/* http://frotznet.googlecode.com/svn/trunk/utils/fdevent.c ** ** Copyright 2006, Brian Swetland ** ** 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 #include #include #include #include #include #include #include #include #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 CRAPTASTIC //HAVE_EPOLL #include static int epoll_fd = -1; static void fdevent_init() { /* XXX: what's a good size for the passed in hint? */ epoll_fd = epoll_create(256); if(epoll_fd < 0) { perror("epoll_create() failed"); exit(1); } /* mark for close-on-exec */ fcntl(epoll_fd, F_SETFD, FD_CLOEXEC); } static void fdevent_connect(fdevent *fde) { struct epoll_event ev; memset(&ev, 0, sizeof(ev)); ev.events = 0; ev.data.ptr = fde; #if 0 if(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fde->fd, &ev)) { perror("epoll_ctl() failed\n"); exit(1); } #endif } 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 #else #include #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); } } }