lib/base/thread.cpp

   1 #include <lib/base/thread.h>
   2
   3 #include <stdio.h>
   4 #include <unistd.h>
   5 #include <assert.h>
   6 #include <lib/base/eerror.h>
   7
   8 void eThread::thread_completed(void *ptr)
   9 {
  10         eThread *p = (eThread*) ptr;
  11         p->m_alive = 0;
  12
  13                 /* recover state */
  14         if (!p->m_state.value())
  15         {
  16                 p->m_state.up();
  17                 assert(p->m_state.value() == 1);
  18         }
  19
  20         p->thread_finished();
  21 }
  22
  23 void *eThread::wrapper(void *ptr)
  24 {
  25         eThread *p = (eThread*)ptr;
  26         pthread_cleanup_push(thread_completed, (void*)p);
  27         p->thread();
  28         pthread_exit(0);
  29         pthread_cleanup_pop(1);
  30         return 0;
  31 }
  32
  33 eThread::eThread()
  34         : the_thread(0), m_alive(0)
  35 {
  36 }
  37
  38 int eThread::runAsync(int prio, int policy)
  39 {
  40         eDebug("before: %d", m_state.value());
  41                 /* the thread might already run. */
  42         if (sync())
  43                 return -1;
  44
  45         eDebug("after: %d", m_state.value());
  46         assert(m_state.value() == 1); /* sync postconditions */
  47         assert(!m_alive);
  48         m_state.down();
  49
  50         m_alive = 1;
  51
  52                 /* start thread. */
  53         pthread_attr_t attr;
  54         pthread_attr_init(&attr);
  55
  56         if (prio || policy)
  57         {
  58                 struct sched_param p;
  59                 p.__sched_priority=prio;
  60                 pthread_attr_setschedpolicy(&attr, policy);
  61                 pthread_attr_setschedparam(&attr, &p);
  62         }
  63
  64         if (pthread_create(&the_thread, &attr, wrapper, this))
  65         {
  66                 pthread_attr_destroy(&attr);
  67                 m_alive = 0;
  68                 eDebug("couldn't create new thread");
  69                 return -1;
  70         }
  71
  72         pthread_attr_destroy(&attr);
  73         return 0;
  74 }
  75
  76 int eThread::run(int prio, int policy)
  77 {
  78         if (runAsync(prio, policy))
  79                 return -1;
  80         sync();
  81         return 0;
  82 }
  83
  84 eThread::~eThread()
  85 {
  86         kill();
  87 }
  88
  89 int eThread::sync(void)
  90 {
  91         int res;
  92         m_state.down(); /* this might block */
  93         res = m_alive;
  94         assert(m_state.value() == 0);
  95         m_state.up();
  96         return res; /* 0: thread is guaranteed not to run. 1: state unknown. */
  97 }
  98
  99 void eThread::sendSignal(int sig)
 100 {
 101         if (m_alive)
 102                 pthread_kill(the_thread, sig);
 103         else
 104                 eDebug("send signal to non running thread");
 105 }
 106
 107 void eThread::kill(bool sendcancel)
 108 {
 109         if (!the_thread) /* already joined */
 110                 return;
 111
 112         if (sync() && sendcancel)
 113         {
 114                 eDebug("send cancel to thread");
 115                 pthread_cancel(the_thread);
 116         }
 117         eDebug("thread joined %d", pthread_join(the_thread, 0));
 118         the_thread = 0;
 119 }
 120
 121 void eThread::hasStarted()
 122 {
 123         assert(!m_state.value());
 124         m_state.up();
 125 }