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[Qemu-devel] [PATCH v2 31/39] qemu-thread: add QemuSemaphore
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH v2 31/39] qemu-thread: add QemuSemaphore |
Date: |
Wed, 31 Oct 2012 16:30:48 +0100 |
The new thread pool will use semaphores instead of condition
variables, because QemuCond does not have qemu_cond_timedwait.
(I also like it more this way).
Signed-off-by: Paolo Bonzini <address@hidden>
---
Difference from previous submission: handle EINTR
qemu-thread-posix.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++
qemu-thread-posix.h | 5 ++++
qemu-thread-win32.c | 35 +++++++++++++++++++++++
qemu-thread-win32.h | 4 +++
qemu-thread.h | 7 +++++
5 file modificati, 131 inserzioni(+)
diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c
index 8fbabda..6a3d3a1 100644
--- a/qemu-thread-posix.c
+++ b/qemu-thread-posix.c
@@ -17,6 +17,9 @@
#include <signal.h>
#include <stdint.h>
#include <string.h>
+#include <limits.h>
+#include <unistd.h>
+#include <sys/time.h>
#include "qemu-thread.h"
static void error_exit(int err, const char *msg)
@@ -115,6 +118,83 @@ void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
error_exit(err, __func__);
}
+void qemu_sem_init(QemuSemaphore *sem, int init)
+{
+ int rc;
+
+ rc = sem_init(&sem->sem, 0, init);
+ if (rc < 0) {
+ error_exit(errno, __func__);
+ }
+}
+
+void qemu_sem_destroy(QemuSemaphore *sem)
+{
+ int rc;
+
+ rc = sem_destroy(&sem->sem);
+ if (rc < 0) {
+ error_exit(errno, __func__);
+ }
+}
+
+void qemu_sem_post(QemuSemaphore *sem)
+{
+ int rc;
+
+ rc = sem_post(&sem->sem);
+ if (rc < 0) {
+ error_exit(errno, __func__);
+ }
+}
+
+int qemu_sem_timedwait(QemuSemaphore *sem, int ms)
+{
+ int rc;
+
+ if (ms <= 0) {
+ /* This is cheaper than sem_timedwait. */
+ do {
+ rc = sem_trywait(&sem->sem);
+ } while (rc == -1 && errno == EINTR);
+ if (rc == -1 && errno == EAGAIN) {
+ return -1;
+ }
+ } else {
+ struct timeval tv;
+ struct timespec ts;
+ gettimeofday(&tv, NULL);
+ ts.tv_nsec = tv.tv_usec * 1000 + (ms % 1000) * 1000000;
+ ts.tv_sec = tv.tv_sec + ms / 1000;
+ if (ts.tv_nsec >= 1000000000) {
+ ts.tv_sec++;
+ ts.tv_nsec -= 1000000000;
+ }
+ do {
+ rc = sem_timedwait(&sem->sem, &ts);
+ } while (rc == -1 && errno == EINTR);
+ if (rc == -1 && errno == ETIMEDOUT) {
+ return -1;
+ }
+ }
+ if (rc < 0) {
+ error_exit(errno, __func__);
+ }
+ return 0;
+}
+
+void qemu_sem_wait(QemuSemaphore *sem)
+{
+ int rc;
+
+ do {
+ rc = sem_wait(&sem->sem);
+ } while (rc == -1 && errno == EINTR);
+ if (rc < 0) {
+ error_exit(errno, __func__);
+ }
+}
+
void qemu_thread_create(QemuThread *thread,
void *(*start_routine)(void*),
void *arg, int mode)
diff --git a/qemu-thread-posix.h b/qemu-thread-posix.h
index ee4618e..2542c15 100644
--- a/qemu-thread-posix.h
+++ b/qemu-thread-posix.h
@@ -1,6 +1,7 @@
#ifndef __QEMU_THREAD_POSIX_H
#define __QEMU_THREAD_POSIX_H 1
#include "pthread.h"
+#include <semaphore.h>
struct QemuMutex {
pthread_mutex_t lock;
@@ -10,6 +11,10 @@ struct QemuCond {
pthread_cond_t cond;
};
+struct QemuSemaphore {
+ sem_t sem;
+};
+
struct QemuThread {
pthread_t thread;
};
diff --git a/qemu-thread-win32.c b/qemu-thread-win32.c
index 177b398..4b3db60 100644
--- a/qemu-thread-win32.c
+++ b/qemu-thread-win32.c
@@ -192,6 +192,41 @@ void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
qemu_mutex_lock(mutex);
}
+void qemu_sem_init(QemuSemaphore *sem, int init)
+{
+ /* Manual reset. */
+ sem->sema = CreateSemaphore(NULL, init, LONG_MAX, NULL);
+}
+
+void qemu_sem_destroy(QemuSemaphore *sem)
+{
+ CloseHandle(sem->sema);
+}
+
+void qemu_sem_post(QemuSemaphore *sem)
+{
+ ReleaseSemaphore(sem->sema, 1, NULL);
+}
+
+int qemu_sem_timedwait(QemuSemaphore *sem, int ms)
+{
+ int rc = WaitForSingleObject(sem->sema, ms);
+ if (rc == WAIT_OBJECT_0) {
+ return 0;
+ }
+ if (rc != WAIT_TIMEOUT) {
+ error_exit(GetLastError(), __func__);
+ }
+ return -1;
+}
+
+void qemu_sem_wait(QemuSemaphore *sem)
+{
+ if (WaitForSingleObject(sem->sema, INFINITE) != WAIT_OBJECT_0) {
+ error_exit(GetLastError(), __func__);
+ }
+}
+
struct QemuThreadData {
/* Passed to win32_start_routine. */
void *(*start_routine)(void *);
diff --git a/qemu-thread-win32.h b/qemu-thread-win32.h
index b9d1be8..13adb95 100644
--- a/qemu-thread-win32.h
+++ b/qemu-thread-win32.h
@@ -13,6 +13,10 @@ struct QemuCond {
HANDLE continue_event;
};
+struct QemuSemaphore {
+ HANDLE sema;
+};
+
typedef struct QemuThreadData QemuThreadData;
struct QemuThread {
QemuThreadData *data;
diff --git a/qemu-thread.h b/qemu-thread.h
index 05fdaaf..3ee2f6b 100644
--- a/qemu-thread.h
+++ b/qemu-thread.h
@@ -6,6 +6,7 @@
typedef struct QemuMutex QemuMutex;
typedef struct QemuCond QemuCond;
+typedef struct QemuSemaphore QemuSemaphore;
typedef struct QemuThread QemuThread;
#ifdef _WIN32
@@ -38,6 +39,12 @@ void qemu_cond_signal(QemuCond *cond);
void qemu_cond_broadcast(QemuCond *cond);
void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex);
+void qemu_sem_init(QemuSemaphore *sem, int init);
+void qemu_sem_post(QemuSemaphore *sem);
+void qemu_sem_wait(QemuSemaphore *sem);
+int qemu_sem_timedwait(QemuSemaphore *sem, int ms);
+void qemu_sem_destroy(QemuSemaphore *sem);
+
void qemu_thread_create(QemuThread *thread,
void *(*start_routine)(void *),
void *arg, int mode);
--
1.7.12.1
- [Qemu-devel] [PATCH v2 29/39] aio: clean up now-unused functions, (continued)
- [Qemu-devel] [PATCH v2 29/39] aio: clean up now-unused functions, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 33/39] threadpool: do not take lock in event_notifier_ready, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 32/39] aio: add generic thread-pool facility, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 34/39] block: switch posix-aio-compat to threadpool, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 35/39] raw: merge posix-aio-compat.c into block/raw-posix.c, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 36/39] raw-posix: rename raw-posix-aio.h, hide unavailable prototypes, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 37/39] raw-win32: add emulated AIO support, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 30/39] linux-aio: use event notifiers, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 14/39] event_notifier: enable it to use pipes, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 15/39] vl: init main loop earlier, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 31/39] qemu-thread: add QemuSemaphore,
Paolo Bonzini <=
- [Qemu-devel] [PATCH v2 13/39] event_notifier: add Win32 implementation, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 28/39] main-loop: use aio_notify for qemu_notify_event, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 16/39] aio: change qemu_aio_set_fd_handler to return void, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 26/39] aio: call aio_notify after setting I/O handlers, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 19/39] aio: add I/O handlers to the AioContext interface, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 39/39] raw-win32: implement native asynchronous I/O, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 38/39] raw-posix: move linux-aio.c to block/, Paolo Bonzini, 2012/10/31
- [Qemu-devel] [PATCH v2 18/39] aio: introduce AioContext, move bottom halves there, Paolo Bonzini, 2012/10/31