MDEV-23526 InnoDB leaks memory for some static objects

Leaks of some members of statically allocated objects are
not being reported by AddressSanitizer or Valgrind, but they
can be reported by implementing SAFEMALLOC instrumentation.

These leaks were identified and original fixes provided
by Michael Widenius and Vicențiu Ciorbaru.

storage/innobase/include/log0log.h

@@ -480,6 +480,11 @@ class log_file_t
   bool writes_are_durable() const noexcept;
   dberr_t write(os_offset_t offset, span<const byte> buf) noexcept;
   dberr_t flush() noexcept;
+  void free()
+  {
+    m_path.clear();
+    m_path.shrink_to_fit();
+  }
 
 private:
   std::unique_ptr<file_io> m_file;

storage/innobase/include/log0recv.h

@@ -302,7 +302,7 @@ struct recv_sys_t
 
   void read(os_offset_t offset, span<byte> buf);
   inline size_t files_size();
-  void close_files() { files.clear(); }
+  void close_files() { files.clear(); files.shrink_to_fit(); }
 
 private:
   /** Attempt to initialize a page based on redo log records.

storage/innobase/log/log0log.cc

@@ -823,11 +823,12 @@ void log_t::file::flush()
 
 void log_t::file::close_file()
 {
-  if (!fd.is_opened())
-    return;
-
+  if (fd.is_opened())
+  {
     if (const dberr_t err= fd.close())
       ib::fatal() << "close(" << fd.get_path() << ") returned " << err;
+  }
+  fd.free();                                    // Free path
 }
 
 /** Initialize the redo log. */

storage/innobase/log/log0recv.cc

@@ -910,26 +910,23 @@ void recv_sys_t::close()
   ut_ad(this == &recv_sys);
   ut_ad(!recv_writer_thread_active);
 
-	if (is_initialised()) {
+  if (is_initialised())
+  {
     dblwr.pages.clear();
     ut_d(mutex_enter(&mutex));
     clear();
     ut_d(mutex_exit(&mutex));
 
-		if (flush_start) {
     os_event_destroy(flush_start);
-		}
-
-		if (flush_end) {
     os_event_destroy(flush_end);
-		}
 
-		if (buf) {
+    if (buf)
+    {
       ut_free_dodump(buf, RECV_PARSING_BUF_SIZE);
-			buf = NULL;
+      buf= nullptr;
     }
 
-		last_stored_lsn = 0;
+    last_stored_lsn= 0;
     mutex_free(&writer_mutex);
     mutex_free(&mutex);
   }
@@ -937,7 +934,7 @@ void recv_sys_t::close()
   recv_spaces.clear();
   mlog_init.clear();
 
-	files.clear();
+  close_files();
 }
 
 /******************************************************************//**
@@ -1067,10 +1064,11 @@ void recv_sys_t::debug_free()
   pages.clear();
   ut_free_dodump(buf, RECV_PARSING_BUF_SIZE);
 
-	buf = NULL;
+  buf= nullptr;
 
   /* wake page cleaner up to progress */
-	if (!srv_read_only_mode) {
+  if (!srv_read_only_mode)
+  {
     ut_ad(!recv_recovery_is_on());
     ut_ad(!recv_writer_thread_active);
     os_event_reset(buf_flush_event);

storage/innobase/srv/srv0srv.cc

@@ -73,7 +73,7 @@ Created 10/8/1995 Heikki Tuuri
 #include "fil0crypt.h"
 #include "fil0pagecompress.h"
 #include "trx0types.h"
-
+#include <list>
 
 #include <my_service_manager.h>
 /* The following is the maximum allowed duration of a lock wait. */
@@ -2110,7 +2110,7 @@ static uint32_t srv_do_purge(ulint* n_total_purged)
 }
 
 
-static std::queue<THD*> purge_thds;
+static std::list<THD*> purge_thds;
 static std::mutex purge_thd_mutex;
 extern void* thd_attach_thd(THD*);
 extern void thd_detach_thd(void *);
@@ -2120,11 +2120,11 @@ THD* acquire_thd(void **ctx)
 	std::unique_lock<std::mutex> lk(purge_thd_mutex);
 	if (purge_thds.empty()) {
 		THD* thd = current_thd;
-		purge_thds.push(innobase_create_background_thd("InnoDB purge worker"));
+		purge_thds.push_back(innobase_create_background_thd("InnoDB purge worker"));
 		set_current_thd(thd);
 	}
 	THD* thd = purge_thds.front();
-	purge_thds.pop();
+	purge_thds.pop_front();
 	lk.unlock();
 
 	/* Set current thd, and thd->mysys_var as well,
@@ -2137,7 +2137,7 @@ void release_thd(THD *thd, void *ctx)
 {
 	thd_detach_thd(ctx);
 	std::unique_lock<std::mutex> lk(purge_thd_mutex);
-	purge_thds.push(thd);
+	purge_thds.push_back(thd);
 	lk.unlock();
 	set_current_thd(0);
 }
@@ -2236,7 +2236,7 @@ static void srv_shutdown_purge_tasks()
   while (!purge_thds.empty())
   {
     innobase_destroy_background_thd(purge_thds.front());
-    purge_thds.pop();
+    purge_thds.pop_front();
   }
 }