Dynamically loading libjulia with SIGCHLD ignored causes error waitpid: No child processes
#57240
Comments
To check for regressions of JuliaLang#57240
To check for regressions of JuliaLang#57240
To check for regressions of JuliaLang#57240
|
Ignoring SIGCHLD makes it invalid to spawn child processes. This is a unix feature and not something julia can change. |
Julia should support running basic programs without needing to spawn child processes then. |
|
Or notice that SIGCHLD is ignored and back off from probing libstdc++ incorrectly |
|
Or just don't block SIGCHLD? There are a lot of ways to set up an invalid configuration which we will not support. |
We at least need a better error message IMO, since this is a report from a real situation in the wild. We're trying to provide a good experience for using Julia-compiled versions of "simple" libraries whose C equivalents do not have so many of these "poorly composing" constraints around signals, thread lifetimes, etc. and trying to minimize that surface area (or else document/guard where it cannot be shrunk) is important, I think . |
…57241) The `fork()` we do here relies on `SIGCHLD` to make sure that we don't race against the child. This is easy to see in an embedding application that dynamically links `libjulia`: ```c int main(int argc, char *argv[]) { signal(SIGCHLD, SIG_IGN); void *handle = dlopen("path/to/libjulia.so", RTLD_LAZY); return 0; } ``` Without this change, this fails with an error message: ``` Error during libstdcxxprobe in parent process: waitpid: No child processes ``` Resolves #57240
…57241) The `fork()` we do here relies on `SIGCHLD` to make sure that we don't race against the child. This is easy to see in an embedding application that dynamically links `libjulia`: ```c int main(int argc, char *argv[]) { signal(SIGCHLD, SIG_IGN); void *handle = dlopen("path/to/libjulia.so", RTLD_LAZY); return 0; } ``` Without this change, this fails with an error message: ``` Error during libstdcxxprobe in parent process: waitpid: No child processes ``` Resolves #57240 (cherry picked from commit daf865e)
…57241) The `fork()` we do here relies on `SIGCHLD` to make sure that we don't race against the child. This is easy to see in an embedding application that dynamically links `libjulia`: ```c int main(int argc, char *argv[]) { signal(SIGCHLD, SIG_IGN); void *handle = dlopen("path/to/libjulia.so", RTLD_LAZY); return 0; } ``` Without this change, this fails with an error message: ``` Error during libstdcxxprobe in parent process: waitpid: No child processes ``` Resolves #57240 (cherry picked from commit daf865e)
The text was updated successfully, but these errors were encountered: