Fix setTimeZone() and use it properly in RSTest/rstime.

BUG=5470134

The original implementation for rsi_ScriptSetTimeZone() never actually did
anything with the bytes received. This change allows it to safely update the
timezone. RSTest is also updated to call setTimeZone(), so that users in
different timezones can accurately get test results.

Change-Id: I6cb1b3a0c3a417749ba39e0fe09cc9c7ab65c2e7

libs/rs/rsScript.cpp

@@ -15,6 +15,7 @@
  */
 
 #include "rsContext.h"
+#include <time.h>
 
 using namespace android;
 using namespace android::renderscript;
@@ -89,8 +90,22 @@ void rsi_ScriptBindAllocation(Context * rsc, RsScript vs, RsAllocation va, uint3
 }
 
 void rsi_ScriptSetTimeZone(Context * rsc, RsScript vs, const char * timeZone, size_t length) {
-    Script *s = static_cast<Script *>(vs);
-    s->mEnviroment.mTimeZone = timeZone;
+    // We unfortunately need to make a new copy of the string, since it is
+    // not NULL-terminated. We then use setenv(), which properly handles
+    // freeing/duplicating the actual string for the environment.
+    char *tz = (char *) malloc(length + 1);
+    if (!tz) {
+        LOGE("Couldn't allocate memory for timezone buffer");
+        return;
+    }
+    strncpy(tz, timeZone, length);
+    tz[length] = '\0';
+    if (setenv("TZ", tz, 1) == 0) {
+        tzset();
+    } else {
+        LOGE("Error setting timezone");
+    }
+    free(tz);
 }
 
 void rsi_ScriptForEach(Context *rsc, RsScript vs, uint32_t slot,

libs/rs/rsScript.h

@@ -59,7 +59,6 @@ public:
     struct Enviroment_t {
         int64_t mStartTimeMillis;
         int64_t mLastDtTime;
-        const char* mTimeZone;
 
         ObjectBaseRef<ProgramVertex> mVertex;
         ObjectBaseRef<ProgramFragment> mFragment;

tests/RenderScriptTests/tests/src/com/android/rs/test/UT_rstime.java

@@ -32,6 +32,7 @@ public class UT_rstime extends UnitTest {
         RenderScript pRS = RenderScript.create(mCtx);
         ScriptC_rstime s = new ScriptC_rstime(pRS, mRes, R.raw.rstime);
         pRS.setMessageHandler(mRsMessage);
+        s.setTimeZone("America/Los_Angeles");
         s.invoke_test_rstime(0, 0);
         pRS.finish();
         waitForMessage();

tests/RenderScriptTests/tests/src/com/android/rs/test/rstime.rs

@@ -19,7 +19,7 @@ static bool basic_test(uint32_t index) {
     rsDebug("tm.tm_yday", tm.tm_yday);
     rsDebug("tm.tm_isdst", tm.tm_isdst);
 
-    // Test a specific time (only valid for PST localtime)
+    // Test a specific time (since we set America/Los_Angeles localtime)
     curTime = 1294438893;
     rsLocaltime(&tm, &curTime);