commit 93ad4e01925d2ff1b3b6b3cdf375d874f6a0a60d
author Miao Wang <miaowang@google.com> Tue Apr 25 16:23:03 2017 -0700
committer Miao Wang <miaowang@google.com> Tue May 23 11:17:12 2017 -0700
tree 13ac02626023b45c1a44bd2873712de612cc3044
parent 2397fd91759f830378ad7391bf7127fc477a9e1c

Protect static global access with a global flag.

  - The global objects are protected by a global flag, during
    application teardown.
  - The following APIs, which could potentially be called during
    application teardown, will be NO-OP if global objects are no
    longer alive.
        rsContextCreate
        rsContextCreateGL
        rsContextDestroy
   - Added a test of the problematic use-cases.

   Detailed discussion:
   https://goto.google.com/rs-static-destructor

Bug: 62027113

Test: mm
Test: Before the change to rsApiStubs.cpp, the test hangs during
termination.
Test: After the change to rsApiStubs.cpp, the test passes without any
problems.
Change-Id: I7a43a61d9ccf848c17a88e047e97d087132addda

(cherry picked from commit 296cd02e03565153f7dff971988adf8e8c6c365a)

rsApiStubs.cpp

diff --git a/rsApiStubs.cpp b/rsApiStubs.cpp
index e0753b0..28f1b1e 100644
--- a/rsApiStubs.cpp
+++ b/rsApiStubs.cpp
@@ -57,6 +57,28 @@
 // supported on Android are built on top of pthread, std::mutex is safe for them.
 static std::mutex contextMapMutex;
 
+// globalObjAlive is a global flag indicating whether the global objects,
+// contextMap & contextMapMutex, are still alive.
+// For the protected functions during application teardown, this
+// flag will be checked before accessing the global objects.
+static bool globalObjAlive;
+
+// GlobalObjGuard manipulates the globalObjAlive flag during construction and
+// destruction. If the guard object is destroyed, globalObjAlive will be set
+// to false, which will make the protected functions NO-OP.
+// https://goto.google.com/rs-static-destructor
+class GlobalObjGuard {
+  public:
+    GlobalObjGuard() {
+        globalObjAlive = true;
+    }
+
+    ~GlobalObjGuard() {
+        globalObjAlive = false;
+    }
+};
+static GlobalObjGuard guard;
+
 // API to find high-level context (RsContextWrapper) given a low level context.
 // This API is only intended to be used by RenderScript debugger.
 extern "C" RsContext rsDebugGetHighLevelContext(RsContext context) {
@@ -96,6 +118,11 @@
 extern "C" RsContext rsContextCreate(RsDevice vdev, uint32_t version, uint32_t sdkVersion,
                                      RsContextType ct, uint32_t flags)
 {
+    if (!globalObjAlive) {
+        ALOGE("rsContextCreate is not allowed during process teardown.");
+        return nullptr;
+    }
+
     RsHidlAdaptation& instance = RsHidlAdaptation::GetInstance();
     RsContext context = instance.GetEntryFuncs()->ContextCreate(vdev, version, sdkVersion, ct, flags);
     // Wait for debugger to attach if RS_CONTEXT_WAIT_FOR_ATTACH flag set.
@@ -155,6 +182,10 @@
 
 extern "C" void rsContextDestroy (RsContext ctxWrapper)
 {
+    if (!globalObjAlive) {
+        return;
+    }
+
     RS_DISPATCH(ctxWrapper, ContextDestroy);
 
     // Lock contextMap when deleting an existing entry.
@@ -683,6 +714,11 @@
 RsContext rsContextCreateGL(RsDevice vdev, uint32_t version, uint32_t sdkVersion,
                             RsSurfaceConfig sc, uint32_t dpi)
 {
+    if (!globalObjAlive) {
+        ALOGE("rsContextCreateGL is not allowed during process teardown.");
+        return nullptr;
+    }
+
     RsFallbackAdaptation& instance = RsFallbackAdaptation::GetInstance();
     RsContext context = instance.GetEntryFuncs()->ContextCreateGL(vdev, version, sdkVersion, sc, dpi);