/*
 * Copyright (C) 2019 Intel Corporation.  All rights reserved.
 * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 */

#ifndef _WASM_EXEC_ENV_H
#define _WASM_EXEC_ENV_H

#include "bh_assert.h"
#if WASM_ENABLE_INTERP != 0
#include "../interpreter/wasm.h"
#endif

#ifdef __cplusplus
extern "C" {
#endif

struct WASMModuleInstanceCommon;
struct WASMInterpFrame;

#if WASM_ENABLE_THREAD_MGR != 0
typedef struct WASMCluster WASMCluster;
#if WASM_ENABLE_DEBUG_INTERP != 0
typedef struct WASMCurrentEnvStatus WASMCurrentEnvStatus;
#endif
#endif

#ifdef OS_ENABLE_HW_BOUND_CHECK
typedef struct WASMJmpBuf {
    struct WASMJmpBuf *prev;
    korp_jmpbuf jmpbuf;
} WASMJmpBuf;
#endif

/* Execution environment */
typedef struct WASMExecEnv {
    /* Next thread's exec env of a WASM module instance. */
    struct WASMExecEnv *next;

    /* Previous thread's exec env of a WASM module instance. */
    struct WASMExecEnv *prev;

    /* Note: field module_inst, argv_buf, native_stack_boundary,
       suspend_flags, aux_stack_boundary, aux_stack_bottom, and
       native_symbol are used by AOTed code, don't change the
       places of them */

    /* The WASM module instance of current thread */
    struct WASMModuleInstanceCommon *module_inst;

#if WASM_ENABLE_AOT != 0
    uint32 *argv_buf;
#endif

    /* The boundary of native stack. When runtime detects that native
       frame may overrun this boundary, it throws stack overflow
       exception. */
    uint8 *native_stack_boundary;

    /* Used to terminate or suspend current thread
        bit 0: need to terminate
        bit 1: need to suspend
        bit 2: need to go into breakpoint
        bit 3: return from pthread_exit */
    union {
        uint32 flags;
        uintptr_t __padding__;
    } suspend_flags;

    /* Auxiliary stack boundary */
    union {
        uint32 boundary;
        uintptr_t __padding__;
    } aux_stack_boundary;

    /* Auxiliary stack bottom */
    union {
        uint32 bottom;
        uintptr_t __padding__;
    } aux_stack_bottom;

#if WASM_ENABLE_AOT != 0
    /* Native symbol list, reserved */
    void **native_symbol;
#endif

#if WASM_ENABLE_THREAD_MGR != 0
    /* thread return value */
    void *thread_ret_value;

    /* Must be provided by thread library */
    void *(*thread_start_routine)(void *);
    void *thread_arg;

    /* pointer to the cluster */
    WASMCluster *cluster;

    /* used to support debugger */
    korp_mutex wait_lock;
    korp_cond wait_cond;
    /* the count of threads which are joining current thread */
    uint32 wait_count;

    /* whether current thread is detached */
    bool thread_is_detached;
#endif

#if WASM_ENABLE_DEBUG_INTERP != 0
    WASMCurrentEnvStatus *current_status;
#endif

    /* attachment for native function */
    void *attachment;

    void *user_data;

    /* Current interpreter frame of current thread */
    struct WASMInterpFrame *cur_frame;

    /* The native thread handle of current thread */
    korp_tid handle;

#if WASM_ENABLE_INTERP != 0 && WASM_ENABLE_FAST_INTERP == 0
    BlockAddr block_addr_cache[BLOCK_ADDR_CACHE_SIZE][BLOCK_ADDR_CONFLICT_SIZE];
#endif

#ifdef OS_ENABLE_HW_BOUND_CHECK
    WASMJmpBuf *jmpbuf_stack_top;
#endif

#if WASM_ENABLE_MEMORY_PROFILING != 0
    uint32 max_wasm_stack_used;
#endif

    /* The WASM stack size */
    uint32 wasm_stack_size;

    /* The WASM stack of current thread */
    union {
        uint64 __make_it_8_byte_aligned_;

        struct {
            /* The top boundary of the stack. */
            uint8 *top_boundary;

            /* Top cell index which is free. */
            uint8 *top;

            /* The WASM stack. */
            uint8 bottom[1];
        } s;
    } wasm_stack;
} WASMExecEnv;

WASMExecEnv *
wasm_exec_env_create_internal(struct WASMModuleInstanceCommon *module_inst,
                              uint32 stack_size);

void
wasm_exec_env_destroy_internal(WASMExecEnv *exec_env);

WASMExecEnv *
wasm_exec_env_create(struct WASMModuleInstanceCommon *module_inst,
                     uint32 stack_size);

void
wasm_exec_env_destroy(WASMExecEnv *exec_env);

/**
 * Allocate a WASM frame from the WASM stack.
 *
 * @param exec_env the current execution environment
 * @param size size of the WASM frame, it must be a multiple of 4
 *
 * @return the WASM frame if there is enough space in the stack area
 * with a protection area, NULL otherwise
 */
static inline void *
wasm_exec_env_alloc_wasm_frame(WASMExecEnv *exec_env, unsigned size)
{
    uint8 *addr = exec_env->wasm_stack.s.top;

    bh_assert(!(size & 3));

    /* For classic interpreter, the outs area doesn't contain the const cells,
       its size cannot be larger than the frame size, so here checking stack
       overflow with multiplying by 2 is enough. For fast interpreter, since
       the outs area contains const cells, its size may be larger than current
       frame size, we should check again before putting the function arguments
       into the outs area. */
    if (addr + size * 2 > exec_env->wasm_stack.s.top_boundary) {
        /* WASM stack overflow. */
        return NULL;
    }

    exec_env->wasm_stack.s.top += size;

#if WASM_ENABLE_MEMORY_PROFILING != 0
    {
        uint32 wasm_stack_used =
            exec_env->wasm_stack.s.top - exec_env->wasm_stack.s.bottom;
        if (wasm_stack_used > exec_env->max_wasm_stack_used)
            exec_env->max_wasm_stack_used = wasm_stack_used;
    }
#endif
    return addr;
}

static inline void
wasm_exec_env_free_wasm_frame(WASMExecEnv *exec_env, void *prev_top)
{
    bh_assert((uint8 *)prev_top >= exec_env->wasm_stack.s.bottom);
    exec_env->wasm_stack.s.top = (uint8 *)prev_top;
}

/**
 * Get the current WASM stack top pointer.
 *
 * @param exec_env the current execution environment
 *
 * @return the current WASM stack top pointer
 */
static inline void *
wasm_exec_env_wasm_stack_top(WASMExecEnv *exec_env)
{
    return exec_env->wasm_stack.s.top;
}

/**
 * Set the current frame pointer.
 *
 * @param exec_env the current execution environment
 * @param frame the WASM frame to be set for the current exec env
 */
static inline void
wasm_exec_env_set_cur_frame(WASMExecEnv *exec_env,
                            struct WASMInterpFrame *frame)
{
    exec_env->cur_frame = frame;
}

/**
 * Get the current frame pointer.
 *
 * @param exec_env the current execution environment
 *
 * @return the current frame pointer
 */
static inline struct WASMInterpFrame *
wasm_exec_env_get_cur_frame(WASMExecEnv *exec_env)
{
    return exec_env->cur_frame;
}

struct WASMModuleInstanceCommon *
wasm_exec_env_get_module_inst(WASMExecEnv *exec_env);

void
wasm_exec_env_set_thread_info(WASMExecEnv *exec_env);

#if WASM_ENABLE_THREAD_MGR != 0
void *
wasm_exec_env_get_thread_arg(WASMExecEnv *exec_env);

void
wasm_exec_env_set_thread_arg(WASMExecEnv *exec_env, void *thread_arg);
#endif

#ifdef OS_ENABLE_HW_BOUND_CHECK
void
wasm_exec_env_push_jmpbuf(WASMExecEnv *exec_env, WASMJmpBuf *jmpbuf);

WASMJmpBuf *
wasm_exec_env_pop_jmpbuf(WASMExecEnv *exec_env);
#endif

#ifdef __cplusplus
}
#endif

#endif /* end of _WASM_EXEC_ENV_H */