From 0c513fd963e79da73c7d77018523ac956a5066bd Mon Sep 17 00:00:00 2001 From: root Date: Fri, 2 Nov 2007 16:54:34 +0000 Subject: [PATCH] implement poll method, handle enomem by closing a 'random' fd --- ev.c | 68 ++++++++++++++++++++++++++----- ev.h | 8 ++-- ev_poll.c | 112 ++++++++++++++++++++++++++-------------------------- ev_select.c | 4 +- 4 files changed, 121 insertions(+), 71 deletions(-) diff --git a/ev.c b/ev.c index e94ede4..c77ad2a 100644 --- a/ev.c +++ b/ev.c @@ -58,6 +58,10 @@ # define EV_USE_SELECT 1 #endif +#ifndef EV_USE_POLL +# define EV_USE_POLL 0 /* poll is usually slower than select, and not as well tested */ +#endif + #ifndef EV_USE_EPOLL # define EV_USE_EPOLL 0 #endif @@ -279,20 +283,44 @@ fd_change (int fd) fdchanges [fdchangecnt - 1] = fd; } +static void +fd_kill (int fd) +{ + struct ev_io *w; + + printf ("killing fd %d\n", fd);//D + while ((w = anfds [fd].head)) + { + ev_io_stop (w); + event ((W)w, EV_ERROR | EV_READ | EV_WRITE); + } +} + /* called on EBADF to verify fds */ static void -fd_recheck (void) +fd_ebadf (void) { int fd; for (fd = 0; fd < anfdmax; ++fd) if (anfds [fd].events) if (fcntl (fd, F_GETFD) == -1 && errno == EBADF) - while (anfds [fd].head) - { - ev_io_stop (anfds [fd].head); - event ((W)anfds [fd].head, EV_ERROR | EV_READ | EV_WRITE); - } + fd_kill (fd); +} + +/* called on ENOMEM in select/poll to kill some fds and retry */ +static void +fd_enomem (void) +{ + int fd = anfdmax; + + while (fd--) + if (anfds [fd].events) + { + close (fd); + fd_kill (fd); + return; + } } /*****************************************************************************/ @@ -456,6 +484,9 @@ childcb (struct ev_signal *sw, int revents) #if EV_USE_EPOLL # include "ev_epoll.c" #endif +#if EV_USE_POLL +# include "ev_poll.c" +#endif #if EV_USE_SELECT # include "ev_select.c" #endif @@ -472,7 +503,15 @@ ev_version_minor (void) return EV_VERSION_MINOR; } -int ev_init (int flags) +/* return true if we are running with elevated privileges and ignore env variables */ +static int +enable_secure () +{ + return getuid () != geteuid () + || getgid () != getegid (); +} + +int ev_init (int methods) { if (!ev_method) { @@ -492,12 +531,21 @@ int ev_init (int flags) if (pipe (sigpipe)) return 0; - ev_method = EVMETHOD_NONE; + if (methods == EVMETHOD_AUTO) + if (!enable_secure () && getenv ("LIBEV_METHODS")) + methods = atoi (getenv ("LIBEV_METHODS")); + else + methods = EVMETHOD_ANY; + + ev_method = 0; #if EV_USE_EPOLL - if (ev_method == EVMETHOD_NONE) epoll_init (flags); + if (!ev_method && (methods & EVMETHOD_EPOLL )) epoll_init (methods); +#endif +#if EV_USE_POLL + if (!ev_method && (methods & EVMETHOD_POLL )) poll_init (methods); #endif #if EV_USE_SELECT - if (ev_method == EVMETHOD_NONE) select_init (flags); + if (!ev_method && (methods & EVMETHOD_SELECT)) select_init (methods); #endif if (ev_method) diff --git a/ev.h b/ev.h index 1ffed6f..66e9bd1 100644 --- a/ev.h +++ b/ev.h @@ -167,12 +167,14 @@ struct ev_child int status; /* rw, holds the exit status, use the macros from sys/wait.h */ }; -#define EVMETHOD_NONE 0 +#define EVMETHOD_AUTO 0 /* consults environment */ #define EVMETHOD_SELECT 1 -#define EVMETHOD_EPOLL 2 +#define EVMETHOD_POLL 2 +#define EVMETHOD_EPOLL 4 +#define EVMETHOD_ANY ~0 /* any method, do not consult env */ #if EV_PROTOTYPES extern int ev_method; -int ev_init (int flags); /* returns ev_method */ +int ev_init (int methods); /* returns ev_method */ int ev_version_major (void); int ev_version_minor (void); diff --git a/ev_poll.c b/ev_poll.c index 4793212..0af63f3 100644 --- a/ev_poll.c +++ b/ev_poll.c @@ -29,82 +29,80 @@ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ -#include +#include -static int epoll_fd = -1; +static struct pollfd *polls; +static int pollmax, pollcnt; +static int *pollidxs; /* maps fds into structure indices */ +static int pollidxmax; static void -epoll_modify (int fd, int oev, int nev) +pollidx_init (int *base, int count) { - int mode = nev ? oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD : EPOLL_CTL_DEL; - - struct epoll_event ev; - ev.data.fd = fd; - ev.events = - (nev & EV_READ ? EPOLLIN : 0) - | (nev & EV_WRITE ? EPOLLOUT : 0); - - epoll_ctl (epoll_fd, mode, fd, &ev); + while (count--) + *base++ = -1; } static void -epoll_postfork_child (void) +poll_modify (int fd, int oev, int nev) { - int fd; + int idx; + array_needsize (pollidxs, pollidxmax, fd + 1, pollidx_init); - epoll_fd = epoll_create (256); - fcntl (epoll_fd, F_SETFD, FD_CLOEXEC); + idx = pollidxs [fd]; - /* re-register interest in fds */ - for (fd = 0; fd < anfdmax; ++fd) - if (anfds [fd].events)//D - epoll_modify (fd, EV_NONE, anfds [fd].events); -} + if (idx < 0) /* need to allocate a new pollfd */ + { + idx = pollcnt++; + array_needsize (polls, pollmax, pollcnt, ); + polls [idx].fd = fd; + } -static struct epoll_event *events; -static int eventmax; + if (nev) + polls [idx].events = + (nev & EV_READ ? POLLIN : 0) + | (nev & EV_WRITE ? POLLOUT : 0); + else /* remove pollfd */ + { + if (idx < pollcnt--) + { + pollidxs [fd] = -1; + polls [idx] = polls [pollcnt]; + pollidxs [polls [idx].fd] = idx; + } + } +} static void -epoll_poll (ev_tstamp timeout) +poll_poll (ev_tstamp timeout) { - int eventcnt = epoll_wait (epoll_fd, events, eventmax, ceil (timeout * 1000.)); - int i; - - if (eventcnt < 0) - return; + int res = poll (polls, pollcnt, ceil (timeout * 1000.)); - for (i = 0; i < eventcnt; ++i) - fd_event ( - events [i].data.fd, - (events [i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) - | (events [i].events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0) - ); - - /* if the receive array was full, increase its size */ - if (expect_false (eventcnt == eventmax)) + if (res > 0) + { + int i; + + for (i = 0; i < pollcnt; ++i) + fd_event ( + polls [i].fd, + (polls [i].revents & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0) + | (polls [i].revents & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0) + ); + } + else if (res < 0) { - free (events); - eventmax = array_roundsize (events, eventmax << 1); - events = malloc (sizeof (struct epoll_event) * eventmax); + if (errno == EBADF) + fd_ebadf (); + else if (errno == ENOMEM) + fd_enomem (); } } static void -epoll_init (int flags) +poll_init (int flags) { - epoll_fd = epoll_create (256); - - if (epoll_fd < 0) - return; - - fcntl (epoll_fd, F_SETFD, FD_CLOEXEC); - - ev_method = EVMETHOD_EPOLL; - method_fudge = 1e-3; /* needed to compensate for epoll returning early */ - method_modify = epoll_modify; - method_poll = epoll_poll; - - eventmax = 64; /* intiial number of events receivable per poll */ - events = malloc (sizeof (struct epoll_event) * eventmax); + ev_method = EVMETHOD_POLL; + method_fudge = 1e-3; /* needed to compensate for select returning early, very conservative */ + method_modify = poll_modify; + method_poll = poll_poll; } - diff --git a/ev_select.c b/ev_select.c index 7bbf622..0333d63 100644 --- a/ev_select.c +++ b/ev_select.c @@ -116,7 +116,9 @@ select_poll (ev_tstamp timeout) else if (res < 0) { if (errno == EBADF) - fd_recheck (); + fd_ebadf (); + else if (errno == ENOMEM) + fd_enomem (); } } -- 2.43.0