Lock.h

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00006  * 
00007  * Intel Open Source License 
00008  * 
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00010  * 
00011  * Redistribution and use in source and binary forms, with or without
00012  * modification, are permitted provided that the following conditions are
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00014  * 
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00018  *   Redistributions in binary form must reproduce the above copyright
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00038 
00039 #ifndef _OASYS_LOCK_H_
00040 #define _OASYS_LOCK_H_
00041 
00042 #include <memory>
00043 
00044 #include "Atomic.h"
00045 #include "Thread.h"
00046 
00047 #include "../debug/Logger.h"
00048 #include "../util/Pointers.h"
00049 
00050 namespace oasys {
00051 
00055 class Lock : public Logger {
00056 public:
00060     Lock() : Logger("Lock", "/lock"),
00061              lock_count_(0),
00062              lock_holder_(0),
00063              lock_holder_name_(0), 
00064              scope_lock_count_(0) 
00065     {}
00066 
00071     virtual ~Lock()
00072     {
00073         if (is_locked()) {
00074             ASSERT(is_locked_by_me());
00075             ASSERT(scope_lock_count_ == 0);
00076         }
00077     }
00078     
00084     virtual int lock(const char* lock_user) = 0;
00085 
00091     virtual int unlock() = 0;
00092 
00098     virtual int try_lock(const char* lock_user) = 0;
00099 
00105     bool is_locked()
00106     {
00107         return (lock_count_.value != 0);
00108     }
00109 
00116     bool is_locked_by_me()
00117     {
00118         return is_locked() &&
00119             pthread_equal(lock_holder_, Thread::current());
00120     }
00121 
00122 protected:
00123     friend class ScopeLock;
00124     friend class ScopeLockIf;
00125 
00131     atomic_t lock_count_;
00132     
00143     volatile pthread_t lock_holder_;
00144 
00149     const char* lock_holder_name_;
00150 
00157     int scope_lock_count_;
00158 };
00159 
00173 class ScopeLock {
00174 public:
00175     ScopeLock(Lock*       l,
00176               const char* lock_user)
00177         : lock_(l)
00178     {
00179         do_lock(lock_user);
00180     }
00181 
00182     ScopeLock(const Lock* l,
00183               const char* lock_user)
00184         : lock_(const_cast<Lock*>(l))
00185     {
00186         do_lock(lock_user);
00187     }
00188 
00189     ScopeLock(oasys::ScopePtr<Lock> l,
00190               const char*           lock_user)
00191         : lock_(l.ptr())
00192     {
00193         do_lock(lock_user);
00194     }
00195 
00196     ScopeLock(std::auto_ptr<Lock> l,
00197               const char*         lock_user)
00198         : lock_(l.get())
00199     {
00200         do_lock(lock_user);
00201     }
00202 
00203     void do_lock(const char* lock_user) {
00204         int ret = lock_->lock(lock_user);       
00205         ASSERT(ret == 0);                       
00206         lock_->scope_lock_count_++;
00207     }
00208     
00209     void unlock() {
00210         lock_->scope_lock_count_--;
00211         lock_->unlock();
00212         lock_ = 0;
00213     }
00214     
00215     ~ScopeLock()
00216     {
00217         if (lock_) {
00218             unlock();
00219         }
00220     }
00221     
00222 protected:
00223     Lock* lock_;
00224 };
00225 
00231 class ScopeLockIf {
00232 public:
00233     ScopeLockIf(Lock*       l,
00234                 const char* lock_user,
00235                 bool        use_lock)
00236         : lock_(l), use_lock_(use_lock)
00237     {
00238         do_lock(lock_user);
00239     }
00240 
00241     ScopeLockIf(const Lock* l,
00242                 const char* lock_user,
00243                 bool        use_lock)
00244         : lock_(const_cast<Lock*>(l)), use_lock_(use_lock)
00245     {
00246         do_lock(lock_user);
00247     }
00248 
00249     ScopeLockIf(oasys::ScopePtr<Lock> l,
00250                 const char*           lock_user,
00251                 bool                  use_lock)
00252         : lock_(l.ptr()), use_lock_(use_lock)
00253     {
00254         do_lock(lock_user);
00255     }
00256     
00257     ScopeLockIf(std::auto_ptr<Lock> l,
00258                 const char*         lock_user,
00259                 bool                use_lock)
00260         : lock_(l.get()), use_lock_(use_lock)
00261     {
00262         do_lock(lock_user);
00263     }
00264 
00265     void do_lock(const char* lock_user) {
00266         if (use_lock_) 
00267         {
00268             int ret = lock_->lock(lock_user);       
00269             ASSERT(ret == 0);                       
00270             lock_->scope_lock_count_++;
00271         }
00272     }
00273     
00274     void unlock() {
00275         if (use_lock_) 
00276         {
00277             lock_->scope_lock_count_--;
00278             lock_->unlock();
00279             lock_ = 0;
00280         }
00281     }
00282     
00283     ~ScopeLockIf()
00284     {
00285         if (use_lock_ && lock_) {
00286             unlock();
00287         }
00288     }
00289     
00290 protected:
00291     Lock* lock_;
00292     bool  use_lock_;
00293 };
00294 
00295 } // namespace oasys
00296 
00297 #endif /* LOCK_h */

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