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Diffstat (limited to 'lib/common/WaitForEvent.cpp')
| -rw-r--r-- | lib/common/WaitForEvent.cpp | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/lib/common/WaitForEvent.cpp b/lib/common/WaitForEvent.cpp new file mode 100644 index 00000000..f7ea7439 --- /dev/null +++ b/lib/common/WaitForEvent.cpp @@ -0,0 +1,235 @@ +// distribution boxbackup-0.10 (svn version: 494) +// +// Copyright (c) 2003 - 2006 +// Ben Summers and contributors. All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions +// are met: +// 1. Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// 2. Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// 3. All use of this software and associated advertising materials must +// display the following acknowledgment: +// This product includes software developed by Ben Summers. +// 4. The names of the Authors may not be used to endorse or promote +// products derived from this software without specific prior written +// permission. +// +// [Where legally impermissible the Authors do not disclaim liability for +// direct physical injury or death caused solely by defects in the software +// unless it is modified by a third party.] +// +// THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR +// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +// DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, +// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +// POSSIBILITY OF SUCH DAMAGE. +// +// +// +// -------------------------------------------------------------------------- +// +// File +// Name: WaitForEvent.cpp +// Purpose: Generic waiting for events, using an efficient method (platform dependent) +// Created: 9/3/04 +// +// -------------------------------------------------------------------------- + +#include "Box.h" + +#ifdef HAVE_UNISTD_H + #include <unistd.h> +#endif + +#include <errno.h> +#include <string.h> + +#include "WaitForEvent.h" + +#include "MemLeakFindOn.h" + +// -------------------------------------------------------------------------- +// +// Function +// Name: WaitForEvent::WaitForEvent() +// Purpose: Constructor +// Created: 9/3/04 +// +// -------------------------------------------------------------------------- +#ifdef HAVE_KQUEUE +WaitForEvent::WaitForEvent(int Timeout) + : mKQueue(::kqueue()), + mpTimeout(0) +{ + if(mKQueue == -1) + { + THROW_EXCEPTION(CommonException, CouldNotCreateKQueue) + } + + // Set the choosen timeout + SetTimeout(Timeout); +} +#else +WaitForEvent::WaitForEvent(int Timeout) + : mTimeout(Timeout), + mpPollInfo(0) +{ +} +#endif + +// -------------------------------------------------------------------------- +// +// Function +// Name: WaitForEvent::~WaitForEvent() +// Purpose: Destructor +// Created: 9/3/04 +// +// -------------------------------------------------------------------------- +WaitForEvent::~WaitForEvent() +{ +#ifdef HAVE_KQUEUE + ::close(mKQueue); + mKQueue = -1; +#else + if(mpPollInfo != 0) + { + ::free(mpPollInfo); + mpPollInfo = 0; + } +#endif +} + + +// -------------------------------------------------------------------------- +// +// Function +// Name: WaitForEvent::SetTimeout +// Purpose: Sets the timeout for future wait calls +// Created: 9/3/04 +// +// -------------------------------------------------------------------------- +void WaitForEvent::SetTimeout(int Timeout) +{ +#ifdef HAVE_KQUEUE + // Generate timeout + if(Timeout != TimeoutInfinite) + { + mTimeout.tv_sec = Timeout / 1000; + mTimeout.tv_nsec = (Timeout % 1000) * 1000000; + } + + // Infinite or not? + mpTimeout = (Timeout != TimeoutInfinite)?(&mTimeout):(NULL); +#else + mTimeout = Timeout; +#endif +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: WaitForEvent::Wait(int) +// Purpose: Wait for an event to take place. Returns a pointer to the object +// which has been signalled, or returns 0 for the timeout condition. +// Timeout specified in milliseconds. +// Created: 9/3/04 +// +// -------------------------------------------------------------------------- +void *WaitForEvent::Wait() +{ +#ifdef HAVE_KQUEUE + // Event return structure + struct kevent e; + ::memset(&e, 0, sizeof(e)); + + switch(::kevent(mKQueue, NULL, 0, &e, 1, mpTimeout)) + { + case 0: + // Timeout + return 0; + break; + + case 1: + // Event happened! + return e.udata; + break; + + default: + // Interrupted system calls aren't an error, just equivalent to a timeout + if(errno != EINTR) + { + THROW_EXCEPTION(CommonException, KEventErrorWait) + } + return 0; + break; + } +#else + // Use poll() instead. + // Need to build the structures? + if(mpPollInfo == 0) + { + // Yes... + mpPollInfo = (struct pollfd *)::malloc((sizeof(struct pollfd) * mItems.size()) + 4); + if(mpPollInfo == 0) + { + throw std::bad_alloc(); + } + + // Build... + for(unsigned int l = 0; l < mItems.size(); ++l) + { + mpPollInfo[l].fd = mItems[l].fd; + mpPollInfo[l].events = mItems[l].events; + mpPollInfo[l].revents = 0; + } + } + + // Make sure everything is reset (don't really have to do this, but don't trust the OS) + for(unsigned int l = 0; l < mItems.size(); ++l) + { + mpPollInfo[l].revents = 0; + } + + // Poll! + switch(::poll(mpPollInfo, mItems.size(), mTimeout)) + { + case -1: + // Interrupted system calls aren't an error, just equivalent to a timeout + if(errno != EINTR) + { + THROW_EXCEPTION(CommonException, KEventErrorWait) + } + return 0; + break; + case 0: // timed out + return 0; + break; + default: // got some thing... + // control flows on... + break; + } + + // Find the item which was ready + for(unsigned int s = 0; s < mItems.size(); ++s) + { + if(mpPollInfo[s].revents & POLLIN) + { + return mItems[s].item; + break; + } + } +#endif + + return 0; +} + |