Clarify use of malloc()/realloc() and comment on it.

libgearman-server/connection.cc

@@ -680,10 +680,10 @@ gearmand_error_t gearman_server_con_add_job_timeout(gearman_server_con_st *con,
         if (con->timeout_event == NULL)
         {
           gearmand_con_st *dcon= con->con.context;
-          con->timeout_event= (struct event *)malloc(sizeof(struct event));
+          con->timeout_event= (struct event *)malloc(sizeof(struct event)); // libevent POD
           if (con->timeout_event == NULL)
           {
-            return gearmand_gerror("creating timeout event", GEARMAN_MEMORY_ALLOCATION_FAILURE);
+            return gearmand_merror("malloc(sizeof(struct event)", struct event, 1);
           }
           timeout_set(con->timeout_event, _server_job_timeout, job);
           event_base_set(dcon->thread->base, con->timeout_event);

libgearman-server/gearmand.cc

@@ -671,10 +671,10 @@ static gearmand_error_t _listen_init(gearmand_st *gearmand)
     }
 
     assert(port->listen_event == NULL);
-    port->listen_event= (struct event *)malloc(sizeof(struct event) * port->listen_count);
+    port->listen_event= (struct event *)malloc(sizeof(struct event) * port->listen_count); // libevent POD
     if (port->listen_event == NULL)
     {
-      return gearmand_merror("malloc", struct event, port->listen_count);
+      return gearmand_merror("malloc(sizeof(struct event) * port->listen_count)", struct event, port->listen_count);
     }
 
     for (uint32_t y= 0; y < port->listen_count; ++y)

libgearman-server/io.cc

@@ -712,12 +712,12 @@ gearmand_error_t gearman_io_recv(gearman_server_con_st *con, bool recv_data)
       break;
     }
 
-    packet->data= static_cast<char *>(malloc(packet->data_size));
+    packet->data= static_cast<char *>(realloc(NULL, packet->data_size));
     if (not packet->data)
     {
       // Server up the memory error first, in case _connection_close()
       // creates any.
-      gearmand_merror("malloc", char, packet->data_size);
+      gearmand_merror("realloc", char, packet->data_size);
       _connection_close(connection);
       return GEARMAN_MEMORY_ALLOCATION_FAILURE;
     }

libgearman-server/packet.cc

@@ -315,7 +315,7 @@ inline static gearmand_error_t packet_create_arg(gearmand_packet_st *packet,
     gearmand_log_debug(GEARMAN_DEFAULT_LOG_PARAM, "resizing packet buffer");
     if (packet->args == packet->args_buffer)
     {
-      packet->args= (char *)malloc(packet->args_size + arg_size);
+      packet->args= (char *)realloc(NULL, packet->args_size + arg_size);
       memcpy(packet->args, packet->args_buffer, packet->args_size);
     }
     else

libgearman-server/server.cc

@@ -1023,10 +1023,10 @@ _server_queue_work_data(gearman_server_job_st *server_job,
       }
       else
       {
-        data= (uint8_t *)malloc(packet->data_size);
+        data= (uint8_t *)realloc(NULL, packet->data_size);
         if (data == NULL)
         {
-          return gearmand_perror(errno, "malloc");
+          return gearmand_perror(errno, "realloc");
         }
 
         memcpy(data, packet->data, packet->data_size);

libgearman-server/text.cc

@@ -55,10 +55,10 @@ gearmand_error_t server_run_text(gearman_server_con_st *server_con,
 {
   size_t total;
 
-  char *data= (char *)malloc(GEARMAN_TEXT_RESPONSE_SIZE);
+  char *data= (char *)realloc(NULL, GEARMAN_TEXT_RESPONSE_SIZE);
   if (data == NULL)
   {
-    return gearmand_perror(errno, "malloc");
+    return gearmand_perror(errno, "realloc");
   }
   total= GEARMAN_TEXT_RESPONSE_SIZE;
   data[0]= 0;