track embedded python distribution

python/gevent/libev/libev.h

@@ -0,0 +1,66 @@
+#if defined(LIBEV_EMBED)
+#include "ev.c"
+#else
+#include "ev.h"
+
+#ifndef _WIN32
+#include <signal.h>
+#endif
+
+#endif
+
+#ifndef _WIN32
+
+static struct sigaction libev_sigchld;
+/*
+ * Track the state of whether we have installed
+ * the libev sigchld handler specifically.
+ * If it's non-zero, libev_sigchld will be valid and set to the action
+ * that libev needs to do.
+ * If it's 1, we need to install libev_sigchld to make libev
+ * child handlers work (on request).
+ */
+static int sigchld_state = 0;
+
+static struct ev_loop* gevent_ev_default_loop(unsigned int flags)
+{
+    struct ev_loop* result;
+    struct sigaction tmp;
+
+    if (sigchld_state)
+        return ev_default_loop(flags);
+
+    //  Request the old SIGCHLD handler
+    sigaction(SIGCHLD, NULL, &tmp);
+    // Get the loop, which will install a SIGCHLD handler
+    result = ev_default_loop(flags);
+    // XXX what if SIGCHLD received there?
+    // Now restore the previous SIGCHLD handler
+    sigaction(SIGCHLD, &tmp, &libev_sigchld);
+    sigchld_state = 1;
+    return result;
+}
+
+
+static void gevent_install_sigchld_handler(void) {
+    if (sigchld_state == 1) {
+        sigaction(SIGCHLD, &libev_sigchld, NULL);
+        sigchld_state = 2;
+    }
+}
+
+static void gevent_reset_sigchld_handler(void) {
+   // We could have any state at this point, depending on
+   // whether the default loop has been used. If it has,
+   // then always be in state 1 ("need to install)
+   if (sigchld_state) {
+       sigchld_state = 1;
+   }
+}
+
+#else
+
+#define gevent_ev_default_loop ev_default_loop
+static void gevent_install_sigchld_handler(void) { }
+
+#endif