Prevent bugs by making DBUG_* expressions syntactically equivalent

to a single statement.
---
Bug#24795: SHOW PROFILE

Profiling is only partially functional on some architectures.  Where 
there is no getrusage() system call, presently Null values are 
returned where it would be required.  Notably, Windows needs some love 
applied to make it as useful.

  Syntax this adds:
  
  SHOW PROFILES
  
  SHOW PROFILE [types] [FOR QUERY n] [OFFSET n] [LIMIT n]
   where "n" is an integer
   and "types" is zero or many (comma-separated) of
      "CPU"
      "MEMORY" (not presently supported)
      "BLOCK IO"
      "CONTEXT SWITCHES"
      "PAGE FAULTS"
      "IPC"
      "SWAPS"
      "SOURCE"
      "ALL"

It also adds a session variable (boolean) "profiling", set to "no"
by default, and (integer) profiling_history_size, set to 15 by 
default.

This patch abstracts setting THDs' "proc_info" behind a macro that 
can be used as a hook into the profiling code when profiling 
support is compiled in.  All future code in this line should use
that mechanism for setting thd->proc_info.

---

Tests are now set to omit the statistics.

---

Adds an Information_schema table, "profiling" for access to 
"show profile" data.
---
Merge zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-5.0-community-3--bug24795
into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-5.0-community
---
Fix merge problems.
---
Fixed one bug in the query_source being NULL.  

Updated test results.
---
Include more thorough profiling tests.

Improve support for prepared statements.

Use session-specific query IDs, starting at zero.
---
Selecting from I_S.profiling is no longer quashed in profiling, as
requested by Giuseppe.

Limit the size of captured query text.

No longer log queries that are zero length.

1 files changed, 502 insertions, 130 deletions

diff --git a/sql/sql_profile.cc b/sql/sql_profile.cc
index 98a5f8d7576..e9b6ef0b522 100644
--- a/sql/sql_profile.cc
+++ b/sql/sql_profile.cc
@@ -14,149 +14,282 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA */
 
+
 #include "mysql_priv.h"
-#include "sp_rcontext.h"
+#include "my_sys.h"
+
+#define TIME_FLOAT_DIGITS 7
+#define MAX_QUERY_LENGTH 300
+
+bool schema_table_store_record(THD *thd, TABLE *table);
+
+/* Reserved for systems that can't record the function name in source. */
+const char *_db_func_= "<unknown>";
+
+/**
+  Connects Information_Schema and Profiling.
+*/
+int fill_query_profile_statistics_info(THD *thd, struct st_table_list *tables, 
+                                       Item *cond)
+{
+#ifdef ENABLED_PROFILING
+  return(thd->profiling.fill_statistics_info(thd, tables, cond));
+#else
+  return(1);
+#endif
+}
 
-#define RUSAGE_USEC(tv)  ((tv).tv_sec*1000000 + (tv).tv_usec)
+ST_FIELD_INFO query_profile_statistics_info[]=
+{
+  /* name, length, type, value, maybe_null, old_name */
+  {"Query_id", 20, MYSQL_TYPE_LONG, 0, false, NULL},
+  {"Seq", 20, MYSQL_TYPE_LONG, 0, false, NULL},
+  {"State", 30, MYSQL_TYPE_STRING, 0, false, NULL},
+  {"Duration", TIME_FLOAT_DIGITS, MYSQL_TYPE_DOUBLE, 0, false, NULL},
+  {"CPU_user", TIME_FLOAT_DIGITS, MYSQL_TYPE_DOUBLE, 0, true, NULL},
+  {"CPU_system", TIME_FLOAT_DIGITS, MYSQL_TYPE_DOUBLE, 0, true, NULL},
+  {"Context_voluntary", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Context_involuntary", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Block_ops_in", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Block_ops_out", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Messages_sent", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Messages_received", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Page_faults_major", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Page_faults_minor", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Swaps", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {"Source_function", 30, MYSQL_TYPE_STRING, 0, true, NULL},
+  {"Source_file", 20, MYSQL_TYPE_STRING, 0, true, NULL},
+  {"Source_line", 20, MYSQL_TYPE_LONG, 0, true, NULL},
+  {NULL, 0, MYSQL_TYPE_STRING, 0, true, NULL}
+};
+
+#ifdef ENABLED_PROFILING
+
+#define RUSAGE_USEC(tv)  ((tv).tv_sec*1000*1000 + (tv).tv_usec)
 #define RUSAGE_DIFF_USEC(tv1, tv2) (RUSAGE_USEC((tv1))-RUSAGE_USEC((tv2)))
 
 PROFILE_ENTRY::PROFILE_ENTRY()
-  :status(NULL), time(0), function(NULL), file(NULL), line(0)
+  :profile(NULL), status(NULL), function(NULL), file(NULL), line(0), 
+  time_usecs(0.0), allocated_status_memory(NULL)
 {
   collect();
 }
 
-PROFILE_ENTRY::PROFILE_ENTRY(PROFILE *profile_arg, const char *status_arg)
-  :profile(profile_arg), function(NULL), file(NULL), line(0)
+PROFILE_ENTRY::PROFILE_ENTRY(QUERY_PROFILE *profile_arg, const char *status_arg)
+  :profile(profile_arg)
 {
   collect();
-  if (status_arg)
-    set_status(status_arg);
+  set_status(status_arg, NULL, NULL, 0);
 }
 
-PROFILE_ENTRY::PROFILE_ENTRY(PROFILE *profile_arg, const char *status_arg,
+PROFILE_ENTRY::PROFILE_ENTRY(QUERY_PROFILE *profile_arg, const char *status_arg,
                              const char *function_arg,
                              const char *file_arg, unsigned int line_arg)
   :profile(profile_arg)
 {
   collect();
-  if (status_arg)
-    set_status(status_arg);
-  if (function_arg)
-    function= strdup_root(&profile->profiling->root, function_arg);
-  if (file_arg)
-    file= strdup_root(&profile->profiling->root, file_arg);
-  line= line_arg;
+  set_status(status_arg, function_arg, file_arg, line_arg);
 }
 
 PROFILE_ENTRY::~PROFILE_ENTRY()
 {
-  if (status)
-    free(status);
-  if (function)
-    free(function);
-  if (file)
-    free(file);
+  if (allocated_status_memory != NULL)
+    my_free(allocated_status_memory, MYF(0));
+  status= function= file= NULL;
 }
   
-void PROFILE_ENTRY::set_status(const char *status_arg)
+void PROFILE_ENTRY::set_status(const char *status_arg, const char *function_arg, const char *file_arg, unsigned int line_arg)
 {
-  status= strdup_root(&profile->profiling->root, status_arg);
+  size_t sizes[3];                              /* 3 == status+function+file */
+  char *cursor;
+
+  /*
+    Compute all the space we'll need to allocate one block for everything
+    we'll need, instead of N mallocs.
+  */
+  if (status_arg != NULL)
+    sizes[0]= strlen(status_arg) + 1;
+  else
+    sizes[0]= 0;
+
+  if (function_arg != NULL)
+    sizes[1]= strlen(function_arg) + 1;
+  else
+    sizes[1]= 0;
+
+  if (file_arg != NULL)
+    sizes[2]= strlen(file_arg) + 1;
+  else
+    sizes[2]= 0;
+    
+  allocated_status_memory= (char *) my_malloc(sizes[0] + sizes[1] + sizes[2], MYF(0));
+  DBUG_ASSERT(allocated_status_memory != NULL);
+
+  cursor= allocated_status_memory;
+
+  if (status_arg != NULL)
+  {
+    strcpy(cursor, status_arg);
+    status= cursor;
+    cursor+= sizes[0];
+  }
+  else
+    status= NULL;
+
+  if (function_arg != NULL)
+  {
+    strcpy(cursor, function_arg);
+    function= cursor;
+    cursor+= sizes[1];
+  }
+  else
+    function= NULL;
+
+  if (file_arg != NULL)
+  {
+    strcpy(cursor, file_arg);
+    file= cursor;
+    cursor+= sizes[2];
+  }
+  else
+    file= NULL;
+
+  line= line_arg;
 }
 
 void PROFILE_ENTRY::collect()
 {
-  time= my_getsystime();
+  time_usecs= (double) my_getsystime() / 10.0;  /* 1 sec was 1e7, now is 1e6 */
+#ifdef HAVE_GETRUSAGE
   getrusage(RUSAGE_SELF, &rusage);
+#endif
 }
 
-PROFILE::PROFILE(PROFILING *profiling_arg)
-  :profiling(profiling_arg)
+QUERY_PROFILE::QUERY_PROFILE(PROFILING *profiling_arg, char *query_source_arg,
+                             uint query_length_arg)
+  :profiling(profiling_arg), server_query_id(-1), profiling_query_id(-1),
+  query_source(NULL)
 {
   profile_end= &profile_start;
+  set_query_source(query_source_arg, query_length_arg);
 }
 
-PROFILE::~PROFILE()
+void QUERY_PROFILE::set_query_source(char *query_source_arg, 
+                                     uint query_length_arg)
 {
+  /* Truncate to avoid DoS attacks. */
+  uint length= min(MAX_QUERY_LENGTH, query_length_arg); 
+  /* TODO?: Provide a way to include the full text, as in  SHOW PROCESSLIST. */
+
+  if (query_source_arg != NULL)
+    query_source= my_strdup_with_length(query_source_arg, length, MYF(0));
+}
+
+QUERY_PROFILE::~QUERY_PROFILE()
+{
+  PROFILE_ENTRY *entry;
+  List_iterator<PROFILE_ENTRY> it(entries);
+  while ((entry= it++) != NULL)
+    delete entry;
   entries.empty();
+
+  if (query_source != NULL)
+    my_free(query_source, MYF(0));
 }
 
-void PROFILE::status(const char *status_arg,
-                     const char *function_arg=NULL,
-                     const char *file_arg=NULL, unsigned int line_arg=0)
+void QUERY_PROFILE::status(const char *status_arg,
+                     const char *function_arg= NULL,
+                     const char *file_arg= NULL, unsigned int line_arg= 0)
 {
-  PROFILE_ENTRY *prof= NULL;
-  MEM_ROOT *old_root= NULL;
   THD *thd= profiling->thd;
-
-  DBUG_ENTER("PROFILE::status");
+  PROFILE_ENTRY *prof;
+  MEM_ROOT *saved_mem_root;
+  DBUG_ENTER("QUERY_PROFILE::status");
 
   /* Blank status.  Just return, and thd->proc_info will be set blank later. */
-  if (unlikely(!status_arg))
+  if (unlikely(status_arg == NULL))
     DBUG_VOID_RETURN;
 
   /* If thd->proc_info is currently set to status_arg, don't profile twice. */
-  if (unlikely(thd->proc_info && !(strcmp(thd->proc_info, status_arg))))
+  if (likely((thd->proc_info != NULL) && 
+      ((thd->proc_info == status_arg) || 
+       (strcmp(thd->proc_info, status_arg) == 0))))
+  {
     DBUG_VOID_RETURN;
+  }
 
   /* Is this the same query as our profile currently contains? */
-  if (unlikely(thd->query_id != query_id && !thd->spcont))
+  if (unlikely((thd->query_id != server_query_id) && !thd->spcont))
     reset();
     
   /*
     In order to keep the profile information between queries (i.e. from
     SELECT to the following SHOW PROFILE command) the following code is
     necessary to keep the profile from getting freed automatically when
-    mysqld cleans up after the query.  This code is shamelessly stolen
-    from SHOW WARNINGS.
+    mysqld cleans up after the query.
+
+    The "entries" list allocates is memory from the current thd's mem_root.
+    We substitute our mem_root temporarily so that we intercept those
+    allocations into our own mem_root.
     
     The thd->mem_root structure is freed after each query is completed,
     so temporarily override it.
   */
-  old_root= thd->mem_root;
-  thd->mem_root= &profiling->root;
-  if (function_arg && file_arg) {
-    if ((profile_end= prof= new PROFILE_ENTRY(this, status_arg, function_arg, file_arg, line_arg)))
+  saved_mem_root= thd->mem_root;
+  thd->mem_root= &profiling->mem_root;
+  //thd->mem_root= NULL;
+
+  if (function_arg && file_arg) 
+  {
+    if ((profile_end= prof= new PROFILE_ENTRY(this, status_arg, function_arg, 
+                                              file_arg, line_arg)))
       entries.push_back(prof);
-  } else {
+  } 
+  else 
+  {
     if ((profile_end= prof= new PROFILE_ENTRY(this, status_arg)))
       entries.push_back(prof);
   }
-  thd->mem_root= old_root;
+
+  /* Restore mem_root */
+  thd->mem_root= saved_mem_root;
 
   DBUG_VOID_RETURN;
 }
 
-void PROFILE::reset()
+void QUERY_PROFILE::reset()
 {
-  DBUG_ENTER("PROFILE::reset");
-  if (profiling->thd->query_id != query_id)
+  DBUG_ENTER("QUERY_PROFILE::reset");
+  if (likely(profiling->thd->query_id != server_query_id))
   {
-    query_id= profiling->thd->query_id;
+    server_query_id= profiling->thd->query_id; /* despite name, is global */
     profile_start.collect();
+
+    PROFILE_ENTRY *entry;
+    List_iterator<PROFILE_ENTRY> it(entries);
+    while ((entry= it++) != NULL)
+      delete entry;
     entries.empty();
   }
   DBUG_VOID_RETURN;
 }
 
-bool PROFILE::show(uint options)
+bool QUERY_PROFILE::show(uint options)
 {  
-  PROFILE_ENTRY *prof;
   THD *thd= profiling->thd;
-  PROFILE_ENTRY *ps= &profile_start;
   List<Item> field_list;
-  DBUG_ENTER("PROFILE::show");
+  DBUG_ENTER("QUERY_PROFILE::show");
 
   field_list.push_back(new Item_empty_string("Status", MYSQL_ERRMSG_SIZE));
-  field_list.push_back(new Item_return_int("Time_elapsed", 20,
-                                           MYSQL_TYPE_LONGLONG));
+  field_list.push_back(new Item_return_int("Duration", TIME_FLOAT_DIGITS,
+                                           MYSQL_TYPE_DOUBLE));
 
   if (options & PROFILE_CPU)
   {
-    field_list.push_back(new Item_return_int("CPU_user", 20,
-                                             MYSQL_TYPE_LONGLONG));
-    field_list.push_back(new Item_return_int("CPU_system", 20, 
-                                             MYSQL_TYPE_LONGLONG));
+    field_list.push_back(new Item_return_int("CPU_user", TIME_FLOAT_DIGITS,
+                                             MYSQL_TYPE_DOUBLE));
+    field_list.push_back(new Item_return_int("CPU_system", TIME_FLOAT_DIGITS, 
+                                             MYSQL_TYPE_DOUBLE));
   }
   
   if (options & PROFILE_MEMORY)
@@ -200,7 +333,7 @@ bool PROFILE::show(uint options)
     field_list.push_back(new Item_return_int("Swaps", 10, MYSQL_TYPE_LONG));
   }
   
-  if(options & PROFILE_SOURCE)
+  if (options & PROFILE_SOURCE)
   {
     field_list.push_back(new Item_empty_string("Source_function",
                                                MYSQL_ERRMSG_SIZE));  
@@ -214,146 +347,231 @@ bool PROFILE::show(uint options)
                                  Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))
     DBUG_RETURN(TRUE);
 
+  Protocol *protocol= thd->protocol;
   SELECT_LEX *sel= &thd->lex->select_lex;
   SELECT_LEX_UNIT *unit= &thd->lex->unit;
   ha_rows idx= 0;
-  Protocol *protocol=thd->protocol;
-
   unit->set_limit(sel);
+  double last_time= profile_start.time_usecs;
+#ifdef HAVE_GETRUSAGE
+  struct rusage *last_rusage= &(profile_start.rusage);
+#endif
 
   List_iterator<PROFILE_ENTRY> it(entries);
-  ulonglong last_time= ps->time;
-  while ((prof= it++))
+  PROFILE_ENTRY *entry;
+  while ((entry= it++) != NULL)
   {
+#ifdef HAVE_GETRUSAGE
+    struct rusage *rusage= &(entry->rusage);
+#endif
+    String elapsed;
+
     if (++idx <= unit->offset_limit_cnt)
       continue;
     if (idx > unit->select_limit_cnt)
       break;
 
     protocol->prepare_for_resend();
-    protocol->store(prof->status, strlen(prof->status), system_charset_info);
-    protocol->store((ulonglong)(prof->time - ps->time)/10);
+    protocol->store(entry->status, strlen(entry->status), system_charset_info);
+    protocol->store((double)(entry->time_usecs - last_time)/(1000.0*1000),
+                    (uint32) TIME_FLOAT_DIGITS-1, &elapsed);
+    //protocol->store((double)(entry->time - last_time)/(1000*1000*10));
 
     if (options & PROFILE_CPU)
     {
-      protocol->store((ulonglong)RUSAGE_DIFF_USEC(prof->rusage.ru_utime,
-                                                  ps->rusage.ru_utime));
-      protocol->store((ulonglong)RUSAGE_DIFF_USEC(prof->rusage.ru_stime,
-                                                  ps->rusage.ru_stime));
+#ifdef HAVE_GETRUSAGE
+      String cpu_utime, cpu_stime;
+      protocol->store((double)(RUSAGE_DIFF_USEC(rusage->ru_utime,
+                      last_rusage->ru_utime))/(1000.0*1000),
+                      (uint32) TIME_FLOAT_DIGITS-1, &cpu_utime);
+      protocol->store((double)(RUSAGE_DIFF_USEC(rusage->ru_stime,
+                      last_rusage->ru_stime))/(1000.0*1000),
+                      (uint32) TIME_FLOAT_DIGITS-1, &cpu_stime);
+#else
+      protocol->store_null();
+      protocol->store_null();
+#endif
     }
     
     if (options & PROFILE_CONTEXT)
     {
-      protocol->store((uint32)(prof->rusage.ru_nvcsw - ps->rusage.ru_nvcsw));
-      protocol->store((uint32)(prof->rusage.ru_nivcsw - ps->rusage.ru_nivcsw));
+#ifdef HAVE_GETRUSAGE
+      protocol->store((uint32)(rusage->ru_nvcsw - last_rusage->ru_nvcsw));
+      protocol->store((uint32)(rusage->ru_nivcsw - last_rusage->ru_nivcsw));
+#else
+      protocol->store_null();
+      protocol->store_null();
+#endif
     }
 
     if (options & PROFILE_BLOCK_IO)
     {
-      protocol->store((uint32)(prof->rusage.ru_inblock-ps->rusage.ru_inblock));
-      protocol->store((uint32)(prof->rusage.ru_oublock-ps->rusage.ru_oublock));
+#ifdef HAVE_GETRUSAGE
+      protocol->store((uint32)(rusage->ru_inblock - last_rusage->ru_inblock));
+      protocol->store((uint32)(rusage->ru_oublock - last_rusage->ru_oublock));
+#else
+      protocol->store_null();
+      protocol->store_null();
+#endif
     }
     
     if (options & PROFILE_IPC)
     {
-      protocol->store((uint32)(prof->rusage.ru_msgsnd - ps->rusage.ru_msgsnd));
-      protocol->store((uint32)(prof->rusage.ru_msgrcv - ps->rusage.ru_msgrcv));
+#ifdef HAVE_GETRUSAGE
+      protocol->store((uint32)(rusage->ru_msgsnd - last_rusage->ru_msgsnd));
+      protocol->store((uint32)(rusage->ru_msgrcv - last_rusage->ru_msgrcv));
+#else
+      protocol->store_null();
+      protocol->store_null();
+#endif
     }
     
     if (options & PROFILE_PAGE_FAULTS)
     {
-      protocol->store((uint32)(prof->rusage.ru_majflt - ps->rusage.ru_majflt));
-      protocol->store((uint32)(prof->rusage.ru_minflt - ps->rusage.ru_minflt));
+#ifdef HAVE_GETRUSAGE
+      protocol->store((uint32)(rusage->ru_majflt - last_rusage->ru_majflt));
+      protocol->store((uint32)(rusage->ru_minflt - last_rusage->ru_minflt));
+#else
+      protocol->store_null();
+      protocol->store_null();
+#endif
     }
 
     if (options & PROFILE_SWAPS)
     {
-      protocol->store((uint32)(prof->rusage.ru_nswap - ps->rusage.ru_nswap));
+#ifdef HAVE_GETRUSAGE
+      protocol->store((uint32)(rusage->ru_nswap - last_rusage->ru_nswap));
+#else
+      protocol->store_null();
+#endif
     }
     
     if (options & PROFILE_SOURCE)
     {
-      if(prof->function && prof->file)
+      if ((entry->function != NULL) && (entry->file != NULL))
       {
-        protocol->store(prof->function, strlen(prof->function), system_charset_info);        
-        protocol->store(prof->file, strlen(prof->file), system_charset_info);
-        protocol->store(prof->line);
+        protocol->store(entry->function, strlen(entry->function),
+                        system_charset_info);        
+        protocol->store(entry->file, strlen(entry->file), system_charset_info);
+        protocol->store(entry->line);
       } else {
-        protocol->store("(unknown)", 10, system_charset_info);
-        protocol->store("(unknown)", 10, system_charset_info);
-        protocol->store((uint32) 0);
+        protocol->store_null();
+        protocol->store_null();
+        protocol->store_null();
       }
     }
 
     if (protocol->write())
       DBUG_RETURN(TRUE);
-    last_time= prof->time;
+
+    last_time= entry->time_usecs;
+#ifdef HAVE_GETRUSAGE
+    last_rusage= &(entry->rusage);
+#endif
+
   }
   send_eof(thd);
   DBUG_RETURN(FALSE);
 }
 
-/* XXX: enabled should be set to the current global profiling setting */
 PROFILING::PROFILING()
-  :enabled(1), keeping(1), current(NULL), last(NULL)
+  :profile_id_counter(0), keeping(1), current(NULL), last(NULL)
 {
-  init_sql_alloc(&root,
+  init_sql_alloc(&mem_root,
                  PROFILE_ALLOC_BLOCK_SIZE,
                  PROFILE_ALLOC_PREALLOC_SIZE);
 }
 
 PROFILING::~PROFILING()
 {
-  free_root(&root, MYF(0));
+  QUERY_PROFILE *prof;
+
+  List_iterator<QUERY_PROFILE> it(history);
+  while ((prof= it++) != NULL)
+    delete prof;
+  history.empty();
+
+  if (current != NULL)
+    delete current;
+
+  free_root(&mem_root, MYF(0));
 }
 
-void PROFILING::status(const char *status_arg,
-                       const char *function_arg,
-                       const char *file_arg, unsigned int line_arg)
+void PROFILING::status_change(const char *status_arg,
+                              const char *function_arg,
+                              const char *file_arg, unsigned int line_arg)
 {
-  DBUG_ENTER("PROFILING::status");
+  DBUG_ENTER("PROFILING::status_change");
   
-  if(!current)
-    reset();
+  if (unlikely((thd->options & OPTION_PROFILING) != 0))
+  {
+    if (unlikely(current == NULL))
+      reset();
+
+    DBUG_ASSERT(current != NULL);
 
-  if(unlikely(enabled))
     current->status(status_arg, function_arg, file_arg, line_arg);
-  
+  }
+
   thd->proc_info= status_arg;
-  
   DBUG_VOID_RETURN;
 }
 
 void PROFILING::store()
 {
-  MEM_ROOT *old_root;
+  MEM_ROOT *saved_mem_root;
   DBUG_ENTER("PROFILING::store");
 
-  if (last && current && (last->query_id == current->query_id))
+  /* Already stored */
+  if (unlikely((last != NULL) && 
+               (current != NULL) && 
+               (last->server_query_id == current->server_query_id)))
+  {
     DBUG_VOID_RETURN;
+  }
 
-  if (history.elements > 10)  /* XXX: global/session var */
+  while (history.elements > thd->variables.profiling_history_size)
   {
-    PROFILE *tmp= history.pop();
+    QUERY_PROFILE *tmp= history.pop();
     delete tmp;
   }
 
-  old_root= thd->mem_root;
-  thd->mem_root= &root;
+  /* 
+    Switch out memory roots so that we're sure that we keep what we need 
+    
+    The "history" list implementation allocates its memory in the current 
+    thd's mem_root.  We substitute our mem_root temporarily so that we
+    intercept those allocations into our own mem_root.
+  */
+
+  saved_mem_root= thd->mem_root;
+  thd->mem_root= &mem_root;
   
-  if (current)
+  if (current != NULL)
   {
-    if (keeping && (!current->entries.is_empty())) {
-      last= current;
+    if (keeping && 
+        (current->query_source != NULL) && 
+        (current->query_source[0] != '\0') && 
+        (!current->entries.is_empty())) 
+    {
+      current->profiling_query_id= next_profile_id();   /* assign an id */
+
+      last= current; /* never contains something that is not in the history. */
       history.push_back(current);
       current= NULL;
-    } else {
+    } 
+    else
+    {
       delete current;
+      current= NULL;
     }
   }
   
-  current= new PROFILE(this);
-  thd->mem_root= old_root;
+  DBUG_ASSERT(current == NULL);
+  current= new QUERY_PROFILE(this, thd->query, thd->query_length);
+
+  /* Restore memory root */
+  thd->mem_root= saved_mem_root;
 
   DBUG_VOID_RETURN;
 }
@@ -364,8 +582,8 @@ void PROFILING::reset()
 
   store();
 
-  current->reset();
-  /*free_root(&root, MYF(0));*/
+  if (current != NULL)
+    current->reset();
   keep();
 
   DBUG_VOID_RETURN;
@@ -373,15 +591,15 @@ void PROFILING::reset()
 
 bool PROFILING::show_profiles()
 {
-  PROFILE *prof;
+  DBUG_ENTER("PROFILING::show_profiles");
+  QUERY_PROFILE *prof;
   List<Item> field_list;
-  DBUG_ENTER("PROFILING::list_all");
 
   field_list.push_back(new Item_return_int("Query_ID", 10,
                                            MYSQL_TYPE_LONG));
-  field_list.push_back(new Item_return_int("Time", 20,
-                                           MYSQL_TYPE_LONGLONG));
-  /* TODO: Add another field that lists the query. */
+  field_list.push_back(new Item_return_int("Duration", TIME_FLOAT_DIGITS-1,
+                                           MYSQL_TYPE_DOUBLE));
+  field_list.push_back(new Item_empty_string("Query", 40));
                                            
   if (thd->protocol->send_fields(&field_list,
                                  Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))
@@ -390,13 +608,15 @@ bool PROFILING::show_profiles()
   SELECT_LEX *sel= &thd->lex->select_lex;
   SELECT_LEX_UNIT *unit= &thd->lex->unit;
   ha_rows idx= 0;
-  Protocol *protocol=thd->protocol;
+  Protocol *protocol= thd->protocol;
 
   unit->set_limit(sel);
   
-  List_iterator<PROFILE> it(history);
-  while ((prof= it++))
+  List_iterator<QUERY_PROFILE> it(history);
+  while ((prof= it++) != NULL)
   {
+    String elapsed;
+
     PROFILE_ENTRY *ps= &prof->profile_start;
     PROFILE_ENTRY *pe=  prof->profile_end;
 
@@ -406,8 +626,14 @@ bool PROFILING::show_profiles()
       break;
 
     protocol->prepare_for_resend();
-    protocol->store((uint32)(prof->query_id));
-    protocol->store((ulonglong)((pe->time - ps->time)/10));
+    protocol->store((uint32)(prof->profiling_query_id));
+    protocol->store((double)(pe->time_usecs - ps->time_usecs)/(1000.0*1000), 
+                    (uint32) TIME_FLOAT_DIGITS-1, &elapsed);
+    if (prof->query_source != NULL)
+      protocol->store(prof->query_source, strlen(prof->query_source), 
+                      system_charset_info);
+    else
+      protocol->store_null();
     
     if (protocol->write())
       DBUG_RETURN(TRUE);
@@ -416,18 +642,37 @@ bool PROFILING::show_profiles()
   DBUG_RETURN(FALSE);
 }
 
-bool PROFILING::show(uint options, uint query_id)
+/*
+  This is an awful hack to let prepared statements tell us the query
+  that they're executing.
+*/
+void PROFILING::set_query_source(char *query_source_arg, uint query_length_arg)
+{
+  DBUG_ENTER("PROFILING::set_query_source");
+
+  /* We can't get this query source through normal means. */
+  DBUG_ASSERT((thd->query == NULL) || (thd->query_length == 0));
+
+  if (current != NULL)
+    current->set_query_source(query_source_arg, query_length_arg);
+  else
+    DBUG_PRINT("info", ("no current profile to send query source to"));
+  DBUG_VOID_RETURN;
+}
+
+bool PROFILING::show(uint options, uint profiling_query_id)
 {
   DBUG_ENTER("PROFILING::show");
-  PROFILE *prof;
+  QUERY_PROFILE *prof;
 
-  List_iterator<PROFILE> it(history);
-  while ((prof= it++))
+  List_iterator<QUERY_PROFILE> it(history);
+  while ((prof= it++) != NULL)
   {
-    if(prof->query_id == query_id)
-      prof->show(options);
+    if(prof->profiling_query_id == profiling_query_id)
+      DBUG_RETURN(prof->show(options));
   }
 
+  my_error(ER_WRONG_ARGUMENTS, MYF(0), "SHOW PROFILE");
   DBUG_RETURN(TRUE);
 }
 
@@ -439,3 +684,130 @@ bool PROFILING::show_last(uint options)
   }
   DBUG_RETURN(TRUE);
 }
+
+
+/**
+  Fill the information schema table, "query_profile", as defined in show.cc .
+*/
+int PROFILING::fill_statistics_info(THD *thd, struct st_table_list *tables, Item *cond)
+{
+  DBUG_ENTER("PROFILING::fill_statistics_info");
+  TABLE *table= tables->table;
+  ulonglong row_number= 0;
+
+  List_iterator<QUERY_PROFILE> query_it(history);
+  QUERY_PROFILE *query;
+  /* Go through each query in this thread's stored history... */
+  while ((query= query_it++) != NULL)
+  {
+    PROFILE_ENTRY *ps= &(query->profile_start);
+    double last_time= ps->time_usecs;
+#ifdef HAVE_GETRUSAGE
+    struct rusage *last_rusage= &(ps->rusage);
+#endif
+
+    /*
+      Because we put all profiling info into a table that may be reordered, let
+      us also include a numbering of each state per query.  The query_id and
+      the "seq" together are unique.
+    */
+    ulonglong seq;
+
+    List_iterator<PROFILE_ENTRY> step_it(query->entries);
+    PROFILE_ENTRY *entry;
+    /* ...and for each query, go through all its state-change steps. */
+    for (seq= 0, entry= step_it++; 
+         entry != NULL; 
+#ifdef HAVE_GETRUSAGE
+         last_rusage= &(entry->rusage),
+#endif
+         seq++, last_time= entry->time_usecs, entry= step_it++, row_number++)
+    {
+      /* Set default values for this row. */
+      restore_record(table, s->default_values);
+
+      /*
+        The order of these fields is set by the  query_profile_statistics_info
+        array.
+      */
+      table->field[0]->store((ulonglong) query->profiling_query_id);
+      table->field[1]->store((ulonglong) seq); /* the step in the sequence */
+      table->field[2]->store(entry->status, strlen(entry->status), 
+                             system_charset_info);
+      table->field[3]->store((double)(entry->time_usecs - last_time)/(1000*1000));
+
+#ifdef HAVE_GETRUSAGE
+      table->field[4]->store((double)RUSAGE_DIFF_USEC(entry->rusage.ru_utime,
+                             last_rusage->ru_utime)/(1000.0*1000));
+      table->field[4]->null_ptr= NULL;
+      table->field[5]->store((double)RUSAGE_DIFF_USEC(entry->rusage.ru_stime,
+                             last_rusage->ru_stime)/(1000.0*1000));
+
+      table->field[5]->null_ptr= NULL;
+#else
+      /* TODO: Add CPU-usage info for non-BSD systems */
+#endif
+      
+#ifdef HAVE_GETRUSAGE
+      table->field[6]->store((uint32)(entry->rusage.ru_nvcsw - last_rusage->ru_nvcsw));
+      table->field[6]->null_ptr= NULL;
+      table->field[7]->store((uint32)(entry->rusage.ru_nivcsw - last_rusage->ru_nivcsw));
+      table->field[7]->null_ptr= NULL;
+#else
+      /* TODO: Add context switch info for non-BSD systems */
+#endif
+
+#ifdef HAVE_GETRUSAGE
+      table->field[8]->store((uint32)(entry->rusage.ru_inblock - last_rusage->ru_inblock));
+      table->field[8]->null_ptr= NULL;
+      table->field[9]->store((uint32)(entry->rusage.ru_oublock - last_rusage->ru_oublock));
+      table->field[9]->null_ptr= NULL;
+#else
+      /* TODO: Add block IO info for non-BSD systems */
+#endif
+    
+#ifdef HAVE_GETRUSAGE
+      table->field[10]->store((uint32)(entry->rusage.ru_msgsnd - last_rusage->ru_msgsnd), true);
+      table->field[10]->null_ptr= NULL;
+      table->field[11]->store((uint32)(entry->rusage.ru_msgrcv - last_rusage->ru_msgrcv), true);
+      table->field[11]->null_ptr= NULL;
+#else
+      /* TODO: Add message info for non-BSD systems */
+#endif
+    
+#ifdef HAVE_GETRUSAGE
+      table->field[12]->store((uint32)(entry->rusage.ru_majflt - last_rusage->ru_majflt), true);
+      table->field[12]->null_ptr= NULL;
+      table->field[13]->store((uint32)(entry->rusage.ru_minflt - last_rusage->ru_minflt), true);
+      table->field[13]->null_ptr= NULL;
+#else
+      /* TODO: Add page fault info for non-BSD systems */
+#endif
+
+#ifdef HAVE_GETRUSAGE
+      table->field[14]->store((uint32)(entry->rusage.ru_nswap - last_rusage->ru_nswap), true);
+      table->field[14]->null_ptr= NULL;
+#else
+      /* TODO: Add swap info for non-BSD systems */
+#endif
+    
+      if ((entry->function != NULL) && (entry->file != NULL))
+      {
+        table->field[15]->store(entry->function, strlen(entry->function),
+                        system_charset_info);        
+        table->field[15]->null_ptr= NULL;
+        table->field[16]->store(entry->file, strlen(entry->file), system_charset_info);
+        table->field[16]->null_ptr= NULL;
+        table->field[17]->store(entry->line, true);
+        table->field[17]->null_ptr= NULL;
+      }
+
+      if (schema_table_store_record(thd, table))
+        DBUG_RETURN(1);
+
+    }
+  }
+
+  DBUG_RETURN(0);
+}
+#endif /* ENABLED_PROFILING */