event: peel out poll and epoll specific code into separate files

code re-org, no change in logic.

Change-Id: Ib1cb3d3f4cf8989a916df7476479c26570d07a84
BUG: 821087
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/3932
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>

1 files changed, 451 insertions, 0 deletions

diff --git a/libglusterfs/src/event-poll.c b/libglusterfs/src/event-poll.c
new file mode 100644
index 00000000000..7f7f560d086
--- /dev/null
+++ b/libglusterfs/src/event-poll.c
@@ -0,0 +1,451 @@
+/*
+  Copyright (c) 2012 Red Hat, Inc. <http://www.redhat.com>
+  This file is part of GlusterFS.
+
+  This file is licensed to you under your choice of the GNU Lesser
+  General Public License, version 3 or any later version (LGPLv3 or
+  later), or the GNU General Public License, version 2 (GPLv2), in all
+  cases as published by the Free Software Foundation.
+*/
+
+#include <sys/poll.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+
+#include "logging.h"
+#include "event.h"
+#include "mem-pool.h"
+#include "common-utils.h"
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+static int
+event_register_poll (struct event_pool *event_pool, int fd,
+                     event_handler_t handler,
+                     void *data, int poll_in, int poll_out);
+
+
+static int
+__flush_fd (int fd, int idx, void *data,
+            int poll_in, int poll_out, int poll_err)
+{
+        char buf[64];
+        int ret = -1;
+
+        if (!poll_in)
+                return ret;
+
+        do {
+                ret = read (fd, buf, 64);
+                if (ret == -1 && errno != EAGAIN) {
+                        gf_log ("poll", GF_LOG_ERROR,
+                                "read on %d returned error (%s)",
+                                fd, strerror (errno));
+                }
+        } while (ret == 64);
+
+        return ret;
+}
+
+
+static int
+__event_getindex (struct event_pool *event_pool, int fd, int idx)
+{
+        int  ret = -1;
+        int  i = 0;
+
+        GF_VALIDATE_OR_GOTO ("event", event_pool, out);
+
+        if (idx > -1 && idx < event_pool->used) {
+                if (event_pool->reg[idx].fd == fd)
+                        ret = idx;
+        }
+
+        for (i=0; ret == -1 && i<event_pool->used; i++) {
+                if (event_pool->reg[i].fd == fd) {
+                        ret = i;
+                        break;
+                }
+        }
+
+out:
+        return ret;
+}
+
+
+static struct event_pool *
+event_pool_new_poll (int count)
+{
+        struct event_pool *event_pool = NULL;
+        int                ret = -1;
+
+        event_pool = GF_CALLOC (1, sizeof (*event_pool),
+                                gf_common_mt_event_pool);
+
+        if (!event_pool)
+                return NULL;
+
+        event_pool->count = count;
+        event_pool->reg = GF_CALLOC (event_pool->count,
+                                     sizeof (*event_pool->reg),
+                                     gf_common_mt_reg);
+
+        if (!event_pool->reg) {
+                GF_FREE (event_pool);
+                return NULL;
+        }
+
+        pthread_mutex_init (&event_pool->mutex, NULL);
+
+        ret = pipe (event_pool->breaker);
+
+        if (ret == -1) {
+                gf_log ("poll", GF_LOG_ERROR,
+                        "pipe creation failed (%s)", strerror (errno));
+                GF_FREE (event_pool->reg);
+                GF_FREE (event_pool);
+                return NULL;
+        }
+
+        ret = fcntl (event_pool->breaker[0], F_SETFL, O_NONBLOCK);
+        if (ret == -1) {
+                gf_log ("poll", GF_LOG_ERROR,
+                        "could not set pipe to non blocking mode (%s)",
+                        strerror (errno));
+                close (event_pool->breaker[0]);
+                close (event_pool->breaker[1]);
+                event_pool->breaker[0] = event_pool->breaker[1] = -1;
+
+                GF_FREE (event_pool->reg);
+                GF_FREE (event_pool);
+                return NULL;
+        }
+
+        ret = fcntl (event_pool->breaker[1], F_SETFL, O_NONBLOCK);
+        if (ret == -1) {
+                gf_log ("poll", GF_LOG_ERROR,
+                        "could not set pipe to non blocking mode (%s)",
+                        strerror (errno));
+
+                close (event_pool->breaker[0]);
+                close (event_pool->breaker[1]);
+                event_pool->breaker[0] = event_pool->breaker[1] = -1;
+
+                GF_FREE (event_pool->reg);
+                GF_FREE (event_pool);
+                return NULL;
+        }
+
+        ret = event_register_poll (event_pool, event_pool->breaker[0],
+                                   __flush_fd, NULL, 1, 0);
+        if (ret == -1) {
+                gf_log ("poll", GF_LOG_ERROR,
+                        "could not register pipe fd with poll event loop");
+                close (event_pool->breaker[0]);
+                close (event_pool->breaker[1]);
+                event_pool->breaker[0] = event_pool->breaker[1] = -1;
+
+                GF_FREE (event_pool->reg);
+                GF_FREE (event_pool);
+                return NULL;
+        }
+
+        return event_pool;
+}
+
+
+static int
+event_register_poll (struct event_pool *event_pool, int fd,
+                     event_handler_t handler,
+                     void *data, int poll_in, int poll_out)
+{
+        int idx = -1;
+
+        GF_VALIDATE_OR_GOTO ("event", event_pool, out);
+
+        pthread_mutex_lock (&event_pool->mutex);
+        {
+                if (event_pool->count == event_pool->used)
+                {
+                        event_pool->count += 256;
+
+                        event_pool->reg = GF_REALLOC (event_pool->reg,
+                                                      event_pool->count *
+                                                      sizeof (*event_pool->reg));
+                        if (!event_pool->reg)
+                                goto unlock;
+                }
+
+                idx = event_pool->used++;
+
+                event_pool->reg[idx].fd = fd;
+                event_pool->reg[idx].events = POLLPRI;
+                event_pool->reg[idx].handler = handler;
+                event_pool->reg[idx].data = data;
+
+                switch (poll_in) {
+                case 1:
+                        event_pool->reg[idx].events |= POLLIN;
+                        break;
+                case 0:
+                        event_pool->reg[idx].events &= ~POLLIN;
+                        break;
+                case -1:
+                        /* do nothing */
+                        break;
+                default:
+                        gf_log ("poll", GF_LOG_ERROR,
+                                "invalid poll_in value %d", poll_in);
+                        break;
+                }
+
+                switch (poll_out) {
+                case 1:
+                        event_pool->reg[idx].events |= POLLOUT;
+                        break;
+                case 0:
+                        event_pool->reg[idx].events &= ~POLLOUT;
+                        break;
+                case -1:
+                        /* do nothing */
+                        break;
+                default:
+                        gf_log ("poll", GF_LOG_ERROR,
+                                "invalid poll_out value %d", poll_out);
+                        break;
+                }
+
+                event_pool->changed = 1;
+
+        }
+unlock:
+        pthread_mutex_unlock (&event_pool->mutex);
+
+out:
+        return idx;
+}
+
+
+static int
+event_unregister_poll (struct event_pool *event_pool, int fd, int idx_hint)
+{
+        int idx = -1;
+
+        GF_VALIDATE_OR_GOTO ("event", event_pool, out);
+
+        pthread_mutex_lock (&event_pool->mutex);
+        {
+                idx = __event_getindex (event_pool, fd, idx_hint);
+
+                if (idx == -1) {
+                        gf_log ("poll", GF_LOG_ERROR,
+                                "index not found for fd=%d (idx_hint=%d)",
+                                fd, idx_hint);
+                        errno = ENOENT;
+                        goto unlock;
+                }
+
+                event_pool->reg[idx] =  event_pool->reg[--event_pool->used];
+                event_pool->changed = 1;
+        }
+unlock:
+        pthread_mutex_unlock (&event_pool->mutex);
+
+out:
+        return idx;
+}
+
+
+static int
+event_select_on_poll (struct event_pool *event_pool, int fd, int idx_hint,
+                      int poll_in, int poll_out)
+{
+        int idx = -1;
+
+        GF_VALIDATE_OR_GOTO ("event", event_pool, out);
+
+        pthread_mutex_lock (&event_pool->mutex);
+        {
+                idx = __event_getindex (event_pool, fd, idx_hint);
+
+                if (idx == -1) {
+                        gf_log ("poll", GF_LOG_ERROR,
+                                "index not found for fd=%d (idx_hint=%d)",
+                                fd, idx_hint);
+                        errno = ENOENT;
+                        goto unlock;
+                }
+
+                switch (poll_in) {
+                case 1:
+                        event_pool->reg[idx].events |= POLLIN;
+                        break;
+                case 0:
+                        event_pool->reg[idx].events &= ~POLLIN;
+                        break;
+                case -1:
+                        /* do nothing */
+                        break;
+                default:
+                        /* TODO: log error */
+                        break;
+                }
+
+                switch (poll_out) {
+                case 1:
+                        event_pool->reg[idx].events |= POLLOUT;
+                        break;
+                case 0:
+                        event_pool->reg[idx].events &= ~POLLOUT;
+                        break;
+                case -1:
+                        /* do nothing */
+                        break;
+                default:
+                        /* TODO: log error */
+                        break;
+                }
+
+                if (poll_in + poll_out > -2)
+                        event_pool->changed = 1;
+        }
+unlock:
+        pthread_mutex_unlock (&event_pool->mutex);
+
+out:
+        return idx;
+}
+
+
+static int
+event_dispatch_poll_handler (struct event_pool *event_pool,
+                             struct pollfd *ufds, int i)
+{
+        event_handler_t  handler = NULL;
+        void            *data = NULL;
+        int              idx = -1;
+        int              ret = 0;
+
+        handler = NULL;
+        data    = NULL;
+
+        pthread_mutex_lock (&event_pool->mutex);
+        {
+                idx = __event_getindex (event_pool, ufds[i].fd, i);
+
+                if (idx == -1) {
+                        gf_log ("poll", GF_LOG_ERROR,
+                                "index not found for fd=%d (idx_hint=%d)",
+                                ufds[i].fd, i);
+                        goto unlock;
+                }
+
+                handler = event_pool->reg[idx].handler;
+                data = event_pool->reg[idx].data;
+        }
+unlock:
+        pthread_mutex_unlock (&event_pool->mutex);
+
+        if (handler)
+                ret = handler (ufds[i].fd, idx, data,
+                               (ufds[i].revents & (POLLIN|POLLPRI)),
+                               (ufds[i].revents & (POLLOUT)),
+                               (ufds[i].revents & (POLLERR|POLLHUP|POLLNVAL)));
+
+        return ret;
+}
+
+
+static int
+event_dispatch_poll_resize (struct event_pool *event_pool,
+                            struct pollfd *ufds, int size)
+{
+        int              i = 0;
+
+        pthread_mutex_lock (&event_pool->mutex);
+        {
+                if (event_pool->changed == 0) {
+                        goto unlock;
+                }
+
+                if (event_pool->used > event_pool->evcache_size) {
+                        GF_FREE (event_pool->evcache);
+
+                        event_pool->evcache = ufds = NULL;
+
+                        event_pool->evcache_size = event_pool->used;
+
+                        ufds = GF_CALLOC (sizeof (struct pollfd),
+                                          event_pool->evcache_size,
+                                          gf_common_mt_pollfd);
+                        if (!ufds)
+                                goto unlock;
+                        event_pool->evcache = ufds;
+                }
+
+                for (i = 0; i < event_pool->used; i++) {
+                        ufds[i].fd = event_pool->reg[i].fd;
+                        ufds[i].events = event_pool->reg[i].events;
+                        ufds[i].revents = 0;
+                }
+
+                size = i;
+        }
+unlock:
+        pthread_mutex_unlock (&event_pool->mutex);
+
+        return size;
+}
+
+
+static int
+event_dispatch_poll (struct event_pool *event_pool)
+{
+        struct pollfd   *ufds = NULL;
+        int              size = 0;
+        int              i = 0;
+        int              ret = -1;
+
+        GF_VALIDATE_OR_GOTO ("event", event_pool, out);
+
+        while (1) {
+                size = event_dispatch_poll_resize (event_pool, ufds, size);
+                ufds = event_pool->evcache;
+
+                ret = poll (ufds, size, 1);
+
+                if (ret == 0)
+                        /* timeout */
+                        continue;
+
+                if (ret == -1 && errno == EINTR)
+                        /* sys call */
+                        continue;
+
+                for (i = 0; i < size; i++) {
+                        if (!ufds[i].revents)
+                                continue;
+
+                        event_dispatch_poll_handler (event_pool, ufds, i);
+                }
+        }
+
+out:
+        return -1;
+}
+
+
+struct event_ops event_ops_poll = {
+        .new              = event_pool_new_poll,
+        .event_register   = event_register_poll,
+        .event_select_on  = event_select_on_poll,
+        .event_unregister = event_unregister_poll,
+        .event_dispatch   = event_dispatch_poll
+};