Thread suspension: Implement for Linux

src/trusted/service_runtime/win/thread_suspension.c

Index: src/trusted/service_runtime/win/thread_suspension.c
diff --git a/src/trusted/service_runtime/win/thread_suspension.c b/src/trusted/service_runtime/win/thread_suspension.c
index 9b7f268a1daad23d570abb7fd31e6b84f066b0f8..ac51a9148d8a9f0cbe86402b47570372a2da0163 100644
--- a/src/trusted/service_runtime/win/thread_suspension.c
+++ b/src/trusted/service_runtime/win/thread_suspension.c
@@ -12,6 +12,21 @@
 #include "native_client/src/trusted/service_runtime/sel_ldr.h"
 
 
+void NaClAppThreadSetSuspendState(struct NaClAppThread *natp,
+                                  enum NaClSuspendState old_state,
+                                  enum NaClSuspendState new_state) {
+  NaClXMutexLock(&natp->mu);
+  while ((natp->suspend_state & NACL_APP_THREAD_SUSPENDING) != 0) {
+    /*
+     * We are being suspended, but SuspendThread() has not taken effect yet.
+     */
+    NaClXCondVarWait(&natp->cv, &natp->mu);
+  }
+  DCHECK(natp->suspend_state == old_state);
+  natp->suspend_state = new_state;
+  NaClXMutexUnlock(&natp->mu);
+}
+
 void NaClUntrustedThreadSuspend(struct NaClAppThread *natp) {
   enum NaClSuspendState old_state;