Commit d0e2fce5 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Kevin Wolf

coroutine: implement coroutines using gthread

On platforms that don't support makecontext(3) use gthread based
coroutine implementation.

Darwin has makecontext(3) but getcontext(3) is stubbed out to return
ENOTSUP.  Andreas Färber <andreas.faerber@web.de> debugged this and
contributed the ./configure test which solves the issue for Darwin/ppc64
(and ppc) v10.5.

[Original patch by Aneesh, made consistent with coroutine-ucontext.c and
switched to GStaticPrivate by Stefan.  Tested on Linux and OpenBSD.]
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
parent 00dccaf1
......@@ -13,7 +13,11 @@ oslib-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-thread-posix.o
#######################################################################
# coroutines
coroutine-obj-y = qemu-coroutine.o
ifeq ($(CONFIG_UCONTEXT_COROUTINE),y)
coroutine-obj-$(CONFIG_POSIX) += coroutine-ucontext.o
else
coroutine-obj-$(CONFIG_POSIX) += coroutine-gthread.o
endif
coroutine-obj-$(CONFIG_WIN32) += coroutine-win32.o
#######################################################################
......
......@@ -2540,6 +2540,20 @@ EOF
fi
fi
##########################################
# check if we have makecontext
ucontext_coroutine=no
if test "$darwin" != "yes"; then
cat > $TMPC << EOF
#include <ucontext.h>
int main(void) { makecontext(0, 0, 0); }
EOF
if compile_prog "" "" ; then
ucontext_coroutine=yes
fi
fi
##########################################
# End of CC checks
# After here, no more $cc or $ld runs
......@@ -3015,6 +3029,10 @@ if test "$rbd" = "yes" ; then
echo "CONFIG_RBD=y" >> $config_host_mak
fi
if test "$ucontext_coroutine" = "yes" ; then
echo "CONFIG_UCONTEXT_COROUTINE=y" >> $config_host_mak
fi
# USB host support
case "$usb" in
linux)
......
/*
* GThread coroutine initialization code
*
* Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
* Copyright (C) 2011 Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.0 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include <glib.h>
#include "qemu-common.h"
#include "qemu-coroutine-int.h"
typedef struct {
Coroutine base;
GThread *thread;
bool runnable;
CoroutineAction action;
} CoroutineGThread;
static GCond *coroutine_cond;
static GStaticMutex coroutine_lock = G_STATIC_MUTEX_INIT;
static GStaticPrivate coroutine_key = G_STATIC_PRIVATE_INIT;
static void __attribute__((constructor)) coroutine_init(void)
{
if (!g_thread_supported()) {
g_thread_init(NULL);
}
coroutine_cond = g_cond_new();
}
static void coroutine_wait_runnable_locked(CoroutineGThread *co)
{
while (!co->runnable) {
g_cond_wait(coroutine_cond, g_static_mutex_get_mutex(&coroutine_lock));
}
}
static void coroutine_wait_runnable(CoroutineGThread *co)
{
g_static_mutex_lock(&coroutine_lock);
coroutine_wait_runnable_locked(co);
g_static_mutex_unlock(&coroutine_lock);
}
static gpointer coroutine_thread(gpointer opaque)
{
CoroutineGThread *co = opaque;
g_static_private_set(&coroutine_key, co, NULL);
coroutine_wait_runnable(co);
co->base.entry(co->base.entry_arg);
qemu_coroutine_switch(&co->base, co->base.caller, COROUTINE_TERMINATE);
return NULL;
}
Coroutine *qemu_coroutine_new(void)
{
CoroutineGThread *co;
co = qemu_mallocz(sizeof(*co));
co->thread = g_thread_create_full(coroutine_thread, co, 0, TRUE, TRUE,
G_THREAD_PRIORITY_NORMAL, NULL);
if (!co->thread) {
qemu_free(co);
return NULL;
}
return &co->base;
}
void qemu_coroutine_delete(Coroutine *co_)
{
CoroutineGThread *co = DO_UPCAST(CoroutineGThread, base, co_);
g_thread_join(co->thread);
qemu_free(co);
}
CoroutineAction qemu_coroutine_switch(Coroutine *from_,
Coroutine *to_,
CoroutineAction action)
{
CoroutineGThread *from = DO_UPCAST(CoroutineGThread, base, from_);
CoroutineGThread *to = DO_UPCAST(CoroutineGThread, base, to_);
g_static_mutex_lock(&coroutine_lock);
from->runnable = false;
from->action = action;
to->runnable = true;
to->action = action;
g_cond_broadcast(coroutine_cond);
if (action != COROUTINE_TERMINATE) {
coroutine_wait_runnable_locked(from);
}
g_static_mutex_unlock(&coroutine_lock);
return from->action;
}
Coroutine *qemu_coroutine_self(void)
{
CoroutineGThread *co = g_static_private_get(&coroutine_key);
if (!co) {
co = qemu_mallocz(sizeof(*co));
co->runnable = true;
g_static_private_set(&coroutine_key, co, (GDestroyNotify)qemu_free);
}
return &co->base;
}
bool qemu_in_coroutine(void)
{
CoroutineGThread *co = g_static_private_get(&coroutine_key);
return co && co->base.caller;
}
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