search for: mcexit

...y that we're leaving */ size_t len = 0; /* assign result for Fedora security settings */ ssize_t n = write(master_fd, &len, sizeof(len)); ... ... } So a pipe write is made in mc_exit, and here's how this function is used in src/library/parallel/R/unix/mcfork.R: mcexit <- function(exit.code = 0L, send = NULL) { if (!is.null(send)) try(sendMaster(send), silent = TRUE) .Call(C_mc_exit, as.integer(exit.code)) } Between sendMaster() and mc_exit() calls, which are made in the child process, the master process may call readChild() followed by rmChild(). rm...

...n = 0; > /* assign result for Fedora security settings */ > ssize_t n = write(master_fd, &len, sizeof(len)); > ... ... > } > > So a pipe write is made in mc_exit, and here's how this function is > used in src/library/parallel/R/unix/mcfork.R: > > mcexit <- function(exit.code = 0L, send = NULL) > { > if (!is.null(send)) try(sendMaster(send), silent = TRUE) > .Call(C_mc_exit, as.integer(exit.code)) > } > > Between sendMaster() and mc_exit() calls, which are made in the child > process, the master process may call re...

...y that we're leaving */ size_t len = 0; /* assign result for Fedora security settings */ ssize_t n = write(master_fd, &len, sizeof(len)); ... ... } So a pipe write is made in mc_exit, and here's how this function is used in src/library/parallel/R/unix/mcfork.R: mcexit <- function(exit.code = 0L, send = NULL) { if (!is.null(send)) try(sendMaster(send), silent = TRUE) .Call(C_mc_exit, as.integer(exit.code)) } Between sendMaster() and mc_exit() calls, which are made in the child process, the master process may call readChild() followed by rmChild(). rm...

...r Fedora security settings */ > > ssize_t n = write(master_fd, &len, sizeof(len)); > > ... ... > > } > > > > So a pipe write is made in mc_exit, and here's how this function is > > used in src/library/parallel/R/unix/mcfork.R: > > > > mcexit <- function(exit.code = 0L, send = NULL) > > { > > if (!is.null(send)) try(sendMaster(send), silent = TRUE) > > .Call(C_mc_exit, as.integer(exit.code)) > > } > > > > Between sendMaster() and mc_exit() calls, which are made in the child > > proc...

...# The problem # Since 3.6.0---and I've tested fresh installs of 3.6.0 and 3.5.3 side- by-side---I've been getting strange messages. Running source("forkTimeout.R") # attached repeat print(forkTimeout({Sys.sleep(1);TRUE}, timeout=3)) results in [1] TRUE [1] TRUE Error in mcexit(0L) : ignoring SIGPIPE signal [1] TRUE [1] TRUE Error in mcexit(0L) : ignoring SIGPIPE signal [1] TRUE [1] TRUE [1] TRUE until interrupted. Running options(error=traceback) repeat print(forkTimeout({Sys.sleep(1);TRUE}, timeout=3)) results in sporadic messages of the form: Error in mcexit(0L...

...39;help()' for on-line help, or 'help.start()' for an HTML browser interface to help. Type 'q()' to quit R. > library(parallel) > simplify2array(mclapply(rep(4, 5), rnorm)) *** caught segfault *** address 0x7fee2a7229d0, cause 'memory not mapped' Traceback: 1: mcexit(0L) 2: FUN(1:2[[1L]], ...) 3: lapply(seq_len(cores), inner.do) 4: mclapply(rep(4, 5), rnorm) 5: lapply(x, length) 6: unlist(lapply(x, length)) 7: unique(unlist(lapply(x, length))) 8: simplify2array(mclapply(rep(4, 5), rnorm)) Possible actions: 1: abort (with core dump, if enabled) 2: normal...

...y be related to an (even more pressing) issue I have with mclapply (package 'parallel'). While > example (mclapply) works as expected, any of my longer parallel jobs result in segfaults: *** caught segfault *** address 0x7f0aeed649d0, cause 'memory not mapped' Traceback: 1: mcexit(0L) 2: mcparallel(FUN(X[[i]], ...), mc.set.seed = mc.set.seed, silent = mc.silent) 3: FUN(1:8[[2L]], ...) 4: lapply(jobid, function(i) mcparallel(FUN(X[[i]], ...), mc.set.seed = mc.set.seed, silent = mc.silent)) 5: mclapply(sppDaysL, predDist, mc.cores = 8) aborting ... To add to the puzzl...

...hild process 15380 started > select_children: added child 15380 (6) > select_children: added child 15379 (5) > select_children: maxfd=6, wlen=2, wcount=2, timeout=-1.000000 > child 15380: send_master (550 bytes) > sr = 1 > - read select 1 children: 15380 > child 15380: 'mcexit' called > child 15380 is waiting for permission to exit > read_child_ci(15380) - read length returned 8 > read_child_ci(15380) - read 550 at 0 returned 550 > select_children: added child 15380 (6) > select_children: added child 15379 (5) > select_children: maxfd=6, wlen=2, wco...

...hild process 15380 started > select_children: added child 15380 (6) > select_children: added child 15379 (5) > select_children: maxfd=6, wlen=2, wcount=2, timeout=-1.000000 > child 15380: send_master (550 bytes) > sr = 1 > - read select 1 children: 15380 > child 15380: 'mcexit' called > child 15380 is waiting for permission to exit > read_child_ci(15380) - read length returned 8 > read_child_ci(15380) - read 550 at 0 returned 550 > select_children: added child 15380 (6) > select_children: added child 15379 (5) > select_children: maxfd=6, wlen=2, wco...

Hi Andreas, thank you very much, good job finding it was EBADF. Now the question is why the pipe has been closed prematurely; it could be accidentally by R (a race condition in the cleanup code in fork.c) or possibly by some other code running in the same process (maybe the R program itself or some other code it runs). Maybe we can take this off the list and come back when we know the cause