;
if(events & FDE_READ) ev.events |= EPOLLIN;
if(events & FDE_WRITE) ev.events |= EPOLLOUT;
if(events & FDE_ERROR) ev.events |= (EPOLLERR | EPOLLHUP);
fde->state = (fde->state & FDE_STATEMASK) | events;
if(active) {
/* we're already active. if we're changing to *no*
** events being monitored, we need to delete, otherwise
** we need to just modify
*/
if(ev.events) {
if(epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fde->fd, &ev)) {
perror("epoll_ctl() failed\n");
exit(1);
}
} else {
if(epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fde->fd, &ev)) {
perror("epoll_ctl() failed\n");
exit(1);
}
}
} else {
/* we're not active. if we're watching events, we need
** to add, otherwise we can just do nothing
*/
if(ev.events) {
if(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fde->fd, &ev)) {
perror("epoll_ctl() failed\n");
exit(1);
}
}
}
}
static void fdevent_process()
{
struct epoll_event events[256];
fdevent *fde;
int i, n;
n = epoll_wait(epoll_fd, events, 256, -1);
if(n < 0) {
if(errno == EINTR) return;
perror("epoll_wait");
exit(1);
}
for(i = 0; i < n; i++) {
struct epoll_event *ev = events + i;
fde = ev->data.ptr;
if(ev->events & EPOLLIN) {
fde->events |= FDE_READ;
}
if(ev->events & EPOLLOUT) {
fde->events |= FDE_WRITE;
}
if(ev->events & (EPOLLERR | EPOLLHUP)) {
fde->events |= FDE_ERROR;
}
if(fde->events) {
if(fde->state & FDE_PENDING) continue;
fde->state |= FDE_PENDING;
fdevent_plist_enqueue(fde);
}
}
}
#else /* USE_SELECT */
#ifdef HAVE_WINSOCK
#include <winsock2.h>
#else
#include <sys/select.h>
#endif
static fd_set read_fds;
static fd_set write_fds;
static fd_set error_fds;
static int select_n = 0;
static void fdevent_init(void)
{
FD_ZERO(&read_fds);
FD_ZERO(&write_fds);
FD_ZERO(&error_fds);
}
static void fdevent_connect(fdevent *fde)
{
if(fde->fd >= select_n) {
select_n = fde->fd + 1;
}
}
static void fdevent_disconnect(fdevent *fde)
{
int i, n;
FD_CLR(fde->fd, &read_fds);
FD_CLR(fde->fd, &write_fds);
FD_CLR(fde->fd, &error_fds);
for(n = 0, i = 0; i < select_n; i++) {
if(fd_table[i] != 0) n = i;
}
select_n = n + 1;
}
static void fdevent_update(fdevent *fde, unsigned events)
{
if(events & FDE_READ) {
FD_SET(fde->fd, &read_fds);
} else {
FD_CLR(fde->fd, &read_fds);
}
if(events & FDE_WRITE) {
FD_SET(fde->fd, &write_fds);
} else {
FD_CLR(fde->fd, &write_fds);
}
if(events & FDE_ERROR) {
FD_SET(fde->fd, &error_fds);
} else {
FD_CLR(fde->fd, &error_fds);
}
fde->state = (fde->state & FDE_STATEMASK) | events;
}
/* Looks at fd_table[] for bad FDs and sets bit in fds.
** Returns the number of bad FDs.
*/
static int fdevent_fd_check(fd_set *fds)
{
int i, n = 0;
fdevent *fde;
for(i = 0; i < select_n; i++) {
fde = fd_table[i];
if(fde == 0) continue;
if(fcntl(i, F_GETFL, NULL) < 0) {
FD_SET(i, fds);
n++;
// fde->state |= FDE_DONT_CLOSE;
}
}
return n;
}
#if !DEBUG
static inline void dump_all_fds(const char *extra_msg) {}
#else
static void dump_all_fds(const char *extra_msg)
{
int i;
fdevent *fde;
// per fd: 4 digits (but really: log10(FD_SETSIZE)), 1 staus, 1 blank
char msg_buff[FD_SETSIZE*6 + 1], *pb=msg_buff;
size_t max_chars = FD_SETSIZE * 6 + 1;
int printed_out;
#define SAFE_SPRINTF(...) \
do { \
printed_out = snprintf(pb, max_chars, __VA_ARGS__); \
if (printed_out <= 0) { \
D("... snprintf failed.\n"); \
return; \
} \
if (max_chars < (unsigned int)printed_out) { \
D("... snprintf out of space.\n"); \
return; \
} \
pb += printed_out; \
max_chars -= printed_out; \
} while(0)
for(i = 0; i < select_n; i++) {
fde = fd_table[i];
SAFE_SPRINTF("%d", i);
if(fde == 0) {
SAFE_SPRINTF("? ");
continue;
}
if(fcntl(i, F_GETFL, NULL) < 0) {
SAFE_SPRINTF("b");
}
SAFE_SPRINTF(" ");
}
D("%s fd_table[]->fd = {%s}\n", extra_msg, msg_buff);
}
#endif
static void fdevent_process()
{
int i, n;
fdevent *fde;
unsigned events;
fd_set rfd, wfd, efd;
memcpy(&rfd, &read_fds, sizeof(fd_set));
memcpy(&wfd, &write_fds, sizeof(fd_set));
memcpy(&efd, &error_fds, sizeof(fd_set));
dump_all_fds("pre select()");
n = select(select_n, &rfd, &wfd, &efd, NULL);
int saved_errno = errno;
D("select() returned n=%d, errno=%d\n", n, n<0?saved_errno:0);
dump_all_fds("post select()");
if(n < 0) {
switch(saved_errno) {
case EINTR: return;
case EBADF:
// Can't trust the FD sets after an error.
FD_ZERO(&wfd);
FD_ZERO(&efd);
FD_ZERO(&rfd);
break;
default:
D("Unexpected select() error=%d\n", saved_errno);
return;
}
}
if(n <= 0) {
// We fake a read, as the rest of the code assumes
// that errors will be detected at that point.
n = fdevent_fd_check(&rfd);
}
for(i = 0; (i < select_n) && (n > 0); i++) {
events = 0;
if(FD_ISSET(i, &rfd)) { events |= FDE_READ; n--; }
if(FD_ISSET(i, &wfd)) { events |= FDE_WRITE; n--; }
if(FD_ISSET(i, &efd)) { events |= FDE_ERROR; n--; }
if(events) {
fde = fd_table[i];
if(fde == 0)
FATAL("missing fde for fd %d\n", i);
fde->events |= events;
D("got events fde->fd=%d events=%04x, state=%04x\n",
fde->fd, fde->events, fde->state);
if(fde->state & FDE_PENDING) continue;
fde->state |= FDE_PENDING;
fdevent_plist_enqueue(fde);
}
}
}
#endif
static void fdevent_register(fdevent *fde)
{
if(fde->fd < 0) {
FATAL("bogus negative fd (%d)\n", fde->fd);
}
if(fde->fd >= fd_table_max) {
int oldmax = fd_table_max;
if(fde->fd > 32000) {
FATAL("bogus huuuuge fd (%d)\n", fde->fd);
}
if(fd_table_max == 0) {
fdevent_init();
fd_table_max = 256;
}
while(fd_table_max <= fde->fd) {
fd_table_max *= 2;
}
fd_table = realloc(fd_table, sizeof(fdevent*) * fd_table_max);
if(fd_table == 0) {
FATAL("could not expand fd_table to %d entries\n", fd_table_max);
}
memset(fd_table + oldmax, 0, sizeof(int) * (fd_table_max - oldmax));
}
fd_table[fde->fd] = fde;
}
static void fdevent_unregister(fdevent *fde)
{
if((fde->fd < 0) || (fde->fd >= fd_table_max)) {
FATAL("fd out of range (%d)\n", fde->fd);
}
if(fd_table[fde->fd] != fde) {
FATAL("fd_table out of sync [%d]\n", fde->fd);
}
fd_table[fde->fd] = 0;
if(!(fde->state & FDE_DONT_CLOSE)) {
dump_fde(fde, "close");
adb_close(fde->fd);
}
}
static void fdevent_plist_enqueue(fdevent *node)
{
fdevent *list = &list_pending;
node->next = list;
node->prev = list->prev;
node->prev->next = node;
list->prev = node;
}
static void fdevent_plist_remove(fdevent *node)
{
node->prev->next = node->next;
node->next->prev = node->prev;
node->next = 0;
node->prev = 0;
}
static fdevent *fdevent_plist_dequeue(void)
{
fdevent *list = &list_pending;
fdevent *node = list->next;
if(node == list) return 0;
list->next = node->next;
list->next->prev = list;
node->next = 0;
node->prev = 0;
return node;
}
static void fdevent_call_fdfunc(fdevent* fde)
{
unsigned events = fde->events;
fde->events = 0;
if(!(fde->state & FDE_PENDING)) return;
fde->state &= (~FDE_PENDING);
dump_fde(fde, "callback");
fde->func(fde->fd, events, fde->arg);
}
static void fdevent_subproc_event_func(int fd, unsigned ev, void *userdata)
{
D("subproc handling on fd=%d ev=%04x\n", fd, ev);
// Hook oneself back into the fde's suitable for select() on read.
if((fd < 0) || (fd >= fd_table_max)) {
FATAL("fd %d out of range for fd_table \n", fd);
}
fdevent *fde = fd_table[fd];
fdevent_add(fde, FDE_READ);
if(ev & FDE_READ){
int subproc_fd;
if(readx(fd, &subproc_fd, sizeof(subproc_fd))) {
FATAL("Failed to read the subproc's fd from fd=%d\n", fd);
}
if((subproc_fd < 0) || (subproc_fd >= fd_table_max)) {
D("subproc_fd %d out of range 0, fd_table_max=%d\n",
subproc_fd, fd_table_max);
return;
}
fdevent *subproc_fde = fd_table[subproc_fd];
if(!subproc_fde) {
D("subproc_fd %d cleared from fd_table\n", subproc_fd);
return;
}
if(subproc_fde->fd != subproc_fd) {
// Already reallocated?
D("subproc_fd %d != fd_table[].fd %d\n", subproc_fd, subproc_fde->fd);
return;
}
subproc_fde->force_eof = 1;
int rcount = 0;
ioctl(subproc_fd, FIONREAD, &rcount);
D("subproc with fd=%d has rcount=%d err=%d\n",
subproc_fd, rcount, errno);
if(rcount) {
// If there is data left, it will show up in the select().
// This works because there is no other thread reading that
// data when in this fd_func().
return;
}
D("subproc_fde.state=%04x\n", subproc_fde->state);
subproc_fde->events |= FDE_READ;
if(subproc_fde->state & FDE_PENDING) {
return;
}
subproc_fde->state |= FDE_PENDING;
fdevent_call_fdfunc(subproc_fde);
}
}
fdevent *fdevent_create(int fd, fd_func func, void *arg)
{
fdevent *fde = (fdevent*) malloc(sizeof(fdevent));
if(fde == 0) return 0;
fdevent_install(fde, fd, func, arg);
fde->state |= FDE_CREATED;
return fde;
}
void fdevent_destroy(fdevent *fde)
{
if(fde == 0) return;
if(!(fde->state & FDE_CREATED)) {
FATAL("fde %p not created by fdevent_create()\n", fde);
}
fdevent_remove(fde);
}
void fdevent_install(fdevent *fde, int fd, fd_func func, void *arg)
{
memset(fde, 0, sizeof(fdevent));
fde->state = FDE_ACTIVE;
fde->fd = fd;
fde->force_eof = 0;
fde->func = func;
fde->arg = arg;
#ifndef HAVE_WINSOCK
fcntl(fd, F_SETFL, O_NONBLOCK);
#endif
fdevent_register(fde);
dump_fde(fde, "connect");
fdevent_connect(fde);
fde->state |= FDE_ACTIVE;
}
void fdevent_remove(fdevent *fde)
{
if(fde->state & FDE_PENDING) {
fdevent_plist_remove(fde);
}
if(fde->state & FDE_ACTIVE) {
fdevent_disconnect(fde);
dump_fde(fde, "disconnect");
fdevent_unregister(fde);
}
fde->state = 0;
fde->events = 0;
}
void fdevent_set(fdevent *fde, unsigned events)
{
events &= FDE_EVENTMASK;
if((fde->state & FDE_EVENTMASK) == events) return;
if(fde->state & FDE_ACTIVE) {
fdevent_update(fde, events);
dump_fde(fde, "update");
}
fde->state = (fde->state & FDE_STATEMASK) | events;
if(fde->state & FDE_PENDING) {
/* if we're pending, make sure
** we don't signal an event that
** is no longer wanted.
*/
fde->events &= (~events);
if(fde->events == 0) {
fdevent_plist_remove(fde);
fde->state &= (~FDE_PENDING);
}
}
}
void fdevent_add(fdevent *fde, unsigned events)
{
fdevent_set(
fde, (fde->state & FDE_EVENTMASK) | (events & FDE_EVENTMASK));
}
void fdevent_del(fdevent *fde, unsigned events)
{
fdevent_set(
fde, (fde->state & FDE_EVENTMASK) & (~(events & FDE_EVENTMASK)));
}
void fdevent_subproc_setup()
{
int s[2];
if(adb_socketpair(s)) {
FATAL("cannot create shell-exit socket-pair\n");
}
SHELL_EXIT_NOTIFY_FD = s[0];
fdevent *fde;
fde = fdevent_create(s[1], fdevent_subproc_event_func, NULL);
if(!fde)
FATAL("cannot create fdevent for shell-exit handler\n");
fdevent_add(fde, FDE_READ);
}
void fdevent_loop()
{
fdevent *fde;
fdevent_subproc_setup();
for(;;) {
D("--- ---- waiting for events\n");
fdevent_process();
while((fde = fdevent_plist_dequeue())) {
fdevent_call_fdfunc(fde);
}
}
}
