diff options
author | normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-06-27 03:14:30 +0000 |
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committer | normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-06-27 03:14:30 +0000 |
commit | 054a412d540e7ed2de63d68da753f585ea6616c3 (patch) | |
tree | 550ff5e80d4735d7a5c3f05605a180cfcba526b2 /vm_core.h | |
parent | e3e22c551d24829e0f9ce84afd3653867582034b (diff) |
hijack SIGCHLD handler for internal use
Use a global SIGCHLD handler to guard all callers of rb_waitpid.
To work safely with multi-threaded programs, we introduce a
VM-wide waitpid_lock to be acquired BEFORE fork/vfork spawns the
process. This is to be combined with the new ruby_waitpid_locked
function used by mjit.c in a non-Ruby thread.
Ruby-level SIGCHLD handlers registered with Signal.trap(:CHLD)
continues to work as before and there should be no regressions
in any existing use cases.
Splitting the wait queues for PID > 0 and groups (PID <= 0)
ensures we favor PID > 0 callers.
The disabling of SIGCHLD in rb_f_system is longer necessary,
as we use deferred signal handling and no longer make ANY
blocking waitpid syscalls in other threads which could "beat"
the waitpid call made by rb_f_system.
We prevent SIGCHLD from firing in normal Ruby Threads and only
enable it in the timer-thread, to prevent spurious wakeups
from in test/-ext-/gvl/test_last_thread.rb with MJIT enabled.
I've tried to guard as much of the code for RUBY_SIGCHLD==0
using C "if" statements rather than CPP "#if" so to reduce
the likelyhood of portability problems as the compiler will
see more code.
We also work to suppress false-positives from
Process.wait(-1, Process::WNOHANG) to quiets warnings from
spec/ruby/core/process/wait2_spec.rb with MJIT enabled.
Lastly, we must implement rb_grantpt for ext/pty. We need a
MJIT-compatible way of supporting grantpt(3) which may spawn
the `pt_chown' binary and call waitpid(2) on it.
[ruby-core:87605] [Ruby trunk Bug#14867]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63758 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'vm_core.h')
-rw-r--r-- | vm_core.h | 13 |
1 files changed, 13 insertions, 0 deletions
@@ -92,6 +92,14 @@ #define RUBY_NSIG NSIG +#if defined(SIGCLD) +# define RUBY_SIGCHLD (SIGCLD) +#elif defined(SIGCHLD) +# define RUBY_SIGCHLD (SIGCHLD) +#else +# define RUBY_SIGCHLD (0) +#endif + #ifdef HAVE_STDARG_PROTOTYPES #include <stdarg.h> #define va_init_list(a,b) va_start((a),(b)) @@ -553,6 +561,9 @@ typedef struct rb_vm_struct { #endif rb_serial_t fork_gen; + rb_nativethread_lock_t waitpid_lock; + struct list_head waiting_pids; /* PID > 0: <=> struct waitpid_state */ + struct list_head waiting_grps; /* PID <= 0: <=> struct waitpid_state */ struct list_head waiting_fds; /* <=> struct waiting_fd */ struct list_head living_threads; VALUE thgroup_default; @@ -1561,6 +1572,8 @@ static inline void rb_vm_living_threads_init(rb_vm_t *vm) { list_head_init(&vm->waiting_fds); + list_head_init(&vm->waiting_pids); + list_head_init(&vm->waiting_grps); list_head_init(&vm->living_threads); vm->living_thread_num = 0; } |