diff options
Diffstat (limited to 'iohandler.c')
| -rw-r--r-- | iohandler.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/iohandler.c b/iohandler.c new file mode 100644 index 0000000000..2b824218e5 --- /dev/null +++ b/iohandler.c @@ -0,0 +1,193 @@ +/* + * QEMU System Emulator - managing I/O handler + * + * Copyright (c) 2003-2008 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "config-host.h" +#include "qemu-common.h" +#include "qemu-char.h" +#include "qemu-queue.h" + +#ifndef _WIN32 +#include <sys/wait.h> +#endif + +typedef struct IOHandlerRecord { + int fd; + IOCanReadHandler *fd_read_poll; + IOHandler *fd_read; + IOHandler *fd_write; + int deleted; + void *opaque; + QLIST_ENTRY(IOHandlerRecord) next; +} IOHandlerRecord; + +static QLIST_HEAD(, IOHandlerRecord) io_handlers = + QLIST_HEAD_INITIALIZER(io_handlers); + + +/* XXX: fd_read_poll should be suppressed, but an API change is + necessary in the character devices to suppress fd_can_read(). */ +int qemu_set_fd_handler2(int fd, + IOCanReadHandler *fd_read_poll, + IOHandler *fd_read, + IOHandler *fd_write, + void *opaque) +{ + IOHandlerRecord *ioh; + + if (!fd_read && !fd_write) { + QLIST_FOREACH(ioh, &io_handlers, next) { + if (ioh->fd == fd) { + ioh->deleted = 1; + break; + } + } + } else { + QLIST_FOREACH(ioh, &io_handlers, next) { + if (ioh->fd == fd) + goto found; + } + ioh = qemu_mallocz(sizeof(IOHandlerRecord)); + QLIST_INSERT_HEAD(&io_handlers, ioh, next); + found: + ioh->fd = fd; + ioh->fd_read_poll = fd_read_poll; + ioh->fd_read = fd_read; + ioh->fd_write = fd_write; + ioh->opaque = opaque; + ioh->deleted = 0; + } + return 0; +} + +int qemu_set_fd_handler(int fd, + IOHandler *fd_read, + IOHandler *fd_write, + void *opaque) +{ + return qemu_set_fd_handler2(fd, NULL, fd_read, fd_write, opaque); +} + +void qemu_iohandler_fill(int *pnfds, fd_set *readfds, fd_set *writefds, fd_set *xfds) +{ + IOHandlerRecord *ioh; + + QLIST_FOREACH(ioh, &io_handlers, next) { + if (ioh->deleted) + continue; + if (ioh->fd_read && + (!ioh->fd_read_poll || + ioh->fd_read_poll(ioh->opaque) != 0)) { + FD_SET(ioh->fd, readfds); + if (ioh->fd > *pnfds) + *pnfds = ioh->fd; + } + if (ioh->fd_write) { + FD_SET(ioh->fd, writefds); + if (ioh->fd > *pnfds) + *pnfds = ioh->fd; + } + } +} + +void qemu_iohandler_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, int ret) +{ + if (ret > 0) { + IOHandlerRecord *pioh, *ioh; + + QLIST_FOREACH_SAFE(ioh, &io_handlers, next, pioh) { + if (!ioh->deleted && ioh->fd_read && FD_ISSET(ioh->fd, readfds)) { + ioh->fd_read(ioh->opaque); + } + if (!ioh->deleted && ioh->fd_write && FD_ISSET(ioh->fd, writefds)) { + ioh->fd_write(ioh->opaque); + } + + /* Do this last in case read/write handlers marked it for deletion */ + if (ioh->deleted) { + QLIST_REMOVE(ioh, next); + qemu_free(ioh); + } + } + } +} + +/* reaping of zombies. right now we're not passing the status to + anyone, but it would be possible to add a callback. */ +#ifndef _WIN32 +typedef struct ChildProcessRecord { + int pid; + QLIST_ENTRY(ChildProcessRecord) next; +} ChildProcessRecord; + +static QLIST_HEAD(, ChildProcessRecord) child_watches = + QLIST_HEAD_INITIALIZER(child_watches); + +static QEMUBH *sigchld_bh; + +static void sigchld_handler(int signal) +{ + qemu_bh_schedule(sigchld_bh); +} + +static void sigchld_bh_handler(void *opaque) +{ + ChildProcessRecord *rec, *next; + + QLIST_FOREACH_SAFE(rec, &child_watches, next, next) { + if (waitpid(rec->pid, NULL, WNOHANG) == rec->pid) { + QLIST_REMOVE(rec, next); + qemu_free(rec); + } + } +} + +static void qemu_init_child_watch(void) +{ + struct sigaction act; + sigchld_bh = qemu_bh_new(sigchld_bh_handler, NULL); + + act.sa_handler = sigchld_handler; + act.sa_flags = SA_NOCLDSTOP; + sigaction(SIGCHLD, &act, NULL); +} + +int qemu_add_child_watch(pid_t pid) +{ + ChildProcessRecord *rec; + + if (!sigchld_bh) { + qemu_init_child_watch(); + } + + QLIST_FOREACH(rec, &child_watches, next) { + if (rec->pid == pid) { + return 1; + } + } + rec = qemu_mallocz(sizeof(ChildProcessRecord)); + rec->pid = pid; + QLIST_INSERT_HEAD(&child_watches, rec, next); + return 0; +} +#endif |