1 mike  1.2 //%2006////////////////////////////////////////////////////////////////////////
  2           //
  3           // Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
  4           // Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
  5           // Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
  6           // IBM Corp.; EMC Corporation, The Open Group.
  7           // Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
  8           // IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
  9           // Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
 10           // EMC Corporation; VERITAS Software Corporation; The Open Group.
 11           // Copyright (c) 2006 Hewlett-Packard Development Company, L.P.; IBM Corp.;
 12           // EMC Corporation; Symantec Corporation; The Open Group.
 13           //
 14           // Permission is hereby granted, free of charge, to any person obtaining a copy
 15           // of this software and associated documentation files (the "Software"), to
 16           // deal in the Software without restriction, including without limitation the
 17           // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 18           // sell copies of the Software, and to permit persons to whom the Software is
 19           // furnished to do so, subject to the following conditions:
 20           // 
 21           // THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
 22 mike  1.2 // ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
 23           // "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
 24           // LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 25           // PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 26           // HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 27           // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 28           // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 29           //
 30           //==============================================================================
 31           //
 32           // Author: Mike Day (mdday@us.ibm.com)
 33           //
 34           //%/////////////////////////////////////////////////////////////////////////////
 35           
 36           #ifndef Pegasus_Semaphore_h
 37           #define Pegasus_Semaphore_h
 38           
 39           #include <Pegasus/Common/Config.h>
 40           #include <Pegasus/Common/Linkage.h>
 41           #include <Pegasus/Common/Threads.h>
 42           
 43 mike  1.2 //==============================================================================
 44           //
 45           // Select sempahore implementation by defining one of these:
 46           //
 47           //    PEGASUS_USE_POSIX_SEMAPHORE
 48           //    PEGASUS_USE_PTHREAD_SEMAPHORE
 49           //    PEGASUS_USE_WINDOWS_SEMAPHORE
 50           //
 51           //==============================================================================
 52           
 53           #if defined(PEGASUS_PLATFORM_ZOS_ZSERIES_IBM) || \
 54               defined(PEGASUS_PLATFORM_AIX_RS_IBMCXX) || \
 55               defined(PEGASUS_PLATFORM_DARWIN_PPC_GNU) || \
 56               defined(PEGASUS_PLATFORM_LINUX_GENERIC_GNU) || \
 57               defined(PEGASUS_PLATFORM_VMS_IA64_DECCXX) || \
 58               defined(PEGASUS_PLATFORM_VMS_ALPHA_DECCXX)
 59           # define PEGASUS_USE_PTHREAD_SEMAPHORE
 60           #elif defined(PEGASUS_OS_TYPE_WINDOWS)
 61           # define PEGASUS_USE_WINDOWS_SEMAPHORE
 62           #else
 63           # define PEGASUS_USE_POSIX_SEMAPHORE
 64 mike  1.2 #endif
 65           
 66           #if defined(PEGASUS_USE_POSIX_SEMAPHORE)
 67           # include <semaphore.h>
 68           #endif
 69           
 70           PEGASUS_NAMESPACE_BEGIN
 71           
 72           //==============================================================================
 73           //
 74           // SemaphoreRep
 75           //
 76           //==============================================================================
 77           
 78           #if defined(PEGASUS_USE_PTHREAD_SEMAPHORE)
 79           struct SemaphoreRep
 80           {
 81               Uint32 waiters;
 82               pthread_mutex_t mutex;
 83               pthread_cond_t cond;
 84               ThreadType owner;
 85 mike  1.2 };
 86           #endif /* PEGASUS_USE_PTHREAD_SEMAPHORE */
 87           
 88           #if defined(PEGASUS_USE_POSIX_SEMAPHORE)
 89           struct SemaphoreRep
 90           {
 91               sem_t sem;
 92               ThreadType owner;
 93           };
 94           #endif /* defined(PEGASUS_USE_POSIX_SEMAPHORE) */
 95           
 96           #if defined(PEGASUS_USE_WINDOWS_SEMAPHORE)
 97           struct SemaphoreRep
 98           {
 99               HANDLE sem;
100               ThreadType owner;
101           };
102           #endif /* PEGASUS_USE_WINDOWS_SEMAPHORE */
103           
104           //==============================================================================
105           //
106 mike  1.2 // Semaphore
107           //
108           //==============================================================================
109           
110           class PEGASUS_COMMON_LINKAGE Semaphore
111           {
112           public:
113           
114               /** Creates a semaphore and sets its initial value as specified.
115                   @param initial The initial value for the Semaphore (defaults to 1).
116               */
117               Semaphore(Uint32 initial = 1);
118           
119               /** Destructor.
120               */
121               ~Semaphore();
122           
123               /** Blocks until this Semaphore is in a signalled state.
124                   @param ignoreInterrupt Indicates whether the wait operation should
125                   continue (true) or an exception should be thrown (false) when an
126                   interrupt is received.
127 mike  1.2         @exception WaitFailed If unable to block on the semaphore.
128                   @exception WaitInterrupted If the operation is interrupted.
129               */
130               void wait(Boolean ignoreInterrupt = true);
131           
132               /** Checks whether the Semaphore is signalled without waiting.  This method
133                   returns normally if the Semaphore has a non-zero count.
134                   @exception WaitFailed If the wait operation does not immediately
135                   succeed.
136               */
137               void try_wait();
138           
139               /** Waits for the Semaphore to be signalled for a specified time interval.
140                   This method returns normally if the Semaphore has a non-zero count or
141                   it is signalled during the specified time interval.
142                   @param milliseconds The time interval to wait (in milliseconds).
143                   @exception TimeOut If the wait operation does not succeed within
144                   the specified time interval.
145               */
146               void time_wait(Uint32 milliseconds);
147           
148 mike  1.2     /** Increments the count of the semaphore.
149               */
150               void signal();
151           
152               /** Return the count of the semaphore.
153               */
154               int count() const;
155           
156           private:
157           
158               Semaphore(const Semaphore& x); // Unimplemented
159               Semaphore& operator=(const Semaphore& x); // Unimplemented
160           
161               mutable int _count;
162               mutable SemaphoreRep _rep;
163               friend class Condition;
164           };
165           
166           PEGASUS_NAMESPACE_END
167           
168           #endif /* Pegasus_Semaphore_h */