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test.c
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1 /*--------------------------------------------------------------------------
2  *
3  * test.c
4  * Test harness code for shared memory message queues.
5  *
6  * Copyright (c) 2013-2017, PostgreSQL Global Development Group
7  *
8  * IDENTIFICATION
9  * src/test/modules/test_shm_mq/test.c
10  *
11  * -------------------------------------------------------------------------
12  */
13 
14 #include "postgres.h"
15 
16 #include "fmgr.h"
17 #include "miscadmin.h"
18 #include "pgstat.h"
19 
20 #include "test_shm_mq.h"
21 
23 
26 
27 void _PG_init(void);
28 
29 static void verify_message(Size origlen, char *origdata, Size newlen,
30  char *newdata);
31 
32 /*
33  * Simple test of the shared memory message queue infrastructure.
34  *
35  * We set up a ring of message queues passing through 1 or more background
36  * processes and eventually looping back to ourselves. We then send a message
37  * through the ring a number of times indicated by the loop count. At the end,
38  * we check whether the final message matches the one we started with.
39  */
40 Datum
42 {
43  int64 queue_size = PG_GETARG_INT64(0);
44  text *message = PG_GETARG_TEXT_PP(1);
45  char *message_contents = VARDATA_ANY(message);
46  int message_size = VARSIZE_ANY_EXHDR(message);
47  int32 loop_count = PG_GETARG_INT32(2);
48  int32 nworkers = PG_GETARG_INT32(3);
49  dsm_segment *seg;
50  shm_mq_handle *outqh;
51  shm_mq_handle *inqh;
52  shm_mq_result res;
53  Size len;
54  void *data;
55 
56  /* A negative loopcount is nonsensical. */
57  if (loop_count < 0)
58  ereport(ERROR,
59  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
60  errmsg("repeat count size must be a non-negative integer")));
61 
62  /*
63  * Since this test sends data using the blocking interfaces, it cannot
64  * send data to itself. Therefore, a minimum of 1 worker is required. Of
65  * course, a negative worker count is nonsensical.
66  */
67  if (nworkers < 1)
68  ereport(ERROR,
69  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
70  errmsg("number of workers must be a positive integer")));
71 
72  /* Set up dynamic shared memory segment and background workers. */
73  test_shm_mq_setup(queue_size, nworkers, &seg, &outqh, &inqh);
74 
75  /* Send the initial message. */
76  res = shm_mq_send(outqh, message_size, message_contents, false);
77  if (res != SHM_MQ_SUCCESS)
78  ereport(ERROR,
79  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
80  errmsg("could not send message")));
81 
82  /*
83  * Receive a message and send it back out again. Do this a number of
84  * times equal to the loop count.
85  */
86  for (;;)
87  {
88  /* Receive a message. */
89  res = shm_mq_receive(inqh, &len, &data, false);
90  if (res != SHM_MQ_SUCCESS)
91  ereport(ERROR,
92  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
93  errmsg("could not receive message")));
94 
95  /* If this is supposed to be the last iteration, stop here. */
96  if (--loop_count <= 0)
97  break;
98 
99  /* Send it back out. */
100  res = shm_mq_send(outqh, len, data, false);
101  if (res != SHM_MQ_SUCCESS)
102  ereport(ERROR,
103  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
104  errmsg("could not send message")));
105  }
106 
107  /*
108  * Finally, check that we got back the same message from the last
109  * iteration that we originally sent.
110  */
111  verify_message(message_size, message_contents, len, data);
112 
113  /* Clean up. */
114  dsm_detach(seg);
115 
116  PG_RETURN_VOID();
117 }
118 
119 /*
120  * Pipelined test of the shared memory message queue infrastructure.
121  *
122  * As in the basic test, we set up a ring of message queues passing through
123  * 1 or more background processes and eventually looping back to ourselves.
124  * Then, we send N copies of the user-specified message through the ring and
125  * receive them all back. Since this might fill up all message queues in the
126  * ring and then stall, we must be prepared to begin receiving the messages
127  * back before we've finished sending them.
128  */
129 Datum
131 {
132  int64 queue_size = PG_GETARG_INT64(0);
133  text *message = PG_GETARG_TEXT_PP(1);
134  char *message_contents = VARDATA_ANY(message);
135  int message_size = VARSIZE_ANY_EXHDR(message);
136  int32 loop_count = PG_GETARG_INT32(2);
137  int32 nworkers = PG_GETARG_INT32(3);
138  bool verify = PG_GETARG_BOOL(4);
139  int32 send_count = 0;
140  int32 receive_count = 0;
141  dsm_segment *seg;
142  shm_mq_handle *outqh;
143  shm_mq_handle *inqh;
144  shm_mq_result res;
145  Size len;
146  void *data;
147 
148  /* A negative loopcount is nonsensical. */
149  if (loop_count < 0)
150  ereport(ERROR,
151  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
152  errmsg("repeat count size must be a non-negative integer")));
153 
154  /*
155  * Using the nonblocking interfaces, we can even send data to ourselves,
156  * so the minimum number of workers for this test is zero.
157  */
158  if (nworkers < 0)
159  ereport(ERROR,
160  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
161  errmsg("number of workers must be a non-negative integer")));
162 
163  /* Set up dynamic shared memory segment and background workers. */
164  test_shm_mq_setup(queue_size, nworkers, &seg, &outqh, &inqh);
165 
166  /* Main loop. */
167  for (;;)
168  {
169  bool wait = true;
170 
171  /*
172  * If we haven't yet sent the message the requisite number of times,
173  * try again to send it now. Note that when shm_mq_send() returns
174  * SHM_MQ_WOULD_BLOCK, the next call to that function must pass the
175  * same message size and contents; that's not an issue here because
176  * we're sending the same message every time.
177  */
178  if (send_count < loop_count)
179  {
180  res = shm_mq_send(outqh, message_size, message_contents, true);
181  if (res == SHM_MQ_SUCCESS)
182  {
183  ++send_count;
184  wait = false;
185  }
186  else if (res == SHM_MQ_DETACHED)
187  ereport(ERROR,
188  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
189  errmsg("could not send message")));
190  }
191 
192  /*
193  * If we haven't yet received the message the requisite number of
194  * times, try to receive it again now.
195  */
196  if (receive_count < loop_count)
197  {
198  res = shm_mq_receive(inqh, &len, &data, true);
199  if (res == SHM_MQ_SUCCESS)
200  {
201  ++receive_count;
202  /* Verifying every time is slow, so it's optional. */
203  if (verify)
204  verify_message(message_size, message_contents, len, data);
205  wait = false;
206  }
207  else if (res == SHM_MQ_DETACHED)
208  ereport(ERROR,
209  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
210  errmsg("could not receive message")));
211  }
212  else
213  {
214  /*
215  * Otherwise, we've received the message enough times. This
216  * shouldn't happen unless we've also sent it enough times.
217  */
218  if (send_count != receive_count)
219  ereport(ERROR,
220  (errcode(ERRCODE_INTERNAL_ERROR),
221  errmsg("message sent %d times, but received %d times",
222  send_count, receive_count)));
223  break;
224  }
225 
226  if (wait)
227  {
228  /*
229  * If we made no progress, wait for one of the other processes to
230  * which we are connected to set our latch, indicating that they
231  * have read or written data and therefore there may now be work
232  * for us to do.
233  */
237  }
238  }
239 
240  /* Clean up. */
241  dsm_detach(seg);
242 
243  PG_RETURN_VOID();
244 }
245 
246 /*
247  * Verify that two messages are the same.
248  */
249 static void
250 verify_message(Size origlen, char *origdata, Size newlen, char *newdata)
251 {
252  Size i;
253 
254  if (origlen != newlen)
255  ereport(ERROR,
256  (errmsg("message corrupted"),
257  errdetail("The original message was %zu bytes but the final message is %zu bytes.",
258  origlen, newlen)));
259 
260  for (i = 0; i < origlen; ++i)
261  if (origdata[i] != newdata[i])
262  ereport(ERROR,
263  (errmsg("message corrupted"),
264  errdetail("The new and original messages differ at byte %zu of %zu.", i, origlen)));
265 }
#define PG_GETARG_INT32(n)
Definition: fmgr.h:225
#define VARDATA_ANY(PTR)
Definition: postgres.h:349
int errcode(int sqlerrcode)
Definition: elog.c:575
#define PG_GETARG_BOOL(n)
Definition: fmgr.h:230
void ResetLatch(volatile Latch *latch)
Definition: latch.c:462
signed int int32
Definition: c.h:253
#define PG_GETARG_TEXT_PP(n)
Definition: fmgr.h:270
int WaitLatch(volatile Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:301
#define ERROR
Definition: elog.h:43
static void verify_message(Size origlen, char *origdata, Size newlen, char *newdata)
Definition: test.c:250
int errdetail(const char *fmt,...)
Definition: elog.c:873
#define ereport(elevel, rest)
Definition: elog.h:122
PG_FUNCTION_INFO_V1(test_shm_mq)
uintptr_t Datum
Definition: postgres.h:374
Datum test_shm_mq(PG_FUNCTION_ARGS)
Definition: test.c:41
#define PG_WAIT_EXTENSION
Definition: pgstat.h:723
void _PG_init(void)
Definition: auth_delay.c:54
shm_mq_result
Definition: shm_mq.h:36
#define PG_RETURN_VOID()
Definition: fmgr.h:293
size_t Size
Definition: c.h:352
shm_mq_result shm_mq_send(shm_mq_handle *mqh, Size nbytes, const void *data, bool nowait)
Definition: shm_mq.c:321
PG_MODULE_MAGIC
Definition: test.c:22
void dsm_detach(dsm_segment *seg)
Definition: dsm.c:715
#define VARSIZE_ANY_EXHDR(PTR)
Definition: postgres.h:342
int errmsg(const char *fmt,...)
Definition: elog.c:797
Datum test_shm_mq_pipelined(PG_FUNCTION_ARGS)
Definition: test.c:130
int i
struct Latch * MyLatch
Definition: globals.c:51
Definition: c.h:434
#define PG_FUNCTION_ARGS
Definition: fmgr.h:150
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:97
shm_mq_result shm_mq_receive(shm_mq_handle *mqh, Size *nbytesp, void **datap, bool nowait)
Definition: shm_mq.c:518
#define PG_GETARG_INT64(n)
Definition: fmgr.h:238
#define WL_LATCH_SET
Definition: latch.h:124
void test_shm_mq_setup(int64 queue_size, int32 nworkers, dsm_segment **segp, shm_mq_handle **output, shm_mq_handle **input)
Definition: setup.c:49