From e2bc6f4153813cc570ae814c8ddb74628009b488 Mon Sep 17 00:00:00 2001 From: Michal Kubecek Date: Mon, 13 Apr 2015 09:21:39 +0200 Subject: initial checkin Check in contents of upstream 1.4.2 tarball, exclude generated files. --- src/threads/sema.cpp | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 src/threads/sema.cpp (limited to 'src/threads/sema.cpp') diff --git a/src/threads/sema.cpp b/src/threads/sema.cpp new file mode 100644 index 0000000..8eb686b --- /dev/null +++ b/src/threads/sema.cpp @@ -0,0 +1,76 @@ +/* + Copyright (C) 2005-2009 Michel de Boer + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#include +#include +#include +#include "sema.h" +#include "util.h" + +using namespace std; + +t_semaphore::t_semaphore(unsigned int value) { + int ret; + + ret = sem_init(&sem, 0, value); + if (ret != 0) { + string err = get_error_str(errno); + string exception = + "t_semaphore::t_semaphore failed to create a semaphore.\n"; + exception += err; + throw exception; + } +} + +t_semaphore::~t_semaphore() { + sem_destroy(&sem); +} + +void t_semaphore::up(void) { + int ret; + + ret = sem_post(&sem); + if (ret != 0) { + string err = get_error_str(errno); + string exception = "t_semaphore::up failed.\n"; + exception += err; + throw exception; + } +} + +void t_semaphore::down(void) { + while (true) { + int ret = sem_wait(&sem); + + if (ret != 0 && errno == EINTR) { + // In NPTL threading sem_wait can be interrupted. + // In LinuxThreads threading sem_wait is non-interruptable. + // Continue with sem_wait if an interrupt is caught. + continue; + } + + break; + } +} + +bool t_semaphore::try_down(void) { + int ret; + + ret = sem_trywait(&sem); + return (ret == 0); +} -- cgit v1.2.3