commit 44deb053252a3bd2f57a007ab9560f4924f62394
author Glenn Kasten <gkasten@google.com> Sun Feb 05 18:09:08 2012 -0800
committer Glenn Kasten <gkasten@google.com> Mon Feb 13 10:30:23 2012 -0800
tree 57fac6fb14c9f7897409b54b360afebef59c2e70
parent 860936d780d98a5968f40e66ca6ae800c67adbc3

Factor out and speed up permission-checking code

Use the caching permission check for dump to save IPC.

Cache getpid() to save kernel call for other permission checks.

The C runtime library getpid() can't cache due to a fork
race condition, but we know that mediaserver doesn't fork.

Don't construct String16 on the stack.

Change-Id: I6be6161dae5155d39ba6ed6228e7683e67be34ed

services/audioflinger/AudioPolicyService.cpp

diff --git a/services/audioflinger/AudioPolicyService.cpp b/services/audioflinger/AudioPolicyService.cpp
index f8b430e..21b5811 100644
--- a/services/audioflinger/AudioPolicyService.cpp
+++ b/services/audioflinger/AudioPolicyService.cpp
@@ -30,6 +30,7 @@
 #include <utils/String16.h>
 #include <utils/threads.h>
 #include "AudioPolicyService.h"
+#include "ServiceUtilities.h"
 #include <cutils/properties.h>
 #include <hardware_legacy/power.h>
 #include <media/AudioEffect.h>
@@ -49,13 +50,6 @@
 static const int kDumpLockRetries = 50;
 static const int kDumpLockSleepUs = 20000;
 
-static bool checkPermission() {
-    if (getpid() == IPCThreadState::self()->getCallingPid()) return true;
-    bool ok = checkCallingPermission(String16("android.permission.MODIFY_AUDIO_SETTINGS"));
-    if (!ok) ALOGE("Request requires android.permission.MODIFY_AUDIO_SETTINGS");
-    return ok;
-}
-
 namespace {
     extern struct audio_policy_service_ops aps_ops;
 };
@@ -157,7 +151,7 @@
     if (mpAudioPolicy == NULL) {
         return NO_INIT;
     }
-    if (!checkPermission()) {
+    if (!settingsAllowed()) {
         return PERMISSION_DENIED;
     }
     if (!audio_is_output_device(device) && !audio_is_input_device(device)) {
@@ -190,7 +184,7 @@
     if (mpAudioPolicy == NULL) {
         return NO_INIT;
     }
-    if (!checkPermission()) {
+    if (!settingsAllowed()) {
         return PERMISSION_DENIED;
     }
     if (uint32_t(state) >= AUDIO_MODE_CNT) {
@@ -213,7 +207,7 @@
     if (mpAudioPolicy == NULL) {
         return NO_INIT;
     }
-    if (!checkPermission()) {
+    if (!settingsAllowed()) {
         return PERMISSION_DENIED;
     }
     if (usage < 0 || usage >= AUDIO_POLICY_FORCE_USE_CNT) {
@@ -388,7 +382,7 @@
     if (mpAudioPolicy == NULL) {
         return NO_INIT;
     }
-    if (!checkPermission()) {
+    if (!settingsAllowed()) {
         return PERMISSION_DENIED;
     }
     if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
@@ -405,7 +399,7 @@
     if (mpAudioPolicy == NULL) {
         return NO_INIT;
     }
-    if (!checkPermission()) {
+    if (!settingsAllowed()) {
         return PERMISSION_DENIED;
     }
     if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
@@ -578,7 +572,7 @@
 
 status_t AudioPolicyService::dump(int fd, const Vector<String16>& args)
 {
-    if (!checkCallingPermission(String16("android.permission.DUMP"))) {
+    if (!dumpAllowed()) {
         dumpPermissionDenial(fd);
     } else {
         bool locked = tryLock(mLock);