minitrace.cpp

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// minitrace
// Copyright 2014 by Henrik Rydgård
// http://www.github.com/hrydgard/minitrace
// Released under the MIT license.

// See minitrace.h for basic documentation.

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

#ifdef _WIN32
#pragma warning (disable:4996)
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#define __thread __declspec(thread)
#define pthread_mutex_t CRITICAL_SECTION
#define pthread_mutex_init(a, b) InitializeCriticalSection(a)
#define pthread_mutex_lock(a) EnterCriticalSection(a)
#define pthread_mutex_unlock(a) LeaveCriticalSection(a)
#define pthread_mutex_destroy(a) DeleteCriticalSection(a)
#else
#include <signal.h>
#include <pthread.h>
#include <sys/time.h>
#include <unistd.h>
#endif

#include "minitrace.h"

#define ARRAY_SIZE(x) sizeof(x)/sizeof(x[0])

namespace minitrace {

// Ugh, this struct is already pretty heavy.
// Will probably need to move arguments to a second buffer to support more than one.
typedef struct raw_event {
        const char *name;
        const char *cat;
        void *id;
        int64_t ts;
        uint32_t pid;
        uint32_t tid;
        char ph;
        mtr_arg_type arg_type;
        const char *arg_name;
        union {
                const char *a_str;
                int a_int;
                double a_double;
        };
} raw_event_t;

static raw_event_t *buffer;
static volatile int count;
static int is_tracing = 0;
static int64_t time_offset;
static int first_line = 1;
static FILE *file;
static __thread int cur_thread_id;      // Thread local storage
static pthread_mutex_t mutex;

#define STRING_POOL_SIZE 100
static char *str_pool[100];

// Tiny portability layer.
// Exposes:
//       get_cur_thread_id()
//       mtr_time_s()
//       pthread basics
#ifdef _WIN32
static int get_cur_thread_id() {
        return (int)GetCurrentThreadId();
}

static uint64_t _frequency = 0;
static uint64_t _starttime = 0;

inline int64_t mtr_time_usec(){
  static int64_t prev = 0;
        if (_frequency == 0) {
                QueryPerformanceFrequency((LARGE_INTEGER*)&_frequency);
                QueryPerformanceCounter((LARGE_INTEGER*)&_starttime);
        }
        __int64 time;
        QueryPerformanceCounter((LARGE_INTEGER*)&time);
  int64_t now = 1.0e6 * ((double) (time - _starttime) / (double) _frequency);
  if( now <= prev) now = prev + 1;
  prev = now;
  return now;
}

// Ctrl+C handling for Windows console apps
static BOOL WINAPI CtrlHandler(DWORD fdwCtrlType) {
        if (is_tracing && fdwCtrlType == CTRL_C_EVENT) {
                printf("Ctrl-C detected! Flushing trace and shutting down.\n\n");
                mtr_flush();
                mtr_shutdown();
        }
        ExitProcess(1);
}

void mtr_register_sigint_handler() {
        // For console apps:
        SetConsoleCtrlHandler(&CtrlHandler, TRUE);
}

#else

static inline int get_cur_thread_id() {
        return (int)(intptr_t)pthread_self();
}

#if defined(BLACKBERRY)
inline int64_t mtr_time_usec(){
  static int64_t prev = 0;
        struct timespec time;
        clock_gettime(CLOCK_MONOTONIC, &time); // Linux must use CLOCK_MONOTONIC_RAW due to time warps
  int64_t now = time.tv_sec*1000000 + time.tv_nsec / 1000;
  if( now <= prev) now = prev + 1;
  prev = now;
  return now;
}
#else
int64_t mtr_time_usec()
{
  static int64_t prev = 0;
        struct timeval tv;
    gettimeofday(&tv, nullptr);
  int64_t now = 1000000*tv.tv_sec + tv.tv_usec;
  if( now <= prev) now = prev + 1;
  prev = now;
  return now;
}
#endif  // !BLACKBERRY

static void termination_handler(int ) {
        if (is_tracing) {
                printf("Ctrl-C detected! Flushing trace and shutting down.\n\n");
                mtr_flush();
        fwrite("\n]}\n", 1, 4, file);
        fclose(file);
        }
        exit(1);
}

void mtr_register_sigint_handler() {
#ifndef MTR_ENABLED
        return;
#endif
        // Avoid altering set-to-be-ignored handlers while registering.
        if (signal(SIGINT, &termination_handler) == SIG_IGN)
                signal(SIGINT, SIG_IGN);
}

#endif

void mtr_init(const char *json_file) {
#ifndef MTR_ENABLED
        return;
#endif
        buffer = (raw_event_t *)malloc(INTERNAL_MINITRACE_BUFFER_SIZE * sizeof(raw_event_t));
        is_tracing = 1;
        count = 0;
    file = fopen(json_file, "wb");
        const char *header = "{\"traceEvents\":[\n";
    fwrite(header, 1, strlen(header), file);
    time_offset = mtr_time_usec();
        first_line = 1;
        pthread_mutex_init(&mutex, 0);
}

void mtr_shutdown() {
        int i;
#ifndef MTR_ENABLED
        return;
#endif
        is_tracing = 0;
        mtr_flush();
    fwrite("\n]}\n", 1, 4, file);
    fclose(file);
        pthread_mutex_destroy(&mutex);
    file = 0;
        free(buffer);
        buffer = 0;
        for (i = 0; i < STRING_POOL_SIZE; i++) {
                if (str_pool[i]) {
                        free(str_pool[i]);
                        str_pool[i] = 0;
                }
        }
}

const char *mtr_pool_string(const char *str) {
        int i;
        for (i = 0; i < STRING_POOL_SIZE; i++) {
                if (!str_pool[i]) {
      str_pool[i] = (char *)malloc(strlen(str) + 1);
                        strcpy(str_pool[i], str);
                        return str_pool[i];
                } else {
                        if (!strcmp(str, str_pool[i]))
                                return str_pool[i];
                }
        }
        return "string pool full";
}

void mtr_start() {
#ifndef MTR_ENABLED
        return;
#endif
        is_tracing = 1;
}

void mtr_stop() {
#ifndef MTR_ENABLED
        return;
#endif
        is_tracing = 0;
}

// TODO: fwrite more than one line at a time.
void mtr_flush() {
#ifndef MTR_ENABLED
        return;
#endif
        int i = 0;
        char linebuf[1024];
        char arg_buf[256];
        char id_buf[256];
        // We have to lock while flushing. So we really should avoid flushing as much as possible.


        pthread_mutex_lock(&mutex);
        int old_tracing = is_tracing;
        is_tracing = 0; // Stop logging even if using interlocked increments instead of the mutex. Can cause data loss.

        for (i = 0; i < count; i++) {
                raw_event_t *raw = &buffer[i];
                int len;
                switch (raw->arg_type) {
                case MTR_ARG_TYPE_INT:
                        snprintf(arg_buf, ARRAY_SIZE(arg_buf), "\"%s\":%i", raw->arg_name, raw->a_int);
                        break;
                case MTR_ARG_TYPE_STRING_CONST:
                        snprintf(arg_buf, ARRAY_SIZE(arg_buf), "\"%s\":\"%s\"", raw->arg_name, raw->a_str);
                        break;
                case MTR_ARG_TYPE_STRING_COPY:
                        if (strlen(raw->a_str) > 700) {
                                ((char*)raw->a_str)[700] = 0;
                        }
                        snprintf(arg_buf, ARRAY_SIZE(arg_buf), "\"%s\":\"%s\"", raw->arg_name, raw->a_str);
                        break;
                case MTR_ARG_TYPE_NONE:
                default:
                        arg_buf[0] = '\0';
                        break;
                }
                if (raw->id) {
                        switch (raw->ph) {
                        case 'S':
                        case 'T':
                        case 'F':
                                // TODO: Support full 64-bit pointers
                                snprintf(id_buf, ARRAY_SIZE(id_buf), ",\"id\":\"0x%08x\"", (uint32_t)(uintptr_t)raw->id);
                                break;
                        case 'X':
                                snprintf(id_buf, ARRAY_SIZE(id_buf), ",\"dur\":%i", (int)raw->a_double);
                                break;
                        }
                } else {
                        id_buf[0] = 0;
                }
                const char *cat = raw->cat;
#ifdef _WIN32
                // On Windows, we often end up with backslashes in category.
                {
                        char temp[256];
                        int len = (int)strlen(cat);
                        int i;
                        if (len > 255) len = 255;
                        for (i = 0; i < len; i++) {
                                temp[i] = cat[i] == '\\' ? '/' : cat[i];
                        }
                        temp[len] = 0;
                        cat = temp;
                }
#endif

                len = snprintf(linebuf, ARRAY_SIZE(linebuf), "%s{\"cat\":\"%s\",\"pid\":%i,\"tid\":%i,\"ts\":%" PRId64 ",\"ph\":\"%c\",\"name\":\"%s\",\"args\":{%s}%s}",
                                first_line ? "" : ",\n",
                                cat, raw->pid, raw->tid, raw->ts - time_offset, raw->ph, raw->name, arg_buf, id_buf);
        fwrite(linebuf, 1, len, file);
        fflush(file);
                first_line = 0;
        }
        count = 0;
        is_tracing = old_tracing;
        pthread_mutex_unlock(&mutex);
}

void internal_mtr_raw_event(const char *category, const char *name, char ph, void *id) {
#ifndef MTR_ENABLED
        return;
#endif
        if (!is_tracing || count >= INTERNAL_MINITRACE_BUFFER_SIZE)
                return;
  int64_t ts = mtr_time_usec();
        if (!cur_thread_id) {
                cur_thread_id = get_cur_thread_id();
        }

#if 0 && _WIN32 // TODO: This needs testing
        int bufPos = InterlockedIncrement(&count);
        raw_event_t *ev = &buffer[count - 1];
#else
        pthread_mutex_lock(&mutex);
        raw_event_t *ev = &buffer[count];
        count++;
        pthread_mutex_unlock(&mutex);
#endif

        ev->cat = category;
        ev->name = name;
        ev->id = id;
        ev->ph = ph;
  if (ev->ph == 'X') {
    int64_t x;
    memcpy(&x, id, sizeof(int64_t));
    ev->ts = x;
    ev->a_double = (ts - x);
  } else {
    ev->ts = ts;
  }
  ev->tid = cur_thread_id;
        ev->pid = 0;
}

void internal_mtr_raw_event_arg(const char *category, const char *name, char ph, void *id, mtr_arg_type arg_type, const char *arg_name, void *arg_value) {
#ifndef MTR_ENABLED
        return;
#endif
        if (!is_tracing || count >= INTERNAL_MINITRACE_BUFFER_SIZE)
                return;
        if (!cur_thread_id) {
                cur_thread_id = get_cur_thread_id();
        }
  int64_t ts = mtr_time_usec();

#if 0 && _WIN32 // TODO: This needs testing
        int bufPos = InterlockedIncrement(&count);
        raw_event_t *ev = &buffer[count - 1];
#else
        pthread_mutex_lock(&mutex);
        raw_event_t *ev = &buffer[count];
        count++;
        pthread_mutex_unlock(&mutex);
#endif

        ev->cat = category;
        ev->name = name;
        ev->id = id;
  ev->ts = ts;
        ev->ph = ph;
        ev->tid = cur_thread_id;
        ev->pid = 0;
        ev->arg_type = arg_type;
        ev->arg_name = arg_name;
        switch (arg_type) {
        case MTR_ARG_TYPE_INT: ev->a_int = (int)(uintptr_t)arg_value; break;
        case MTR_ARG_TYPE_STRING_CONST: ev->a_str = (const char*)arg_value; break;
        case MTR_ARG_TYPE_STRING_COPY: ev->a_str = strdup((const char*)arg_value); break;
        default:
                break;
        }
}

}