darshan-core.c 23.2 KB
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/*
 *  (C) 2009 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */

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#define _GNU_SOURCE
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#include "darshan-runtime-config.h"

#include <stdio.h>
#ifdef HAVE_MNTENT_H
#include <mntent.h>
#endif
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#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <limits.h>
#include <pthread.h>
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#include <sys/types.h>
#include <sys/stat.h>
#include <sys/vfs.h>
#include <mpi.h>
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#include "darshan-core.h"

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/* TODO is __progname_full needed here */
extern char* __progname;
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/* internal variables */
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static struct darshan_core_job_runtime *darshan_core_job = NULL;
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static pthread_mutex_t darshan_mutex = PTHREAD_MUTEX_INITIALIZER;
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static int my_rank = -1;
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static int nprocs = -1;
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static void darshan_core_initialize(int *argc, char ***argv);
static void darshan_core_shutdown(void);
static void darshan_core_cleanup(struct darshan_core_job_runtime* job);
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static void darshan_get_logfile_name(char* logfile_name, int jobid, struct tm* start_tm);
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static void darshan_log_record_hints_and_ver(struct darshan_core_job_runtime* job);
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#define DARSHAN_LOCK() pthread_mutex_lock(&darshan_mutex)
#define DARSHAN_UNLOCK() pthread_mutex_unlock(&darshan_mutex)

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/* intercept MPI initialize and finalize to manage darshan core runtime */
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int MPI_Init(int *argc, char ***argv)
{
    int ret;

    ret = DARSHAN_MPI_CALL(PMPI_Init)(argc, argv);
    if(ret != MPI_SUCCESS)
    {
        return(ret);
    }

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    darshan_core_initialize(argc, argv);
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    return(ret);
}

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int MPI_Init_thread(int *argc, char ***argv, int required, int *provided)
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{
    int ret;

    ret = DARSHAN_MPI_CALL(PMPI_Init_thread)(argc, argv, required, provided);
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    if(ret != MPI_SUCCESS)
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    {
        return(ret);
    }

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    darshan_core_initialize(argc, argv);
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    return(ret);
}

int MPI_Finalize(void)
{
    int ret;

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    darshan_core_shutdown();
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    ret = DARSHAN_MPI_CALL(PMPI_Finalize)();
    return(ret);
}

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

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static void darshan_core_initialize(int *argc, char ***argv)
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{
    int i;
    int internal_timing_flag = 0;
    double init_start, init_time, init_max;
    char* truncate_string = "<TRUNCATED>";
    int truncate_offset;
    int chars_left = 0;

    DARSHAN_MPI_CALL(PMPI_Comm_size)(MPI_COMM_WORLD, &nprocs);
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    DARSHAN_MPI_CALL(PMPI_Comm_rank)(MPI_COMM_WORLD, &my_rank);
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    if(getenv("DARSHAN_INTERNAL_TIMING"))
        internal_timing_flag = 1;

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    if(internal_timing_flag)
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        init_start = DARSHAN_MPI_CALL(PMPI_Wtime)();

    /* setup darshan runtime if darshan is enabled and hasn't been initialized already */
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    if(!getenv("DARSHAN_DISABLE") && !darshan_core_job)
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    {
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        /* allocate structure to track darshan_core_job information */
        darshan_core_job = malloc(sizeof(*darshan_core_job));
        if(darshan_core_job)
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        {
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            memset(darshan_core_job, 0, sizeof(*darshan_core_job));
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            strcpy(darshan_core_job->log_job.version_string, CP_VERSION);
            darshan_core_job->log_job.magic_nr = CP_MAGIC_NR;
            darshan_core_job->log_job.uid = getuid();
            darshan_core_job->log_job.start_time = time(NULL);
            darshan_core_job->log_job.nprocs = nprocs;
            darshan_core_job->wtime_offset = DARSHAN_MPI_CALL(PMPI_Wtime)();
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            /* record exe and arguments */
            for(i=0; i<(*argc); i++)
            {
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                chars_left = CP_EXE_LEN-strlen(darshan_core_job->exe);
                strncat(darshan_core_job->exe, *(argv[i]), chars_left);
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                if(i < ((*argc)-1))
                {
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                    chars_left = CP_EXE_LEN-strlen(darshan_core_job->exe);
                    strncat(darshan_core_job->exe, " ", chars_left);
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                }
            }

            /* if we don't see any arguments, then use glibc symbol to get
             * program name at least (this happens in fortran)
             */
            if(argc == 0)
            {
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                chars_left = CP_EXE_LEN-strlen(darshan_core_job->exe);
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                strncat(darshan_core_job->exe, __progname, chars_left);
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                chars_left = CP_EXE_LEN-strlen(darshan_core_job->exe);
                strncat(darshan_core_job->exe, " <unknown args>", chars_left);
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            }

            if(chars_left == 0)
            {
                /* we ran out of room; mark that string was truncated */
                truncate_offset = CP_EXE_LEN - strlen(truncate_string);
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                sprintf(&darshan_core_job->exe[truncate_offset], "%s",
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                    truncate_string);
            }
        }
    }

    if(internal_timing_flag)
    {
        init_time = DARSHAN_MPI_CALL(PMPI_Wtime)() - init_start;
        DARSHAN_MPI_CALL(PMPI_Reduce)(&init_time, &init_max, 1,
            MPI_DOUBLE, MPI_MAX, 0, MPI_COMM_WORLD);
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        if(my_rank == 0)
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        {
            printf("#darshan:<op>\t<nprocs>\t<time>\n");
            printf("darshan:init\t%d\t%f\n", nprocs, init_max);
        }
    }

    return;
}

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static void darshan_core_shutdown()
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{
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    char *logfile_name;
    struct darshan_core_job_runtime* final_job;
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    struct darshan_core_module *mod, *tmp;
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    int internal_timing_flag = 0;
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    char* envjobid;
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    char* jobid_str;
    int jobid;
    struct tm* start_tm;
    time_t start_time_tmp;
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    int ret = 0;
    int all_ret = 0;
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    int64_t first_start_time;
    int64_t last_end_time;
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    int local_mod_use[DARSHAN_MAX_MODS] = {0};
    int global_mod_use_count[DARSHAN_MAX_MODS] = {0};
    int i;
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    char* key;
    char* value;
    char* hints;
    char* tok_str;
    char* orig_tok_str;
    char* saveptr = NULL;
    char* mod_index;
    char* new_logfile_name;
    double start_log_time;
    double end_log_time;
    long offset;
    MPI_File log_fh;
    MPI_Info info;
    MPI_Status status;
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    if(getenv("DARSHAN_INTERNAL_TIMING"))
        internal_timing_flag = 1;

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    DARSHAN_LOCK();
    if(!darshan_core_job)
    {
        DARSHAN_UNLOCK();
        return;
    }
    /* disable further tracing while hanging onto the data so that we can
     * write it out
     */
    final_job = darshan_core_job;
    darshan_core_job = NULL;
    DARSHAN_UNLOCK();

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    start_log_time = DARSHAN_MPI_CALL(PMPI_Wtime)();

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    logfile_name = malloc(PATH_MAX);
    if(!logfile_name)
    {
        darshan_core_cleanup(final_job);
        return;
    }

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    /* set darshan job id/metadata and constuct log file name on rank 0 */
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    if(my_rank == 0)
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    {
        /* Use CP_JOBID_OVERRIDE for the env var or CP_JOBID */
        envjobid = getenv(CP_JOBID_OVERRIDE);
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        if(!envjobid)
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        {
            envjobid = CP_JOBID;
        }

        jobid_str = getenv(envjobid);
        if(jobid_str)
        {
            /* in cobalt we can find it in env var */
            ret = sscanf(jobid_str, "%d", &jobid);
        }
        if(!jobid_str || ret != 1)
        {
            /* use pid as fall back */
            jobid = getpid();
        }

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        final_job->log_job.jobid = (int64_t)jobid;
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        /* if we are using any hints to write the log file, then record those
         * hints in the log file header
         */
        darshan_log_record_hints_and_ver(final_job);

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        /* use human readable start time format in log filename */
        start_time_tmp = final_job->log_job.start_time;
        start_tm = localtime(&start_time_tmp);
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        /* construct log file name */
        darshan_get_logfile_name(logfile_name, jobid, start_tm);
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    }

    /* broadcast log file name */
    DARSHAN_MPI_CALL(PMPI_Bcast)(logfile_name, PATH_MAX, MPI_CHAR, 0,
        MPI_COMM_WORLD);

    if(strlen(logfile_name) == 0)
    {
        /* failed to generate log file name */
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        free(logfile_name);
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        darshan_core_cleanup(final_job);
        return;
    }

    final_job->log_job.end_time = time(NULL);

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    /* reduce to report first start time and last end time across all ranks
     * at rank 0
     */
    DARSHAN_MPI_CALL(PMPI_Reduce)(&final_job->log_job.start_time, &first_start_time, 1, MPI_LONG_LONG, MPI_MIN, 0, MPI_COMM_WORLD);
    DARSHAN_MPI_CALL(PMPI_Reduce)(&final_job->log_job.end_time, &last_end_time, 1, MPI_LONG_LONG, MPI_MAX, 0, MPI_COMM_WORLD);
    if(my_rank == 0)
    {
        final_job->log_job.start_time = first_start_time;
        final_job->log_job.end_time = last_end_time;
    }
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    /* set which local modules were actually used */
    for(i = 0; i < DARSHAN_MAX_MODS; i++)
    {
        if(final_job->mod_array[i])
            local_mod_use[i] = 1;
    }

    /* reduce the number of times a module was opened globally and bcast to everyone */   
    DARSHAN_MPI_CALL(PMPI_Allreduce)(local_mod_use, global_mod_use_count, DARSHAN_MAX_MODS, MPI_INT, MPI_SUM, MPI_COMM_WORLD);

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    MPI_Info_create(&info);

    /* check environment variable to see if the default MPI file hints have
     * been overridden
     */
    hints = getenv(CP_LOG_HINTS_OVERRIDE);
    if(!hints)
    {
        hints = __CP_LOG_HINTS;
    }

    if(hints && strlen(hints) > 0)
    {
        tok_str = strdup(hints);
        if(tok_str)
        {
            orig_tok_str = tok_str;
            do
            {
                /* split string on semicolon */
                key = strtok_r(tok_str, ";", &saveptr);
                if(key)
                {
                    tok_str = NULL;
                    /* look for = sign splitting key/value pairs */
                    value = index(key, '=');
                    if(value)
                    {
                        /* break key and value into separate null terminated strings */
                        value[0] = '\0';
                        value++;
                        if(strlen(key) > 0)
                            MPI_Info_set(info, key, value);
                    }
                }
            }while(key != NULL);
            free(orig_tok_str);
        }
    }

    /* open the darshan log file for writing */
    ret = DARSHAN_MPI_CALL(PMPI_File_open)(MPI_COMM_WORLD, logfile_name,
        MPI_MODE_CREATE | MPI_MODE_WRONLY | MPI_MODE_EXCL, info, &log_fh);
    MPI_Info_free(&info);

    /* error out if unable to open log file */
    DARSHAN_MPI_CALL(PMPI_Allreduce)(&ret, &all_ret, 1, MPI_INT,
        MPI_LOR, MPI_COMM_WORLD);
    if(all_ret != 0)
    {
        if(my_rank == 0)
        {
            int msg_len;
            char msg[MPI_MAX_ERROR_STRING] = {0};

            MPI_Error_string(ret, msg, &msg_len);
            fprintf(stderr, "darshan library warning: unable to open log file %s: %s\n",
                    logfile_name, msg);
            unlink(logfile_name);
        }
        free(logfile_name);
        darshan_core_cleanup(final_job);
        return;
    }

    /* TODO: is there another header, or is job info first data ? */
    /* TODO: are MPI data types necessary or can we just write buffers of MPI_BYTEs? */

    /* write the job info on rank 0 */
    if(my_rank == 0)
    {
        ret = DARSHAN_MPI_CALL(PMPI_File_write_at)(log_fh, 0, &(final_job->log_job),
            sizeof(struct darshan_job), MPI_BYTE, &status);
        if(ret != MPI_SUCCESS)
        {
            int msg_len;
            char msg[MPI_MAX_ERROR_STRING] = {0};

            MPI_Error_string(ret, msg, &msg_len);
            fprintf(stderr, "darshan library warning: unable to write job data to log file %s: %s\n",
                    logfile_name, msg);
            unlink(logfile_name);
            free(logfile_name);
            darshan_core_cleanup(final_job);
            return;
        }
    }

    /* TODO: id->file name map write */

    /* loop over globally used darshan modules and:
     *      - get final output buffer
     *      - compress (zlib/bzip2) provided output buffer
     *      - write compressed buffer to log file
     *      - shutdown the module
     */
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    for(i = 0; i < DARSHAN_MAX_MODS; i++)
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    {
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        struct darshan_core_module* this_mod = final_job->mod_array[i];
        MPI_Comm mod_comm;
        void* mod_buf = NULL;
        int mod_buf_size = 0;
        void* comp_buf = NULL;
        long comp_buf_size = 0;
        long scan_offset = 0;

        if(!global_mod_use_count[i])
            continue;

        /* create a communicator to use for shutting down the module */
        if(global_mod_use_count[i] == nprocs)
        {
            MPI_Comm_dup(MPI_COMM_WORLD, &mod_comm);
        }
        else
        {
            MPI_Comm_split(MPI_COMM_WORLD, local_mod_use[i], 0, &mod_comm);
        }
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        /* if module is registered locally, get the corresponding output buffer */
        if(local_mod_use[i])
        {
            /* get output buffer from module */
            this_mod->mod_funcs.get_output_data(mod_comm, &mod_buf, &mod_buf_size);
        }

        if(mod_buf_size > 0)
        {
            /* TODO generic compression */
            comp_buf = mod_buf;
            comp_buf_size = mod_buf_size;
        }

        /* get current file size on rank 0 so we can calculate offset correctly */
        scan_offset = comp_buf_size;
        if(my_rank == 0)
        {
            MPI_Offset tmp_off;
            
            ret = MPI_File_get_size(log_fh, &tmp_off);
            if(ret != MPI_SUCCESS)
            {
                int msg_len;
                char msg[MPI_MAX_ERROR_STRING] = {0};

                MPI_Error_string(ret, msg, &msg_len);
                fprintf(stderr, "darshan library warning: unable to write module data to log file %s: %s\n",
                        logfile_name, msg);
                DARSHAN_MPI_CALL(PMPI_File_close)(&log_fh);
                unlink(logfile_name);
                free(logfile_name);
                darshan_core_cleanup(final_job);
                return;
            }
            scan_offset += tmp_off;
        }

        /* figure out everyone's offset using scan */
        DARSHAN_MPI_CALL(PMPI_Scan)(&scan_offset, &offset, 1, MPI_LONG, MPI_SUM, MPI_COMM_WORLD);
        offset -= comp_buf_size;

        /* collectively write out each rank's contributing data (maybe nothing) */
        ret = DARSHAN_MPI_CALL(PMPI_File_write_at_all)(log_fh, offset, comp_buf,
            comp_buf_size, MPI_BYTE, &status);

        /* error out if unable to write */
        DARSHAN_MPI_CALL(PMPI_Allreduce)(&ret, &all_ret, 1, MPI_INT,
            MPI_LOR, MPI_COMM_WORLD);
        if(all_ret != 0)
        {
            DARSHAN_MPI_CALL(PMPI_File_close)(&log_fh);
            if(my_rank == 0)
            {
                int msg_len;
                char msg[MPI_MAX_ERROR_STRING] = {0};

                MPI_Error_string(ret, msg, &msg_len);
                fprintf(stderr, "darshan library warning: unable to write module data to log file %s: %s\n",
                        logfile_name, msg);
                unlink(logfile_name);
            }
            free(logfile_name);
            darshan_core_cleanup(final_job);
            return;
        }

        /* shutdown module if registered locally */
        if(local_mod_use[i])
        {
            this_mod->mod_funcs.shutdown();
            this_mod = NULL;
        }

        MPI_Comm_free(&mod_comm);
    }

    DARSHAN_MPI_CALL(PMPI_File_close)(&log_fh);

    /* if we got this far, there are no errors, so rename from *.darshan_partial
     * to *-<logwritetime>.darshan.gz, which indicates that this log file is
     * complete and ready for analysis
     */
    new_logfile_name = malloc(PATH_MAX);
    if(new_logfile_name)
    {
        new_logfile_name[0] = '\0';
        end_log_time = DARSHAN_MPI_CALL(PMPI_Wtime)();
        strcat(new_logfile_name, logfile_name);
        mod_index = strstr(new_logfile_name, ".darshan_partial");
        sprintf(mod_index, "_%d.darshan.gz", (int)(end_log_time-start_log_time+1));
        rename(logfile_name, new_logfile_name);
        /* set permissions on log file */
#ifdef __CP_GROUP_READABLE_LOGS
        chmod(new_logfile_name, (S_IRUSR|S_IRGRP));
#else
        chmod(new_logfile_name, (S_IRUSR));
#endif
        free(new_logfile_name);
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    }
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    free(logfile_name);
    darshan_core_cleanup(final_job);

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    if(internal_timing_flag)
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    {
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        /* TODO: what do we want to time in new darshan version? */
    }
    
    return;
}
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/* free darshan core data structures to shutdown */
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static void darshan_core_cleanup(struct darshan_core_job_runtime* job)
{
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    int i;
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    for(i = 0; i < DARSHAN_MAX_MODS; i++)
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    {
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        if(job->mod_array[i])
        {        
            free(job->mod_array[i]);
            job->mod_array[i] = NULL;
        }
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    }
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    free(job);
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    return;
}

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/* construct the darshan log file name */
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static void darshan_get_logfile_name(char* logfile_name, int jobid, struct tm* start_tm)
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{
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    char* logpath;
    char* logname_string;
    char* logpath_override = NULL;
#ifdef __CP_LOG_ENV
    char env_check[256];
    char* env_tok;
#endif
    uint64_t hlevel;
    char hname[HOST_NAME_MAX];
    uint64_t logmod;
    char cuser[L_cuserid] = {0};
    int ret;

    /* Use CP_LOG_PATH_OVERRIDE for the value or __CP_LOG_PATH */
    logpath = getenv(CP_LOG_PATH_OVERRIDE);
    if(!logpath)
    {
#ifdef __CP_LOG_PATH
        logpath = __CP_LOG_PATH;
#endif
    }

    /* get the username for this job.  In order we will try each of the
     * following until one of them succeeds:
     *
     * - cuserid()
     * - getenv("LOGNAME")
     * - snprintf(..., geteuid());
     *
     * Note that we do not use getpwuid() because it generally will not
     * work in statically compiled binaries.
     */

#ifndef DARSHAN_DISABLE_CUSERID
    cuserid(cuser);
#endif

    /* if cuserid() didn't work, then check the environment */
    if(strcmp(cuser, "") == 0)
    {
        logname_string = getenv("LOGNAME");
        if(logname_string)
        {
            strncpy(cuser, logname_string, (L_cuserid-1));
        }

    }

    /* if cuserid() and environment both fail, then fall back to uid */
    if(strcmp(cuser, "") == 0)
    {
        uid_t uid = geteuid();
        snprintf(cuser, sizeof(cuser), "%u", uid);
    }

    /* generate a random number to help differentiate the log */
    hlevel=DARSHAN_MPI_CALL(PMPI_Wtime)() * 1000000;
    (void)gethostname(hname, sizeof(hname));
    logmod = darshan_hash((void*)hname,strlen(hname),hlevel);

    /* see if darshan was configured using the --with-logpath-by-env
     * argument, which allows the user to specify an absolute path to
     * place logs via an env variable.
     */
#ifdef __CP_LOG_ENV
    /* just silently skip if the environment variable list is too big */
    if(strlen(__CP_LOG_ENV) < 256)
    {
        /* copy env variable list to a temporary buffer */
        strcpy(env_check, __CP_LOG_ENV);
        /* tokenize the comma-separated list */
        env_tok = strtok(env_check, ",");
        if(env_tok)
        {
            do
            {
                /* check each env variable in order */
                logpath_override = getenv(env_tok);
                if(logpath_override)
                {
                    /* stop as soon as we find a match */
                    break;
                }
            }while((env_tok = strtok(NULL, ",")));
        }
    }
#endif

    if(logpath_override)
    {
        ret = snprintf(logfile_name, PATH_MAX,
            "%s/%s_%s_id%d_%d-%d-%d-%" PRIu64 ".darshan_partial",
            logpath_override,
            cuser, __progname, jobid,
            (start_tm->tm_mon+1),
            start_tm->tm_mday,
            (start_tm->tm_hour*60*60 + start_tm->tm_min*60 + start_tm->tm_sec),
            logmod);
        if(ret == (PATH_MAX-1))
        {
            /* file name was too big; squish it down */
            snprintf(logfile_name, PATH_MAX,
                "%s/id%d.darshan_partial",
                logpath_override, jobid);
        }
    }
    else if(logpath)
    {
        ret = snprintf(logfile_name, PATH_MAX,
            "%s/%d/%d/%d/%s_%s_id%d_%d-%d-%d-%" PRIu64 ".darshan_partial",
            logpath, (start_tm->tm_year+1900),
            (start_tm->tm_mon+1), start_tm->tm_mday,
            cuser, __progname, jobid,
            (start_tm->tm_mon+1),
            start_tm->tm_mday,
            (start_tm->tm_hour*60*60 + start_tm->tm_min*60 + start_tm->tm_sec),
            logmod);
        if(ret == (PATH_MAX-1))
        {
            /* file name was too big; squish it down */
            snprintf(logfile_name, PATH_MAX,
                "%s/id%d.darshan_partial",
                logpath, jobid);
        }
    }
    else
    {
        logfile_name[0] = '\0';
    }

    return;
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}

685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730
/* record any hints used to write the darshan log in the log header */
static void darshan_log_record_hints_and_ver(struct darshan_core_job_runtime* job)
{
    char* hints;
    char* header_hints;
    int meta_remain = 0;
    char* m;

    /* check environment variable to see if the default MPI file hints have
     * been overridden
     */
    hints = getenv(CP_LOG_HINTS_OVERRIDE);
    if(!hints)
    {
        hints = __CP_LOG_HINTS;
    }

    if(!hints || strlen(hints) < 1)
        return;

    header_hints = strdup(hints);
    if(!header_hints)
        return;

    meta_remain = DARSHAN_JOB_METADATA_LEN -
        strlen(job->log_job.metadata) - 1;
    if(meta_remain >= (strlen(PACKAGE_VERSION) + 9))
    {
        sprintf(job->log_job.metadata, "lib_ver=%s\n", PACKAGE_VERSION);
        meta_remain -= (strlen(PACKAGE_VERSION) + 9);
    }
    if(meta_remain >= (3 + strlen(header_hints)))
    {
        m = job->log_job.metadata + strlen(job->log_job.metadata);
        /* We have room to store the hints in the metadata portion of
         * the job header.  We just prepend an h= to the hints list.  The
         * metadata parser will ignore = characters that appear in the value
         * portion of the metadata key/value pair.
         */
        sprintf(m, "h=%s\n", header_hints);
    }
    free(header_hints);

    return;
}

731
/* ********************************************************* */
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void darshan_core_register_module(
734
    darshan_module_id id,
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    char *name,
    struct darshan_module_funcs *funcs,
    int *runtime_mem_limit)
{
739
    struct darshan_core_module* mod;
740

741 742
    DARSHAN_LOCK();

743
    *runtime_mem_limit = 0;
744
    if(!darshan_core_job || (id >= DARSHAN_MAX_MODS))
745 746
    {
        DARSHAN_UNLOCK();
747
        return;
748
    }
749 750

    /* see if this module is already registered */
751
    if(darshan_core_job->mod_array[id])
752
    {
753
        /* if module is already registered just return */
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        /* NOTE: we do not recalculate memory limit here, just set to 0 */
        DARSHAN_UNLOCK();
        return;
757 758
    }

759
    /* this module has not been registered yet, allocate and initialize it */
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    mod = malloc(sizeof(*mod));
    if(!mod)
762 763 764 765
    {
        DARSHAN_UNLOCK();
        return;
    }
766
    memset(mod, 0, sizeof(*mod));
767

768
    mod->id = id;
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    strncpy(mod->name, name, DARSHAN_MOD_NAME_LEN);
    mod->mod_funcs = *funcs;
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    /* register module with darshan */
    darshan_core_job->mod_array[id] = mod;
774

775 776
    /* TODO: something smarter than just 2 MiB per module */
    *runtime_mem_limit = 2 * 1024 * 1024;
777

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    DARSHAN_UNLOCK();

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    return;
}

void darshan_core_lookup_id(
    void *name,
    int len,
    int printable_flag,
    darshan_file_id *id)
{
789
    darshan_file_id tmp_id;
790

791
    if(!darshan_core_job)
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        return;

    /* TODO: what do you do with printable flag? */

    /* hash the input name to get a unique id for this record */
    tmp_id = darshan_hash(name, len, 0);
    
    /* TODO: how to store the filename to hash mapping? */

    *id = tmp_id;
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    return;
}

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double darshan_core_wtime()
{
807
    if(!darshan_core_job)
808 809 810 811
    {
        return(0);
    }

812
    return(DARSHAN_MPI_CALL(PMPI_Wtime)() - darshan_core_job->wtime_offset);
813
}
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/*
 * Local variables:
 *  c-indent-level: 4
 *  c-basic-offset: 4
 * End:
 *
 * vim: ts=8 sts=4 sw=4 expandtab
 */