/*

* Copyright(c) 2019 Intel Corporation

*

* This source code is subject to the terms of the BSD 2 Clause License and

* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License

* was not distributed with this source code in the LICENSE file, you can

* obtain it at https://www.aomedia.org/license/software-license. If the Alliance for Open

* Media Patent License 1.0 was not distributed with this source code in the

* PATENTS file, you can obtain it at https://www.aomedia.org/license/patent-license.

*/

// Summary:

// EbThreads contains wrappers functions that hide

// platform specific objects such as threads, semaphores,

// and mutexs.  The goal is to eliminiate platform #define

// in the code.

#include "EbSvtAv1.h"

#if defined(__has_feature)

#if __has_feature(thread_sanitizer)

#define EB_THREAD_SANITIZER_ENABLED 1

#endif

#endif

#ifndef EB_THREAD_SANITIZER_ENABLED

#define EB_THREAD_SANITIZER_ENABLED 0

#endif

/****************************************

 * Universal Includes

 ****************************************/

#include <stdbool.h>

#include <stdlib.h>

#include <string.h>

#include "svt_threads.h"

#include "svt_log.h"

#if SVT_AV1_NVTX

#include "svt_nvtx.h"

#include <sys/syscall.h>

#endif

/****************************************

  * Win32 Includes

  ****************************************/

#ifdef _WIN32

#include <windows.h>

#else

#include <stdio.h>

#include <errno.h>

#include <fcntl.h>

#include <pthread.h>

#include <semaphore.h>

#include <unistd.h>

#endif // _WIN32

#ifdef __APPLE__

#include <dispatch/dispatch.h>

#endif

#if PRINTF_TIME

#include <time.h>

#ifdef _WIN32

void printfTime(const char* fmt, ...) {

    va_list args;

    va_start(args, fmt);

    SVT_LOG("  [%i ms]\t", ((int32_t)clock()));

    vprintf(fmt, args);

    va_end(args);

}

#endif

#endif

#ifndef _WIN32

static void* dummy_func(void* arg) {

    (void)arg;

    return NULL;

}

/*

 * pthread_setname_np has different signatures across platforms; the trampoline

 * always invokes this from inside the new thread, so Apple's self-only form is

 * naturally compatible.

 */

static inline void svt_thread_self_setname(const char* name) {

#if defined(__APPLE__)

    (void)pthread_setname_np(name);

#elif defined(__linux__) || defined(__GLIBC__) || defined(__ANDROID__)

    (void)pthread_setname_np(pthread_self(), name);

#else

    (void)name;

#endif

}

/*

 * Self-naming trampoline. nsys snapshots the thread name early (often before a

 * spawner-side pthread_setname_np lands), so we let the new thread rename

 * itself before it enters user_fn. This makes svt-* names visible in Nsight

 * timelines, /proc/<tid>/comm, and ps/top.

 */

typedef struct SvtThreadStart {

    void* (*fn)(void*);

    void* arg;

    char  name[16];

} SvtThreadStart;

static void* svt_thread_trampoline(void* p) {

    SvtThreadStart* payload = (SvtThreadStart*)p;

    void* (*fn)(void*)      = payload->fn;

    void* arg               = payload->arg;

    char  name[16];

    strncpy(name, payload->name, sizeof(name) - 1);

    name[sizeof(name) - 1] = '\0';

    free(payload);

    if (name[0]) {

        svt_thread_self_setname(name);

#if SVT_AV1_NVTX

        // syscall(SYS_gettid) instead of gettid(): gettid() needs glibc 2.30+

        // (Aug 2019); the raw syscall works on older glibc and musl too.

        SVT_NVTX_NAME_OS_THREAD((unsigned long)syscall(SYS_gettid), name);

#endif

    }

    return fn(arg);

}

// These can stay with pthread_once_t since this is specific to pthreads implementation

static pthread_once_t checked_once = PTHREAD_ONCE_INIT;

static bool           can_use_prio = false;

static void check_set_prio(void) {

    /* We can only use realtime priority if we are running as root, so

     * check if geteuid() == 0 (meaning either root or sudo).

     * If we don't do this check, we will eventually run into memory

     * issues if the encoder is uninitialized and re-initialized multiple

     * times in one executable due to a bug in glibc.

     * https://sourceware.org/bugzilla/show_bug.cgi?id=19511

     *

     * We still need to exclude the case of thread sanitizer because we

     * run the test as root inside the container and trying to change

     * the thread priority will __always__ fail the thread sanitizer.

     * https://github.com/google/sanitizers/issues/1088

     */

    if (EB_THREAD_SANITIZER_ENABLED || geteuid() != 0) {

        return;

    }

    pthread_attr_t attr;

    int            ret;

    if ((ret = pthread_attr_init(&attr))) {

        SVT_WARN("Failed to initialize thread attributes: %s\n", strerror(ret));

        return;

    }

    struct sched_param param;

    if ((ret = pthread_attr_getschedparam(&attr, &param))) {

        SVT_WARN("Failed to get thread priority: %s\n", strerror(ret));

        goto end;

    }

    param.sched_priority = 99;

    if ((ret = pthread_attr_setschedparam(&attr, &param))) {

        SVT_WARN("Failed to set thread priority: %s\n", strerror(ret));

        goto end;

    }

    pthread_t th;

    if ((ret = pthread_create(&th, &attr, dummy_func, NULL))) {

        SVT_WARN("Failed to create thread: %s\n", strerror(ret));

        goto end;

    }

    can_use_prio = true;

    pthread_join(th, NULL);

end:

    if ((ret = pthread_attr_destroy(&attr))) {

        SVT_WARN("Failed to destroy thread attributes: %s\n", strerror(ret));

    }

}

#endif

void svt_format_thread_name(char* buf, size_t size, const char* prefix, uint32_t index) {

    snprintf(buf, size, "%s%u", prefix, index);

}

/****************************************

 * svt_create_thread

 ****************************************/

EbHandle svt_create_thread(void* thread_function(void*), void* thread_context, const char* name) {

    EbHandle thread_handle = NULL;

    // Drop the `svt_aom_` prefix that EB_CREATE_THREAD pulls in via

    // `#thread_function`. Linux's TASK_COMM_LEN is 15 chars; without the strip

    // `svt_aom_picture_decision_kernel` and `svt_aom_picture_manager_kernel`

    // collapse to the same `svt_aom_picture` label in /proc/.../comm and the

    // Nsight ThreadNames table.

    if (name && !strncmp(name, "svt_aom_", 8)) {

        name += 8;

    }

#ifdef _WIN32

    thread_handle = (EbHandle)CreateThread(

        NULL, // default security attributes

        0, // default stack size

        (LPTHREAD_START_ROUTINE)thread_function, // function to be tied to the new thread

        thread_context, // context to be tied to the new thread

        0, // thread active when created

        NULL); // new thread ID

    // SetThreadDescription (Windows 10 1607+) — best effort. Older Windows

    // returns E_NOTIMPL; nothing else we can do here.

    if (thread_handle && name && *name) {

        // Mirror Linux's TASK_COMM_LEN (15 + NUL); MultiByteToWideChar fails if

        // the source doesn't fit, so truncate first.

        char    truncated[16];

        wchar_t wname[16];

        strncpy(truncated, name, sizeof(truncated) - 1);

        truncated[sizeof(truncated) - 1] = '\0';

        if (MultiByteToWideChar(CP_UTF8, 0, truncated, -1, wname, (int)(sizeof(wname) / sizeof(wname[0]))) > 0) {

            (void)SetThreadDescription((HANDLE)thread_handle, wname);

        }

    }

#else

    if (pthread_once(&checked_once, check_set_prio)) {

        SVT_ERROR("Failed to run pthread_once to check if we can set priority\n");

        return NULL;

    }

    pthread_attr_t attr;

    if (pthread_attr_init(&attr)) {

        SVT_ERROR("Failed to initialize thread attributes\n");

        return NULL;

    }

    if (can_use_prio) {

        // As described in https://docs.oracle.com/cd/E19455-01/806-5257/attrib-16/index.html

        struct sched_param param;

        pthread_attr_getschedparam(&attr, &param);

        param.sched_priority = 99;

        pthread_attr_setschedparam(&attr, &param);

    }

    // 1 MiB in bytes for now since we can't easily change the stack size after creation

    const size_t min_stack_size = 1024 * 1024;

    // We don't care if this fails, it's just a hint for the min size we are expecting.

    (void)pthread_attr_setstacksize(&attr, min_stack_size);

    pthread_t* th = malloc(sizeof(*th));

    if (th == NULL) {

        SVT_ERROR("Failed to allocate thread handle\n");

        pthread_attr_destroy(&attr);

        return NULL;

    }

    SvtThreadStart* payload = malloc(sizeof(*payload));

    if (payload == NULL) {

        SVT_ERROR("Failed to allocate thread start payload\n");

        free(th);

        pthread_attr_destroy(&attr);

        return NULL;

    }

    payload->fn  = thread_function;

    payload->arg = thread_context;

    if (name && *name) {

        strncpy(payload->name, name, sizeof(payload->name) - 1);

        payload->name[sizeof(payload->name) - 1] = '\0';

    } else {

        payload->name[0] = '\0';

    }

    int ret;

    if ((ret = pthread_create(th, &attr, svt_thread_trampoline, payload))) {

        SVT_ERROR("Failed to create thread: %s\n", strerror(ret));

        free(payload);

        free(th);

        pthread_attr_destroy(&attr);

        return NULL;

    }

    pthread_attr_destroy(&attr);

    thread_handle = th;

#endif // _WIN32

    return thread_handle;

}

/****************************************

 * svt_destroy_thread

 ****************************************/

EbErrorType svt_destroy_thread(EbHandle thread_handle) {

    EbErrorType error_return;

#ifdef _WIN32

    WaitForSingleObject(thread_handle, INFINITE);

    error_return = CloseHandle(thread_handle) ? EB_ErrorNone : EB_ErrorDestroyThreadFailed;

#else

    error_return = pthread_join(*((pthread_t*)thread_handle), NULL) ? EB_ErrorDestroyThreadFailed : EB_ErrorNone;

    free(thread_handle);

#endif // _WIN32

    return error_return;

}

/***************************************

 * svt_create_semaphore

 ***************************************/

EbHandle svt_create_semaphore(uint32_t initial_count, uint32_t max_count) {

    EbHandle semaphore_handle;

#if defined(_WIN32)

    semaphore_handle = (EbHandle)CreateSemaphore(NULL, // default security attributes

                                                 initial_count, // initial semaphore count

                                                 max_count, // maximum semaphore count

                                                 NULL); // semaphore is not named

#elif defined(__APPLE__)

    UNUSED(max_count);

    semaphore_handle = (EbHandle)dispatch_semaphore_create(initial_count);

#else

    UNUSED(max_count);

    semaphore_handle = (sem_t*)malloc(sizeof(sem_t));

    if (semaphore_handle != NULL) {

        sem_init((sem_t*)semaphore_handle, // semaphore handle

                 0, // shared semaphore (not local)

                 initial_count); // initial count

    }

#endif

    return semaphore_handle;

}

/***************************************

 * svt_post_semaphore

 ***************************************/

EbErrorType svt_post_semaphore(EbHandle semaphore_handle) {

    EbErrorType return_error;

#ifdef _WIN32

    return_error = !ReleaseSemaphore(semaphore_handle, // semaphore handle

                                     1, // amount to increment the semaphore

                                     NULL) // pointer to previous count (optional)

        ? EB_ErrorSemaphoreUnresponsive

        : EB_ErrorNone;

#elif defined(__APPLE__)

    dispatch_semaphore_signal((dispatch_semaphore_t)semaphore_handle);

    return_error = EB_ErrorNone;

#else

    return_error = sem_post((sem_t*)semaphore_handle) ? EB_ErrorSemaphoreUnresponsive : EB_ErrorNone;

#endif

    return return_error;

}

/***************************************

 * svt_block_on_semaphore

 ***************************************/

EbErrorType svt_block_on_semaphore(EbHandle semaphore_handle) {

    EbErrorType return_error;

#ifdef _WIN32

    return_error = WaitForSingleObject((HANDLE)semaphore_handle, INFINITE) ? EB_ErrorSemaphoreUnresponsive

                                                                           : EB_ErrorNone;

#elif defined(__APPLE__)

    return_error = dispatch_semaphore_wait((dispatch_semaphore_t)semaphore_handle, DISPATCH_TIME_FOREVER)

        ? EB_ErrorSemaphoreUnresponsive

        : EB_ErrorNone;

#else

    int ret;

    do {

        ret = sem_wait((sem_t*)semaphore_handle);

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

    return_error = ret ? EB_ErrorSemaphoreUnresponsive : EB_ErrorNone;

#endif

    return return_error;

}

/***************************************

 * svt_destroy_semaphore

 ***************************************/

EbErrorType svt_destroy_semaphore(EbHandle semaphore_handle) {

    EbErrorType return_error;

#ifdef _WIN32

    return_error = !CloseHandle((HANDLE)semaphore_handle) ? EB_ErrorDestroySemaphoreFailed : EB_ErrorNone;

#elif defined(__APPLE__)

    dispatch_release((dispatch_semaphore_t)semaphore_handle);

    return_error = EB_ErrorNone;

#else

    return_error = sem_destroy((sem_t*)semaphore_handle) ? EB_ErrorDestroySemaphoreFailed : EB_ErrorNone;

    free(semaphore_handle);

#endif

    return return_error;

}

/***************************************

 * svt_create_mutex

 ***************************************/

EbHandle svt_create_mutex(void) {

    EbHandle mutex_handle;

#ifdef _WIN32

    mutex_handle = (EbHandle)CreateMutex(NULL, // default security attributes

                                         false, // false := not initially owned

                                         NULL); // mutex is not named

#else

    mutex_handle = (EbHandle)malloc(sizeof(pthread_mutex_t));

    if (mutex_handle != NULL) {

        pthread_mutex_init((pthread_mutex_t*)mutex_handle,

                           NULL); // default attributes

    }

#endif

    return mutex_handle;

}

/***************************************

 * svt_release_mutex

 ***************************************/

EbErrorType svt_release_mutex(EbHandle mutex_handle) {

    EbErrorType return_error;

#ifdef _WIN32

    return_error = !ReleaseMutex((HANDLE)mutex_handle) ? EB_ErrorMutexUnresponsive : EB_ErrorNone;

#else

    return_error = pthread_mutex_unlock((pthread_mutex_t*)mutex_handle) ? EB_ErrorMutexUnresponsive : EB_ErrorNone;

#endif

    return return_error;

}

/***************************************

 * svt_block_on_mutex

 ***************************************/

EbErrorType svt_block_on_mutex(EbHandle mutex_handle) {

    EbErrorType return_error;

#ifdef _WIN32

    return_error = WaitForSingleObject((HANDLE)mutex_handle, INFINITE) ? EB_ErrorMutexUnresponsive : EB_ErrorNone;

#else

    return_error = pthread_mutex_lock((pthread_mutex_t*)mutex_handle) ? EB_ErrorMutexUnresponsive : EB_ErrorNone;

#endif

    return return_error;

}

/***************************************

 * svt_destroy_mutex

 ***************************************/

EbErrorType svt_destroy_mutex(EbHandle mutex_handle) {

    EbErrorType return_error;

#ifdef _WIN32

    return_error = CloseHandle((HANDLE)mutex_handle) ? EB_ErrorDestroyMutexFailed : EB_ErrorNone;

#else

    return_error = pthread_mutex_destroy((pthread_mutex_t*)mutex_handle) ? EB_ErrorDestroyMutexFailed : EB_ErrorNone;

    free(mutex_handle);

#endif

    return return_error;

}

/*

    set an atomic variable to an input value

*/

void svt_aom_atomic_set_u32(AtomicVarU32* var, uint32_t in) {

    svt_block_on_mutex(var->mutex);

    var->obj = in;

    svt_release_mutex(var->mutex);

}

/*

    create condition variable

    Condition variables are synchronization primitives that enable

    threads to wait until a particular condition occurs.

    Condition variables enable threads to atomically release

    a lock(mutex) and enter the sleeping state.

    it could be seen as a combined: wait and release mutex

*/

EbErrorType svt_create_cond_var(CondVar* cond_var) {

    EbErrorType return_error;

    cond_var->val = 0;

#ifdef _WIN32

    InitializeCriticalSection(&cond_var->cs);

    InitializeConditionVariable(&cond_var->cv);

    return_error = EB_ErrorNone;

#else

    pthread_mutex_init(&cond_var->m_mutex, NULL);

    return_error = pthread_cond_init(&cond_var->m_cond, NULL);

#endif

    return return_error;

}

/*

    set a  condition variable to the new value

*/

EbErrorType svt_set_cond_var(CondVar* cond_var, int32_t newval) {

    EbErrorType return_error;

#ifdef _WIN32

    EnterCriticalSection(&cond_var->cs);

    cond_var->val = newval;

    WakeAllConditionVariable(&cond_var->cv);

    LeaveCriticalSection(&cond_var->cs);

    return_error = EB_ErrorNone;

#else

    return_error  = pthread_mutex_lock(&cond_var->m_mutex);

    cond_var->val = newval;

    return_error |= pthread_cond_broadcast(&cond_var->m_cond);

    return_error |= pthread_mutex_unlock(&cond_var->m_mutex);

#endif

    return return_error;

}

/*

    wait until the cond variable changes to a value

    different than input

*/

EbErrorType svt_wait_cond_var(CondVar* cond_var, int32_t input) {

#ifdef _WIN32

    EnterCriticalSection(&cond_var->cs);

    while (cond_var->val == input) {

        SleepConditionVariableCS(&cond_var->cv, &cond_var->cs, INFINITE);

    }

    LeaveCriticalSection(&cond_var->cs);

#else

    if (pthread_mutex_lock(&cond_var->m_mutex)) {

        return EB_ErrorMutexUnresponsive;

    }

    while (cond_var->val == input) {

        if (pthread_cond_wait(&cond_var->m_cond, &cond_var->m_mutex)) {

            (void)pthread_mutex_unlock(&cond_var->m_mutex);

            return EB_ErrorMutexUnresponsive;

        }

    }

    if (pthread_mutex_unlock(&cond_var->m_mutex)) {

        return EB_ErrorMutexUnresponsive;

    }

#endif

    return EB_ErrorNone;

}

void svt_run_once(OnceType* once_control, OnceFn init_routine) {

#ifdef _WIN32

    InitOnceExecuteOnce(once_control, init_routine, NULL, NULL);

#else

    pthread_once(once_control, init_routine);

#endif

}