libmultipath/log_pthread.c

   1 /*
   2  * Copyright (c) 2005 Christophe Varoqui
   3  */
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <stdarg.h>
   7 #include <syslog.h>
   8 #include <pthread.h>
   9 #include <sys/mman.h>
  10
  11 #include <memory.h>
  12
  13 #include "log_pthread.h"
  14 #include "log.h"
  15 #include "lock.h"
  16
  17 pthread_t log_thr;
  18
  19 pthread_mutex_t logq_lock;
  20 pthread_mutex_t logev_lock;
  21 pthread_cond_t logev_cond;
  22
  23 int logq_running;
  24
  25 void log_safe (int prio, const char * fmt, va_list ap)
  26 {
  27         if (log_thr == (pthread_t)0) {
  28                 syslog(prio, fmt, ap);
  29                 return;
  30         }
  31
  32         pthread_mutex_lock(&logq_lock);
  33         log_enqueue(prio, fmt, ap);
  34         pthread_mutex_unlock(&logq_lock);
  35
  36         pthread_mutex_lock(&logev_lock);
  37         pthread_cond_signal(&logev_cond);
  38         pthread_mutex_unlock(&logev_lock);
  39 }
  40
  41 void log_thread_flush (void)
  42 {
  43         int empty;
  44
  45         do {
  46                 pthread_mutex_lock(&logq_lock);
  47                 empty = log_dequeue(la->buff);
  48                 pthread_mutex_unlock(&logq_lock);
  49                 if (!empty)
  50                         log_syslog(la->buff);
  51         } while (empty == 0);
  52 }
  53
  54 static void flush_logqueue (void)
  55 {
  56         int empty;
  57
  58         do {
  59                 pthread_mutex_lock(&logq_lock);
  60                 empty = log_dequeue(la->buff);
  61                 pthread_mutex_unlock(&logq_lock);
  62                 if (!empty)
  63                         log_syslog(la->buff);
  64         } while (empty == 0);
  65 }
  66
  67 static void * log_thread (void * et)
  68 {
  69         int running;
  70
  71         pthread_mutex_lock(&logev_lock);
  72         logq_running = 1;
  73         pthread_mutex_unlock(&logev_lock);
  74
  75         mlockall(MCL_CURRENT | MCL_FUTURE);
  76         logdbg(stderr,"enter log_thread\n");
  77
  78         while (1) {
  79                 pthread_mutex_lock(&logev_lock);
  80                 pthread_cond_wait(&logev_cond, &logev_lock);
  81                 running = logq_running;
  82                 pthread_mutex_unlock(&logev_lock);
  83                 if (!running)
  84                         break;
  85                 log_thread_flush();
  86         }
  87         return NULL;
  88 }
  89
  90 void log_thread_start (pthread_attr_t *attr)
  91 {
  92         logdbg(stderr,"enter log_thread_start\n");
  93
  94         pthread_mutex_init(&logq_lock, NULL);
  95         pthread_mutex_init(&logev_lock, NULL);
  96         pthread_cond_init(&logev_cond, NULL);
  97
  98         if (log_init("multipathd", 0)) {
  99                 fprintf(stderr,"can't initialize log buffer\n");
 100                 exit(1);
 101         }
 102         if (pthread_create(&log_thr, attr, log_thread, NULL)) {
 103                 fprintf(stderr,"can't start log thread\n");
 104                 exit(1);
 105         }
 106
 107         return;
 108 }
 109
 110 void log_thread_stop (void)
 111 {
 112         logdbg(stderr,"enter log_thread_stop\n");
 113
 114         pthread_mutex_lock(&logev_lock);
 115         logq_running = 0;
 116         pthread_cond_signal(&logev_cond);
 117         pthread_mutex_unlock(&logev_lock);
 118
 119         pthread_mutex_lock(&logq_lock);
 120         pthread_cancel(log_thr);
 121         pthread_mutex_unlock(&logq_lock);
 122         pthread_join(log_thr, NULL);
 123         log_thr = (pthread_t)0;
 124
 125         flush_logqueue();
 126
 127         pthread_mutex_destroy(&logq_lock);
 128         pthread_mutex_destroy(&logev_lock);
 129         pthread_cond_destroy(&logev_cond);
 130
 131         log_close();
 132 }
 133