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[Qemu-devel] [PATCH 01/13] Add aiocb_mutex and aiocb_completion.
From: |
Arun R Bharadwaj |
Subject: |
[Qemu-devel] [PATCH 01/13] Add aiocb_mutex and aiocb_completion. |
Date: |
Tue, 04 Jan 2011 10:57:08 +0530 |
User-agent: |
StGit/0.15 |
This patch adds the aiocb_mutex to protect aiocb.
This patch also removes the infinite loop present in paio_cancel.
Since there can only be one cancellation at a time, we need to
introduce a condition variable. For this, we need a
global aiocb_completion condition variable.
This patch also adds the Makefile entry to compile qemu-thread.c
when CONFIG_POSIX is set, instead of the unused CONFIG_THREAD.
Signed-off-by: Arun R Bharadwaj <address@hidden>
---
Makefile.objs | 2 +-
posix-aio-compat.c | 37 ++++++++++++++++++++++++++++---------
2 files changed, 29 insertions(+), 10 deletions(-)
diff --git a/Makefile.objs b/Makefile.objs
index cd5a24b..3b7ec27 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -9,6 +9,7 @@ qobject-obj-y += qerror.o
block-obj-y = cutils.o cache-utils.o qemu-malloc.o qemu-option.o module.o
block-obj-y += nbd.o block.o aio.o aes.o osdep.o qemu-config.o
+block-obj-$(CONFIG_POSIX) += qemu-thread.o
block-obj-$(CONFIG_POSIX) += posix-aio-compat.o
block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
@@ -124,7 +125,6 @@ endif
common-obj-y += $(addprefix ui/, $(ui-obj-y))
common-obj-y += iov.o acl.o
-common-obj-$(CONFIG_THREAD) += qemu-thread.o
common-obj-y += notify.o event_notifier.o
common-obj-y += qemu-timer.o
diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index 7b862b5..ae5e20e 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -27,9 +27,12 @@
#include "qemu-common.h"
#include "trace.h"
#include "block_int.h"
+#include "qemu-thread.h"
#include "block/raw-posix-aio.h"
+static QemuMutex aiocb_mutex;
+static QemuCond aiocb_completion;
struct qemu_paiocb {
BlockDriverAIOCB common;
@@ -351,10 +354,14 @@ static void *aio_thread(void *unused)
}
mutex_lock(&lock);
- aiocb->ret = ret;
idle_threads++;
mutex_unlock(&lock);
+ qemu_mutex_lock(&aiocb_mutex);
+ aiocb->ret = ret;
+ qemu_cond_broadcast(&aiocb_completion);
+ qemu_mutex_unlock(&aiocb_mutex);
+
if (kill(pid, aiocb->ev_signo)) die("kill failed");
}
@@ -383,8 +390,11 @@ static void spawn_thread(void)
static void qemu_paio_submit(struct qemu_paiocb *aiocb)
{
+ qemu_mutex_lock(&aiocb_mutex);
aiocb->ret = -EINPROGRESS;
aiocb->active = 0;
+ qemu_mutex_unlock(&aiocb_mutex);
+
mutex_lock(&lock);
if (idle_threads == 0 && cur_threads < max_threads)
spawn_thread();
@@ -397,9 +407,9 @@ static ssize_t qemu_paio_return(struct qemu_paiocb *aiocb)
{
ssize_t ret;
- mutex_lock(&lock);
+ qemu_mutex_lock(&aiocb_mutex);
ret = aiocb->ret;
- mutex_unlock(&lock);
+ qemu_mutex_unlock(&aiocb_mutex);
return ret;
}
@@ -545,13 +555,19 @@ static void paio_cancel(BlockDriverAIOCB *blockacb)
}
mutex_unlock(&lock);
- if (active) {
- /* fail safe: if the aio could not be canceled, we wait for
- it */
- while (qemu_paio_error(acb) == EINPROGRESS)
- ;
+ qemu_mutex_lock(&aiocb_mutex);
+ if (!active) {
+ acb->ret = -ECANCELED;
+ } else {
+ while (acb->ret == -EINPROGRESS) {
+ /*
+ * fail safe: if the aio could not be canceled,
+ * we wait for it
+ */
+ qemu_cond_wait(&aiocb_completion, &aiocb_mutex);
+ }
}
-
+ qemu_mutex_unlock(&aiocb_mutex);
paio_remove(acb);
}
@@ -623,6 +639,9 @@ int paio_init(void)
if (posix_aio_state)
return 0;
+ qemu_mutex_init(&aiocb_mutex);
+ qemu_cond_init(&aiocb_completion);
+
s = qemu_malloc(sizeof(PosixAioState));
sigfillset(&act.sa_mask);