Archipelago » qemu

/*

 * Wrappers around mutex/cond/thread functions

 *

 * Copyright Red Hat, Inc. 2009

 *

 * Author:

 *  Marcelo Tosatti <mtosatti@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2 or later.

 * See the COPYING file in the top-level directory.

 *

 */

#include <stdlib.h>

#include <stdio.h>

#include <errno.h>

#include <time.h>

#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)

{

    fprintf(stderr, "qemu: %s: %s\n", msg, strerror(err));

    abort();

}

void qemu_mutex_init(QemuMutex *mutex)

{

    int err;

    pthread_mutexattr_t mutexattr;

    pthread_mutexattr_init(&mutexattr);

    pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_ERRORCHECK);

    err = pthread_mutex_init(&mutex->lock, &mutexattr);

    pthread_mutexattr_destroy(&mutexattr);

    if (err)

        error_exit(err, __func__);

}

void qemu_mutex_destroy(QemuMutex *mutex)

{

    int err;

    err = pthread_mutex_destroy(&mutex->lock);

    if (err)

        error_exit(err, __func__);

}

void qemu_mutex_lock(QemuMutex *mutex)

{

    int err;

    err = pthread_mutex_lock(&mutex->lock);

    if (err)

        error_exit(err, __func__);

}

int qemu_mutex_trylock(QemuMutex *mutex)

{

    return pthread_mutex_trylock(&mutex->lock);

}

void qemu_mutex_unlock(QemuMutex *mutex)

{

    int err;

    err = pthread_mutex_unlock(&mutex->lock);

    if (err)

        error_exit(err, __func__);

}

void qemu_cond_init(QemuCond *cond)

{

    int err;

    err = pthread_cond_init(&cond->cond, NULL);

    if (err)

        error_exit(err, __func__);

}

void qemu_cond_destroy(QemuCond *cond)

{

    int err;

    err = pthread_cond_destroy(&cond->cond);

    if (err)

        error_exit(err, __func__);

}

void qemu_cond_signal(QemuCond *cond)

{

    int err;

    err = pthread_cond_signal(&cond->cond);

    if (err)

        error_exit(err, __func__);

}

void qemu_cond_broadcast(QemuCond *cond)

{

    int err;

    err = pthread_cond_broadcast(&cond->cond);

    if (err)

        error_exit(err, __func__);

}

void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)

{

    int err;

    err = pthread_cond_wait(&cond->cond, &mutex->lock);

    if (err)

        error_exit(err, __func__);

}

void qemu_sem_init(QemuSemaphore *sem, int init)

{

    int rc;

#if defined(__APPLE__) || defined(__NetBSD__)

    rc = pthread_mutex_init(&sem->lock, NULL);

    if (rc != 0) {

        error_exit(rc, __func__);

    }

    rc = pthread_cond_init(&sem->cond, NULL);

    if (rc != 0) {

        error_exit(rc, __func__);

    }

    if (init < 0) {

        error_exit(EINVAL, __func__);

    }

    sem->count = init;

#else

    rc = sem_init(&sem->sem, 0, init);

    if (rc < 0) {

        error_exit(errno, __func__);

    }

#endif

}

void qemu_sem_destroy(QemuSemaphore *sem)

{

    int rc;

#if defined(__APPLE__) || defined(__NetBSD__)

    rc = pthread_cond_destroy(&sem->cond);

    if (rc < 0) {

        error_exit(rc, __func__);

    }

    rc = pthread_mutex_destroy(&sem->lock);

    if (rc < 0) {

        error_exit(rc, __func__);

    }

#else

    rc = sem_destroy(&sem->sem);

    if (rc < 0) {

        error_exit(errno, __func__);

    }

#endif

}

void qemu_sem_post(QemuSemaphore *sem)

{

    int rc;

#if defined(__APPLE__) || defined(__NetBSD__)

    pthread_mutex_lock(&sem->lock);

    if (sem->count == INT_MAX) {

        rc = EINVAL;

    } else if (sem->count++ < 0) {

        rc = pthread_cond_signal(&sem->cond);

    } else {

        rc = 0;

    }

    pthread_mutex_unlock(&sem->lock);

    if (rc != 0) {

        error_exit(rc, __func__);

    }

#else

    rc = sem_post(&sem->sem);

    if (rc < 0) {

        error_exit(errno, __func__);

    }

#endif

}

static void compute_abs_deadline(struct timespec *ts, int ms)

{

    struct timeval tv;

    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;

    }

}

int qemu_sem_timedwait(QemuSemaphore *sem, int ms)

{

    int rc;

    struct timespec ts;

#if defined(__APPLE__) || defined(__NetBSD__)

    compute_abs_deadline(&ts, ms);

    pthread_mutex_lock(&sem->lock);

    --sem->count;

    while (sem->count < 0) {

        rc = pthread_cond_timedwait(&sem->cond, &sem->lock, &ts);

        if (rc == ETIMEDOUT) {

            ++sem->count;

            break;

        }

        if (rc != 0) {

            error_exit(rc, __func__);

        }

    }

    pthread_mutex_unlock(&sem->lock);

    return (rc == ETIMEDOUT ? -1 : 0);

#else

    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 {

        compute_abs_deadline(&ts, ms);

        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;

#endif

}

void qemu_sem_wait(QemuSemaphore *sem)

{

#if defined(__APPLE__) || defined(__NetBSD__)

    pthread_mutex_lock(&sem->lock);

    --sem->count;

    while (sem->count < 0) {

        pthread_cond_wait(&sem->cond, &sem->lock);

    }

    pthread_mutex_unlock(&sem->lock);

#else

    int rc;

    do {

        rc = sem_wait(&sem->sem);

    } while (rc == -1 && errno == EINTR);

    if (rc < 0) {

        error_exit(errno, __func__);

    }

#endif

}

void qemu_thread_create(QemuThread *thread,

                       void *(*start_routine)(void*),

                       void *arg, int mode)

{

    sigset_t set, oldset;

    int err;

    pthread_attr_t attr;

    err = pthread_attr_init(&attr);

    if (err) {

        error_exit(err, __func__);

    }

    if (mode == QEMU_THREAD_DETACHED) {

        err = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

        if (err) {

            error_exit(err, __func__);

        }

    }

    /* Leave signal handling to the iothread.  */

    sigfillset(&set);

    pthread_sigmask(SIG_SETMASK, &set, &oldset);

    err = pthread_create(&thread->thread, &attr, start_routine, arg);

    if (err)

        error_exit(err, __func__);

    pthread_sigmask(SIG_SETMASK, &oldset, NULL);

    pthread_attr_destroy(&attr);

}

void qemu_thread_get_self(QemuThread *thread)

{

    thread->thread = pthread_self();

}

bool qemu_thread_is_self(QemuThread *thread)

{

   return pthread_equal(pthread_self(), thread->thread);

}

void qemu_thread_exit(void *retval)

{

    pthread_exit(retval);

}

void *qemu_thread_join(QemuThread *thread)

{

    int err;

    void *ret;

    err = pthread_join(thread->thread, &ret);

    if (err) {

        error_exit(err, __func__);

    }

    return ret;

}