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.

00279         curr.tid = pthread_self();
00280         <span class="keywordflow">return</span> curr;
00281     }
00282 };
00283 
00284 <span class="preprocessor">#else // NO_PTHREAD</span>
00285 <span class="preprocessor"></span>
00286 <span class="comment">// Non pthread based threads, mutexes, etc.</span>
00287 <span class="comment">// Maps to skeleton  functions, this implementation isn't using threads.</span>
00288 
00289 <span class="keyword">class </span>dbMutex {
00290     <span class="keywordtype">bool</span> initialized;
00291 
00292    <span class="keyword">public</span>:
00293     dbMutex() {
00294         initialized = <span class="keyword">true</span>;
00295     }
00296 
00297     ~dbMutex() { 
00298         initialized = <span class="keyword">false</span>;
00299     }
00300 
00301     <span class="keywordtype">bool</span> isInitialized() { 
00302         <span class="keywordflow">return</span> initialized;
00303     }
00304 
00305     <span class="keywordtype">void</span> lock() {}
00306     <span class="keywordtype">void</span> unlock() {}
00307 };
00308 
00309 <span class="keyword">class </span>dbThread { 
00310   <span class="keyword">public</span>:
00311     <span class="keyword">typedef</span> void (thread_proc* thread_proc_t)(<span class="keywordtype">void</span>*);
00312     <span class="keywordtype">void</span> create(thread_proc_t f, <span class="keywordtype">void</span>* arg) { f(arg); }
00313     <span class="keywordtype">void</span> join() {}
00314     <span class="keywordtype">void</span> detach() {}
00315     <span class="keyword">enum</span> ThreadPriority { 
00316         THR_PRI_LOW, 
00317         THR_PRI_HIGH
00318     };
00319     <span class="keywordtype">void</span> setPriority(ThreadPriority pri) { }
00320     <span class="keyword">static</span> <span class="keywordtype">int</span> numberOfProcessors() { <span class="keywordflow">return</span> 1; }
00321 };
00322 
00323 <span class="keyword">class </span>dbLocalSemaphore { 
00324     <span class="keywordtype">int</span> count;
00325   <span class="keyword">public</span>:
00326     <span class="keywordtype">void</span> wait(dbMutex&amp;) { 
00327         assert (count &gt; 0);
00328         count -= 1;
00329     }
00330     <span class="keywordtype">void</span> signal(<span class="keywordtype">unsigned</span> inc = 1) {
00331         count += inc;
00332     }
00333     <span class="keywordtype">void</span> open(<span class="keywordtype">unsigned</span> initValue = 0) {
00334         count = initValue;
00335     }
00336     <span class="keywordtype">void</span> close() {}
00337 };
00338 
00339 <span class="keyword">class </span>dbLocalEvent { 
00340     <span class="keywordtype">bool</span> signaled;
00341   <span class="keyword">public</span>:
00342     <span class="keywordtype">void</span> wait(dbMutex&amp;) { 
00343         assert(signaled);
00344     }
00345     <span class="keywordtype">bool</span> wait(dbMutex&amp; mutex, time_t timeout) {
00346         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00347     }
00348     <span class="keywordtype">void</span> signal() {
00349         signaled = <span class="keyword">true</span>;
00350     }
00351     <span class="keywordtype">void</span> reset() {
00352         signaled = <span class="keyword">false</span>;
00353     }
00354     <span class="keywordtype">void</span> open(<span class="keywordtype">bool</span> initValue = <span class="keyword">false</span>) {
00355         signaled = initValue;
00356     }
00357     <span class="keywordtype">void</span> close() {}
00358 };
00359 
00360 <span class="keyword">template</span>&lt;<span class="keyword">class</span> T&gt;
00361 <span class="keyword">class </span>dbThreadContext { 
00362     T* value;
00363   <span class="keyword">public</span>:
00364     T* get() { 
00365         <span class="keywordflow">return</span> value;
00366     }
00367     <span class="keywordtype">void</span> set(T* value) { 
00368         this-&gt;value = value;
00369     }
00370     dbThreadContext() { value = NULL; }
00371 };
00372 
00373 
00374 <span class="keyword">class </span>dbProcessId { 
00375     <span class="keywordtype">int</span>       pid;
00376   <span class="keyword">public</span>:
00377     <span class="keywordtype">bool</span> operator != (dbProcessId <span class="keyword">const</span>&amp; other)<span class="keyword"> const </span>{ 
00378         <span class="keywordflow">return</span> pid != other.pid;
00379     }
00380     
00381     <span class="keywordtype">void</span> clear() { 
00382         pid = 0;
00383     }
00384 
00385     <span class="keyword">static</span> dbProcessId getCurrent() {
00386         dbProcessId curr;
00387         curr.pid = getpid();
00388         <span class="keywordflow">return</span> curr;
00389     }
00390 };
00391 
00392 <span class="preprocessor">#endif // NO_PTHREAD</span>
00393 <span class="preprocessor"></span>
00394 
00395 <span class="preprocessor">#define INFINITE (~0U)</span>
00396 <span class="preprocessor"></span>
00397 
00398 <span class="preprocessor">#ifdef USE_POSIX_SEMAPHORES</span>
00399 <span class="preprocessor"></span>
00400 <span class="comment">// Initialization Mutex using Posix based semaphores</span>
00401 <span class="keyword">class </span>dbInitializationMutex { 
00402     sem_t* sem;
00403   <span class="keyword">public</span>: 
00404     <span class="keyword">enum</span> initializationStatus { 
00405         InitializationError, 
00406         AlreadyInitialized,
00407         NotYetInitialized
00408     };
00409     initializationStatus initialize(<span class="keywordtype">char</span> <span class="keyword">const</span>* name) { 
00410         initializationStatus status;
00411         <span class="keywordtype">char</span>* tmp = NULL;
00412         <span class="keywordflow">if</span> (*name != <span class="charliteral">'/'</span>) { 
00413             tmp = <span class="keyword">new</span> <span class="keywordtype">char</span>[strlen(name)+2];
00414             strcpy(tmp+1, name);
00415             *tmp = <span class="charliteral">'/'</span>;
00416             name = tmp;
00417         }
00418         <span class="keywordflow">while</span> (true) {
00419             sem = sem_open(name, 0);
00420             <span class="keywordflow">if</span> (sem == SEM_FAILED) { 
00421                 <span class="keywordflow">if</span> (errno == ENOENT) {
00422                     sem = sem_open(name, O_CREAT|O_EXCL, 0777, 0);
00423                     <span class="keywordflow">if</span> (sem != SEM_FAILED) { 
00424                         status = NotYetInitialized;
00425                         <span class="keywordflow">break</span>;
00426                     } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (errno != EEXIST) { 
00427                         status = InitializationError;
00428                         <span class="keywordflow">break</span>;
00429                     }
00430                 } <span class="keywordflow">else</span> { 
00431                     status = InitializationError;
00432                     <span class="keywordflow">break</span>;
00433                 }
00434             } <span class="keywordflow">else</span> { 
00435                 status = (sem_wait(sem) == 0 &amp;&amp; sem_post(sem) == 0) 
00436                     ? AlreadyInitialized : InitializationError;
00437                 <span class="keywordflow">break</span>;
00438             }
00439         }
00440         <span class="keyword">delete</span>[] tmp;
00441         <span class="keywordflow">return</span> status;
00442     }
00443 
00444     <span class="keywordtype">void</span> done() { 
00445         sem_post(sem);
00446     }
00447     <span class="keywordtype">bool</span> close() {
00448         sem_close(sem);
00449         <span class="keywordflow">return</span> <span class="keyword">false</span>;
00450     }
00451     <span class="keywordtype">void</span> erase() { 
00452         close();
00453     }
00454 };
00455 
00456 <span class="keyword">class </span>dbSemaphore { 
00457   <span class="keyword">protected</span>:
00458     sem_t* sem;
00459   <span class="keyword">public</span>:
00460     <span class="keywordtype">void</span> wait() { 
00461         <span class="keywordtype">int</span> rc = sem_wait(sem);
00462         assert(rc == 0);
00463     }
00464 
00465     <span class="keywordtype">bool</span> wait(<span class="keywordtype">unsigned</span> msec) { 
00466 <span class="preprocessor">#ifdef POSIX_1003_1d</span>
00467 <span class="preprocessor"></span>        <span class="keyword">struct </span>timespec abs_ts;
00468         <span class="keyword">struct </span>timeval  cur_tv;
00469         clock_gettime(CLOCK_REALTIME, &amp;cur_tv);
00470         abs_ts.tv_sec = cur_tv.tv_sec + (msec + cur_tv.tv_usec / 1000) / 1000000; 
00471         abs_ts.tv_nsec = (msec + cur_tv.tv_usec / 1000) % 1000000 * 1000;
00472         <span class="keywordtype">int</span> rc = sem_timedwait(sem, &amp;abs_ts);
00473         <span class="keywordflow">if</span> (rc &lt; 0) { 
00474             assert(errno == ETIMEDOUT);
00475             <span class="keywordflow">return</span> <span class="keyword">false</span>;
00476         }
00477         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00478 <span class="preprocessor">#else </span>
00479 <span class="preprocessor"></span>        <span class="keywordtype">int</span> rc = sem_wait(sem);
00480         assert(rc == 0);
00481         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00482 <span class="preprocessor">#endif  </span>
00483 <span class="preprocessor"></span>    }
00484 
00485     <span class="keywordtype">void</span> signal(<span class="keywordtype">unsigned</span> inc = 1) {
00486         <span class="keywordflow">while</span> (--inc &gt; 0) { 
00487             sem_post(sem);
00488         }
00489     }
00490     <span class="keywordtype">void</span> reset() { 
00491         <span class="keywordflow">while</span> (sem_trywait(sem) == 0);
00492     }    
00493     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, <span class="keywordtype">unsigned</span> initValue = 0) {
00494         <span class="keywordtype">char</span>* tmp = NULL;
00495         <span class="keywordflow">if</span> (*name != <span class="charliteral">'/'</span>) { 
00496             tmp = <span class="keyword">new</span> <span class="keywordtype">char</span>[strlen(name)+2];
00497             strcpy(tmp+1, name);
00498             *tmp = <span class="charliteral">'/'</span>;
00499             name = tmp;
00500         }
00501         sem = sem_open(name, O_CREAT, 0777, initValue);
00502         <span class="keyword">delete</span>[] tmp;
00503         <span class="keywordflow">return</span> sem != NULL; 
00504     }
00505     <span class="keywordtype">void</span> close() {
00506         sem_close(sem);
00507     }
00508     <span class="keywordtype">void</span> erase() { 
00509         close();
00510     }
00511 };
00512 
00513 <span class="keyword">class </span>dbEvent : <span class="keyword">public</span> dbSemaphore { 
00514   <span class="keyword">public</span>:
00515     <span class="keywordtype">void</span> wait() { 
00516         dbSemaphore::wait();
00517         sem_post(sem);
00518     }
00519     <span class="keywordtype">bool</span> wait(<span class="keywordtype">unsigned</span> msec) { 
00520         <span class="keywordflow">if</span> (dbSemaphore::wait(msec)) { 
00521             sem_post(sem);
00522             <span class="keywordflow">return</span> <span class="keyword">true</span>;
00523         }
00524         <span class="keywordflow">return</span> <span class="keyword">false</span>;
00525     }
00526     <span class="keywordtype">void</span> signal() {
00527         <span class="keywordflow">while</span> (sem_trywait(sem) == 0);
00528         sem_post(sem);
00529     }
00530     <span class="keywordtype">void</span> reset() {
00531         <span class="keywordflow">while</span> (sem_trywait(sem) == 0);
00532     }
00533     <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>) {
00534         <span class="keywordflow">return</span> dbSemaphore::open(name, (<span class="keywordtype">int</span>)signaled);
00535     }
00536 };
00537 <span class="preprocessor">#else // USE_POSIX_SEMAPHORES</span>
00538 <span class="preprocessor"></span>
00539 <span class="keyword">class </span>FASTDB_DLL_ENTRY dbWatchDog { 
00540     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>* name, <span class="keywordtype">int</span> flags);
00541   <span class="keyword">public</span>:
00542     <span class="keywordtype">bool</span> watch();
00543     <span class="keywordtype">void</span> close(); 
00544     <span class="keywordtype">bool</span> open(<span class="keywordtype">char</span> <span class="keyword">const</span>* name);
00545     <span class="keywordtype">bool</span> create(<span class="keywordtype">char</span> <span class="keyword">const</span>* name);
00546     <span class="keywordtype">int</span> id;
00547 };
00548 
00549 <span class="comment">// Define local implemenation of InitializationMutex in sync.cpp</span>
00550 <span class="keyword">class </span>dbInitializationMutex { 
00551     <span class="keywordtype">int</span> semid;
00552   <span class="keyword">public</span>: 
00553     <span class="keyword">enum</span> initializationStatus { 
00554         InitializationError, 
00555         AlreadyInitialized,
00556         NotYetInitialized
00557     };
00558     initializationStatus initialize(<span class="keywordtype">char</span> <span class="keyword">const</span>* name);
00559     <span class="keywordtype">void</span> done(); 
00560     <span class="keywordtype">bool</span> close();
00561     <span class="keywordtype">void</span> erase();
00562 };
00563