From: Rabin Vincent <[email protected]> When tclsh forks it can create new threads in the child process, in a pthread_atfork() handler. Running this under pseudo results in a deadlock since the pseudo_lock() call in the new thread in the child process premanently believes that the mutex is already locked by another thread (which actually only existed in the parent process).
The provided test cases reproduces this. Similar hangs can also been seen in other cases, such as when attempting to use vim's cscope support under pseudo. Fix it by reseting the mutex in a pthread_atfork() child function. Signed-off-by: Rabin Vincent <[email protected]> --- pseudo_wrappers.c | 10 ++++++++++ test/test-tclsh-fork.sh | 6 ++++++ 2 files changed, 16 insertions(+) create mode 100755 test/test-tclsh-fork.sh diff --git a/pseudo_wrappers.c b/pseudo_wrappers.c index 615ac9a..12bc541 100644 --- a/pseudo_wrappers.c +++ b/pseudo_wrappers.c @@ -98,8 +98,18 @@ extern int (*pseudo_real_lsetxattr)(const char *, const char *, const void *, si extern int (*pseudo_real_fsetxattr)(int, const char *, const void *, size_t, int); #endif +static void libpseudo_atfork_child(void) +{ + pthread_mutex_init(&pseudo_mutex, NULL); + pseudo_mutex_recursion = 0; + pseudo_mutex_holder = 0; +} + static void _libpseudo_init(void) { + if (!_libpseudo_initted) + pthread_atfork(NULL, NULL, libpseudo_atfork_child); + pseudo_getlock(); pseudo_antimagic(); _libpseudo_initted = 1; diff --git a/test/test-tclsh-fork.sh b/test/test-tclsh-fork.sh new file mode 100755 index 0000000..e9dec66 --- /dev/null +++ b/test/test-tclsh-fork.sh @@ -0,0 +1,6 @@ +#!/bin/bash + +# Check that tclsh doesn't hang. Note that the timeout is not needed to +# reproduce the hang in tclsh, it's only there to ensure that this test script +# doesn't hang in case of a failing test. +timeout 2s bash -c "echo 'open {|true} r+' | tclsh" -- 2.1.4 -- _______________________________________________ yocto mailing list [email protected] https://lists.yoctoproject.org/listinfo/yocto
