parallel-processing

问题 The following is my code. I am trying get the list of all the files (~20000) that end with .idat and read each file using the function illuminaio::readIDAT . library(illuminaio) library(parallel) library(data.table) # number of cores to use ncores = 8 # this gets all the files with .idat extension ~20000 files files <- list.files(path = './', pattern = "*.idat", full.names = TRUE) # function to read the idat file and create a data.table of filename, and two more columns # write out as csv

问题 The following is my code. I am trying get the list of all the files (~20000) that end with .idat and read each file using the function illuminaio::readIDAT . library(illuminaio) library(parallel) library(data.table) # number of cores to use ncores = 8 # this gets all the files with .idat extension ~20000 files files <- list.files(path = './', pattern = "*.idat", full.names = TRUE) # function to read the idat file and create a data.table of filename, and two more columns # write out as csv

问题 The following is my code. I am trying get the list of all the files (~20000) that end with .idat and read each file using the function illuminaio::readIDAT . library(illuminaio) library(parallel) library(data.table) # number of cores to use ncores = 8 # this gets all the files with .idat extension ~20000 files files <- list.files(path = './', pattern = "*.idat", full.names = TRUE) # function to read the idat file and create a data.table of filename, and two more columns # write out as csv

问题 I need to update a 100M-element array and would like to do it in parallel. std::for_each(std::execution::par, ...) seems great for this, except that the update needs to access elements of other arrays depending on the index that I am updating. A minimal serial working example of the kind of thing I'm trying to parallelize might look like this: for (size_t i = 0; i < 100'000'000; i++) d[i] = combine(d[i], s[2*i], s[2*i+1]); I could of course manually spawn threads, but that is a lot more code

问题 I need to update a 100M-element array and would like to do it in parallel. std::for_each(std::execution::par, ...) seems great for this, except that the update needs to access elements of other arrays depending on the index that I am updating. A minimal serial working example of the kind of thing I'm trying to parallelize might look like this: for (size_t i = 0; i < 100'000'000; i++) d[i] = combine(d[i], s[2*i], s[2*i+1]); I could of course manually spawn threads, but that is a lot more code

问题 I have a table ImportSourceMetadata which I use to control an import batch process. It contains a PK column SourceId and a data column LastCheckpoint . The import batch process reads the LastCheckpoint for a given SourceId , performs some logic (on other tables), then updates the LastCheckpoint for that SourceId or inserts it if it doesn't exist yet . Multiple instances of the process run at the same time, usually with disjunct SourceIds , and I need high parallelity for those cases. However,

问题 I'm playing around with BlockingCollection to try to understand them better, but I'm struggling to understand why my code hangs when it finishes processing all my items when I use a Parallel.For I'm just adding a number to it (producer?): var blockingCollection = new BlockingCollection<long>(); Task.Factory.StartNew(() => { while (count <= 10000) { blockingCollection.Add(count); count++; } }); Then I'm trying to process (Consumer?): Parallel.For(0, 5, x => { foreach (long value in

问题 I'm playing around with BlockingCollection to try to understand them better, but I'm struggling to understand why my code hangs when it finishes processing all my items when I use a Parallel.For I'm just adding a number to it (producer?): var blockingCollection = new BlockingCollection<long>(); Task.Factory.StartNew(() => { while (count <= 10000) { blockingCollection.Add(count); count++; } }); Then I'm trying to process (Consumer?): Parallel.For(0, 5, x => { foreach (long value in

问题 I'm playing around with BlockingCollection to try to understand them better, but I'm struggling to understand why my code hangs when it finishes processing all my items when I use a Parallel.For I'm just adding a number to it (producer?): var blockingCollection = new BlockingCollection<long>(); Task.Factory.StartNew(() => { while (count <= 10000) { blockingCollection.Add(count); count++; } }); Then I'm trying to process (Consumer?): Parallel.For(0, 5, x => { foreach (long value in

问题 I'm playing around with BlockingCollection to try to understand them better, but I'm struggling to understand why my code hangs when it finishes processing all my items when I use a Parallel.For I'm just adding a number to it (producer?): var blockingCollection = new BlockingCollection<long>(); Task.Factory.StartNew(() => { while (count <= 10000) { blockingCollection.Add(count); count++; } }); Then I'm trying to process (Consumer?): Parallel.For(0, 5, x => { foreach (long value in