qemu-patch-raspberry4/include/qemu/thread-posix.h
Izumi Tsutsui 79761c6681 semaphore: fix a hangup problem under load on NetBSD hosts.
Fix following bugs in "fallback implementation of counting semaphores
with mutex+condvar" added in c166cb72f1676855816340666c3b618beef4b976:
 - waiting threads are not restarted properly if more than one threads
   are waiting unblock signals in qemu_sem_timedwait()
 - possible missing pthread_cond_signal(3) calls when waiting threads
   are returned by ETIMEDOUT
 - fix an uninitialized variable
The problem is analyzed by and fix is provided by Noriyuki Soda.

Also put additional cleanup suggested by Laszlo Ersek:
 - make QemuSemaphore.count unsigned (it won't be negative)
 - check a return value of in pthread_cond_wait() in qemu_sem_wait()

Signed-off-by: Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1372841894-10634-1-git-send-email-tsutsui@ceres.dti.ne.jp
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-08-05 11:48:00 -05:00

29 lines
432 B
C

#ifndef __QEMU_THREAD_POSIX_H
#define __QEMU_THREAD_POSIX_H 1
#include "pthread.h"
#include <semaphore.h>
struct QemuMutex {
pthread_mutex_t lock;
};
struct QemuCond {
pthread_cond_t cond;
};
struct QemuSemaphore {
#if defined(__APPLE__) || defined(__NetBSD__)
pthread_mutex_t lock;
pthread_cond_t cond;
unsigned int count;
#else
sem_t sem;
#endif
};
struct QemuThread {
pthread_t thread;
};
#endif