/*
    Copyright (c) 2014 Intel Corporation.  All Rights Reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

      * Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.
      * Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.
      * Neither the name of Intel Corporation nor the names of its
        contributors may be used to endorse or promote products derived
        from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


#include "offload_engine.h"
#include <signal.h>
#include <errno.h>

#include <algorithm>
#include <vector>

#include "offload_host.h"
#include "offload_table.h"

const char* Engine::m_func_names[Engine::c_funcs_total] =
{
    "server_compute",
#ifdef MYO_SUPPORT
    "server_myoinit",
    "server_myofini",
#endif // MYO_SUPPORT
    "server_init",
    "server_var_table_size",
    "server_var_table_copy"
};

// Symbolic representation of system signals. Fix for CQ233593
const char* Engine::c_signal_names[Engine::c_signal_max] =
{
    "Unknown SIGNAL",
    "SIGHUP",    /*  1, Hangup (POSIX).  */
    "SIGINT",    /*  2, Interrupt (ANSI).  */
    "SIGQUIT",   /*  3, Quit (POSIX).  */
    "SIGILL",    /*  4, Illegal instruction (ANSI).  */
    "SIGTRAP",   /*  5, Trace trap (POSIX).  */
    "SIGABRT",   /*  6, Abort (ANSI).  */
    "SIGBUS",    /*  7, BUS error (4.2 BSD).  */
    "SIGFPE",    /*  8, Floating-point exception (ANSI).  */
    "SIGKILL",   /*  9, Kill, unblockable (POSIX).  */
    "SIGUSR1",   /* 10, User-defined signal 1 (POSIX).  */
    "SIGSEGV",   /* 11, Segmentation violation (ANSI).  */
    "SIGUSR2",   /* 12, User-defined signal 2 (POSIX).  */
    "SIGPIPE",   /* 13, Broken pipe (POSIX).  */
    "SIGALRM",   /* 14, Alarm clock (POSIX).  */
    "SIGTERM",   /* 15, Termination (ANSI).  */
    "SIGSTKFLT", /* 16, Stack fault.  */
    "SIGCHLD",   /* 17, Child status has changed (POSIX).  */
    "SIGCONT",   /* 18, Continue (POSIX).  */
    "SIGSTOP",   /* 19, Stop, unblockable (POSIX).  */
    "SIGTSTP",   /* 20, Keyboard stop (POSIX).  */
    "SIGTTIN",   /* 21, Background read from tty (POSIX).  */
    "SIGTTOU",   /* 22, Background write to tty (POSIX).  */
    "SIGURG",    /* 23, Urgent condition on socket (4.2 BSD).  */
    "SIGXCPU",   /* 24, CPU limit exceeded (4.2 BSD).  */
    "SIGXFSZ",   /* 25, File size limit exceeded (4.2 BSD).  */
    "SIGVTALRM", /* 26, Virtual alarm clock (4.2 BSD).  */
    "SIGPROF",   /* 27, Profiling alarm clock (4.2 BSD).  */
    "SIGWINCH",  /* 28, Window size change (4.3 BSD, Sun).  */
    "SIGIO",     /* 29, I/O now possible (4.2 BSD).  */
    "SIGPWR",    /* 30, Power failure restart (System V).  */
    "SIGSYS"     /* 31, Bad system call.  */
};

void Engine::init(void)
{
    if (!m_ready) {
        mutex_locker_t locker(m_lock);

        if (!m_ready) {
            // start process if not done yet
            if (m_process == 0) {
                init_process();
            }

            // load penging images
            load_libraries();

            // and (re)build pointer table
            init_ptr_data();

            // it is ready now
            m_ready = true;
        }
    }
}

void Engine::init_process(void)
{
    COIENGINE engine;
    COIRESULT res;
    const char **environ;

    // create environment for the target process
    environ = (const char**) mic_env_vars.create_environ_for_card(m_index);
    if (environ != 0) {
        for (const char **p = environ; *p != 0; p++) {
            OFFLOAD_DEBUG_TRACE(3, "Env Var for card %d: %s\n", m_index, *p);
        }
    }

    // Create execution context in the specified device
    OFFLOAD_DEBUG_TRACE(2, "Getting device %d (engine %d) handle\n", m_index,
                        m_physical_index);
    res = COI::EngineGetHandle(COI_ISA_KNC, m_physical_index, &engine);
    check_result(res, c_get_engine_handle, m_index, res);

    // Target executable should be available by the time when we
    // attempt to initialize the device
    if (__target_exe == 0) {
        LIBOFFLOAD_ERROR(c_no_target_exe);
        exit(1);
    }

    OFFLOAD_DEBUG_TRACE(2,
        "Loading target executable \"%s\" from %p, size %lld\n",
        __target_exe->name, __target_exe->data, __target_exe->size);

    res = COI::ProcessCreateFromMemory(
        engine,                 // in_Engine
        __target_exe->name,     // in_pBinaryName
        __target_exe->data,     // in_pBinaryBuffer
        __target_exe->size,     // in_BinaryBufferLength,
        0,                      // in_Argc
        0,                      // in_ppArgv
        environ == 0,           // in_DupEnv
        environ,                // in_ppAdditionalEnv
        mic_proxy_io,           // in_ProxyActive
        mic_proxy_fs_root,      // in_ProxyfsRoot
        mic_buffer_size,        // in_BufferSpace
        mic_library_path,       // in_LibrarySearchPath
        __target_exe->origin,   // in_FileOfOrigin
        __target_exe->offset,   // in_FileOfOriginOffset
        &m_process              // out_pProcess
    );
    check_result(res, c_process_create, m_index, res);

    // get function handles
    res = COI::ProcessGetFunctionHandles(m_process, c_funcs_total,
                                         m_func_names, m_funcs);
    check_result(res, c_process_get_func_handles, m_index, res);

    // initialize device side
    pid_t pid = init_device();

    // For IDB
    if (__dbg_is_attached) {
        // TODO: we have in-memory executable now.
        // Check with IDB team what should we provide them now?
        if (strlen(__target_exe->name) < MAX_TARGET_NAME) {
            strcpy(__dbg_target_exe_name, __target_exe->name);
        }
        __dbg_target_so_pid = pid;
        __dbg_target_id = m_physical_index;
        __dbg_target_so_loaded();
    }
}

void Engine::fini_process(bool verbose)
{
    if (m_process != 0) {
        uint32_t sig;
        int8_t ret;

        // destroy target process
        OFFLOAD_DEBUG_TRACE(2, "Destroying process on the device %d\n",
                            m_index);

        COIRESULT res = COI::ProcessDestroy(m_process, -1, 0, &ret, &sig);
        m_process = 0;

        if (res == COI_SUCCESS) {
            OFFLOAD_DEBUG_TRACE(3, "Device process: signal %d, exit code %d\n",
                                sig, ret);
            if (verbose) {
                if (sig != 0) {
                    LIBOFFLOAD_ERROR(
                        c_mic_process_exit_sig, m_index, sig,
                        c_signal_names[sig >= c_signal_max ? 0 : sig]);
                }
                else {
                    LIBOFFLOAD_ERROR(c_mic_process_exit_ret, m_index, ret);
                }
            }

            // for idb
            if (__dbg_is_attached) {
                __dbg_target_so_unloaded();
            }
        }
        else {
            if (verbose) {
                LIBOFFLOAD_ERROR(c_mic_process_exit, m_index);
            }
        }
    }
}

void Engine::load_libraries()
{
    // load libraries collected so far
    for (TargetImageList::iterator it = m_images.begin();
         it != m_images.end(); it++) {
        OFFLOAD_DEBUG_TRACE(2, "Loading library \"%s\" from %p, size %llu\n",
                            it->name, it->data, it->size);

        // load library to the device
        COILIBRARY lib;
        COIRESULT res;
        res = COI::ProcessLoadLibraryFromMemory(m_process,
                                                it->data,
                                                it->size,
                                                it->name,
                                                mic_library_path,
                                                it->origin,
                                                it->offset,
                                                COI_LOADLIBRARY_V1_FLAGS,
                                                &lib);

        if (res != COI_SUCCESS && res != COI_ALREADY_EXISTS) {
            check_result(res, c_load_library, m_index, res);
        }
    }
    m_images.clear();
}

static bool target_entry_cmp(
    const VarList::BufEntry &l,
    const VarList::BufEntry &r
)
{
    const char *l_name = reinterpret_cast<const char*>(l.name);
    const char *r_name = reinterpret_cast<const char*>(r.name);
    return strcmp(l_name, r_name) < 0;
}

static bool host_entry_cmp(
    const VarTable::Entry *l,
    const VarTable::Entry *r
)
{
    return strcmp(l->name, r->name) < 0;
}

void Engine::init_ptr_data(void)
{
    COIRESULT res;
    COIEVENT event;

    // Prepare table of host entries
    std::vector<const VarTable::Entry*> host_table(__offload_vars.begin(),
                                                   __offload_vars.end());

    // no need to do anything further is host table is empty
    if (host_table.size() <= 0) {
        return;
    }

    // Get var table entries from the target.
    // First we need to get size for the buffer to copy data
    struct {
        int64_t nelems;
        int64_t length;
    } params;

    res = COI::PipelineRunFunction(get_pipeline(),
                                   m_funcs[c_func_var_table_size],
                                   0, 0, 0,
                                   0, 0,
                                   0, 0,
                                   &params, sizeof(params),
                                   &event);
    check_result(res, c_pipeline_run_func, m_index, res);

    res = COI::EventWait(1, &event, -1, 1, 0, 0);
    check_result(res, c_event_wait, res);

    if (params.length == 0) {
        return;
    }

    // create buffer for target entries and copy data to host
    COIBUFFER buffer;
    res = COI::BufferCreate(params.length, COI_BUFFER_NORMAL, 0, 0, 1,
                            &m_process, &buffer);
    check_result(res, c_buf_create, m_index, res);

    COI_ACCESS_FLAGS flags = COI_SINK_WRITE;
    res = COI::PipelineRunFunction(get_pipeline(),
                                   m_funcs[c_func_var_table_copy],
                                   1, &buffer, &flags,
                                   0, 0,
                                   &params.nelems, sizeof(params.nelems),
                                   0, 0,
                                   &event);
    check_result(res, c_pipeline_run_func, m_index, res);

    res = COI::EventWait(1, &event, -1, 1, 0, 0);
    check_result(res, c_event_wait, res);

    // patch names in target data
    VarList::BufEntry *target_table;
    COIMAPINSTANCE map_inst;
    res = COI::BufferMap(buffer, 0, params.length, COI_MAP_READ_ONLY, 0, 0,
                         0, &map_inst,
                         reinterpret_cast<void**>(&target_table));
    check_result(res, c_buf_map, res);

    VarList::table_patch_names(target_table, params.nelems);

    // and sort entries
    std::sort(target_table, target_table + params.nelems, target_entry_cmp);
    std::sort(host_table.begin(), host_table.end(), host_entry_cmp);

    // merge host and target entries and enter matching vars map
    std::vector<const VarTable::Entry*>::const_iterator hi =
        host_table.begin();
    std::vector<const VarTable::Entry*>::const_iterator he =
        host_table.end();
    const VarList::BufEntry *ti = target_table;
    const VarList::BufEntry *te = target_table + params.nelems;

    while (hi != he && ti != te) {
        int res = strcmp((*hi)->name, reinterpret_cast<const char*>(ti->name));
        if (res == 0) {
            // add matching entry to var map
            std::pair<PtrSet::iterator, bool> res =
                m_ptr_set.insert(PtrData((*hi)->addr, (*hi)->size));

            // store address for new entries
            if (res.second) {
                PtrData *ptr = const_cast<PtrData*>(res.first.operator->());
                ptr->mic_addr = ti->addr;
                ptr->is_static = true;
            }

            hi++;
            ti++;
        }
        else if (res < 0) {
            hi++;
        }
        else {
            ti++;
        }
    }

    // cleanup
    res = COI::BufferUnmap(map_inst, 0, 0, 0);
    check_result(res, c_buf_unmap, res);

    res = COI::BufferDestroy(buffer);
    check_result(res, c_buf_destroy, res);
}

COIRESULT Engine::compute(
    const std::list<COIBUFFER> &buffers,
    const void*         data,
    uint16_t            data_size,
    void*               ret,
    uint16_t            ret_size,
    uint32_t            num_deps,
    const COIEVENT*     deps,
    COIEVENT*           event
) /* const */
{
    COIBUFFER *bufs;
    COI_ACCESS_FLAGS *flags;
    COIRESULT res;

    // convert buffers list to array
    int num_bufs = buffers.size();
    if (num_bufs > 0) {
        bufs = (COIBUFFER*) alloca(num_bufs * sizeof(COIBUFFER));
        flags = (COI_ACCESS_FLAGS*) alloca(num_bufs *
                                           sizeof(COI_ACCESS_FLAGS));

        int i = 0;
        for (std::list<COIBUFFER>::const_iterator it = buffers.begin();
             it != buffers.end(); it++) {
            bufs[i] = *it;

            // TODO: this should be fixed
            flags[i++] = COI_SINK_WRITE;
        }
    }
    else {
        bufs = 0;
        flags = 0;
    }

    // start computation
    res = COI::PipelineRunFunction(get_pipeline(),
                                   m_funcs[c_func_compute],
                                   num_bufs, bufs, flags,
                                   num_deps, deps,
                                   data, data_size,
                                   ret, ret_size,
                                   event);
    return res;
}

pid_t Engine::init_device(void)
{
    struct init_data {
        int  device_index;
        int  devices_total;
        int  console_level;
        int  offload_report_level;
    } data;
    COIRESULT res;
    COIEVENT event;
    pid_t pid;

    OFFLOAD_DEBUG_TRACE_1(2, 0, c_offload_init,
                          "Initializing device with logical index %d "
                          "and physical index %d\n",
                           m_index, m_physical_index);

    // setup misc data
    data.device_index = m_index;
    data.devices_total = mic_engines_total;
    data.console_level = console_enabled;
    data.offload_report_level = offload_report_level;

    res = COI::PipelineRunFunction(get_pipeline(),
                                   m_funcs[c_func_init],
                                   0, 0, 0, 0, 0,
                                   &data, sizeof(data),
                                   &pid, sizeof(pid),
                                   &event);
    check_result(res, c_pipeline_run_func, m_index, res);

    res = COI::EventWait(1, &event, -1, 1, 0, 0);
    check_result(res, c_event_wait, res);

    OFFLOAD_DEBUG_TRACE(2, "Device process pid is %d\n", pid);

    return pid;
}

// data associated with each thread
struct Thread {
    Thread(long* addr_coipipe_counter) {
        m_addr_coipipe_counter = addr_coipipe_counter;
        memset(m_pipelines, 0, sizeof(m_pipelines));
    }

    ~Thread() {
#ifndef TARGET_WINNT
        __sync_sub_and_fetch(m_addr_coipipe_counter, 1);
#else // TARGET_WINNT
        _InterlockedDecrement(m_addr_coipipe_counter);
#endif // TARGET_WINNT
        for (int i = 0; i < mic_engines_total; i++) {
            if (m_pipelines[i] != 0) {
                COI::PipelineDestroy(m_pipelines[i]);
            }
        }
    }

    COIPIPELINE get_pipeline(int index) const {
        return m_pipelines[index];
    }

    void set_pipeline(int index, COIPIPELINE pipeline) {
        m_pipelines[index] = pipeline;
    }

    AutoSet& get_auto_vars() {
        return m_auto_vars;
    }

private:
    long*       m_addr_coipipe_counter;
    AutoSet     m_auto_vars;
    COIPIPELINE m_pipelines[MIC_ENGINES_MAX];
};

COIPIPELINE Engine::get_pipeline(void)
{
    Thread* thread = (Thread*) thread_getspecific(mic_thread_key);
    if (thread == 0) {
        thread = new Thread(&m_proc_number);
        thread_setspecific(mic_thread_key, thread);
    }

    COIPIPELINE pipeline = thread->get_pipeline(m_index);
    if (pipeline == 0) {
        COIRESULT res;
        int proc_num;

#ifndef TARGET_WINNT
        proc_num = __sync_fetch_and_add(&m_proc_number, 1);
#else // TARGET_WINNT
        proc_num = _InterlockedIncrement(&m_proc_number);
#endif // TARGET_WINNT

        if (proc_num > COI_PIPELINE_MAX_PIPELINES) {
            LIBOFFLOAD_ERROR(c_coipipe_max_number, COI_PIPELINE_MAX_PIPELINES);
            LIBOFFLOAD_ABORT;
        }
        // create pipeline for this thread
        res = COI::PipelineCreate(m_process, 0, mic_stack_size, &pipeline);
        check_result(res, c_pipeline_create, m_index, res);

        thread->set_pipeline(m_index, pipeline);
    }
    return pipeline;
}

AutoSet& Engine::get_auto_vars(void)
{
    Thread* thread = (Thread*) thread_getspecific(mic_thread_key);
    if (thread == 0) {
        thread = new Thread(&m_proc_number);
        thread_setspecific(mic_thread_key, thread);
    }

    return thread->get_auto_vars();
}

void Engine::destroy_thread_data(void *data)
{
    delete static_cast<Thread*>(data);
}