/*

 * Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <openssl/configuration.h>

#include <openssl/e_os2.h>

#include <openssl/types.h>

#include <openssl/crypto.h>

#include <internal/thread.h>

#include <internal/thread_arch.h>

#if !defined(OPENSSL_NO_DEFAULT_THREAD_POOL)

static ossl_inline uint64_t _ossl_get_avail_threads(OSSL_LIB_CTX_THREADS *tdata)

{

    /* assumes that tdata->lock is taken */

    return tdata->max_threads - tdata->active_threads;

}

uint64_t ossl_get_avail_threads(OSSL_LIB_CTX *ctx)

{

    uint64_t retval = 0;

    OSSL_LIB_CTX_THREADS *tdata = OSSL_LIB_CTX_GET_THREADS(ctx);

    if (tdata == NULL)

        return retval;

    ossl_crypto_mutex_lock(tdata->lock);

    retval = _ossl_get_avail_threads(tdata);

    ossl_crypto_mutex_unlock(tdata->lock);

    return retval;

}

void *ossl_crypto_thread_start(OSSL_LIB_CTX *ctx, CRYPTO_THREAD_ROUTINE start,

                               void *data)

{

    CRYPTO_THREAD *thread;

    OSSL_LIB_CTX_THREADS *tdata = OSSL_LIB_CTX_GET_THREADS(ctx);

    if (tdata == NULL)

        return NULL;

    ossl_crypto_mutex_lock(tdata->lock);

    if (tdata == NULL || tdata->max_threads == 0) {

        ossl_crypto_mutex_unlock(tdata->lock);

        return NULL;

    }

    while (_ossl_get_avail_threads(tdata) == 0)

        ossl_crypto_condvar_wait(tdata->cond_finished, tdata->lock);

    tdata->active_threads++;

    ossl_crypto_mutex_unlock(tdata->lock);

    thread = ossl_crypto_thread_native_start(start, data, 1);

    if (thread == NULL) {

        ossl_crypto_mutex_lock(tdata->lock);

        tdata->active_threads--;

        ossl_crypto_mutex_unlock(tdata->lock);

        goto fail;

    }

    thread->ctx = ctx;

fail:

    return (void *) thread;

}

int ossl_crypto_thread_join(void *vhandle, CRYPTO_THREAD_RETVAL *retval)

{

    CRYPTO_THREAD *handle = vhandle;

    OSSL_LIB_CTX_THREADS *tdata;

    if (vhandle == NULL)

        return 0;

    tdata = OSSL_LIB_CTX_GET_THREADS(handle->ctx);

    if (tdata == NULL)

        return 0;

    if (ossl_crypto_thread_native_join(handle, retval) == 0)

        return 0;

    ossl_crypto_mutex_lock(tdata->lock);

    tdata->active_threads--;

    ossl_crypto_condvar_signal(tdata->cond_finished);

    ossl_crypto_mutex_unlock(tdata->lock);

    return 1;

}

int ossl_crypto_thread_clean(void *vhandle)

{

    CRYPTO_THREAD *handle = vhandle;

    return ossl_crypto_thread_native_clean(handle);

}

#else

ossl_inline uint64_t ossl_get_avail_threads(OSSL_LIB_CTX *ctx)

{

    return 0;

}

void *ossl_crypto_thread_start(OSSL_LIB_CTX *ctx, CRYPTO_THREAD_ROUTINE start,

                               void *data)

{

    return NULL;

}

int ossl_crypto_thread_join(void *vhandle, CRYPTO_THREAD_RETVAL *retval)

{

    return 0;

}

int ossl_crypto_thread_clean(void *vhandle)

{

    return 0;

}

#endif

void *ossl_threads_ctx_new(OSSL_LIB_CTX *ctx)

{

    struct openssl_threads_st *t = OPENSSL_zalloc(sizeof(*t));

    if (t == NULL)

        return NULL;

    t->lock = ossl_crypto_mutex_new();

    t->cond_finished = ossl_crypto_condvar_new();

    if (t->lock == NULL || t->cond_finished == NULL)

        goto fail;

    return t;

fail:

    ossl_threads_ctx_free((void *)t);

    return NULL;

}

void ossl_threads_ctx_free(void *vdata)

{

    OSSL_LIB_CTX_THREADS *t = (OSSL_LIB_CTX_THREADS *) vdata;

    if (t == NULL)

        return;

    ossl_crypto_mutex_free(&t->lock);

    ossl_crypto_condvar_free(&t->cond_finished);

    OPENSSL_free(t);

}