sync__unix_8h-source.html

俄罗斯牛人KK的作品,著名的ORDBMS,这里上传最新的3.39版本源代码.希望了解对象关系数据库的同好,请不要错过.

00564 
00565 <span class="keyword">class </span>dbSemaphore { 
00566     <span class="keywordtype">int</span> s;
00567   <span class="keyword">public</span>:
00568     <span class="keywordtype">bool</span> wait(<span class="keywordtype">unsigned</span> msec = INFINITE);
00569     <span class="keywordtype">void</span> signal(<span class="keywordtype">unsigned</span> inc = 1);
00570     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, <span class="keywordtype">unsigned</span> initValue = 0);
00571     <span class="keywordtype">void</span> reset();
00572     <span class="keywordtype">void</span> close();
00573     <span class="keywordtype">void</span> erase();
00574 };
00575 
00576 <span class="keyword">class </span>dbEvent { 
00577     <span class="keywordtype">int</span> e;
00578   <span class="keyword">public</span>:
00579     <span class="keywordtype">bool</span> wait(<span class="keywordtype">unsigned</span> msec = INFINITE);
00580     <span class="keywordtype">void</span> signal();
00581     <span class="keywordtype">void</span> reset();
00582     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, <span class="keywordtype">bool</span> signaled = <span class="keyword">false</span>);
00583     <span class="keywordtype">void</span> close();
00584     <span class="keywordtype">void</span> erase();
00585 };
00586 <span class="preprocessor">#endif // USE_POSIX_SEMAPHORES</span>
00587 <span class="preprocessor"></span>
00588 
00589 <span class="comment">// Define dbSharedObject and dbSharedMemory</span>
00590 <span class="preprocessor">#if defined(USE_POSIX_MMAP) &amp;&amp; USE_POSIX_MMAP</span>
00591 <span class="preprocessor"></span>
00592 <span class="comment">// For POSIX dbSharedObject, we use mmap()</span>
00593 <span class="keyword">template</span>&lt;<span class="keyword">class</span> T&gt;
00594 <span class="keyword">class </span>dbSharedObject { 
00595     <span class="keywordtype">char</span>* name;
00596     T*  ptr;
00597     <span class="keywordtype">int</span> fd;
00598   <span class="keyword">public</span>:
00599 
00600     dbSharedObject() { 
00601         name = NULL;
00602         ptr = NULL;
00603         fd = -1;
00604     }
00605 
00606     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span>* fileName) { 
00607         <span class="keyword">delete</span>[] name;
00608         name = <span class="keyword">new</span> <span class="keywordtype">char</span>[strlen(fileName) + 1];
00609         strcpy(name, fileName);
00610         fd = ::open(fileName, O_RDWR|O_CREAT, 0777);
00611         <span class="keywordflow">if</span> (fd &lt; 0) { 
00612             <span class="keywordflow">return</span> <span class="keyword">false</span>;
00613         }
00614         <span class="keywordflow">if</span> (ftruncate(fd, <span class="keyword">sizeof</span>(T)) &lt; 0) {
00615             ::close(fd);
00616             <span class="keywordflow">return</span> <span class="keyword">false</span>;
00617         }
00618         ptr = (T*)mmap(NULL,
00619                        DOALIGN(<span class="keyword">sizeof</span>(T), 4096),
00620                        PROT_READ|PROT_WRITE,
00621                        MAP_SHARED,
00622                        fd,
00623                        0);
00624         <span class="keywordflow">if</span> (ptr == MAP_FAILED) { 
00625             ptr = NULL;
00626             ::close(fd);
00627             <span class="keywordflow">return</span> <span class="keyword">false</span>;
00628         }
00629         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00630     }
00631 
00632     T* get() { <span class="keywordflow">return</span> ptr; }
00633 
00634     <span class="keywordtype">void</span> close() { 
00635         <span class="keywordflow">if</span> (ptr != NULL) { 
00636             munmap((<span class="keywordtype">char</span>*)ptr, DOALIGN(<span class="keyword">sizeof</span>(T), 4096));
00637         }
00638         <span class="keywordflow">if</span> (fd &gt; 0) { 
00639             ::close(fd);
00640         }
00641     }
00642     <span class="keywordtype">void</span> erase() {
00643         close();
00644         unlink(name);   
00645     }  
00646 
00647     ~dbSharedObject() { 
00648         <span class="keyword">delete</span>[] name;
00649     }
00650 };
00651 
00652 <span class="preprocessor">#else // USE_POSIX_MMAP</span>
00653 <span class="preprocessor"></span>
00654 <span class="comment">// Non POSIX, internal implementations of SharedMemory and SharedObject</span>
00655 <span class="keyword">extern</span> <span class="keywordtype">char</span> <span class="keyword">const</span>* keyFileDir; <span class="comment">// default value: "/tmp/" </span>
00656 <span class="keyword">class </span>dbSharedMemory { 
00657   <span class="keyword">protected</span>:
00658     <span class="keywordtype">char</span>*  ptr;
00659     <span class="keywordtype">int</span>    shm;
00660 
00661   <span class="keyword">public</span>:
00662     <span class="keywordtype">bool</span>  open(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, size_t size); 
00663     <span class="keywordtype">void</span>  close();
00664     <span class="keywordtype">void</span>  erase(); 
00665     <span class="keywordtype">char</span>* get_base() { 
00666         <span class="keywordflow">return</span> ptr;
00667     }
00668 };
00669 
00670 <span class="keyword">template</span>&lt;<span class="keyword">class</span> T&gt;
00671 <span class="keyword">class </span>dbSharedObject : <span class="keyword">public</span> dbSharedMemory { 
00672   <span class="keyword">public</span>:
00673     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span>* name) { 
00674         <span class="keywordflow">return</span> dbSharedMemory::open(name, <span class="keyword">sizeof</span>(T));
00675     }
00676     T* get() { <span class="keywordflow">return</span> (T*)ptr; }
00677 };
00678 
00679 <span class="preprocessor">#endif</span>
00680 <span class="preprocessor"></span>
00682 <span class="comment">// Define dBGlobalCriticalSection for various platforms</span>
00683 
00684 <span class="comment">// QNX uses a pthread based mutex for its implementation</span>
00685 <span class="comment">//     Use only if pthread support is also enabled, else we'll use the default case</span>
00686 <span class="preprocessor">#if defined(__QNX__) &amp;&amp; !defined(NO_PTHREADS)</span>
00687 <span class="preprocessor"></span><span class="keyword">typedef</span> pthread_mutex_t sharedsem_t;
00688 
00689 <span class="keyword">class </span>dbGlobalCriticalSection { 
00690     pthread_mutexattr_t attr;
00691     sharedsem_t* sem;
00692   <span class="keyword">public</span>:
00693     <span class="keywordtype">void</span> enter() {
00694         <span class="keywordtype">int</span> rc = pthread_mutex_lock(sem);
00695         assert(rc == 0);
00696     }
00697     <span class="keywordtype">void</span> leave() { 
00698         <span class="keywordtype">int</span> rc = pthread_mutex_unlock(sem);
00699         assert(rc == 0);
00700     }
00701     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>*, sharedsem_t* shr) { 
00702         sem = shr;
00703         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00704     }
00705     <span class="keywordtype">bool</span> create(<span class="keywordtype">char</span> <span class="keyword">const</span>*, sharedsem_t* shr) { 
00706         sem = shr;
00707         pthread_mutexattr_init(&amp;attr);
00708         pthread_mutexattr_setpshared(&amp;attr, PTHREAD_PROCESS_SHARED);
00709         pthread_mutexattr_setrecursive(&amp;attr, PTHREAD_RECURSIVE_ENABLE);
00710         pthread_mutex_init(sem, &amp;attr);
00711         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00712     }
00713     <span class="keywordtype">void</span> close() {}
00714     <span class="keywordtype">void</span> erase() {
00715         pthread_mutex_destroy(sem);
00716     }
00717 };
00718 
00719 
00720 <span class="preprocessor">#elif defined(__osf__) &amp;&amp; !defined(RECOVERABLE_CRITICAL_SECTION)</span>
00721 <span class="preprocessor"></span><span class="comment">// OSF uses "shared memory semaphores", located within a region mapped with mmap().</span>
00722 <span class="preprocessor">#include &lt;errno.h&gt;</span>
00723 <span class="keyword">typedef</span> msemaphore sharedsem_t;
00724 
00725 <span class="keyword">class </span>dbGlobalCriticalSection { 
00726     sharedsem_t* sem;
00727   <span class="keyword">public</span>:
00728     <span class="keywordtype">void</span> enter() { 
00729         <span class="keywordtype">int</span> rc;
00730         <span class="keywordflow">while</span> ((rc = msem_lock(sem, 0)) &lt; 0 &amp;&amp; errno == EINTR);
00731         assert(rc == 0);
00732     }
00733     <span class="keywordtype">void</span> leave() { 
00734         <span class="keywordtype">int</span> rc = msem_unlock(sem, 0);
00735         assert(rc == 0);        
00736     }
00737     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>*, sharedsem_t* shr) { 
00738         sem = shr;
00739         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00740     }
00741     <span class="keywordtype">bool</span> create(<span class="keywordtype">char</span> <span class="keyword">const</span>*, sharedsem_t* shr) { 
00742         sem = shr;
00743         msem_init(shr, MSEM_UNLOCKED);
00744         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00745     }
00746     <span class="keywordtype">void</span> close() {}
00747     <span class="keywordtype">void</span> erase() {
00748         msem_remove(sem);
00749     }
00750 };
00751         
00752 
00753 <span class="preprocessor">#elif defined(__sun) &amp;&amp; !defined(RECOVERABLE_CRITICAL_SECTION)</span>
00754 <span class="preprocessor"></span><span class="comment">// Sun uses the Solaris style semaphore implemenation (sema_init(), sema_post())</span>
00755 <span class="preprocessor">#include &lt;synch.h&gt;</span>
00756 <span class="preprocessor">#include &lt;errno.h&gt;</span>
00757 <span class="keyword">typedef</span> sema_t sharedsem_t;
00758 
00759 <span class="keyword">class </span>dbGlobalCriticalSection { 
00760     sharedsem_t* sem;
00761   <span class="keyword">public</span>:
00762     <span class="keywordtype">void</span> enter() { 
00763         <span class="keywordtype">int</span> rc;
00764         <span class="keywordflow">while</span> ((rc = sema_wait(sem)) &lt; 0 &amp;&amp; errno == EINTR);
00765         assert(rc == 0);
00766     }
00767     <span class="keywordtype">void</span> leave() { 
00768         <span class="keywordtype">int</span> rc = sema_post(sem);
00769         assert(rc == 0);
00770     }
00771     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>*, sharedsem_t* shr) { 
00772         sem = shr;
00773         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00774     }
00775     <span class="keywordtype">bool</span> create(<span class="keywordtype">char</span> <span class="keyword">const</span>*, sharedsem_t* shr) { 
00776         sem = shr;
00777         <span class="keywordflow">return</span> sema_init(shr, 1, USYNC_PROCESS, NULL) == 0;
00778     }
00779     <span class="keywordtype">void</span> close() {}
00780     <span class="keywordtype">void</span> erase() {
00781         sema_destroy(sem);
00782     }
00783 };
00784 
00785 <span class="preprocessor">#elif defined(USE_POSIX_SEMAPHORES) &amp;&amp; !defined(RECOVERABLE_CRITICAL_SECTION)</span>
00786 <span class="preprocessor"></span><span class="comment">// Everyone else uses the POSIX style semaphores (sem_wait(), sem_post(), etc) if defined</span>
00787 <span class="keyword">typedef</span> sem_t sharedsem_t;
00788 
00789 <span class="keyword">class </span>dbGlobalCriticalSection { 
00790     sharedsem_t* sem;
00791 
00792   <span class="keyword">public</span>:
00793     <span class="keywordtype">void</span> enter() { 
00794         <span class="keywordtype">int</span> rc = sem_wait(sem);
00795         assert(rc == 0);
00796     }
00797     <span class="keywordtype">void</span> leave() { 
00798         <span class="keywordtype">int</span> rc = sem_post(sem);
00799         assert(rc == 0);
00800     }
00801     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, sharedsem_t* shr) { 
00802         sem = shr;
00803         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00804     }
00805 
00806     <span class="keywordtype">bool</span> create(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, sharedsem_t* shr) {   
00807         sem = shr;
00808         <span class="keywordflow">return</span> sem_init(sem, 1, 1) == 0;
00809     }
00810 
00811     <span class="keywordtype">void</span> close() {}
00812     <span class="keywordtype">void</span> erase() { 
00813         sem_destroy(sem);
00814     }
00815 };
00816 
00817 <span class="preprocessor">#else</span>
00818 <span class="preprocessor"></span>
00819 <span class="preprocessor">#define USE_LOCAL_CS_IMPL</span>
00820 <span class="preprocessor"></span>
00821 <span class="comment">// Lastly, use the local implementation</span>
00822 <span class="keyword">typedef</span> <span class="keywordtype">long</span> sharedsem_t;
00823 
00824 <span class="keyword">class </span>dbGlobalCriticalSection { 
00825     <span class="keywordtype">int</span>          semid;
00826     sharedsem_t* count;
00827 
00828   <span class="keyword">public</span>:
00829     <span class="keywordtype">void</span> enter(); 
00830     <span class="keywordtype">void</span> leave();
00831     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, sharedsem_t* shr);
00832     <span class="keywordtype">bool</span> create(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, sharedsem_t* shr);
00833     <span class="keywordtype">void</span> close() {}
00834     <span class="keywordtype">void</span> erase();
00835 };
00836 <span class="preprocessor">#endif //dbGLobalCriticalSection switch</span>
00837 <span class="preprocessor"></span>
00838 END_FASTDB_NAMESPACE
00839 
00840 <span class="preprocessor">#endif //__SYNC_UNIX_H__</span>
</pre></div><hr><address style="align: right;"><small>Generated on Mon Oct 23 13:23:58 2006 for FastDB by
<a href="http://www.doxygen.org/index.html">
<img src="doxygen.png" alt="doxygen" align="middle" border=0 
width=110 height=53></a>1.2.18 </small></address>
</body>
</html>