src/thread/thread.h

   1 /* $Id: thread.h 26349 2014-02-16 21:37:05Z frosch $ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file thread.h Base of all threads. */
  11
  12 #ifndef THREAD_H
  13 #define THREAD_H
  14
  15 /** Definition of all thread entry functions. */
  16 typedef void (*OTTDThreadFunc)(void *);
  17
  18 /** Signal used for signalling we knowingly want to end the thread. */
  19 class OTTDThreadExitSignal { };
  20
  21 /**
  22  * A Thread Object which works on all our supported OSes.
  23  */
  24 class ThreadObject {
  25 public:
  26         /**
  27          * Virtual destructor to allow 'delete' operator to work properly.
  28          */
  29         virtual ~ThreadObject() {};
  30
  31         /**
  32          * Exit this thread.
  33          */
  34         virtual bool Exit() = 0;
  35
  36         /**
  37          * Join this thread.
  38          */
  39         virtual void Join() = 0;
  40
  41         /**
  42          * Create a thread; proc will be called as first function inside the thread,
  43          *  with optional params.
  44          * @param proc The procedure to call inside the thread.
  45          * @param param The params to give with 'proc'.
  46          * @param thread Place to store a pointer to the thread in. May be NULL.
  47          * @param name A name for the thread. May be NULL.
  48          * @return True if the thread was started correctly.
  49          */
  50         static bool New(OTTDThreadFunc proc, void *param, ThreadObject **thread = NULL, const char *name = NULL);
  51 };
  52
  53 /**
  54  * Cross-platform Mutex
  55  */
  56 class ThreadMutex {
  57 public:
  58         /**
  59          * Create a new mutex.
  60          */
  61         static ThreadMutex *New();
  62
  63         /**
  64          * Virtual Destructor to avoid compiler warnings.
  65          */
  66         virtual ~ThreadMutex() {};
  67
  68         /**
  69          * Begin the critical section
  70          * @param allow_recursive Whether recursive locking is intentional.
  71          *                        If false, NOT_REACHED() will be called when the mutex is already locked
  72          *                        by the current thread.
  73          */
  74         virtual void BeginCritical(bool allow_recursive = false) = 0;
  75
  76         /**
  77          * End of the critical section
  78          * @param allow_recursive Whether recursive unlocking is intentional.
  79          *                        If false, NOT_REACHED() will be called when the mutex was locked more
  80          *                        than once by the current thread.
  81          */
  82         virtual void EndCritical(bool allow_recursive = false) = 0;
  83
  84         /**
  85          * Wait for a signal to be send.
  86          * @pre You must be in the critical section.
  87          * @note While waiting the critical section is left.
  88          * @post You will be in the critical section.
  89          */
  90         virtual void WaitForSignal() = 0;
  91
  92         /**
  93          * Send a signal and wake the 'thread' that was waiting for it.
  94          */
  95         virtual void SendSignal() = 0;
  96 };
  97
  98 /**
  99  * Simple mutex locker to keep a mutex locked until the locker goes out of scope.
 100  */
 101 class ThreadMutexLocker {
 102 public:
 103         /**
 104          * Lock the mutex and keep it locked for the life time of this object.
 105          * @param mutex Mutex to be locked.
 106          */
 107         ThreadMutexLocker(ThreadMutex *mutex) : mutex(mutex) { mutex->BeginCritical(); }
 108
 109         /**
 110          * Unlock the mutex.
 111          */
 112         ~ThreadMutexLocker() { this->mutex->EndCritical(); }
 113
 114 private:
 115         ThreadMutexLocker(const ThreadMutexLocker &) { NOT_REACHED(); }
 116         ThreadMutexLocker &operator=(const ThreadMutexLocker &) { NOT_REACHED(); return *this; }
 117         ThreadMutex *mutex;
 118 };
 119
 120 /**
 121  * Get number of processor cores in the system, including HyperThreading or similar.
 122  * @return Total number of processor cores.
 123  */
 124 uint GetCPUCoreCount();
 125
 126 #endif /* THREAD_H */