diff options
author | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-05-18 13:18:31 +0300 |
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committer | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-05-18 13:42:15 +0300 |
commit | 437fd90c0250dee670290f9b714253671a990160 (patch) | |
tree | b871786c360704244a07411c69fb58da9ead4a06 /qemu/util/qemu-coroutine.c | |
parent | 5bbd6fe9b8bab2a93e548c5a53b032d1939eec05 (diff) |
These changes are the raw update to qemu-2.6.
Collission happened in the following patches:
migration: do cleanup operation after completion(738df5b9)
Bug fix.(1750c932f86)
kvmclock: add a new function to update env->tsc.(b52baab2)
The code provided by the patches was already in the upstreamed
version.
Change-Id: I3cc11841a6a76ae20887b2e245710199e1ea7f9a
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'qemu/util/qemu-coroutine.c')
-rw-r--r-- | qemu/util/qemu-coroutine.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/qemu/util/qemu-coroutine.c b/qemu/util/qemu-coroutine.c new file mode 100644 index 000000000..5816702cc --- /dev/null +++ b/qemu/util/qemu-coroutine.c @@ -0,0 +1,147 @@ +/* + * QEMU coroutines + * + * Copyright IBM, Corp. 2011 + * + * Authors: + * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> + * Kevin Wolf <kwolf@redhat.com> + * + * This work is licensed under the terms of the GNU LGPL, version 2 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#include "qemu/osdep.h" +#include "trace.h" +#include "qemu-common.h" +#include "qemu/thread.h" +#include "qemu/atomic.h" +#include "qemu/coroutine.h" +#include "qemu/coroutine_int.h" + +enum { + POOL_BATCH_SIZE = 64, +}; + +/** Free list to speed up creation */ +static QSLIST_HEAD(, Coroutine) release_pool = QSLIST_HEAD_INITIALIZER(pool); +static unsigned int release_pool_size; +static __thread QSLIST_HEAD(, Coroutine) alloc_pool = QSLIST_HEAD_INITIALIZER(pool); +static __thread unsigned int alloc_pool_size; +static __thread Notifier coroutine_pool_cleanup_notifier; + +static void coroutine_pool_cleanup(Notifier *n, void *value) +{ + Coroutine *co; + Coroutine *tmp; + + QSLIST_FOREACH_SAFE(co, &alloc_pool, pool_next, tmp) { + QSLIST_REMOVE_HEAD(&alloc_pool, pool_next); + qemu_coroutine_delete(co); + } +} + +Coroutine *qemu_coroutine_create(CoroutineEntry *entry) +{ + Coroutine *co = NULL; + + if (CONFIG_COROUTINE_POOL) { + co = QSLIST_FIRST(&alloc_pool); + if (!co) { + if (release_pool_size > POOL_BATCH_SIZE) { + /* Slow path; a good place to register the destructor, too. */ + if (!coroutine_pool_cleanup_notifier.notify) { + coroutine_pool_cleanup_notifier.notify = coroutine_pool_cleanup; + qemu_thread_atexit_add(&coroutine_pool_cleanup_notifier); + } + + /* This is not exact; there could be a little skew between + * release_pool_size and the actual size of release_pool. But + * it is just a heuristic, it does not need to be perfect. + */ + alloc_pool_size = atomic_xchg(&release_pool_size, 0); + QSLIST_MOVE_ATOMIC(&alloc_pool, &release_pool); + co = QSLIST_FIRST(&alloc_pool); + } + } + if (co) { + QSLIST_REMOVE_HEAD(&alloc_pool, pool_next); + alloc_pool_size--; + } + } + + if (!co) { + co = qemu_coroutine_new(); + } + + co->entry = entry; + QTAILQ_INIT(&co->co_queue_wakeup); + return co; +} + +static void coroutine_delete(Coroutine *co) +{ + co->caller = NULL; + + if (CONFIG_COROUTINE_POOL) { + if (release_pool_size < POOL_BATCH_SIZE * 2) { + QSLIST_INSERT_HEAD_ATOMIC(&release_pool, co, pool_next); + atomic_inc(&release_pool_size); + return; + } + if (alloc_pool_size < POOL_BATCH_SIZE) { + QSLIST_INSERT_HEAD(&alloc_pool, co, pool_next); + alloc_pool_size++; + return; + } + } + + qemu_coroutine_delete(co); +} + +void qemu_coroutine_enter(Coroutine *co, void *opaque) +{ + Coroutine *self = qemu_coroutine_self(); + CoroutineAction ret; + + trace_qemu_coroutine_enter(self, co, opaque); + + if (co->caller) { + fprintf(stderr, "Co-routine re-entered recursively\n"); + abort(); + } + + co->caller = self; + co->entry_arg = opaque; + ret = qemu_coroutine_switch(self, co, COROUTINE_ENTER); + + qemu_co_queue_run_restart(co); + + switch (ret) { + case COROUTINE_YIELD: + return; + case COROUTINE_TERMINATE: + trace_qemu_coroutine_terminate(co); + coroutine_delete(co); + return; + default: + abort(); + } +} + +void coroutine_fn qemu_coroutine_yield(void) +{ + Coroutine *self = qemu_coroutine_self(); + Coroutine *to = self->caller; + + trace_qemu_coroutine_yield(self, to); + + if (!to) { + fprintf(stderr, "Co-routine is yielding to no one\n"); + abort(); + } + + self->caller = NULL; + qemu_coroutine_switch(self, to, COROUTINE_YIELD); +} |