Make Ctrl-C in the debugger works again.

src/signal-handling.c

@@ -53,12 +53,32 @@ static int jl_check_force_sigint(void)
  return 0;
 }
 
-// Force sigint requires pressing `Ctrl-C` repeatedly.
-// Ignore sigint for a short time after that to avoid rethrowing sigint too
-// quickly again. (Code that has this issue is inherently racy but this is
-// an interactive feature anyway.)
+#ifndef _OS_WINDOWS_
+// Not thread local, should only be accessed by the signal handler thread.
+static volatile int jl_sigint_passed = 0;
+static sigset_t jl_sigint_sset;
+#endif
+
 static int jl_ignore_sigint(void)
 {
+ // On Unix, we get the SIGINT before the debugger which makes it very
+ // hard to interrupt a running process in the debugger with `Ctrl-C`.
+ // Manually raise a `SIGINT` on current thread with the signal temporarily
+ // unblocked and use it's behavior to decide if we need to handle the signal.
+#ifndef _OS_WINDOWS_
+ jl_sigint_passed = 0;
+ pthread_sigmask(SIG_UNBLOCK, &jl_sigint_sset, NULL);
+ // This can swallow an external `SIGINT` but it's not an issue
+ // since we don't deliver the same number of signals anyway.
+ pthread_kill(pthread_self(), SIGINT);
+ pthread_sigmask(SIG_BLOCK, &jl_sigint_sset, NULL);
+ if (!jl_sigint_passed)
+ return 1;
+#endif
+ // Force sigint requires pressing `Ctrl-C` repeatedly.
+ // Ignore sigint for a short time after that to avoid rethrowing sigint too
+ // quickly again. (Code that has this issue is inherently racy but this is
+ // an interactive feature anyway.)
  return jl_disable_sigint_time && jl_disable_sigint_time > uv_hrtime();
 }
 

src/signals-unix.c

@@ -519,12 +519,14 @@ static void *signal_listener(void *arg)
 # endif
 #endif
  if (sig == SIGINT) {
- if (exit_on_sigint) {
+ if (jl_ignore_sigint()) {
+ continue;
+ }
+ else if (exit_on_sigint) {
  critical = 1;
  }
  else {
- if (!jl_ignore_sigint())
- jl_try_deliver_sigint();
+ jl_try_deliver_sigint();
  continue;
  }
  }
@@ -600,6 +602,9 @@ static void *signal_listener(void *arg)
 
 void restore_signals(void)
 {
+ sigemptyset(&jl_sigint_sset);
+ sigaddset(&jl_sigint_sset, SIGINT);
+
  sigset_t sset;
  jl_sigsetset(&sset);
  sigprocmask(SIG_SETMASK, &sset, 0);
@@ -625,6 +630,11 @@ void fpe_handler(int sig, siginfo_t *info, void *context)
  jl_throw_in_ctx(ptls, jl_diverror_exception, context);
 }
 
+void sigint_handler(int sig)
+{
+ jl_sigint_passed = 1;
+}
+
 void jl_install_default_signal_handlers(void)
 {
  struct sigaction actf;
@@ -635,6 +645,14 @@ void jl_install_default_signal_handlers(void)
  if (sigaction(SIGFPE, &actf, NULL) < 0) {
  jl_errorf("fatal error: sigaction: %s", strerror(errno));
  }
+ struct sigaction actint;
+ memset(&actint, 0, sizeof(struct sigaction));
+ sigemptyset(&actint.sa_mask);
+ actint.sa_handler = sigint_handler;
+ actint.sa_flags = 0;
+ if (sigaction(SIGINT, &actint, NULL) < 0) {
+ jl_errorf("fatal error: sigaction: %s", strerror(errno));
+ }
  if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
  jl_error("fatal error: Couldn't set SIGPIPE");
  }

src/signals-win.c

@@ -79,10 +79,11 @@ void __cdecl crt_sig_handler(int sig, int num)
  break;
  case SIGINT:
  signal(SIGINT, (void (__cdecl *)(int))crt_sig_handler);
- if (exit_on_sigint)
- jl_exit(130); // 128 + SIGINT
- if (!jl_ignore_sigint())
+ if (!jl_ignore_sigint()) {
+ if (exit_on_sigint)
+  jl_exit(130); // 128 + SIGINT
  jl_try_throw_sigint();
+ }
  break;
  default: // SIGSEGV, (SSIGTERM, IGILL)
  memset(&Context, 0, sizeof(Context));
@@ -179,10 +180,11 @@ static BOOL WINAPI sigint_handler(DWORD wsig) //This needs winapi types to guara
  // etc.
  default: sig = SIGTERM; break;
  }
- if (exit_on_sigint)
- jl_exit(128 + sig); // 128 + SIGINT
- if (!jl_ignore_sigint())
+ if (!jl_ignore_sigint()) {
+ if (exit_on_sigint)
+  jl_exit(128 + sig); // 128 + SIGINT
  jl_try_deliver_sigint();
+ }
  return 1;
 }