block: move AioContext, QEMUTimer, main-loop to libqemuutil

AioContext is fairly self contained, the only dependency is QEMUTimer but
that in turn doesn't need anything else.  So move them out of block-obj-y
to avoid introducing a dependency from io/ to block-obj-y.

main-loop and its dependency iohandler also need to be moved, because
later in this series io/ will call iohandler_get_aio_context.

[Changed copyright "the QEMU team" to "other QEMU contributors" as
suggested by Daniel Berrange and agreed by Paolo.
--Stefan]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-2-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 0 insertions, 422 deletions

diff --git a/async.c b/async.c
deleted file mode 100644
index 0d218ab0e0..0000000000
--- a/async.c
+++ /dev/null
@@ -1,422 +0,0 @@
-/*
- * QEMU System Emulator
- *
- * 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 "qemu/osdep.h"
-#include "qapi/error.h"
-#include "qemu-common.h"
-#include "block/aio.h"
-#include "block/thread-pool.h"
-#include "qemu/main-loop.h"
-#include "qemu/atomic.h"
-#include "block/raw-aio.h"
-
-/***********************************************************/
-/* bottom halves (can be seen as timers which expire ASAP) */
-
-struct QEMUBH {
-    AioContext *ctx;
-    QEMUBHFunc *cb;
-    void *opaque;
-    QEMUBH *next;
-    bool scheduled;
-    bool idle;
-    bool deleted;
-};
-
-void aio_bh_schedule_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
-{
-    QEMUBH *bh;
-    bh = g_new(QEMUBH, 1);
-    *bh = (QEMUBH){
-        .ctx = ctx,
-        .cb = cb,
-        .opaque = opaque,
-    };
-    qemu_lockcnt_lock(&ctx->list_lock);
-    bh->next = ctx->first_bh;
-    bh->scheduled = 1;
-    bh->deleted = 1;
-    /* Make sure that the members are ready before putting bh into list */
-    smp_wmb();
-    ctx->first_bh = bh;
-    qemu_lockcnt_unlock(&ctx->list_lock);
-    aio_notify(ctx);
-}
-
-QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
-{
-    QEMUBH *bh;
-    bh = g_new(QEMUBH, 1);
-    *bh = (QEMUBH){
-        .ctx = ctx,
-        .cb = cb,
-        .opaque = opaque,
-    };
-    qemu_lockcnt_lock(&ctx->list_lock);
-    bh->next = ctx->first_bh;
-    /* Make sure that the members are ready before putting bh into list */
-    smp_wmb();
-    ctx->first_bh = bh;
-    qemu_lockcnt_unlock(&ctx->list_lock);
-    return bh;
-}
-
-void aio_bh_call(QEMUBH *bh)
-{
-    bh->cb(bh->opaque);
-}
-
-/* Multiple occurrences of aio_bh_poll cannot be called concurrently */
-int aio_bh_poll(AioContext *ctx)
-{
-    QEMUBH *bh, **bhp, *next;
-    int ret;
-    bool deleted = false;
-
-    qemu_lockcnt_inc(&ctx->list_lock);
-
-    ret = 0;
-    for (bh = atomic_rcu_read(&ctx->first_bh); bh; bh = next) {
-        next = atomic_rcu_read(&bh->next);
-        /* The atomic_xchg is paired with the one in qemu_bh_schedule.  The
-         * implicit memory barrier ensures that the callback sees all writes
-         * done by the scheduling thread.  It also ensures that the scheduling
-         * thread sees the zero before bh->cb has run, and thus will call
-         * aio_notify again if necessary.
-         */
-        if (atomic_xchg(&bh->scheduled, 0)) {
-            /* Idle BHs don't count as progress */
-            if (!bh->idle) {
-                ret = 1;
-            }
-            bh->idle = 0;
-            aio_bh_call(bh);
-        }
-        if (bh->deleted) {
-            deleted = true;
-        }
-    }
-
-    /* remove deleted bhs */
-    if (!deleted) {
-        qemu_lockcnt_dec(&ctx->list_lock);
-        return ret;
-    }
-
-    if (qemu_lockcnt_dec_and_lock(&ctx->list_lock)) {
-        bhp = &ctx->first_bh;
-        while (*bhp) {
-            bh = *bhp;
-            if (bh->deleted && !bh->scheduled) {
-                *bhp = bh->next;
-                g_free(bh);
-            } else {
-                bhp = &bh->next;
-            }
-        }
-        qemu_lockcnt_unlock(&ctx->list_lock);
-    }
-    return ret;
-}
-
-void qemu_bh_schedule_idle(QEMUBH *bh)
-{
-    bh->idle = 1;
-    /* Make sure that idle & any writes needed by the callback are done
-     * before the locations are read in the aio_bh_poll.
-     */
-    atomic_mb_set(&bh->scheduled, 1);
-}
-
-void qemu_bh_schedule(QEMUBH *bh)
-{
-    AioContext *ctx;
-
-    ctx = bh->ctx;
-    bh->idle = 0;
-    /* The memory barrier implicit in atomic_xchg makes sure that:
-     * 1. idle & any writes needed by the callback are done before the
-     *    locations are read in the aio_bh_poll.
-     * 2. ctx is loaded before scheduled is set and the callback has a chance
-     *    to execute.
-     */
-    if (atomic_xchg(&bh->scheduled, 1) == 0) {
-        aio_notify(ctx);
-    }
-}
-
-
-/* This func is async.
- */
-void qemu_bh_cancel(QEMUBH *bh)
-{
-    bh->scheduled = 0;
-}
-
-/* This func is async.The bottom half will do the delete action at the finial
- * end.
- */
-void qemu_bh_delete(QEMUBH *bh)
-{
-    bh->scheduled = 0;
-    bh->deleted = 1;
-}
-
-int64_t
-aio_compute_timeout(AioContext *ctx)
-{
-    int64_t deadline;
-    int timeout = -1;
-    QEMUBH *bh;
-
-    for (bh = atomic_rcu_read(&ctx->first_bh); bh;
-         bh = atomic_rcu_read(&bh->next)) {
-        if (bh->scheduled) {
-            if (bh->idle) {
-                /* idle bottom halves will be polled at least
-                 * every 10ms */
-                timeout = 10000000;
-            } else {
-                /* non-idle bottom halves will be executed
-                 * immediately */
-                return 0;
-            }
-        }
-    }
-
-    deadline = timerlistgroup_deadline_ns(&ctx->tlg);
-    if (deadline == 0) {
-        return 0;
-    } else {
-        return qemu_soonest_timeout(timeout, deadline);
-    }
-}
-
-static gboolean
-aio_ctx_prepare(GSource *source, gint    *timeout)
-{
-    AioContext *ctx = (AioContext *) source;
-
-    atomic_or(&ctx->notify_me, 1);
-
-    /* We assume there is no timeout already supplied */
-    *timeout = qemu_timeout_ns_to_ms(aio_compute_timeout(ctx));
-
-    if (aio_prepare(ctx)) {
-        *timeout = 0;
-    }
-
-    return *timeout == 0;
-}
-
-static gboolean
-aio_ctx_check(GSource *source)
-{
-    AioContext *ctx = (AioContext *) source;
-    QEMUBH *bh;
-
-    atomic_and(&ctx->notify_me, ~1);
-    aio_notify_accept(ctx);
-
-    for (bh = ctx->first_bh; bh; bh = bh->next) {
-        if (bh->scheduled) {
-            return true;
-        }
-    }
-    return aio_pending(ctx) || (timerlistgroup_deadline_ns(&ctx->tlg) == 0);
-}
-
-static gboolean
-aio_ctx_dispatch(GSource     *source,
-                 GSourceFunc  callback,
-                 gpointer     user_data)
-{
-    AioContext *ctx = (AioContext *) source;
-
-    assert(callback == NULL);
-    aio_dispatch(ctx, true);
-    return true;
-}
-
-static void
-aio_ctx_finalize(GSource     *source)
-{
-    AioContext *ctx = (AioContext *) source;
-
-    thread_pool_free(ctx->thread_pool);
-
-#ifdef CONFIG_LINUX_AIO
-    if (ctx->linux_aio) {
-        laio_detach_aio_context(ctx->linux_aio, ctx);
-        laio_cleanup(ctx->linux_aio);
-        ctx->linux_aio = NULL;
-    }
-#endif
-
-    qemu_lockcnt_lock(&ctx->list_lock);
-    assert(!qemu_lockcnt_count(&ctx->list_lock));
-    while (ctx->first_bh) {
-        QEMUBH *next = ctx->first_bh->next;
-
-        /* qemu_bh_delete() must have been called on BHs in this AioContext */
-        assert(ctx->first_bh->deleted);
-
-        g_free(ctx->first_bh);
-        ctx->first_bh = next;
-    }
-    qemu_lockcnt_unlock(&ctx->list_lock);
-
-    aio_set_event_notifier(ctx, &ctx->notifier, false, NULL, NULL);
-    event_notifier_cleanup(&ctx->notifier);
-    qemu_rec_mutex_destroy(&ctx->lock);
-    qemu_lockcnt_destroy(&ctx->list_lock);
-    timerlistgroup_deinit(&ctx->tlg);
-}
-
-static GSourceFuncs aio_source_funcs = {
-    aio_ctx_prepare,
-    aio_ctx_check,
-    aio_ctx_dispatch,
-    aio_ctx_finalize
-};
-
-GSource *aio_get_g_source(AioContext *ctx)
-{
-    g_source_ref(&ctx->source);
-    return &ctx->source;
-}
-
-ThreadPool *aio_get_thread_pool(AioContext *ctx)
-{
-    if (!ctx->thread_pool) {
-        ctx->thread_pool = thread_pool_new(ctx);
-    }
-    return ctx->thread_pool;
-}
-
-#ifdef CONFIG_LINUX_AIO
-LinuxAioState *aio_get_linux_aio(AioContext *ctx)
-{
-    if (!ctx->linux_aio) {
-        ctx->linux_aio = laio_init();
-        laio_attach_aio_context(ctx->linux_aio, ctx);
-    }
-    return ctx->linux_aio;
-}
-#endif
-
-void aio_notify(AioContext *ctx)
-{
-    /* Write e.g. bh->scheduled before reading ctx->notify_me.  Pairs
-     * with atomic_or in aio_ctx_prepare or atomic_add in aio_poll.
-     */
-    smp_mb();
-    if (ctx->notify_me) {
-        event_notifier_set(&ctx->notifier);
-        atomic_mb_set(&ctx->notified, true);
-    }
-}
-
-void aio_notify_accept(AioContext *ctx)
-{
-    if (atomic_xchg(&ctx->notified, false)) {
-        event_notifier_test_and_clear(&ctx->notifier);
-    }
-}
-
-static void aio_timerlist_notify(void *opaque)
-{
-    aio_notify(opaque);
-}
-
-static void event_notifier_dummy_cb(EventNotifier *e)
-{
-}
-
-/* Returns true if aio_notify() was called (e.g. a BH was scheduled) */
-static bool event_notifier_poll(void *opaque)
-{
-    EventNotifier *e = opaque;
-    AioContext *ctx = container_of(e, AioContext, notifier);
-
-    return atomic_read(&ctx->notified);
-}
-
-AioContext *aio_context_new(Error **errp)
-{
-    int ret;
-    AioContext *ctx;
-
-    ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext));
-    aio_context_setup(ctx);
-
-    ret = event_notifier_init(&ctx->notifier, false);
-    if (ret < 0) {
-        error_setg_errno(errp, -ret, "Failed to initialize event notifier");
-        goto fail;
-    }
-    g_source_set_can_recurse(&ctx->source, true);
-    qemu_lockcnt_init(&ctx->list_lock);
-    aio_set_event_notifier(ctx, &ctx->notifier,
-                           false,
-                           (EventNotifierHandler *)
-                           event_notifier_dummy_cb,
-                           event_notifier_poll);
-#ifdef CONFIG_LINUX_AIO
-    ctx->linux_aio = NULL;
-#endif
-    ctx->thread_pool = NULL;
-    qemu_rec_mutex_init(&ctx->lock);
-    timerlistgroup_init(&ctx->tlg, aio_timerlist_notify, ctx);
-
-    ctx->poll_ns = 0;
-    ctx->poll_max_ns = 0;
-    ctx->poll_grow = 0;
-    ctx->poll_shrink = 0;
-
-    return ctx;
-fail:
-    g_source_destroy(&ctx->source);
-    return NULL;
-}
-
-void aio_context_ref(AioContext *ctx)
-{
-    g_source_ref(&ctx->source);
-}
-
-void aio_context_unref(AioContext *ctx)
-{
-    g_source_unref(&ctx->source);
-}
-
-void aio_context_acquire(AioContext *ctx)
-{
-    qemu_rec_mutex_lock(&ctx->lock);
-}
-
-void aio_context_release(AioContext *ctx)
-{
-    qemu_rec_mutex_unlock(&ctx->lock);
-}