Refactor audio_processing: Free functions return void

There is no point in returning an error when Free() fails. In fact it can only happen if we have a null pointer as object. There is further no place where the return value is used.

Affected components are
- aec
- aecm
- agc
- ns

BUG=441
R=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/50579004

Cr-Commit-Position: refs/heads/master@{#8966}

webrtc/modules/audio_processing/aec/aec_core.c

@@ -1471,10 +1471,10 @@ int WebRtcAec_CreateAec(AecCore** aecInst) {
   return 0;
 }
 
-int WebRtcAec_FreeAec(AecCore* aec) {
+void WebRtcAec_FreeAec(AecCore* aec) {
   int i;
   if (aec == NULL) {
-    return -1;
+    return;
   }
 
   WebRtc_FreeBuffer(aec->nearFrBuf);
@@ -1498,7 +1498,6 @@ int WebRtcAec_FreeAec(AecCore* aec) {
   WebRtc_FreeDelayEstimatorFarend(aec->delay_estimator_farend);
 
   free(aec);
-  return 0;
 }
 
 #ifdef WEBRTC_AEC_DEBUG_DUMP

webrtc/modules/audio_processing/aec/aec_core.h

@@ -52,7 +52,7 @@ typedef struct Stats {
 typedef struct AecCore AecCore;
 
 int WebRtcAec_CreateAec(AecCore** aec);
-int WebRtcAec_FreeAec(AecCore* aec);
+void WebRtcAec_FreeAec(AecCore* aec);
 int WebRtcAec_InitAec(AecCore* aec, int sampFreq);
 void WebRtcAec_InitAec_SSE2(void);
 #if defined(MIPS_FPU_LE)

webrtc/modules/audio_processing/aec/aec_resampler.c

@@ -63,11 +63,9 @@ int WebRtcAec_InitResampler(void* resampInst, int deviceSampleRateHz) {
   return 0;
 }
 
-int WebRtcAec_FreeResampler(void* resampInst) {
+void WebRtcAec_FreeResampler(void* resampInst) {
   AecResampler* obj = (AecResampler*)resampInst;
   free(obj);
-
-  return 0;
 }
 
 void WebRtcAec_ResampleLinear(void* resampInst,

webrtc/modules/audio_processing/aec/aec_resampler.h

@@ -23,7 +23,7 @@ enum {
 // Unless otherwise specified, functions return 0 on success and -1 on error
 int WebRtcAec_CreateResampler(void** resampInst);
 int WebRtcAec_InitResampler(void* resampInst, int deviceSampleRateHz);
-int WebRtcAec_FreeResampler(void* resampInst);
+void WebRtcAec_FreeResampler(void* resampInst);
 
 // Estimates skew from raw measurement.
 int WebRtcAec_GetSkew(void* resampInst, int rawSkew, float* skewEst);

webrtc/modules/audio_processing/aec/echo_cancellation.c

@@ -171,11 +171,11 @@ int32_t WebRtcAec_Create(void** aecInst) {
   return 0;
 }
 
-int32_t WebRtcAec_Free(void* aecInst) {
+void WebRtcAec_Free(void* aecInst) {
   Aec* aecpc = aecInst;
 
   if (aecpc == NULL) {
-    return -1;
+    return;
   }
 
   WebRtc_FreeBuffer(aecpc->far_pre_buf);
@@ -189,8 +189,6 @@ int32_t WebRtcAec_Free(void* aecInst) {
   WebRtcAec_FreeAec(aecpc->aec);
   WebRtcAec_FreeResampler(aecpc->resampler);
   free(aecpc);
-
-  return 0;
 }
 
 int32_t WebRtcAec_Init(void* aecInst, int32_t sampFreq, int32_t scSampFreq) {

webrtc/modules/audio_processing/aec/echo_cancellation_unittest.cc

@@ -23,13 +23,13 @@ extern "C" {
 
 namespace webrtc {
 
-TEST(EchoCancellationTest, CreateAndFreeHandlesErrors) {
+TEST(EchoCancellationTest, CreateAndFreeHasExpectedBehavior) {
   EXPECT_EQ(-1, WebRtcAec_Create(NULL));
   void* handle = NULL;
   ASSERT_EQ(0, WebRtcAec_Create(&handle));
   EXPECT_TRUE(handle != NULL);
-  EXPECT_EQ(-1, WebRtcAec_Free(NULL));
-  EXPECT_EQ(0, WebRtcAec_Free(handle));
+  WebRtcAec_Free(nullptr);
+  WebRtcAec_Free(handle);
 }
 
 TEST(EchoCancellationTest, ApplyAecCoreHandle) {
@@ -44,7 +44,7 @@ TEST(EchoCancellationTest, ApplyAecCoreHandle) {
   int delay = 111;
   WebRtcAec_SetSystemDelay(aec_core, delay);
   EXPECT_EQ(delay, WebRtcAec_system_delay(aec_core));
-  EXPECT_EQ(0, WebRtcAec_Free(handle));
+  WebRtcAec_Free(handle);
 }
 
 }  // namespace webrtc

webrtc/modules/audio_processing/aec/include/echo_cancellation.h

@@ -84,13 +84,8 @@ int32_t WebRtcAec_Create(void** aecInst);
  * Inputs                       Description
  * -------------------------------------------------------------------
  * void*        aecInst         Pointer to the AEC instance
- *
- * Outputs                      Description
- * -------------------------------------------------------------------
- * int32_t      return          0: OK
- *                             -1: error
  */
-int32_t WebRtcAec_Free(void* aecInst);
+void WebRtcAec_Free(void* aecInst);
 
 /*
  * Initializes an AEC instance.

webrtc/modules/audio_processing/aec/system_delay_unittest.cc

@@ -73,7 +73,7 @@ void SystemDelayTest::SetUp() {
 
 void SystemDelayTest::TearDown() {
   // Free AEC
-  ASSERT_EQ(0, WebRtcAec_Free(handle_));
+  WebRtcAec_Free(handle_);
   handle_ = NULL;
 }