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-rw-r--r--src/ev_select.c335
1 files changed, 335 insertions, 0 deletions
diff --git a/src/ev_select.c b/src/ev_select.c
new file mode 100644
index 0000000..eadd588
--- /dev/null
+++ b/src/ev_select.c
@@ -0,0 +1,335 @@
+/*
+ * FD polling functions for generic select()
+ *
+ * Copyright 2000-2014 Willy Tarreau <w@1wt.eu>
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include <haproxy/activity.h>
+#include <haproxy/api.h>
+#include <haproxy/clock.h>
+#include <haproxy/fd.h>
+#include <haproxy/global.h>
+#include <haproxy/task.h>
+#include <haproxy/ticks.h>
+
+
+/* private data */
+static int maxfd; /* # of the highest fd + 1 */
+static unsigned int *fd_evts[2];
+static THREAD_LOCAL fd_set *tmp_evts[2];
+
+/* Immediately remove the entry upon close() */
+static void __fd_clo(int fd)
+{
+ hap_fd_clr(fd, fd_evts[DIR_RD]);
+ hap_fd_clr(fd, fd_evts[DIR_WR]);
+}
+
+static void _update_fd(int fd, int *max_add_fd)
+{
+ int en;
+ ulong pr, ps;
+
+ en = fdtab[fd].state;
+ pr = _HA_ATOMIC_LOAD(&polled_mask[fd].poll_recv);
+ ps = _HA_ATOMIC_LOAD(&polled_mask[fd].poll_send);
+
+ /* we have a single state for all threads, which is why we
+ * don't check the tid_bit. First thread to see the update
+ * takes it for every other one.
+ */
+ if (!(en & FD_EV_ACTIVE_RW)) {
+ if (!(pr | ps)) {
+ /* fd was not watched, it's still not */
+ return;
+ }
+ /* fd totally removed from poll list */
+ hap_fd_clr(fd, fd_evts[DIR_RD]);
+ hap_fd_clr(fd, fd_evts[DIR_WR]);
+ _HA_ATOMIC_AND(&polled_mask[fd].poll_recv, 0);
+ _HA_ATOMIC_AND(&polled_mask[fd].poll_send, 0);
+ }
+ else {
+ /* OK fd has to be monitored, it was either added or changed */
+ if (!(en & FD_EV_ACTIVE_R)) {
+ hap_fd_clr(fd, fd_evts[DIR_RD]);
+ if (pr & ti->ltid_bit)
+ _HA_ATOMIC_AND(&polled_mask[fd].poll_recv, ~ti->ltid_bit);
+ } else {
+ hap_fd_set(fd, fd_evts[DIR_RD]);
+ if (!(pr & ti->ltid_bit))
+ _HA_ATOMIC_OR(&polled_mask[fd].poll_recv, ti->ltid_bit);
+ }
+
+ if (!(en & FD_EV_ACTIVE_W)) {
+ hap_fd_clr(fd, fd_evts[DIR_WR]);
+ if (ps & ti->ltid_bit)
+ _HA_ATOMIC_AND(&polled_mask[fd].poll_send, ~ti->ltid_bit);
+ } else {
+ hap_fd_set(fd, fd_evts[DIR_WR]);
+ if (!(ps & ti->ltid_bit))
+ _HA_ATOMIC_OR(&polled_mask[fd].poll_send, ti->ltid_bit);
+ }
+
+ if (fd > *max_add_fd)
+ *max_add_fd = fd;
+ }
+}
+
+/*
+ * Select() poller
+ */
+static void _do_poll(struct poller *p, int exp, int wake)
+{
+ int status;
+ int fd, i;
+ struct timeval delta;
+ int delta_ms;
+ int fds;
+ int updt_idx;
+ char count;
+ int readnotnull, writenotnull;
+ int old_maxfd, new_maxfd, max_add_fd;
+ int old_fd;
+
+ max_add_fd = -1;
+
+ /* first, scan the update list to find changes */
+ for (updt_idx = 0; updt_idx < fd_nbupdt; updt_idx++) {
+ fd = fd_updt[updt_idx];
+
+ _HA_ATOMIC_AND(&fdtab[fd].update_mask, ~ti->ltid_bit);
+ if (!fdtab[fd].owner) {
+ activity[tid].poll_drop_fd++;
+ continue;
+ }
+ _update_fd(fd, &max_add_fd);
+ }
+ /* Now scan the global update list */
+ for (old_fd = fd = update_list[tgid - 1].first; fd != -1; fd = fdtab[fd].update.next) {
+ if (fd == -2) {
+ fd = old_fd;
+ continue;
+ }
+ else if (fd <= -3)
+ fd = -fd -4;
+ if (fd == -1)
+ break;
+ if (fdtab[fd].update_mask & ti->ltid_bit) {
+ /* Cheat a bit, as the state is global to all pollers
+ * we don't need every thread to take care of the
+ * update.
+ */
+ _HA_ATOMIC_AND(&fdtab[fd].update_mask, ~tg->threads_enabled);
+ done_update_polling(fd);
+ } else
+ continue;
+ if (!fdtab[fd].owner)
+ continue;
+ _update_fd(fd, &max_add_fd);
+ }
+
+
+ /* maybe we added at least one fd larger than maxfd */
+ for (old_maxfd = maxfd; old_maxfd <= max_add_fd; ) {
+ if (_HA_ATOMIC_CAS(&maxfd, &old_maxfd, max_add_fd + 1))
+ break;
+ }
+
+ /* maxfd doesn't need to be precise but it needs to cover *all* active
+ * FDs. Thus we only shrink it if we have such an opportunity. The algo
+ * is simple : look for the previous used place, try to update maxfd to
+ * point to it, abort if maxfd changed in the mean time.
+ */
+ old_maxfd = maxfd;
+ do {
+ new_maxfd = old_maxfd;
+ while (new_maxfd - 1 >= 0 && !fdtab[new_maxfd - 1].owner)
+ new_maxfd--;
+ if (new_maxfd >= old_maxfd)
+ break;
+ } while (!_HA_ATOMIC_CAS(&maxfd, &old_maxfd, new_maxfd));
+
+ thread_idle_now();
+ thread_harmless_now();
+
+ fd_nbupdt = 0;
+
+ /* let's restore fdset state */
+ readnotnull = 0; writenotnull = 0;
+ for (i = 0; i < (maxfd + FD_SETSIZE - 1)/(8*sizeof(int)); i++) {
+ readnotnull |= (*(((int*)tmp_evts[DIR_RD])+i) = *(((int*)fd_evts[DIR_RD])+i)) != 0;
+ writenotnull |= (*(((int*)tmp_evts[DIR_WR])+i) = *(((int*)fd_evts[DIR_WR])+i)) != 0;
+ }
+
+ /* now let's wait for events */
+ delta_ms = wake ? 0 : compute_poll_timeout(exp);
+ delta.tv_sec = (delta_ms / 1000);
+ delta.tv_usec = (delta_ms % 1000) * 1000;
+ clock_entering_poll();
+ status = select(maxfd,
+ readnotnull ? tmp_evts[DIR_RD] : NULL,
+ writenotnull ? tmp_evts[DIR_WR] : NULL,
+ NULL,
+ &delta);
+ clock_update_date(delta_ms, status);
+ fd_leaving_poll(delta_ms, status);
+
+ if (status <= 0)
+ return;
+
+ activity[tid].poll_io++;
+
+ for (fds = 0; (fds * BITS_PER_INT) < maxfd; fds++) {
+ if ((((int *)(tmp_evts[DIR_RD]))[fds] | ((int *)(tmp_evts[DIR_WR]))[fds]) == 0)
+ continue;
+
+ for (count = BITS_PER_INT, fd = fds * BITS_PER_INT; count && fd < maxfd; count--, fd++) {
+ unsigned int n = 0;
+
+ if (FD_ISSET(fd, tmp_evts[DIR_RD]))
+ n |= FD_EV_READY_R;
+
+ if (FD_ISSET(fd, tmp_evts[DIR_WR]))
+ n |= FD_EV_READY_W;
+
+ if (!n)
+ continue;
+
+#ifdef DEBUG_FD
+ _HA_ATOMIC_INC(&fdtab[fd].event_count);
+#endif
+
+ fd_update_events(fd, n);
+ }
+ }
+}
+
+static int init_select_per_thread()
+{
+ int fd_set_bytes;
+
+ fd_set_bytes = sizeof(fd_set) * (global.maxsock + FD_SETSIZE - 1) / FD_SETSIZE;
+ tmp_evts[DIR_RD] = calloc(1, fd_set_bytes);
+ if (tmp_evts[DIR_RD] == NULL)
+ goto fail;
+ tmp_evts[DIR_WR] = calloc(1, fd_set_bytes);
+ if (tmp_evts[DIR_WR] == NULL)
+ goto fail;
+ return 1;
+ fail:
+ free(tmp_evts[DIR_RD]);
+ free(tmp_evts[DIR_WR]);
+ return 0;
+}
+
+static void deinit_select_per_thread()
+{
+ ha_free(&tmp_evts[DIR_WR]);
+ ha_free(&tmp_evts[DIR_RD]);
+}
+
+/*
+ * Initialization of the select() poller.
+ * Returns 0 in case of failure, non-zero in case of success. If it fails, it
+ * disables the poller by setting its pref to 0.
+ */
+static int _do_init(struct poller *p)
+{
+ int fd_set_bytes;
+
+ p->private = NULL;
+
+ /* this old poller uses a process-wide FD list that cannot work with
+ * groups.
+ */
+ if (global.nbtgroups > 1)
+ goto fail_srevt;
+
+ if (global.maxsock > FD_SETSIZE)
+ goto fail_srevt;
+
+ fd_set_bytes = sizeof(fd_set) * (global.maxsock + FD_SETSIZE - 1) / FD_SETSIZE;
+
+ if ((fd_evts[DIR_RD] = calloc(1, fd_set_bytes)) == NULL)
+ goto fail_srevt;
+ if ((fd_evts[DIR_WR] = calloc(1, fd_set_bytes)) == NULL)
+ goto fail_swevt;
+
+ hap_register_per_thread_init(init_select_per_thread);
+ hap_register_per_thread_deinit(deinit_select_per_thread);
+
+ return 1;
+
+ fail_swevt:
+ free(fd_evts[DIR_RD]);
+ fail_srevt:
+ p->pref = 0;
+ return 0;
+}
+
+/*
+ * Termination of the select() poller.
+ * Memory is released and the poller is marked as unselectable.
+ */
+static void _do_term(struct poller *p)
+{
+ free(fd_evts[DIR_WR]);
+ free(fd_evts[DIR_RD]);
+ p->private = NULL;
+ p->pref = 0;
+}
+
+/*
+ * Check that the poller works.
+ * Returns 1 if OK, otherwise 0.
+ */
+static int _do_test(struct poller *p)
+{
+ if (global.maxsock > FD_SETSIZE)
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Registers the poller.
+ */
+static void _do_register(void)
+{
+ struct poller *p;
+
+ if (nbpollers >= MAX_POLLERS)
+ return;
+ p = &pollers[nbpollers++];
+
+ p->name = "select";
+ p->pref = 150;
+ p->flags = 0;
+ p->private = NULL;
+
+ p->clo = __fd_clo;
+ p->test = _do_test;
+ p->init = _do_init;
+ p->term = _do_term;
+ p->poll = _do_poll;
+}
+
+INITCALL0(STG_REGISTER, _do_register);
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ */