1) remove unnecessary initialization;

2) correct comment grammar issue;
3) fix the newly caught leaks;

include/grpc/impl/codegen/sync_posix.h

@@ -26,20 +26,20 @@
 #include <pthread.h>
 
 #ifdef GRPC_ASAN_ENABLED
-/* The member |leak_checker| is used to check whether there is memory leak
- * that may be caused by upper layer logic which missing the |gpr_xx_destroy|
- * call to this object before freeing.
+/* The member |leak_checker| is used to check whether there is a memory leak
+ * caused by upper layer logic that's missing the |gpr_xx_destroy| call
+ * to the object before freeing it.
  * This issue was reported at https://github.com/grpc/grpc/issues/17563
  * and discussed at https://github.com/grpc/grpc/pull/17586
  */
 typedef struct {
   pthread_mutex_t mutex;
-  int *leak_checker;
+  int* leak_checker;
 } gpr_mu;
 
 typedef struct {
   pthread_cond_t cond_var;
-  int *leak_checker;
+  int* leak_checker;
 } gpr_cv;
 #else
 typedef pthread_mutex_t gpr_mu;

src/core/ext/filters/max_age/max_age_filter.cc

@@ -499,7 +499,10 @@ static grpc_error* init_channel_elem(grpc_channel_element* elem,
 }
 
 /* Destructor for channel_data. */
-static void destroy_channel_elem(grpc_channel_element* elem) {}
+static void destroy_channel_elem(grpc_channel_element* elem) {
+  channel_data* chand = static_cast<channel_data*>(elem->channel_data);
+  gpr_mu_destroy(&chand->max_age_timer_mu);
+}
 
 const grpc_channel_filter grpc_max_age_filter = {
     grpc_call_next_op,

src/core/lib/gpr/sync_posix.cc

@@ -16,8 +16,8 @@
  *
  */
 
-#include <grpc/support/port_platform.h>
 #include <grpc/support/alloc.h>
+#include <grpc/support/port_platform.h>
 
 #ifdef GPR_POSIX_SYNC
 
@@ -77,11 +77,6 @@ void gpr_mu_init(gpr_mu* mu) {
   GPR_ASSERT(pthread_mutex_init(&mu->mutex, nullptr) == 0);
   mu->leak_checker = (int*)gpr_malloc(sizeof(*mu->leak_checker));
   GPR_ASSERT(mu->leak_checker != nullptr);
-  /* Initial it with a magic number, make no sense, just use the memory.
-  * This only take effect when ASAN enabled, so,
-  * if memory allocation failed, let it crash.
-  */
-  *mu->leak_checker = 0x12F34D0;
 #else
   GPR_ASSERT(pthread_mutex_init(mu, nullptr) == 0);
 #endif
@@ -142,11 +137,6 @@ void gpr_cv_init(gpr_cv* cv) {
   GPR_ASSERT(pthread_cond_init(&cv->cond_var, &attr) == 0);
   cv->leak_checker = (int*)gpr_malloc(sizeof(*cv->leak_checker));
   GPR_ASSERT(cv->leak_checker != nullptr);
-  /* Initial it with a magic number, make no sense, just use the memory.
-  * This only take effect when ASAN enabled, so,
-  * if memory allocation failed, let it crash.
-  */
-  *cv->leak_checker = 0x12F34D0;
 #else
   GPR_ASSERT(pthread_cond_init(cv, &attr) == 0);
 #endif

src/core/lib/iomgr/ev_epollex_linux.cc

@@ -612,6 +612,7 @@ static void pollable_unref(pollable* p, int line, const char* reason) {
     close(p->epfd);
     grpc_wakeup_fd_destroy(&p->wakeup);
     gpr_mu_destroy(&p->owner_orphan_mu);
+    gpr_mu_destroy(&p->mu);
     gpr_free(p);
   }
 }

src/core/lib/iomgr/ev_poll_posix.cc

@@ -1535,6 +1535,9 @@ static void cache_harvest_locked() {
                   gpr_inf_future(GPR_CLOCK_MONOTONIC));
     }
     args->poller_thd.Join();
+    gpr_cv_destroy(&args->trigger);
+    gpr_cv_destroy(&args->harvest);
+    gpr_cv_destroy(&args->join);
     gpr_free(args);
   }
 }
@@ -1713,6 +1716,7 @@ static int cvfd_poll(struct pollfd* fds, nfds_t nfds, int timeout) {
   }
 
   gpr_free(fd_cvs);
+  gpr_cv_destroy(pollcv->cv);
   gpr_free(pollcv);
   if (result) {
     decref_poll_result(result);