diff options
Diffstat (limited to 'ace/SV_Semaphore_Complex.cpp')
| -rw-r--r-- | ace/SV_Semaphore_Complex.cpp | 152 |
1 files changed, 78 insertions, 74 deletions
diff --git a/ace/SV_Semaphore_Complex.cpp b/ace/SV_Semaphore_Complex.cpp index cb81d8838f3..ce3c0b07858 100644 --- a/ace/SV_Semaphore_Complex.cpp +++ b/ace/SV_Semaphore_Complex.cpp @@ -11,6 +11,8 @@ ACE_RCSID(ace, SV_Semaphore_Complex, "$Id$") +ACE_BEGIN_VERSIONED_NAMESPACE_DECL + ACE_ALLOC_HOOK_DEFINE(ACE_SV_Semaphore_Complex) void @@ -27,46 +29,46 @@ const int ACE_SV_Semaphore_Complex::BIGCOUNT_ = 10000; // Define the ACE_SV_Semaphore operation arrays for the semop() calls. sembuf ACE_SV_Semaphore_Complex::op_lock_[2] = { - {0, 0, 0}, // Wait for [0] (lock) to equal 0 - {0, 1, SEM_UNDO}, // then increment [0] to 1 - this locks it. + {0, 0, 0}, // Wait for [0] (lock) to equal 0 + {0, 1, SEM_UNDO}, // then increment [0] to 1 - this locks it. // UNDO to release the lock if processes exit - // before explicitly unlocking. + // before explicitly unlocking. }; sembuf ACE_SV_Semaphore_Complex::op_endcreate_[2] = { - {1, -1, SEM_UNDO}, // Decrement [1] (proc counter) with undo on + {1, -1, SEM_UNDO}, // Decrement [1] (proc counter) with undo on // exit, UNDO to adjust proc counter if - // process exits before explicitly calling close() - {0, -1, SEM_UNDO}, // the decrement [0] (lock) back to 0 + // process exits before explicitly calling close() + {0, -1, SEM_UNDO}, // the decrement [0] (lock) back to 0 }; sembuf ACE_SV_Semaphore_Complex::op_open_[1] = { - {1, -1, SEM_UNDO}, // Decrement [1] (proc counter) with undo on + {1, -1, SEM_UNDO}, // Decrement [1] (proc counter) with undo on // exit. }; sembuf ACE_SV_Semaphore_Complex::op_close_[3] = { - {0, 0, 0}, // Wait for [0] (lock) to equal 0 - {0, 1, SEM_UNDO}, // then increment [0] to 1 - this lock it - {1, 1, SEM_UNDO}, // then increment [1] (proc counter) + {0, 0, 0}, // Wait for [0] (lock) to equal 0 + {0, 1, SEM_UNDO}, // then increment [0] to 1 - this lock it + {1, 1, SEM_UNDO}, // then increment [1] (proc counter) }; sembuf ACE_SV_Semaphore_Complex::op_unlock_[1] = { - {0, -1, SEM_UNDO}, // Decrement [0] (lock) back to 0 + {0, -1, SEM_UNDO}, // Decrement [0] (lock) back to 0 }; // Open or create an array of SV_Semaphores. We return 0 if all is OK, else -1. int ACE_SV_Semaphore_Complex::open (key_t k, - int create, - int initial_value, - u_short nsems, - int perms) + short create, + int initial_value, + u_short nsems, + mode_t perms) { ACE_TRACE ("ACE_SV_Semaphore_Complex::open"); if (k == IPC_PRIVATE) @@ -83,35 +85,35 @@ ACE_SV_Semaphore_Complex::open (key_t k, int result; do - { - this->internal_id_ = ACE_OS::semget + { + this->internal_id_ = ACE_OS::semget (this->key_, (u_short) 2 + nsems, perms | ACE_SV_Semaphore_Complex::ACE_CREATE); - if (this->internal_id_ == -1) - return -1; // permission problem or tables full - - // When the <ACE_SV_Semaphore_Complex> is created, we know - // that the value of all 3 members is 0. Get a lock on the - // <ACE_SV_Semaphore_Complex> by waiting for [0] to equal 0, - // then increment it. - - // There is a race condition here. There is the possibility - // that between the <semget> above and the <semop> below, - // another process can call out <close> function which can - // remove the <ACE_SV_Semaphore> if that process is the last - // one using it. Therefor we handle the error condition of - // an invalid <ACE_SV_Semaphore> ID specifically below, and - // if it does happen, we just go back and create it again. - result = ACE_OS::semop (this->internal_id_, - &ACE_SV_Semaphore_Complex::op_lock_[0], - 2); - } + if (this->internal_id_ == -1) + return -1; // permission problem or tables full + + // When the <ACE_SV_Semaphore_Complex> is created, we know + // that the value of all 3 members is 0. Get a lock on the + // <ACE_SV_Semaphore_Complex> by waiting for [0] to equal 0, + // then increment it. + + // There is a race condition here. There is the possibility + // that between the <semget> above and the <semop> below, + // another process can call out <close> function which can + // remove the <ACE_SV_Semaphore> if that process is the last + // one using it. Therefor we handle the error condition of + // an invalid <ACE_SV_Semaphore> ID specifically below, and + // if it does happen, we just go back and create it again. + result = ACE_OS::semop (this->internal_id_, + &ACE_SV_Semaphore_Complex::op_lock_[0], + 2); + } while (result == -1 && (errno == EINVAL || errno == EIDRM)); if (result == -1) - return -1; + return -1; // Get the value of the process counter. If it equals 0, then no // one has initialized the ACE_SV_Semaphore yet. @@ -119,53 +121,53 @@ ACE_SV_Semaphore_Complex::open (key_t k, int semval = ACE_SV_Semaphore_Simple::control (GETVAL, 0, 1); if (semval == -1) - return this->init (); + return this->init (); else if (semval == 0) - { - // We should initialize by doing a SETALL, but that would - // clear the adjust value that we set when we locked the - // ACE_SV_Semaphore above. Instead we do system calls to - // initialize [1], as well as all the nsems SV_Semaphores. - - if (ACE_SV_Semaphore_Simple::control (SETVAL, - ACE_SV_Semaphore_Complex::BIGCOUNT_, - 1) == -1) - return -1; - else - for (u_short i = 0; i < nsems; i++) - if (this->control (SETVAL, initial_value, i) == -1) - return -1; - } + { + // We should initialize by doing a SETALL, but that would + // clear the adjust value that we set when we locked the + // ACE_SV_Semaphore above. Instead we do system calls to + // initialize [1], as well as all the nsems SV_Semaphores. + + if (ACE_SV_Semaphore_Simple::control (SETVAL, + ACE_SV_Semaphore_Complex::BIGCOUNT_, + 1) == -1) + return -1; + else + for (u_short i = 0; i < nsems; i++) + if (this->control (SETVAL, initial_value, i) == -1) + return -1; + } // Decrement the process counter and then release the lock. return ACE_OS::semop (this->internal_id_, - &ACE_SV_Semaphore_Complex::op_endcreate_[0], - 2); + &ACE_SV_Semaphore_Complex::op_endcreate_[0], + 2); } else { this->internal_id_ = ACE_OS::semget (this->key_, 2 + nsems, 0); if (this->internal_id_ == -1) - return -1; // doesn't exist or tables full + return -1; // doesn't exist or tables full // Decrement the process counter. We don't need a lock to do this. if (ACE_OS::semop (this->internal_id_, - &ACE_SV_Semaphore_Complex::op_open_[0], 1) < 0) - return this->init (); + &ACE_SV_Semaphore_Complex::op_open_[0], 1) < 0) + return this->init (); return 0; } } int ACE_SV_Semaphore_Complex::open (const char *name, - int flags, - int initial_value, - u_short nsems, - int perms) + short flags, + int initial_value, + u_short nsems, + mode_t perms) { ACE_TRACE ("ACE_SV_Semaphore_Complex::open"); return this->open (ACE_SV_Semaphore_Simple::name_2_key (name), - flags, initial_value, nsems, perms); + flags, initial_value, nsems, perms); } // Close a ACE_SV_Semaphore. Unlike the remove above, this function @@ -187,8 +189,8 @@ ACE_SV_Semaphore_Complex::close (void) // then increments [1] - the process number. if (ACE_OS::semop (this->internal_id_, - &ACE_SV_Semaphore_Complex::op_close_[0], - 3) == -1) + &ACE_SV_Semaphore_Complex::op_close_[0], + 3) == -1) return -1; // Now that we have a lock, read the value of the process counter to @@ -205,17 +207,17 @@ ACE_SV_Semaphore_Complex::close (void) else { int result = ACE_OS::semop (this->internal_id_, - &ACE_SV_Semaphore_Complex::op_unlock_[0], 1); + &ACE_SV_Semaphore_Complex::op_unlock_[0], 1); this->init (); return result; } } ACE_SV_Semaphore_Complex::ACE_SV_Semaphore_Complex (key_t k, - int flags, - int initial_value, - u_short nsems, - int perms) + short flags, + int initial_value, + u_short nsems, + mode_t perms) { ACE_TRACE ("ACE_SV_Semaphore_Complex::ACE_SV_Semaphore_Complex"); if (this->open (k, flags, initial_value, nsems, perms) == -1) @@ -223,10 +225,10 @@ ACE_SV_Semaphore_Complex::ACE_SV_Semaphore_Complex (key_t k, } ACE_SV_Semaphore_Complex::ACE_SV_Semaphore_Complex (const char *name, - int flags, - int initial_value, - u_short nsems, - int perms) + short flags, + int initial_value, + u_short nsems, + mode_t perms) { ACE_TRACE ("ACE_SV_Semaphore_Complex::ACE_SV_Semaphore_Complex"); @@ -253,3 +255,5 @@ ACE_SV_Semaphore_Complex::ACE_SV_Semaphore_Complex (void) ACE_TRACE ("ACE_SV_Semaphore_Complex::ACE_SV_Semaphore_Complex"); this->init (); } + +ACE_END_VERSIONED_NAMESPACE_DECL |