// vim: ts=4 sw=4 expandtab ft=c

// Copyright (C) 1995-1998, 2000-2002, 2006 The University of Melbourne.
// Copyright (C) 2013-2016, 2018 The Mercury team.
// This file is distributed under the terms specified in COPYING.LIB.

// Profiling module
//
// Main Author: petdr

#include        "mercury_imp.h"

#ifdef MR_HAVE_UNISTD_H
  #include  <unistd.h>
#endif

#include    <stdio.h>
#include    <errno.h>
#include    <string.h>

#include    "mercury_prof.h"
#include    "mercury_heap_profile.h" // for MR_prof_output_mem_tables()
#include    "mercury_prof_time.h"    // for MR_turn_on_time_profiling()
#include    "mercury_prof_mem.h"     // for prof_malloc()

#include    "mercury_signal.h"
#include    "mercury_std.h"
#include    "mercury_timing.h"
#include    "mercury_runtime_util.h"

#include    <signal.h>      // for SIGINT

// XXX Ought to make these command line options.

#define CALL_TABLE_SIZE 4096
#define TIME_TABLE_SIZE 4096

// Profiling node information.

typedef struct s_prof_call_node {
    MR_Code                 *Callee;
    MR_Code                 *Caller;
    unsigned long           count;
    struct s_prof_call_node *left;
    struct s_prof_call_node *right;
} prof_call_node;

typedef struct s_prof_time_node {
    MR_Code                 *Addr;
    unsigned long           count;
    struct s_prof_time_node *left;
    struct s_prof_time_node *right;
} prof_time_node;

// Macro definitions.

#define hash_addr_pair(Callee, Caller)                                      \
        (int) ((( (MR_Unsigned)(Callee) ^ (MR_Unsigned)(Caller) ) >> 2)     \
                % CALL_TABLE_SIZE )

#define hash_prof_addr(Addr)                                                \
        (int) ( (( (MR_Unsigned)(Addr) ) >> 2) % TIME_TABLE_SIZE )

// Global Variables.

MR_Code * volatile      MR_prof_current_proc;

#ifdef MR_MPROF_PROFILE_CALLS
  MR_Code               *MR_prof_ho_caller_proc;
#endif

// Private global variables.

#if defined(MR_MPROF_PROFILE_CALLS) || defined(MR_MPROF_PROFILE_TIME)
  static volatile int     in_profiling_code = MR_FALSE;
#endif

#ifdef MR_MPROF_PROFILE_CALLS
  static MR_bool        profile_calls = MR_TRUE;
  static FILE           *MR_prof_decl_fptr = NULL;
  static prof_call_node *addr_pair_table[CALL_TABLE_SIZE] = {NULL};
#endif

#ifdef MR_MPROF_PROFILE_TIME
  static MR_bool        profile_time = MR_FALSE;
  static prof_time_node *addr_table[TIME_TABLE_SIZE] = {NULL};
#endif

// Local function declarations.

#ifdef MR_MPROF_PROFILE_TIME
  static void   prof_handle_tick(int);
  static void   prof_output_addr_table(void);
  static void   print_time_node(FILE *fptr, prof_time_node *node);
#endif

#ifdef MR_MPROF_PROFILE_CALLS
  static void   print_addr_pair_node(FILE *fptr, prof_call_node *node);
  static void   prof_output_addr_pair_table(void);
#endif

#ifdef MR_MPROF_PROFILE_MEMORY
  static void   prof_output_mem_tables(void);
  static void   print_memory_node(FILE *words_fptr, FILE *cells_fptr,
                    MR_memprof_record *node);
#endif

#if defined(MR_MPROF_PROFILE_TIME) || defined(MR_MPROF_PROFILE_CALLS) \
        || defined(MR_MPROF_PROFILE_MEMORY)
  static void   prof_handle_sigint(void);
#endif

////////////////////////////////////////////////////////////////////////////

#ifdef MR_MPROF_PROFILE_CALLS

// prof_call_profile:
//
// Saves the callee, caller pair into a hash table. If the address pair
// already exists, then it increments a count.

void
MR_prof_call_profile(MR_Code *Callee, MR_Code *Caller)
{
    prof_call_node  *node;
    prof_call_node  **node_addr;
    prof_call_node  *new_node;
    int             hash_value;

    if (!profile_calls) {
        return;
    }

    in_profiling_code = MR_TRUE;

    hash_value = hash_addr_pair(Callee, Caller);

    node_addr = &addr_pair_table[hash_value];
    while ((node = *node_addr) != NULL) {
        if (node->Callee < Callee) {
            node_addr = &node->left;
        } else if (node->Callee > Callee) {
            node_addr = &node->right;
        } else if (node->Caller < Caller) {
            node_addr = &node->left;
        } else if (node->Caller > Caller) {
            node_addr = &node->right;
        } else {
            node->count++;
            in_profiling_code = MR_FALSE;
            return;
        }
    }

    new_node = MR_PROF_NEW(prof_call_node);
    new_node->Callee = Callee;
    new_node->Caller = Caller;
    new_node->count  = 1;
    new_node->left   = NULL;
    new_node->right  = NULL;
    *node_addr = new_node;

    in_profiling_code = MR_FALSE;
    return;
}

#endif // MR_MPROF_PROFILE_CALLS

////////////////////////////////////////////////////////////////////////////

#ifdef MR_MPROF_PROFILE_TIME

// prof_handle_tick:
//
// Signal handler to be called whenever a profiling signal is received.
// Saves the current code address into a hash table.
// If the address already exists, it increments its count.

static void
prof_handle_tick(int signum)
{
    prof_time_node  *node;
    prof_time_node  **node_addr;
    prof_time_node  *new_node;
    int             hash_value;
    MR_Code         *current_proc;

    // Ignore any signals we get in this function or in prof_call_profile.
    if (in_profiling_code) {
        return;
    }

    in_profiling_code = MR_TRUE;

    current_proc = MR_prof_current_proc;
    hash_value = hash_prof_addr(current_proc);

    node_addr = &addr_table[hash_value];
    while ((node = *node_addr) != NULL) {
        if (node->Addr < current_proc) {
            node_addr = &node->left;
        } else if (node->Addr > current_proc) {
            node_addr = &node->right;
        } else {
            node->count++;
            in_profiling_code = MR_FALSE;
            return;
        }
    }

    new_node = MR_PROF_NEW(prof_time_node);
    new_node->Addr  = current_proc;
    new_node->count = 1;
    new_node->left  = NULL;
    new_node->right = NULL;
    *node_addr = new_node;

    in_profiling_code = MR_FALSE;
    return;
} // end prof_handle_tick()

#endif // MR_MPROF_PROFILE_TIME

////////////////////////////////////////////////////////////////////////////

#ifdef MR_MPROF_PROFILE_CALLS

// prof_output_addr_pair_table:
//
// Writes the hash table to a file called "Prof.CallPair".
// Caller then callee followed by count.

static void
prof_output_addr_pair_table(void)
{
    FILE    *fptr;
    int     i;

    fptr = MR_checked_fopen("Prof.CallPair", "create", "w");

    for (i = 0; i < CALL_TABLE_SIZE ; i++) {
        print_addr_pair_node(fptr, addr_pair_table[i]);
    }

    MR_checked_fclose(fptr, "Prof.CallPair");
}

static void
print_addr_pair_node(FILE *fptr, prof_call_node *node)
{
    if (node != NULL) {
        fprintf(fptr, "%" MR_INTEGER_LENGTH_MODIFIER "d %"
            MR_INTEGER_LENGTH_MODIFIER "d %lu\n",
            (MR_Integer) node->Caller, (MR_Integer) node->Callee, node->count);
        print_addr_pair_node(fptr, node->left);
        print_addr_pair_node(fptr, node->right);
    }
}

#endif // MR_MPROF_PROFILE_CALLS

////////////////////////////////////////////////////////////////////////////

#if defined(MR_MPROF_PROFILE_CALLS)

// prof_output_addr_decl:
//
// Outputs an entry label name and its corresponding machine address to a file
// called "Prof.Decl". This is called from insert_entry() in mercury_label.c.

void
MR_prof_output_addr_decl(const char *name, const MR_Code *address)
{
    if (!MR_prof_decl_fptr) {
        MR_prof_decl_fptr = MR_checked_fopen("Prof.Decl", "create", "w");
    }
    fprintf(MR_prof_decl_fptr, "%" MR_INTEGER_LENGTH_MODIFIER "d\t%s\n",
        (MR_Integer) address, name);
}

#endif // MR_MPROF_PROFILE_CALLS

////////////////////////////////////////////////////////////////////////////

#ifdef MR_MPROF_PROFILE_TIME

// prof_output_addr_table:
//
// Writes out the time profiling counts recorded by the profile signal handler
// to the file `Prof.Counts'.

static void
prof_output_addr_table(void)
{
    FILE    *fptr;
    int     i;
    double  scale;
    double  rate;

    fptr = MR_checked_fopen("Prof.Counts", "create", "w");

    // Write out header line indicating what we are profiling,
    // the scale factor, and the units.
    // The scale factor is the time per profiling interrupt.
    // The units are seconds.

    #if defined(MR_CLOCK_TICKS_PER_SECOND)
        scale = (double) MR_CLOCK_TICKS_PER_PROF_SIG /
            (double) MR_CLOCK_TICKS_PER_SECOND;
        fprintf(fptr, "%s %f %s\n", MR_time_method, scale, "seconds");
    #else
        #error "Time profiling not supported on this system"
    #endif

    // Write out the time profiling data: one one-line entry per node.

    for (i = 0; i < TIME_TABLE_SIZE ; i++) {
        print_time_node(fptr, addr_table[i]);
    }

    MR_checked_fclose(fptr, "Prof.Counts");
}

static void
print_time_node(FILE *fptr, prof_time_node *node)
{
    if (node != (prof_time_node *) NULL) {
        fprintf(fptr, "%" MR_INTEGER_LENGTH_MODIFIER "d %lu\n",
            (MR_Integer) node->Addr, node->count);
        print_time_node(fptr, node->left);
        print_time_node(fptr, node->right);
    }
}

#endif // MR_MPROF_PROFILE_TIME

////////////////////////////////////////////////////////////////////////////

#ifdef MR_MPROF_PROFILE_MEMORY

// prof_output_mem_tables:
//
// Writes the by-procedure memory profiling counts to the files
// `Prof.MemoryWords' and `Prof.MemoryCells'.

static void
prof_output_mem_tables(void)
{
    FILE    *words_fptr;
    FILE    *cells_fptr;
    int     i;

    words_fptr = MR_checked_fopen("Prof.MemoryWords", "create", "w");
    cells_fptr = MR_checked_fopen("Prof.MemoryCells", "create", "w");

    fprintf(words_fptr, "%s %f %s\n", "memory-words", 0.001, "kilowords");
    fprintf(cells_fptr, "%s %f %s\n", "memory-cells", 0.001, "kilocells");

    print_memory_node(words_fptr, cells_fptr, MR_memprof_procs.root);

    MR_checked_fclose(words_fptr, "Prof.MemoryWords");
    MR_checked_fclose(cells_fptr, "Prof.MemoryCells");
}

static void
print_memory_node(FILE *words_fptr, FILE *cells_fptr, MR_memprof_record *node)
{
    if (node != NULL) {
        MR_Dword    cells;
        MR_Dword    words;
        double      cells_double;
        double      words_double;

        cells = node->counter.cells_at_period_start;
        words = node->counter.words_at_period_start;

        MR_add_two_dwords(cells, node->counter.cells_since_period_start);
        MR_add_two_dwords(words, node->counter.words_since_period_start);

        MR_convert_dword_to_double(words, words_double);
        MR_convert_dword_to_double(cells, cells_double);

        fprintf(words_fptr, "%" MR_INTEGER_LENGTH_MODIFIER "d %.0f\n",
            (MR_Integer) node->proc, words_double);
        fprintf(cells_fptr, "%" MR_INTEGER_LENGTH_MODIFIER "d %.0f\n",
            (MR_Integer) node->proc, cells_double);

        print_memory_node(words_fptr, cells_fptr, node->left);
        print_memory_node(words_fptr, cells_fptr, node->right);
    }
}

#endif // MR_MPROF_PROFILE_MEMORY

////////////////////////////////////////////////////////////////////////////

void
MR_prof_init(void)
{
#ifdef MR_MPROF_PROFILE_TIME
    MR_init_time_profile_method();
#endif

#if defined(MR_MPROF_PROFILE_TIME) || defined(MR_MPROF_PROFILE_CALLS) \
        || defined(MR_MPROF_PROFILE_MEMORY)
    MR_checked_atexit(MR_prof_finish);
  #ifdef SIGINT
    MR_setup_signal(SIGINT, prof_handle_sigint, MR_FALSE,
        "cannot install signal handler");
  #endif
#endif
}

#if defined(MR_MPROF_PROFILE_TIME) || defined(MR_MPROF_PROFILE_CALLS) \
        || defined(MR_MPROF_PROFILE_MEMORY)
static void
prof_handle_sigint(void)
{
    // exit() will call MR_prof_finish(), which we registered with atexit().

    exit(EXIT_FAILURE);
}
#endif

void
MR_prof_finish(void)
{
    // Ensure this routine only gets run once, even if called twice.
    static MR_bool done = MR_FALSE;
    if (done) {
        return;
    }

    done = MR_TRUE;

#ifdef MR_MPROF_PROFILE_CALLS
    prof_output_addr_pair_table();
#endif

#ifdef MR_MPROF_PROFILE_TIME
    MR_turn_off_time_profiling();
    prof_output_addr_table();
#endif

#ifdef MR_MPROF_PROFILE_MEMORY
    prof_output_mem_tables();
#endif

#ifdef MR_MPROF_PROFILE_MEMORY_ATTRIBUTION
    MR_finish_prof_snapshots_file();
#endif
}

void MR_close_prof_decl_file(void)
{
#ifdef MR_MPROF_PROFILE_CALLS
    if (MR_prof_decl_fptr) {
        MR_checked_fclose(MR_prof_decl_fptr, "Prof.Decl");
    }
#endif
}

#ifdef MR_MPROF_PROFILE_CALLS
void
MR_prof_turn_on_call_profiling(void)
{
    profile_calls = MR_TRUE;
}

void MR_prof_turn_off_call_profiling(void)
{
    profile_calls = MR_FALSE;
}
#endif

#ifdef MR_MPROF_PROFILE_TIME

void
MR_prof_turn_on_time_profiling(void)
{
    if (!profile_time) {
        MR_turn_on_time_profiling(prof_handle_tick);
        profile_time = MR_TRUE;
    }
}

void
MR_prof_turn_off_time_profiling(void)
{
    if (profile_time) {
        MR_turn_off_time_profiling();
        profile_time = MR_FALSE;
    }
}

#endif

////////////////////////////////////////////////////////////////////////////