1 // gold-threads.cc -- thread support for gold
2 
3 // Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5 
6 // This file is part of gold.
7 
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12 
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17 
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22 
23 #include "gold.h"
24 
25 #include <cstring>
26 
27 #ifdef ENABLE_THREADS
28 #include <pthread.h>
29 #endif
30 
31 #include "options.h"
32 #include "parameters.h"
33 #include "gold-threads.h"
34 
35 namespace gold
36 {
37 
38 class Condvar_impl_nothreads;
39 
40 // The non-threaded version of Lock_impl.
41 
42 class Lock_impl_nothreads : public Lock_impl
43 {
44  public:
45   Lock_impl_nothreads()
46     : acquired_(false)
47   { }
48 
49   ~Lock_impl_nothreads()
50   { gold_assert(!this->acquired_); }
51 
52   void
53   acquire()
54   {
55     gold_assert(!this->acquired_);
56     this->acquired_ = true;
57   }
58 
59   void
60   release()
61   {
62     gold_assert(this->acquired_);
63     this->acquired_ = false;
64   }
65 
66  private:
67   friend class Condvar_impl_nothreads;
68 
69   bool acquired_;
70 };
71 
72 #ifdef ENABLE_THREADS
73 
74 class Condvar_impl_threads;
75 
76 // The threaded version of Lock_impl.
77 
78 class Lock_impl_threads : public Lock_impl
79 {
80  public:
81   Lock_impl_threads();
82   ~Lock_impl_threads();
83 
84   void acquire();
85 
86   void release();
87 
88 private:
89   // This class can not be copied.
90   Lock_impl_threads(const Lock_impl_threads&);
91   Lock_impl_threads& operator=(const Lock_impl_threads&);
92 
93   friend class Condvar_impl_threads;
94 
95   pthread_mutex_t mutex_;
96 };
97 
98 Lock_impl_threads::Lock_impl_threads()
99 {
100   pthread_mutexattr_t attr;
101   int err = pthread_mutexattr_init(&attr);
102   if (err != 0)
103     gold_fatal(_("pthead_mutextattr_init failed: %s"), strerror(err));
104 #ifdef PTHREAD_MUTEXT_ADAPTIVE_NP
105   err = pthread_mutextattr_settype(&attr, PTHREAD_MUTEX_ADAPTIVE_NP);
106   if (err != 0)
107     gold_fatal(_("pthread_mutextattr_settype failed: %s"), strerror(err));
108 #endif
109 
110   err = pthread_mutex_init (&this->mutex_, &attr);
111   if (err != 0)
112     gold_fatal(_("pthread_mutex_init failed: %s"), strerror(err));
113 
114   err = pthread_mutexattr_destroy(&attr);
115   if (err != 0)
116     gold_fatal(_("pthread_mutexattr_destroy failed: %s"), strerror(err));
117 }
118 
119 Lock_impl_threads::~Lock_impl_threads()
120 {
121   int err = pthread_mutex_destroy(&this->mutex_);
122   if (err != 0)
123     gold_fatal(_("pthread_mutex_destroy failed: %s"), strerror(err));
124 }
125 
126 void
127 Lock_impl_threads::acquire()
128 {
129   int err = pthread_mutex_lock(&this->mutex_);
130   if (err != 0)
131     gold_fatal(_("pthread_mutex_lock failed: %s"), strerror(err));
132 }
133 
134 void
135 Lock_impl_threads::release()
136 {
137   int err = pthread_mutex_unlock(&this->mutex_);
138   if (err != 0)
139     gold_fatal(_("pthread_mutex_unlock failed: %s"), strerror(err));
140 }
141 
142 #endif // defined(ENABLE_THREADS)
143 
144 // Class Lock.
145 
146 Lock::Lock()
147 {
148   if (!parameters->options().threads())
149     this->lock_ = new Lock_impl_nothreads;
150   else
151     {
152 #ifdef ENABLE_THREADS
153       this->lock_ = new Lock_impl_threads;
154 #else
155       gold_unreachable();
156 #endif
157     }
158 }
159 
160 Lock::~Lock()
161 {
162   delete this->lock_;
163 }
164 
165 // The non-threaded version of Condvar_impl.
166 
167 class Condvar_impl_nothreads : public Condvar_impl
168 {
169  public:
170   Condvar_impl_nothreads()
171   { }
172 
173   ~Condvar_impl_nothreads()
174   { }
175 
176   void
177   wait(Lock_impl* li)
178   { gold_assert(static_cast<Lock_impl_nothreads*>(li)->acquired_); }
179 
180   void
181   signal()
182   { }
183 
184   void
185   broadcast()
186   { }
187 };
188 
189 #ifdef ENABLE_THREADS
190 
191 // The threaded version of Condvar_impl.
192 
193 class Condvar_impl_threads : public Condvar_impl
194 {
195  public:
196   Condvar_impl_threads();
197   ~Condvar_impl_threads();
198 
199   void
200   wait(Lock_impl*);
201 
202   void
203   signal();
204 
205   void
206   broadcast();
207 
208  private:
209   // This class can not be copied.
210   Condvar_impl_threads(const Condvar_impl_threads&);
211   Condvar_impl_threads& operator=(const Condvar_impl_threads&);
212 
213   pthread_cond_t cond_;
214 };
215 
216 Condvar_impl_threads::Condvar_impl_threads()
217 {
218   int err = pthread_cond_init(&this->cond_, NULL);
219   if (err != 0)
220     gold_fatal(_("pthread_cond_init failed: %s"), strerror(err));
221 }
222 
223 Condvar_impl_threads::~Condvar_impl_threads()
224 {
225   int err = pthread_cond_destroy(&this->cond_);
226   if (err != 0)
227     gold_fatal(_("pthread_cond_destroy failed: %s"), strerror(err));
228 }
229 
230 void
231 Condvar_impl_threads::wait(Lock_impl* li)
232 {
233   Lock_impl_threads* lit = static_cast<Lock_impl_threads*>(li);
234   int err = pthread_cond_wait(&this->cond_, &lit->mutex_);
235   if (err != 0)
236     gold_fatal(_("pthread_cond_wait failed: %s"), strerror(err));
237 }
238 
239 void
240 Condvar_impl_threads::signal()
241 {
242   int err = pthread_cond_signal(&this->cond_);
243   if (err != 0)
244     gold_fatal(_("pthread_cond_signal failed: %s"), strerror(err));
245 }
246 
247 void
248 Condvar_impl_threads::broadcast()
249 {
250   int err = pthread_cond_broadcast(&this->cond_);
251   if (err != 0)
252     gold_fatal(_("pthread_cond_broadcast failed: %s"), strerror(err));
253 }
254 
255 #endif // defined(ENABLE_THREADS)
256 
257 // Methods for Condvar class.
258 
259 Condvar::Condvar(Lock& lock)
260   : lock_(lock)
261 {
262   if (!parameters->options().threads())
263     this->condvar_ = new Condvar_impl_nothreads;
264   else
265     {
266 #ifdef ENABLE_THREADS
267       this->condvar_ = new Condvar_impl_threads;
268 #else
269       gold_unreachable();
270 #endif
271     }
272 }
273 
274 Condvar::~Condvar()
275 {
276   delete this->condvar_;
277 }
278 
279 } // End namespace gold.
280