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pgrowlocks.c File Reference
#include "postgres.h"
#include "access/multixact.h"
#include "access/relscan.h"
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "storage/bufmgr.h"
#include "storage/procarray.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
#include "utils/tqual.h"
#include "utils/varlena.h"
Include dependency graph for pgrowlocks.c:

Go to the source code of this file.

Data Structures

struct  MyData
 

Macros

#define NCHARS   32
 
#define Atnum_tid   0
 
#define Atnum_xmax   1
 
#define Atnum_ismulti   2
 
#define Atnum_xids   3
 
#define Atnum_modes   4
 
#define Atnum_pids   5
 

Functions

 PG_FUNCTION_INFO_V1 (pgrowlocks)
 
Datum pgrowlocks (PG_FUNCTION_ARGS)
 

Variables

 PG_MODULE_MAGIC
 

Macro Definition Documentation

#define Atnum_ismulti   2

Definition at line 64 of file pgrowlocks.c.

Referenced by pgrowlocks().

#define Atnum_modes   4

Definition at line 66 of file pgrowlocks.c.

Referenced by pgrowlocks().

#define Atnum_pids   5

Definition at line 67 of file pgrowlocks.c.

Referenced by pgrowlocks().

#define Atnum_tid   0

Definition at line 62 of file pgrowlocks.c.

Referenced by pgrowlocks().

#define Atnum_xids   3

Definition at line 65 of file pgrowlocks.c.

Referenced by pgrowlocks().

#define Atnum_xmax   1

Definition at line 63 of file pgrowlocks.c.

Referenced by pgrowlocks().

#define NCHARS   32

Definition at line 53 of file pgrowlocks.c.

Referenced by pgrowlocks().

Function Documentation

PG_FUNCTION_INFO_V1 ( pgrowlocks  )
Datum pgrowlocks ( PG_FUNCTION_ARGS  )

Definition at line 70 of file pgrowlocks.c.

References AccessShareLock, ACL_KIND_CLASS, ACL_SELECT, aclcheck_error(), ACLCHECK_NO_PRIV, ACLCHECK_OK, Atnum_ismulti, Atnum_modes, Atnum_pids, Atnum_tid, Atnum_xids, Atnum_xmax, FuncCallContext::attinmeta, BackendXidGetPid(), buf, BUFFER_LOCK_SHARE, BUFFER_LOCK_UNLOCK, BuildTupleFromCStrings(), DEFAULT_ROLE_STAT_SCAN_TABLES, DirectFunctionCall1, elog, ERROR, ForwardScanDirection, get_call_result_type(), GetActiveSnapshot(), GetCurrentCommandId(), GetMultiXactIdMembers(), GetUserId(), heap_beginscan(), heap_close, heap_endscan(), heap_getnext(), HEAP_KEYS_UPDATED, HEAP_LOCKED_UPGRADED, heap_openrv(), HEAP_XMAX_IS_EXCL_LOCKED, HEAP_XMAX_IS_KEYSHR_LOCKED, HEAP_XMAX_IS_MULTI, HEAP_XMAX_IS_SHR_LOCKED, HEAP_XMAX_LOCK_ONLY, HeapTupleBeingUpdated, HeapTupleGetDatum, HeapTupleHeaderGetRawXmax, HeapTupleSatisfiesUpdate(), is_member_of_role(), LockBuffer(), makeRangeVarFromNameList(), MemoryContextSwitchTo(), FuncCallContext::multi_call_memory_ctx, MultiXactStatusForKeyShare, MultiXactStatusForNoKeyUpdate, MultiXactStatusForShare, MultiXactStatusForUpdate, MultiXactStatusNoKeyUpdate, MultiXactStatusUpdate, tupleDesc::natts, NCHARS, MyData::ncolumns, NULL, palloc(), pg_class_aclcheck(), PG_GETARG_TEXT_PP, PointerGetDatum, pstrdup(), MyData::rel, RelationGetRelationName, RelationGetRelid, result, HeapScanDescData::rs_cbuf, MyData::scan, snprintf(), SRF_FIRSTCALL_INIT, SRF_IS_FIRSTCALL, SRF_PERCALL_SETUP, SRF_RETURN_DONE, SRF_RETURN_NEXT, status(), HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleHeaderData::t_infomask2, HeapTupleData::t_self, textToQualifiedNameList(), tidout(), TupleDescGetAttInMetadata(), TYPEFUNC_COMPOSITE, FuncCallContext::user_fctx, and values.

71 {
72  FuncCallContext *funcctx;
73  HeapScanDesc scan;
74  HeapTuple tuple;
75  TupleDesc tupdesc;
76  AttInMetadata *attinmeta;
77  Datum result;
78  MyData *mydata;
79  Relation rel;
80 
81  if (SRF_IS_FIRSTCALL())
82  {
83  text *relname;
84  RangeVar *relrv;
85  MemoryContext oldcontext;
86  AclResult aclresult;
87 
88  funcctx = SRF_FIRSTCALL_INIT();
89  oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
90 
91  /* Build a tuple descriptor for our result type */
92  if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
93  elog(ERROR, "return type must be a row type");
94 
95  attinmeta = TupleDescGetAttInMetadata(tupdesc);
96  funcctx->attinmeta = attinmeta;
97 
98  relname = PG_GETARG_TEXT_PP(0);
100  rel = heap_openrv(relrv, AccessShareLock);
101 
102  /* check permissions: must have SELECT on table or be in pg_stat_scan_tables */
103  aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
104  ACL_SELECT);
105  if (aclresult != ACLCHECK_OK)
107 
108  if (aclresult != ACLCHECK_OK)
109  aclcheck_error(aclresult, ACL_KIND_CLASS,
111 
112  scan = heap_beginscan(rel, GetActiveSnapshot(), 0, NULL);
113  mydata = palloc(sizeof(*mydata));
114  mydata->rel = rel;
115  mydata->scan = scan;
116  mydata->ncolumns = tupdesc->natts;
117  funcctx->user_fctx = mydata;
118 
119  MemoryContextSwitchTo(oldcontext);
120  }
121 
122  funcctx = SRF_PERCALL_SETUP();
123  attinmeta = funcctx->attinmeta;
124  mydata = (MyData *) funcctx->user_fctx;
125  scan = mydata->scan;
126 
127  /* scan the relation */
128  while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
129  {
130  HTSU_Result htsu;
131  TransactionId xmax;
132  uint16 infomask;
133 
134  /* must hold a buffer lock to call HeapTupleSatisfiesUpdate */
136 
137  htsu = HeapTupleSatisfiesUpdate(tuple,
138  GetCurrentCommandId(false),
139  scan->rs_cbuf);
140  xmax = HeapTupleHeaderGetRawXmax(tuple->t_data);
141  infomask = tuple->t_data->t_infomask;
142 
143  /*
144  * A tuple is locked if HTSU returns BeingUpdated.
145  */
146  if (htsu == HeapTupleBeingUpdated)
147  {
148  char **values;
149 
150  values = (char **) palloc(mydata->ncolumns * sizeof(char *));
151 
152  values[Atnum_tid] = (char *) DirectFunctionCall1(tidout,
153  PointerGetDatum(&tuple->t_self));
154 
155  values[Atnum_xmax] = palloc(NCHARS * sizeof(char));
156  snprintf(values[Atnum_xmax], NCHARS, "%d", xmax);
157  if (infomask & HEAP_XMAX_IS_MULTI)
158  {
159  MultiXactMember *members;
160  int nmembers;
161  bool first = true;
162  bool allow_old;
163 
164  values[Atnum_ismulti] = pstrdup("true");
165 
166  allow_old = HEAP_LOCKED_UPGRADED(infomask);
167  nmembers = GetMultiXactIdMembers(xmax, &members, allow_old,
168  false);
169  if (nmembers == -1)
170  {
171  values[Atnum_xids] = "{0}";
172  values[Atnum_modes] = "{transient upgrade status}";
173  values[Atnum_pids] = "{0}";
174  }
175  else
176  {
177  int j;
178 
179  values[Atnum_xids] = palloc(NCHARS * nmembers);
180  values[Atnum_modes] = palloc(NCHARS * nmembers);
181  values[Atnum_pids] = palloc(NCHARS * nmembers);
182 
183  strcpy(values[Atnum_xids], "{");
184  strcpy(values[Atnum_modes], "{");
185  strcpy(values[Atnum_pids], "{");
186 
187  for (j = 0; j < nmembers; j++)
188  {
189  char buf[NCHARS];
190 
191  if (!first)
192  {
193  strcat(values[Atnum_xids], ",");
194  strcat(values[Atnum_modes], ",");
195  strcat(values[Atnum_pids], ",");
196  }
197  snprintf(buf, NCHARS, "%d", members[j].xid);
198  strcat(values[Atnum_xids], buf);
199  switch (members[j].status)
200  {
202  snprintf(buf, NCHARS, "Update");
203  break;
205  snprintf(buf, NCHARS, "No Key Update");
206  break;
208  snprintf(buf, NCHARS, "For Update");
209  break;
211  snprintf(buf, NCHARS, "For No Key Update");
212  break;
214  snprintf(buf, NCHARS, "Share");
215  break;
217  snprintf(buf, NCHARS, "Key Share");
218  break;
219  }
220  strcat(values[Atnum_modes], buf);
221  snprintf(buf, NCHARS, "%d",
222  BackendXidGetPid(members[j].xid));
223  strcat(values[Atnum_pids], buf);
224 
225  first = false;
226  }
227 
228  strcat(values[Atnum_xids], "}");
229  strcat(values[Atnum_modes], "}");
230  strcat(values[Atnum_pids], "}");
231  }
232  }
233  else
234  {
235  values[Atnum_ismulti] = pstrdup("false");
236 
237  values[Atnum_xids] = palloc(NCHARS * sizeof(char));
238  snprintf(values[Atnum_xids], NCHARS, "{%d}", xmax);
239 
240  values[Atnum_modes] = palloc(NCHARS);
241  if (infomask & HEAP_XMAX_LOCK_ONLY)
242  {
243  if (HEAP_XMAX_IS_SHR_LOCKED(infomask))
244  snprintf(values[Atnum_modes], NCHARS, "{For Share}");
245  else if (HEAP_XMAX_IS_KEYSHR_LOCKED(infomask))
246  snprintf(values[Atnum_modes], NCHARS, "{For Key Share}");
247  else if (HEAP_XMAX_IS_EXCL_LOCKED(infomask))
248  {
249  if (tuple->t_data->t_infomask2 & HEAP_KEYS_UPDATED)
250  snprintf(values[Atnum_modes], NCHARS, "{For Update}");
251  else
252  snprintf(values[Atnum_modes], NCHARS, "{For No Key Update}");
253  }
254  else
255  /* neither keyshare nor exclusive bit it set */
256  snprintf(values[Atnum_modes], NCHARS,
257  "{transient upgrade status}");
258  }
259  else
260  {
261  if (tuple->t_data->t_infomask2 & HEAP_KEYS_UPDATED)
262  snprintf(values[Atnum_modes], NCHARS, "{Update}");
263  else
264  snprintf(values[Atnum_modes], NCHARS, "{No Key Update}");
265  }
266 
267  values[Atnum_pids] = palloc(NCHARS * sizeof(char));
268  snprintf(values[Atnum_pids], NCHARS, "{%d}",
269  BackendXidGetPid(xmax));
270  }
271 
273 
274  /* build a tuple */
275  tuple = BuildTupleFromCStrings(attinmeta, values);
276 
277  /* make the tuple into a datum */
278  result = HeapTupleGetDatum(tuple);
279 
280  /*
281  * no need to pfree what we allocated; it's on a short-lived
282  * memory context anyway
283  */
284 
285  SRF_RETURN_NEXT(funcctx, result);
286  }
287  else
288  {
290  }
291  }
292 
293  heap_endscan(scan);
294  heap_close(mydata->rel, AccessShareLock);
295 
296  SRF_RETURN_DONE(funcctx);
297 }
#define NCHARS
Definition: pgrowlocks.c:53
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:87
TypeFuncClass get_call_result_type(FunctionCallInfo fcinfo, Oid *resultTypeId, TupleDesc *resultTupleDesc)
Definition: funcapi.c:211
#define HEAP_XMAX_LOCK_ONLY
Definition: htup_details.h:182
void heap_endscan(HeapScanDesc scan)
Definition: heapam.c:1578
uint32 TransactionId
Definition: c.h:397
HTSU_Result HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid, Buffer buffer)
Definition: tqual.c:460
Oid GetUserId(void)
Definition: miscinit.c:283
#define SRF_IS_FIRSTCALL()
Definition: funcapi.h:285
#define PointerGetDatum(X)
Definition: postgres.h:562
char * pstrdup(const char *in)
Definition: mcxt.c:1077
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
Snapshot GetActiveSnapshot(void)
Definition: snapmgr.c:834
#define HEAP_LOCKED_UPGRADED(infomask)
Definition: htup_details.h:238
#define AccessShareLock
Definition: lockdefs.h:36
return result
Definition: formatting.c:1618
int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3
RangeVar * makeRangeVarFromNameList(List *names)
Definition: namespace.c:2913
#define heap_close(r, l)
Definition: heapam.h:97
#define DirectFunctionCall1(func, arg1)
Definition: fmgr.h:584
#define SRF_PERCALL_SETUP()
Definition: funcapi.h:289
int natts
Definition: tupdesc.h:73
HeapTuple BuildTupleFromCStrings(AttInMetadata *attinmeta, char **values)
Definition: execTuples.c:1115
#define PG_GETARG_TEXT_PP(n)
Definition: fmgr.h:273
#define HEAP_XMAX_IS_SHR_LOCKED(infomask)
Definition: htup_details.h:248
HeapTupleHeader t_data
Definition: htup.h:67
#define Atnum_tid
Definition: pgrowlocks.c:62
#define SRF_RETURN_NEXT(_funcctx, _result)
Definition: funcapi.h:291
Relation rel
Definition: pgrowlocks.c:57
#define HeapTupleHeaderGetRawXmax(tup)
Definition: htup_details.h:369
unsigned short uint16
Definition: c.h:267
#define ERROR
Definition: elog.h:43
ItemPointerData t_self
Definition: htup.h:65
static char * buf
Definition: pg_test_fsync.c:66
void aclcheck_error(AclResult aclerr, AclObjectKind objectkind, const char *objectname)
Definition: aclchk.c:3399
AttInMetadata * attinmeta
Definition: funcapi.h:99
HTSU_Result
Definition: snapshot.h:119
#define RelationGetRelationName(relation)
Definition: rel.h:437
List * textToQualifiedNameList(text *textval)
Definition: varlena.c:3182
int BackendXidGetPid(TransactionId xid)
Definition: procarray.c:2402
#define Atnum_modes
Definition: pgrowlocks.c:66
AclResult
Definition: acl.h:170
uintptr_t Datum
Definition: postgres.h:372
#define ACL_SELECT
Definition: parsenodes.h:73
AttInMetadata * TupleDescGetAttInMetadata(TupleDesc tupdesc)
Definition: execTuples.c:1068
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3546
#define HEAP_KEYS_UPDATED
Definition: htup_details.h:264
HeapTuple heap_getnext(HeapScanDesc scan, ScanDirection direction)
Definition: heapam.c:1794
#define HEAP_XMAX_IS_MULTI
Definition: htup_details.h:194
Relation heap_openrv(const RangeVar *relation, LOCKMODE lockmode)
Definition: heapam.c:1312
bool is_member_of_role(Oid member, Oid role)
Definition: acl.c:4837
Buffer rs_cbuf
Definition: relscan.h:70
#define NULL
Definition: c.h:229
MemoryContext multi_call_memory_ctx
Definition: funcapi.h:109
#define HeapTupleGetDatum(tuple)
Definition: funcapi.h:222
HeapScanDesc scan
Definition: pgrowlocks.c:58
AclResult pg_class_aclcheck(Oid table_oid, Oid roleid, AclMode mode)
Definition: aclchk.c:4422
static Datum values[MAXATTR]
Definition: bootstrap.c:163
#define Atnum_xids
Definition: pgrowlocks.c:65
void * user_fctx
Definition: funcapi.h:90
void * palloc(Size size)
Definition: mcxt.c:849
#define BUFFER_LOCK_SHARE
Definition: bufmgr.h:88
Definition: c.h:439
#define Atnum_pids
Definition: pgrowlocks.c:67
int ncolumns
Definition: pgrowlocks.c:59
#define HEAP_XMAX_IS_EXCL_LOCKED(infomask)
Definition: htup_details.h:250
CommandId GetCurrentCommandId(bool used)
Definition: xact.c:687
int GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **members, bool from_pgupgrade, bool onlyLock)
Definition: multixact.c:1202
#define elog
Definition: elog.h:219
#define DEFAULT_ROLE_STAT_SCAN_TABLES
Definition: pg_authid.h:113
#define HEAP_XMAX_IS_KEYSHR_LOCKED(infomask)
Definition: htup_details.h:252
static void static void status(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:224
HeapScanDesc heap_beginscan(Relation relation, Snapshot snapshot, int nkeys, ScanKey key)
Definition: heapam.c:1391
Datum tidout(PG_FUNCTION_ARGS)
Definition: tid.c:105
#define RelationGetRelid(relation)
Definition: rel.h:417
#define Atnum_xmax
Definition: pgrowlocks.c:63
#define SRF_RETURN_DONE(_funcctx)
Definition: funcapi.h:309
#define Atnum_ismulti
Definition: pgrowlocks.c:64
#define SRF_FIRSTCALL_INIT()
Definition: funcapi.h:287

Variable Documentation

PG_MODULE_MAGIC

Definition at line 43 of file pgrowlocks.c.