// SPDX-License-Identifier: GPL-2.0
#include "mutex.h"

#include "debug.h"
#include <linux/string.h>
#include <errno.h>

static void check_err(const char *fn, int err)
{
        char sbuf[STRERR_BUFSIZE];

        if (err == 0)
                return;

        pr_err("%s error: '%s'\n", fn, str_error_r(err, sbuf, sizeof(sbuf)));
}

#define CHECK_ERR(err) check_err(__func__, err)

static void __mutex_init(struct mutex *mtx, bool pshared, bool recursive)
{
        pthread_mutexattr_t attr;

        CHECK_ERR(pthread_mutexattr_init(&attr));

#ifndef NDEBUG
        /* In normal builds enable error checking, such as recursive usage. */
        CHECK_ERR(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK));
#endif
        if (recursive)
                CHECK_ERR(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE));
        if (pshared)
                CHECK_ERR(pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED));
        CHECK_ERR(pthread_mutex_init(&mtx->lock, &attr));
        CHECK_ERR(pthread_mutexattr_destroy(&attr));
}

void mutex_init(struct mutex *mtx)
{
        __mutex_init(mtx, /*pshared=*/false, /*recursive=*/false);
}

void mutex_init_pshared(struct mutex *mtx)
{
        __mutex_init(mtx, /*pshared=*/true, /*recursive=*/false);
}

void mutex_init_recursive(struct mutex *mtx)
{
        __mutex_init(mtx, /*pshared=*/false, /*recursive=*/true);
}

void mutex_destroy(struct mutex *mtx)
{
        CHECK_ERR(pthread_mutex_destroy(&mtx->lock));
}

void mutex_lock(struct mutex *mtx)
        NO_THREAD_SAFETY_ANALYSIS
{
        CHECK_ERR(pthread_mutex_lock(&mtx->lock));
}

void mutex_unlock(struct mutex *mtx)
        NO_THREAD_SAFETY_ANALYSIS
{
        CHECK_ERR(pthread_mutex_unlock(&mtx->lock));
}

bool mutex_trylock(struct mutex *mtx)
{
        int ret = pthread_mutex_trylock(&mtx->lock);

        if (ret == 0)
                return true; /* Lock acquired. */

        if (ret == EBUSY)
                return false; /* Lock busy. */

        /* Print error. */
        CHECK_ERR(ret);
        return false;
}

static void __cond_init(struct cond *cnd, bool pshared)
{
        pthread_condattr_t attr;

        CHECK_ERR(pthread_condattr_init(&attr));
        if (pshared)
                CHECK_ERR(pthread_condattr_setpshared(&attr, PTHREAD_PROCESS_SHARED));

        CHECK_ERR(pthread_cond_init(&cnd->cond, &attr));
        CHECK_ERR(pthread_condattr_destroy(&attr));
}

void cond_init(struct cond *cnd)
{
        __cond_init(cnd, /*pshared=*/false);
}

void cond_init_pshared(struct cond *cnd)
{
        __cond_init(cnd, /*pshared=*/true);
}

void cond_destroy(struct cond *cnd)
{
        CHECK_ERR(pthread_cond_destroy(&cnd->cond));
}

void cond_wait(struct cond *cnd, struct mutex *mtx)
{
        CHECK_ERR(pthread_cond_wait(&cnd->cond, &mtx->lock));
}

void cond_signal(struct cond *cnd)
{
        CHECK_ERR(pthread_cond_signal(&cnd->cond));
}

void cond_broadcast(struct cond *cnd)
{
        CHECK_ERR(pthread_cond_broadcast(&cnd->cond));
}