LXR qemu/qemu-coroutine.c

   1/*
   2 * QEMU coroutines
   3 *
   4 * Copyright IBM, Corp. 2011
   5 *
   6 * Authors:
   7 *  Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
   8 *  Kevin Wolf         <kwolf@redhat.com>
   9 *
  10 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
  11 * See the COPYING.LIB file in the top-level directory.
  12 *
  13 */
  14
  15#include "trace.h"
  16#include "qemu-common.h"
  17#include "qemu-coroutine.h"
  18#include "qemu-coroutine-int.h"
  19
  20Coroutine *qemu_coroutine_create(CoroutineEntry *entry)
  21{
  22    Coroutine *co = qemu_coroutine_new();
  23    co->entry = entry;
  24    return co;
  25}
  26
  27static void coroutine_swap(Coroutine *from, Coroutine *to)
  28{
  29    CoroutineAction ret;
  30
  31    ret = qemu_coroutine_switch(from, to, COROUTINE_YIELD);
  32
  33    switch (ret) {
  34    case COROUTINE_YIELD:
  35        return;
  36    case COROUTINE_TERMINATE:
  37        trace_qemu_coroutine_terminate(to);
  38        qemu_coroutine_delete(to);
  39        return;
  40    default:
  41        abort();
  42    }
  43}
  44
  45void qemu_coroutine_enter(Coroutine *co, void *opaque)
  46{
  47    Coroutine *self = qemu_coroutine_self();
  48
  49    trace_qemu_coroutine_enter(self, co, opaque);
  50
  51    if (co->caller) {
  52        fprintf(stderr, "Co-routine re-entered recursively\n");
  53        abort();
  54    }
  55
  56    co->caller = self;
  57    co->entry_arg = opaque;
  58    coroutine_swap(self, co);
  59}
  60
  61void coroutine_fn qemu_coroutine_yield(void)
  62{
  63    Coroutine *self = qemu_coroutine_self();
  64    Coroutine *to = self->caller;
  65
  66    trace_qemu_coroutine_yield(self, to);
  67
  68    if (!to) {
  69        fprintf(stderr, "Co-routine is yielding to no one\n");
  70        abort();
  71    }
  72
  73    self->caller = NULL;
  74    coroutine_swap(self, to);
  75}
  76