Platform-specific gettid. Closes #3404, #3405.

Author: brixen

configure

@@ -1220,6 +1220,10 @@ int main() { return tgetnum(""); }
       @defines << "HAVE_INOTIFY"
     end
 
+    if has_function("gettid", ["unistd.d", "sys/types.h"])
+      @defines << "HAVE_GETTID"
+    end
+
     # glibc has useless lchmod() so we don't try to use lchmod() on linux
     if !@linux and has_function("lchmod", ["sys/stat.h", "unistd.h"])
       @have_lchmod = true

vm/builtin/thread.cpp

@@ -20,7 +20,7 @@
 #include "metrics.hpp"
 #include "util/logger.hpp"
 
-#include <sys/syscall.h>
+#include "missing/gettid.h"
 
 /* HACK: returns a value that should identify a native thread
  * for debugging threading issues. The winpthreads library
@@ -291,11 +291,7 @@ namespace rubinius {
 
     NativeMethod::init_thread(state);
 
-#ifdef __APPLE__
-    vm->thread->pid(state, Fixnum::from(syscall(SYS_thread_selfid)));
-#else
-    vm->thread->pid(state, Fixnum::from(syscall(SYS_gettid)));
-#endif
+    vm->thread->pid(state, Fixnum::from(gettid()));
 
     // Lock the thread object and unlock it at __run__ in the ruby land.
     vm->thread->alive(state, cTrue);

vm/missing/gettid.cpp

@@ -0,0 +1,19 @@
+#include "vm/missing/gettid.h"
+
+#ifndef HAVE_GETTID
+#include <sys/syscall.h>
+
+pid_t gettid(void) {
+#if defined(__APPLE__)
+  return (pid_t)syscall(SYS_thread_selfid);
+#elif defined(__FreeBSD__)
+  long tid;
+  syscall(SYS_thr_self, &tid);
+  return (pid_t)(tid);
+#elif defined(SYS_gettid)
+  return (pid_t)syscall(SYS_gettid);
+#else
+  return 0;
+#endif
+}
+#endif

vm/missing/gettid.h

@@ -0,0 +1,11 @@
+#include "vm/config.h"
+
+#include <unistd.h>
+
+#ifdef HAVE_GETTID
+#include <sys/types.h>
+#else
+extern "C" {
+pid_t gettid(void);
+}
+#endif