1 /* 2 * QEMU coroutine sleep 3 * 4 * Copyright IBM, Corp. 2011 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 10 * See the COPYING.LIB file in the top-level directory. 11 * 12 */ 13 14 #include "qemu/osdep.h" 15 #include "qemu/coroutine.h" 16 #include "qemu/coroutine_int.h" 17 #include "qemu/timer.h" 18 #include "block/aio.h" 19 20 typedef struct CoSleepCB { 21 QEMUTimer *ts; 22 Coroutine *co; 23 } CoSleepCB; 24 25 static void co_sleep_cb(void *opaque) 26 { 27 CoSleepCB *sleep_cb = opaque; 28 29 /* Write of schedule protected by barrier write in aio_co_schedule */ 30 atomic_set(&sleep_cb->co->scheduled, NULL); 31 aio_co_wake(sleep_cb->co); 32 } 33 34 void coroutine_fn qemu_co_sleep_ns(QEMUClockType type, int64_t ns) 35 { 36 AioContext *ctx = qemu_get_current_aio_context(); 37 CoSleepCB sleep_cb = { 38 .co = qemu_coroutine_self(), 39 }; 40 41 const char *scheduled = atomic_cmpxchg(&sleep_cb.co->scheduled, NULL, 42 __func__); 43 if (scheduled) { 44 fprintf(stderr, 45 "%s: Co-routine was already scheduled in '%s'\n", 46 __func__, scheduled); 47 abort(); 48 } 49 sleep_cb.ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &sleep_cb); 50 timer_mod(sleep_cb.ts, qemu_clock_get_ns(type) + ns); 51 qemu_coroutine_yield(); 52 timer_del(sleep_cb.ts); 53 timer_free(sleep_cb.ts); 54 } 55