X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fcompat%2Fpoll.h;h=7dce4e6eb836c34f3337675bbb4bba722734bdd7;hp=bb046c3427af53f49a76997874a3d43b1808ba37;hb=ab5be9fa2eb5ba9600a82cd18fd3cfcbac69169a;hpb=b2c3836f9872dfe8c0328c03fa5a01efe0ed6017 diff --git a/src/common/compat/poll.h b/src/common/compat/poll.h index bb046c342..7dce4e6eb 100644 --- a/src/common/compat/poll.h +++ b/src/common/compat/poll.h @@ -1,42 +1,19 @@ /* - * Copyright (C) 2011 - David Goulet + * Copyright (C) 2011 David Goulet * - * 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; only version 2 of the License. + * SPDX-License-Identifier: GPL-2.0-only * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 59 Temple - * Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifndef _LTT_POLL_H #define _LTT_POLL_H +#include #include #include #include -/* - * Maximum number of fd we can monitor. - * - * For epoll(7), /proc/sys/fs/epoll/max_user_watches (since Linux 2.6.28) will - * be used for the maximum size of the poll set. If this interface is not - * available, according to the manpage, the max_user_watches value is 1/25 (4%) - * of the available low memory divided by the registration cost in bytes which - * is 90 bytes on a 32-bit kernel and 160 bytes on a 64-bit kernel. - * - * For poll(2), the max fds must not exceed RLIMIT_NOFILE given by - * getrlimit(2). - */ -extern unsigned int poll_max_size; - /* * Used by lttng_poll_clean to free the events structure in a lttng_poll_event. */ @@ -50,6 +27,9 @@ static inline void __lttng_poll_free(void *events) */ #ifdef HAVE_EPOLL #include +#include +#include +#include /* See man epoll(7) for this define path */ #define COMPAT_EPOLL_PROC_PATH "/proc/sys/fs/epoll/max_user_watches" @@ -69,17 +49,41 @@ enum { LPOLLNVAL = EPOLLHUP, LPOLLRDHUP = EPOLLRDHUP, /* Close on exec feature of epoll */ +#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC) LTTNG_CLOEXEC = EPOLL_CLOEXEC, +#else + /* + * EPOLL_CLOEXEC was added in glibc 2.8 (usually used in conjunction with + * epoll_create1(..)), but since neither EPOLL_CLOEXEC exists nor + * epoll_create1(..), we set it to FD_CLOEXEC so that we can pass it + * directly to fcntl(..) instead. + */ + LTTNG_CLOEXEC = FD_CLOEXEC, +#endif }; struct compat_epoll_event { int epfd; uint32_t nb_fd; /* Current number of fd in events */ - uint32_t events_size; /* Size of events array */ + uint32_t alloc_size; /* Size of events array */ + uint32_t init_size; /* Initial size of events array */ struct epoll_event *events; }; #define lttng_poll_event compat_epoll_event +static inline int __lttng_epoll_get_prev_fd(struct lttng_poll_event *events, + int index, uint32_t nb_fd) +{ + assert(events); + assert(index != nb_fd); + + if (index == 0 || nb_fd == 0) { + return -1; + } else { + return events->events[index - 1].data.fd; + } +} + /* * For the following calls, consider 'e' to be a lttng_poll_event pointer and i * being the index of the events array. @@ -88,22 +92,46 @@ struct compat_epoll_event { #define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].events #define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd #define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size +#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \ + __lttng_epoll_get_prev_fd(LTTNG_REF(e), i, nb_fd) -/* - * Create the epoll set. No memory allocation is done here. - */ +/* Create the epoll set. */ extern int compat_epoll_create(struct lttng_poll_event *events, int size, int flags); #define lttng_poll_create(events, size, flags) \ compat_epoll_create(events, size, flags) +#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC) +static inline int compat_glibc_epoll_create(int size __attribute__((unused)), + int flags) +{ + return epoll_create1(flags); +} +#else +static inline int compat_glibc_epoll_create(int size, int flags) +{ + /* + * epoll_create1 was added in glibc 2.9, but unfortunatly reverting to + * epoll_create(..) also means that we lose the possibility to + * directly set the EPOLL_CLOEXEC, so try and do it anyway but through + * fcntl(..). + */ + int efd = epoll_create(size); + assert(fcntl(efd, F_SETFD, flags) != -1); + return efd; +} +#endif + /* * Wait on epoll set with the number of fd registered to the lttng_poll_event * data structure (events). */ -extern int compat_epoll_wait(struct lttng_poll_event *events, int timeout); +extern int compat_epoll_wait(struct lttng_poll_event *events, int timeout, + bool interruptible); #define lttng_poll_wait(events, timeout) \ - compat_epoll_wait(events, timeout) + compat_epoll_wait(events, timeout, false) +#define lttng_poll_wait_interruptible(events, timeout) \ + compat_epoll_wait(events, timeout, true) /* * Add a fd to the epoll set and resize the epoll_event structure if needed. @@ -120,10 +148,18 @@ extern int compat_epoll_del(struct lttng_poll_event *events, int fd); #define lttng_poll_del(events, fd) \ compat_epoll_del(events, fd) +/* + * Modify an fd's events in the epoll set. + */ +extern int compat_epoll_mod(struct lttng_poll_event *events, + int fd, uint32_t req_events); +#define lttng_poll_mod(events, fd, req_events) \ + compat_epoll_mod(events, fd, req_events) + /* * Set up the poll set limits variable poll_max_size */ -extern void compat_epoll_set_max_size(void); +extern int compat_epoll_set_max_size(void); #define lttng_poll_set_max_size() \ compat_epoll_set_max_size() @@ -140,16 +176,37 @@ static inline void lttng_poll_reset(struct lttng_poll_event *events) } } +/* + * Initialize an already allocated poll event data structure. For epoll(), the + * epfd is set to -1 to indicate that it's not usable. + */ +static inline void lttng_poll_init(struct lttng_poll_event *events) +{ + memset(events, 0, sizeof(struct lttng_poll_event)); + /* Set fd to -1 so if clean before created, we don't close 0. */ + events->epfd = -1; +} + /* * Clean the events structure of a lttng_poll_event. It's the caller * responsability to free the lttng_poll_event memory. */ static inline void lttng_poll_clean(struct lttng_poll_event *events) { - if (events) { - close(events->epfd); - __lttng_poll_free((void *) events->events); + int ret; + + if (!events) { + return; + } + + if (events->epfd >= 0) { + ret = close(events->epfd); + if (ret) { + PERROR("close"); + } } + + __lttng_poll_free((void *) events->events); } #else /* HAVE_EPOLL */ @@ -182,7 +239,7 @@ enum { #if __linux__ LPOLLMSG = POLLMSG, LPOLLRDHUP = POLLRDHUP, -#elif defined(__FreeBSD__) +#elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__)) LPOLLMSG = 0, LPOLLRDHUP = 0, #else @@ -194,21 +251,56 @@ enum { LTTNG_CLOEXEC = 0xdead, }; -struct compat_poll_event { +struct compat_poll_event_array { uint32_t nb_fd; /* Current number of fd in events */ - uint32_t events_size; /* Size of events array */ + uint32_t alloc_size; /* Size of events array */ + /* Initial size of the pollset. We never shrink below that. */ + uint32_t init_size; struct pollfd *events; }; + +struct compat_poll_event { + /* + * Modified by the wait action. Updated using current fields if the + * need_update flag is set. + */ + struct compat_poll_event_array wait; + /* + * This is modified by add/del actions being the _current_ flow of + * execution before a poll wait is done. + */ + struct compat_poll_event_array current; + + /* Indicate if wait.events need to be updated from current. */ + int need_update:1; +}; #define lttng_poll_event compat_poll_event +static inline int __lttng_poll_get_prev_fd(struct lttng_poll_event *events, + int index, uint32_t nb_fd) +{ + assert(events); + assert(index != nb_fd); + + if (index == 0 || nb_fd == 0) { + return -1; + } else { + return events->current.events[index - 1].fd; + } +} + /* * For the following calls, consider 'e' to be a lttng_poll_event pointer and i * being the index of the events array. + * LTTNG_POLL_GETNB is always used after lttng_poll_wait, thus we can use the + * current list for test compatibility purposes. */ -#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].fd -#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].revents -#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd -#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size +#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->wait.events[i].fd +#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->wait.events[i].revents +#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->current.nb_fd +#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->wait.events_size +#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \ + __lttng_poll_get_prev_fd(LTTNG_REF(e), i, nb_fd) /* * Create a pollfd structure of size 'size'. @@ -221,9 +313,12 @@ extern int compat_poll_create(struct lttng_poll_event *events, int size); * Wait on poll(2) event with nb_fd registered to the lttng_poll_event data * structure. */ -extern int compat_poll_wait(struct lttng_poll_event *events, int timeout); +extern int compat_poll_wait(struct lttng_poll_event *events, int timeout, + bool interruptible); #define lttng_poll_wait(events, timeout) \ - compat_poll_wait(events, timeout) + compat_poll_wait(events, timeout, false) +#define lttng_poll_wait_interruptible(events, timeout) \ + compat_poll_wait(events, timeout, true) /* * Add the fd to the pollfd structure. Resize if needed. @@ -242,10 +337,18 @@ extern int compat_poll_del(struct lttng_poll_event *events, int fd); #define lttng_poll_del(events, fd) \ compat_poll_del(events, fd) +/* + * Modify an fd's events in the poll set. + */ +extern int compat_poll_mod(struct lttng_poll_event *events, + int fd, uint32_t req_events); +#define lttng_poll_mod(events, fd, req_events) \ + compat_poll_mod(events, fd, req_events) + /* * Set up the poll set limits variable poll_max_size */ -extern void compat_poll_set_max_size(void); +extern int compat_poll_set_max_size(void); #define lttng_poll_set_max_size() \ compat_poll_set_max_size() @@ -255,6 +358,14 @@ extern void compat_poll_set_max_size(void); static inline void lttng_poll_reset(struct lttng_poll_event *events) {} +/* + * Initialize an already allocated poll event data structure. + */ +static inline void lttng_poll_init(struct lttng_poll_event *events) +{ + memset(events, 0, sizeof(struct lttng_poll_event)); +} + /* * Clean the events structure of a lttng_poll_event. It's the caller * responsability to free the lttng_poll_event memory. @@ -262,7 +373,8 @@ static inline void lttng_poll_reset(struct lttng_poll_event *events) static inline void lttng_poll_clean(struct lttng_poll_event *events) { if (events) { - __lttng_poll_free((void *) events->events); + __lttng_poll_free((void *) events->wait.events); + __lttng_poll_free((void *) events->current.events); } }