Rwmutex block #39
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Rwmutex block #39
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… a global way, this converts the cache size limit to per dataset
… once the dataset is deleted.
…with RasterBands that do not have a dataset.
…heMax in various spots in the code. In many situations this should be pulling the size of the non global cache size in the situation where a dataset specific cache size was specified. Added methods to access the RBM from the Dataset and RasterBand as well.
…heMax in various spots in the code. In many situations this should be pulling the size of the non global cache size in the situation where a dataset specific cache size was specified. Added methods to access the RBM from the Dataset and RasterBand as well.
…ible order all to fix a very small problem
…ng protected object.
…r during driver destruction.
…es during rasterio operations.
… a global way, this converts the cache size limit to per dataset
… once the dataset is deleted.
…with RasterBands that do not have a dataset.
…heMax in various spots in the code. In many situations this should be pulling the size of the non global cache size in the situation where a dataset specific cache size was specified. Added methods to access the RBM from the Dataset and RasterBand as well.
…heMax in various spots in the code. In many situations this should be pulling the size of the non global cache size in the situation where a dataset specific cache size was specified. Added methods to access the RBM from the Dataset and RasterBand as well.
…ng protected object.
…r during driver destruction.
…es during rasterio operations.
…eventing a segfault when destroying a mutex that was already NULL.
…atasets in a multi-threaded manner.
… a global way, this converts the cache size limit to per dataset
… once the dataset is deleted.
…with RasterBands that do not have a dataset.
…heMax in various spots in the code. In many situations this should be pulling the size of the non global cache size in the situation where a dataset specific cache size was specified. Added methods to access the RBM from the Dataset and RasterBand as well.
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For more details on this change please see: |
…le prior to the adding the lock for it on another thread. This could cause the block to be deleted while another thread was still attempting to operate on the block
…if a block was added to the Band block array prior to being read, it could cause the block to be empty when read via TryGetLockedBlockRef
| @@ -1127,6 +1130,11 @@ static void *CPLCreateMutexInternal(int bAlreadyInGlobalLock); | |||
| int CPLCreateOrAcquireMutex( void **phMutex, double dfWaitInSeconds ) | |||
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| { | |||
| // Check before going into the global lock, otherwise | |||
| // we risk using the global lock too often. | |||
| if ( NULL != *phMutex ) | |||
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Write a test to make sure that this isn't occuring http://en.wikipedia.org/wiki/Double-checked_locking
…to be intialized.
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ZOMG THE CHANGES!
This is a pull requests of a different way of dealing with caching, and reads and writes in GDAL. The biggest part of this change is the addition of a different way to do IReadBlock, IWriteBlock, IRasterIO, etc. There is now a mutex being passed as well as the data, so that the source data might be protected during writing. It also prevents deadlocks by being very picky in the drivers when it locks and when it does not. The downside is obvious. LOTS OF CHANGES, lots to go wrong.
I haven't fully tested everything yet, but wanted to put this here so we can compare against the other ways doing the locking.