Condition.cpp revision 1b584ebc1de8b50fe375cffb5fb33ad13be10046 
1//===-- Condition.cpp -------------------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include <errno.h>
11
12#include "lldb/Host/Condition.h"
13#include "lldb/Host/TimeValue.h"
14
15
16using namespace lldb_private;
17
18//----------------------------------------------------------------------
19// Default constructor
20//
21// The default constructor will initialize a new pthread condition
22// and maintain the condition in the object state.
23//----------------------------------------------------------------------
24Condition::Condition () :
25    m_condition()
26{
27    ::pthread_cond_init (&m_condition, NULL);
28}
29
30//----------------------------------------------------------------------
31// Destructor
32//
33// Destroys the pthread condition that the object owns.
34//----------------------------------------------------------------------
35Condition::~Condition ()
36{
37    ::pthread_cond_destroy (&m_condition);
38}
39
40//----------------------------------------------------------------------
41// Unblock all threads waiting for a condition variable
42//----------------------------------------------------------------------
43int
44Condition::Broadcast ()
45{
46    return ::pthread_cond_broadcast (&m_condition);
47}
48
49//----------------------------------------------------------------------
50// Get accessor to the pthread condition object
51//----------------------------------------------------------------------
52pthread_cond_t *
53Condition::GetCondition ()
54{
55    return &m_condition;
56}
57
58//----------------------------------------------------------------------
59// Unblocks one thread waiting for the condition variable
60//----------------------------------------------------------------------
61int
62Condition::Signal ()
63{
64    return ::pthread_cond_signal (&m_condition);
65}
66
67//----------------------------------------------------------------------
68// The Wait() function atomically blocks the current thread
69// waiting on the owned condition variable, and unblocks the mutex
70// specified by "mutex".  The waiting thread unblocks only after
71// another thread calls Signal(), or Broadcast() with the same
72// condition variable, or if "abstime" is valid (non-NULL) this
73// function will return when the system time reaches the time
74// specified in "abstime". If "abstime" is NULL this function will
75// wait for an infinite amount of time for the condition variable
76// to be signaled or broadcasted.
77//
78// The current thread re-acquires the lock on "mutex".
79//----------------------------------------------------------------------
80int
81Condition::Wait (Mutex &mutex, const TimeValue *abstime, bool *timed_out)
82{
83    int err = 0;
84    do
85    {
86        if (abstime && abstime->IsValid())
87        {
88            struct timespec abstime_ts = abstime->GetAsTimeSpec();
89            err = ::pthread_cond_timedwait (&m_condition, mutex.GetMutex(), &abstime_ts);
90        }
91        else
92            err = ::pthread_cond_wait (&m_condition, mutex.GetMutex());
93    } while (err == EINTR);
94
95    if (timed_out != NULL)
96    {
97        if (err == ETIMEDOUT)
98            *timed_out = true;
99        else
100            *timed_out = false;
101    }
102
103
104    return err;
105}
106
107