NSPR 2.0: Thread management

      1 /* Copyright © 1998 Netscape Communications Corporation */
      2
      3 #include "prinit.h"
      4 #include "prlock.h"
      5 #include "prcvar.h"
      6 #include "prmem.h"
      7 #include "prinrval.h"
      8 #include "prlog.h"
      9 #include "prthread.h"
     10 #include "prprf.h"
     11 #include "plerror.h"
     12
     13 #define INNER_LOOPS 100
     14 #define DEFAULT_LOOPS 100
     15 #define DEFAULT_THREADS 10
     16
     17 typedef struct Shared
     18 {
     19     PRLock *ml;
     20     PRCondVar *cv;
     21     PRBool twiddle;
     22     PRThread *thread;
     23     struct Shared *next;
     24 } Shared;
     25
     26 static PRFileDesc *debug_out = NULL;
     27 static PRBool debug_mode = PR_FALSE, verbosity = PR_TRUE, failed = PR_FALSE;
     28 static Shared home;
     29
     30 static void Help(void);
     31 static void PR_CALLBACK Notified(void *arg);
     32 static PRIntn PR_CALLBACK Switch(PRIntn argc, char **argv);
     33
     34 /* Root function for the threads in this sample (except primordial thread, which runs main) */
     35 static void PR_CALLBACK Notified(void *arg)
     36 {
     37     Shared *shared = arg;
     38     PRStatus status = PR_SUCCESS;
     39     while (PR_SUCCESS == status)
     40     {
     41         PR_Lock(shared->ml);
     42         while (shared->twiddle && (PR_SUCCESS == status))
     43             status = PR_WaitCondVar(shared->cv, PR_INTERVAL_NO_TIMEOUT);
     44         if (verbosity) PR_fprintf(debug_out, "+");
     45         shared->twiddle = PR_TRUE;
     46         shared->next->twiddle = PR_FALSE;
     47         PR_NotifyCondVar(shared->next->cv);
     48         PR_Unlock(shared->ml);
     49     }
     50 }  /* Notified */
     51
     52 static PRIntn PR_CALLBACK Switch(PRIntn argc, char **argv)
     53 {
     54     PRStatus status;
     55     PRBool help = PR_FALSE;
     56     PRUintn concurrency = 1;
     57     Shared *shared, *link;
     58     PRIntervalTime timein, timeout;
     59     PRBool global_threads = PR_FALSE;
     60     PRThreadScope thread_scope = PR_LOCAL_THREAD;
     61     PRUintn thread_count, inner_count, loop_count, average;
     62     PRUintn thread_limit = DEFAULT_THREADS, loop_limit = DEFAULT_LOOPS;
     63
     64     if (help) return -1;
     65
     66     if (PR_TRUE == debug_mode)
     67     {
     68         debug_out = PR_STDOUT;
     69         PR_fprintf(debug_out, "Test parameters\n");
     70         PR_fprintf(debug_out, "\tThreads involved: %d\n", thread_limit);
     71         PR_fprintf(debug_out, "\tIteration limit: %d\n", loop_limit);
     72         PR_fprintf(debug_out, "\tConcurrency: %d\n", concurrency);
     73         PR_fprintf(
     74             debug_out, "\tThread type: %s\n",
     75             (PR_GLOBAL_THREAD == thread_scope) ? "GLOBAL" : "LOCAL");
     76     }
     77
     78     PR_SetConcurrency(concurrency);
     79
     80 /*'home' is "Shared" object for the primordial thread, at the end of the chain. */
     81     link = &home;
     82     home.ml = PR_NewLock();
     83     home.cv = PR_NewCondVar(home.ml);
     84     home.twiddle = PR_TRUE;
     85     home.next = NULL;
     86     timeout = 0;
     87
     88 /* Create "thread_limit" number of additional threads, each with its own "Shared" object. */
     89     for (thread_count = 1; thread_count <= thread_limit; ++thread_count)
     90     {
     91         shared = PR_NEWZAP(Shared);
     92         shared->ml = home.ml;
     93         shared->cv = PR_NewCondVar(home.ml);
     94         shared->twiddle = PR_TRUE;
     95         shared->next = link;
     96         link = shared;
     97         shared->thread = PR_CreateThread(
     98             PR_USER_THREAD, Notified, shared,
     99             PR_PRIORITY_HIGH, thread_scope,
    100             PR_JOINABLE_THREAD, 0);
    101         PR_ASSERT(shared->thread != NULL);
    102         if (NULL == shared->thread)
    103             failed = PR_TRUE;
    104     }
    105
    106 /* "Shared" now points to the head of the chain, and "home" is the tail of the chain. */
    107     for (loop_count = 1; loop_count <= loop_limit; ++loop_count)
    108     {
    109         timein = PR_IntervalNow();
    110         for (inner_count = 0; inner_count < INNER_LOOPS; ++inner_count)
    111         {
    112             PR_Lock(home.ml);
    113             home.twiddle = PR_TRUE;
    114             shared->twiddle = PR_FALSE;
    115             PR_NotifyCondVar(shared->cv);
    116             while (home.twiddle)
    117             {
    118                 status = PR_WaitCondVar(home.cv, PR_INTERVAL_NO_TIMEOUT);
    119                 if (PR_FAILURE == status)
    120                     failed = PR_TRUE;
    121             }
    122             PR_Unlock(home.ml);
    123         }
    124         timeout += (PR_IntervalNow() - timein);
    125     }
    126
    127     if (debug_mode)
    128     {
    129         average = PR_IntervalToMicroseconds(timeout)
    130             / (INNER_LOOPS * loop_limit * thread_count);
    131         PR_fprintf(
    132             debug_out, "Average switch times %d usecs for %d threads\n",
    133             average, thread_limit);
    134     }
    135     /* Test completed. Remainder of sample cleanly shuts down the test. */
    136     link = shared;
    137     for (thread_count = 1; thread_count <= thread_limit; ++thread_count)
    138     {
    139         if (&home == link) break;
    140         status = PR_Interrupt(link->thread);
    141         if (PR_SUCCESS != status)
    142         {
    143             failed = PR_TRUE;
    144             if (debug_mode)
    145                 PL_FPrintError(debug_out, "Failed to interrupt");
    146         }
    147         link = link->next;
    148     }
    149
    150     for (thread_count = 1; thread_count <= thread_limit; ++thread_count)
    151     {
    152         link = shared->next;
    153         status = PR_JoinThread(shared->thread);
    154         if (PR_SUCCESS != status)
    155         {
    156             failed = PR_TRUE;
    157             if (debug_mode)
    158                 PL_FPrintError(debug_out, "Failed to join");
    159         }
    160         PR_DestroyCondVar(shared->cv);
    161         PR_DELETE(shared);
    162         if (&home == link) break;
    163         shared = link;
    164     }
    165     PR_DestroyCondVar(home.cv);
    166     PR_DestroyLock(home.ml);
    167
    168     PR_fprintf(PR_STDOUT, ((failed) ? "FAILED\n" : "PASSED\n"));
    169     return ((failed) ? 1 : 0);
    170 }  /* Switch */
    171
    172 PRIntn main(PRIntn argc, char **argv)
    173 {
    174     PRIntn result;
    175     PR_STDIO_INIT();
    176     result = PR_Initialize(Switch, argc, argv, 0);
    177     return result;
    178 }  /* main */
    179
    180 /* switch.c */