| /* |
| * 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-common.h" |
| #include "block/aio.h" |
| #include "qemu/main-loop.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; |
| }; |
| |
| QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque) |
| { |
| QEMUBH *bh; |
| bh = g_malloc0(sizeof(QEMUBH)); |
| bh->ctx = ctx; |
| bh->cb = cb; |
| bh->opaque = opaque; |
| bh->next = ctx->first_bh; |
| ctx->first_bh = bh; |
| return bh; |
| } |
| |
| int aio_bh_poll(AioContext *ctx) |
| { |
| QEMUBH *bh, **bhp, *next; |
| int ret; |
| |
| ctx->walking_bh++; |
| |
| ret = 0; |
| for (bh = ctx->first_bh; bh; bh = next) { |
| next = bh->next; |
| if (!bh->deleted && bh->scheduled) { |
| bh->scheduled = 0; |
| if (!bh->idle) |
| ret = 1; |
| bh->idle = 0; |
| bh->cb(bh->opaque); |
| } |
| } |
| |
| ctx->walking_bh--; |
| |
| /* remove deleted bhs */ |
| if (!ctx->walking_bh) { |
| bhp = &ctx->first_bh; |
| while (*bhp) { |
| bh = *bhp; |
| if (bh->deleted) { |
| *bhp = bh->next; |
| g_free(bh); |
| } else { |
| bhp = &bh->next; |
| } |
| } |
| } |
| |
| return ret; |
| } |
| |
| void qemu_bh_schedule_idle(QEMUBH *bh) |
| { |
| if (bh->scheduled) |
| return; |
| bh->scheduled = 1; |
| bh->idle = 1; |
| } |
| |
| void qemu_bh_schedule(QEMUBH *bh) |
| { |
| if (bh->scheduled) |
| return; |
| bh->scheduled = 1; |
| bh->idle = 0; |
| aio_notify(bh->ctx); |
| } |
| |
| void qemu_bh_cancel(QEMUBH *bh) |
| { |
| bh->scheduled = 0; |
| } |
| |
| void qemu_bh_delete(QEMUBH *bh) |
| { |
| bh->scheduled = 0; |
| bh->deleted = 1; |
| } |
| |
| static gboolean |
| aio_ctx_prepare(GSource *source, gint *timeout) |
| { |
| AioContext *ctx = (AioContext *) source; |
| QEMUBH *bh; |
| |
| for (bh = ctx->first_bh; bh; bh = bh->next) { |
| if (!bh->deleted && bh->scheduled) { |
| if (bh->idle) { |
| /* idle bottom halves will be polled at least |
| * every 10ms */ |
| *timeout = 10; |
| } else { |
| /* non-idle bottom halves will be executed |
| * immediately */ |
| *timeout = 0; |
| return true; |
| } |
| } |
| } |
| |
| return false; |
| } |
| |
| static gboolean |
| aio_ctx_check(GSource *source) |
| { |
| AioContext *ctx = (AioContext *) source; |
| QEMUBH *bh; |
| |
| for (bh = ctx->first_bh; bh; bh = bh->next) { |
| if (!bh->deleted && bh->scheduled) { |
| return true; |
| } |
| } |
| return aio_pending(ctx); |
| } |
| |
| static gboolean |
| aio_ctx_dispatch(GSource *source, |
| GSourceFunc callback, |
| gpointer user_data) |
| { |
| AioContext *ctx = (AioContext *) source; |
| |
| assert(callback == NULL); |
| aio_poll(ctx, false); |
| return true; |
| } |
| |
| static void |
| aio_ctx_finalize(GSource *source) |
| { |
| AioContext *ctx = (AioContext *) source; |
| |
| aio_set_event_notifier(ctx, &ctx->notifier, NULL, NULL); |
| event_notifier_cleanup(&ctx->notifier); |
| g_array_free(ctx->pollfds, TRUE); |
| } |
| |
| 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; |
| } |
| |
| void aio_notify(AioContext *ctx) |
| { |
| event_notifier_set(&ctx->notifier); |
| } |
| |
| AioContext *aio_context_new(void) |
| { |
| AioContext *ctx; |
| ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext)); |
| ctx->pollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD)); |
| event_notifier_init(&ctx->notifier, false); |
| aio_set_event_notifier(ctx, &ctx->notifier, |
| (EventNotifierHandler *) |
| event_notifier_test_and_clear, NULL); |
| |
| return ctx; |
| } |
| |
| void aio_context_ref(AioContext *ctx) |
| { |
| g_source_ref(&ctx->source); |
| } |
| |
| void aio_context_unref(AioContext *ctx) |
| { |
| g_source_unref(&ctx->source); |
| } |