16302681875

Committed 15 Jul 2025 07:37PM UTC coverage: 92.07% (-0.3%) from 92.322%

Build # 16302681875

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push

github

Committed by

steve-chavez

Commit Message

bump to 0.19.2

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476 of 517 relevant lines covered (92.07%)

209.18 hits per line

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94.44

/src/worker.c

#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <inttypes.h>

#define PG_PRELUDE_IMPL
#include "pg_prelude.h"
#include "curl_prelude.h"
#include "util.h"
#include "errors.h"
#include "core.h"
#include "event.h"

#define MIN_LIBCURL_VERSION_NUM 0x075300 // This is the 7.83.0 version in hex as defined in curl/curlver.h
#define REQUIRED_LIBCURL_ERR_MSG "libcurl >= 7.83.0 is required, we use the curl_easy_nextheader() function added in this version"
_Static_assert(LIBCURL_VERSION_NUM, REQUIRED_LIBCURL_ERR_MSG); // test for older libcurl versions that don't even have LIBCURL_VERSION_NUM defined (e.g. libcurl 6.5).
_Static_assert(LIBCURL_VERSION_NUM >= MIN_LIBCURL_VERSION_NUM, REQUIRED_LIBCURL_ERR_MSG);

PG_MODULE_MAGIC;

typedef enum {
  WORKER_WAIT_NO_TIMEOUT,
  WORKER_WAIT_ONE_SECOND,
} WorkerWait;

static WorkerState *worker_state = NULL;

static const int                curl_handle_event_timeout_ms = 1000;
static const int                net_worker_restart_time_sec = 1;
static const long               no_timeout = -1L;
static bool                     wake_commit_cb_active = false;
static bool                     worker_should_restart = false;
static const size_t             total_extension_tables = 2;

static char*                    guc_ttl;
static int                      guc_batch_size;
static char*                    guc_database_name;
static char*                    guc_username;
static MemoryContext            CurlMemContext = NULL;
static shmem_startup_hook_type  prev_shmem_startup_hook = NULL;
static volatile sig_atomic_t    got_sighup = false;

void _PG_init(void);

#if PG_VERSION_NUM >= 180000
  PGDLLEXPORT pg_noreturn void pg_net_worker(Datum main_arg);
#else
  PGDLLEXPORT void pg_net_worker(Datum main_arg) pg_attribute_noreturn();
#endif

PG_FUNCTION_INFO_V1(worker_restart);
Datum worker_restart(__attribute__ ((unused)) PG_FUNCTION_ARGS) {
  bool result = DatumGetBool(DirectFunctionCall1(pg_reload_conf, (Datum) NULL)); // reload the config
  pg_atomic_write_u32(&worker_state->got_restart, 1);
  pg_write_barrier();
  if (worker_state)
    SetLatch(&worker_state->latch);
  PG_RETURN_BOOL(result); // TODO is not necessary to return a bool here, but we do it to maintain backward compatibility
}

static void wait_until_state(WorkerState *ws, WorkerStatus expected_status){
  if (pg_atomic_read_u32(&ws->status) == expected_status) // fast return without sleeping, in case condition is fulfilled
    return;

  ConditionVariablePrepareToSleep(&ws->cv);
  while (pg_atomic_read_u32(&ws->status) != expected_status) {
    ConditionVariableSleep(&ws->cv, PG_WAIT_EXTENSION);
  }
  ConditionVariableCancelSleep();
}

PG_FUNCTION_INFO_V1(wait_until_running);
Datum wait_until_running(__attribute__ ((unused)) PG_FUNCTION_ARGS){
  wait_until_state(worker_state, WS_RUNNING);

  PG_RETURN_VOID();
}

// only wake at commit time to prevent excessive and unnecessary wakes.
// e.g only one wake when doing `select net.http_get('http://localhost:8080/pathological?status=200') from generate_series(1,100000);`
static void wake_at_commit(XactEvent event, __attribute__ ((unused)) void *arg){
  elog(DEBUG2, "pg_net xact callback received: %s", xact_event_name(event));

  switch(event){
    case XACT_EVENT_COMMIT:
    case XACT_EVENT_PARALLEL_COMMIT:
      if(wake_commit_cb_active){
        uint32 expected = 0;
        bool success = pg_atomic_compare_exchange_u32(&worker_state->should_wake, &expected, 1);
        pg_write_barrier();

        if (success) // only wake the worker on first put, so if many concurrent wakes come we only wake once
          SetLatch(&worker_state->latch);

        wake_commit_cb_active = false;
      }
      break;
    // TODO: `PREPARE TRANSACTION 'xx';` and `COMMIT PREPARED TRANSACTION 'xx';` do not wake the worker automatically, they require a manual `net.wake()`
    // These are disabled by default and rarely used, see `max_prepared_transactions` https://www.postgresql.org/docs/17/runtime-config-resource.html#GUC-MAX-PREPARED-TRANSACTIONS
    case XACT_EVENT_PREPARE:
    // abort the callback on rollback
    case XACT_EVENT_ABORT:
    case XACT_EVENT_PARALLEL_ABORT:
      wake_commit_cb_active = false;
      break;
    default:
      break;
  }
}

PG_FUNCTION_INFO_V1(wake);
Datum wake(__attribute__ ((unused)) PG_FUNCTION_ARGS) {
  if (!wake_commit_cb_active) { // register only one callback per transaction
    RegisterXactCallback(wake_at_commit, NULL);
    wake_commit_cb_active = true;
  }

  PG_RETURN_VOID();
}

static void
handle_sigterm(__attribute__ ((unused)) SIGNAL_ARGS)
{
  int save_errno = errno;
  pg_atomic_write_u32(&worker_state->got_restart, 1);
  pg_write_barrier();
  if (worker_state)
    SetLatch(&worker_state->latch);
  errno = save_errno;
}

static void
handle_sighup(__attribute__ ((unused)) SIGNAL_ARGS)
{
  int     save_errno = errno;
  got_sighup = true;
  if (worker_state)
    SetLatch(&worker_state->latch);
  errno = save_errno;
}

static void publish_state(WorkerStatus s) {
  pg_atomic_write_u32(&worker_state->status, (uint32)s);
  pg_write_barrier();
  ConditionVariableBroadcast(&worker_state->cv);
}

static void
net_on_exit(__attribute__ ((unused)) int code, __attribute__ ((unused)) Datum arg){
  worker_should_restart = false;
  pg_atomic_write_u32(&worker_state->should_wake, 1); // ensure the remaining work will continue since we'll restart

  DisownLatch(&worker_state->latch);

  ev_monitor_close(worker_state);

  curl_multi_cleanup(worker_state->curl_mhandle);
  curl_global_cleanup();
}

// wait according to the wait type while ensuring interrupts are processed while waiting
static void wait_while_processing_interrupts(WorkerWait ww, bool *should_restart){
  switch(ww){
    case WORKER_WAIT_NO_TIMEOUT:
      WaitLatch(&worker_state->latch,
                WL_LATCH_SET | WL_EXIT_ON_PM_DEATH,
                no_timeout,
                PG_WAIT_EXTENSION);
      ResetLatch(&worker_state->latch);
      break;
    case WORKER_WAIT_ONE_SECOND:
      WaitLatch(&worker_state->latch, WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH, 1000, PG_WAIT_EXTENSION);
      ResetLatch(&worker_state->latch);
      break;
  }

  CHECK_FOR_INTERRUPTS();

  if (got_sighup) {
    got_sighup = false;
    ProcessConfigFile(PGC_SIGHUP);
  }

  if (pg_atomic_exchange_u32(&worker_state->got_restart, 0)){
    *should_restart = true;
  }
}

static bool is_extension_locked(Oid ext_table_oids[static total_extension_tables]){
  Oid net_oid = get_namespace_oid("net", true);

  if(!OidIsValid(net_oid)){
    return false;
  }

  Oid queue_oid = get_relname_relid("http_request_queue", net_oid);
  Oid resp_oid = get_relname_relid("_http_response", net_oid);

  bool is_locked = ConditionalLockRelationOid(queue_oid, AccessShareLock) && ConditionalLockRelationOid(resp_oid, AccessShareLock);

  if (is_locked) {
    ext_table_oids[0] = queue_oid;
    ext_table_oids[1] = resp_oid;
  }

  return is_locked;
}

static void unlock_extension(Oid ext_table_oids[static total_extension_tables]){
  UnlockRelationOid(ext_table_oids[0], AccessShareLock);
  UnlockRelationOid(ext_table_oids[1], AccessShareLock);
}

void pg_net_worker(__attribute__ ((unused)) Datum main_arg) {
  on_proc_exit(net_on_exit, 0);

  OwnLatch(&worker_state->latch);

  BackgroundWorkerUnblockSignals();
  pqsignal(SIGTERM, handle_sigterm);
  pqsignal(SIGHUP, handle_sighup);
  pqsignal(SIGUSR1, procsignal_sigusr1_handler);

  BackgroundWorkerInitializeConnection(guc_database_name, guc_username, 0);
  pgstat_report_appname("pg_net " EXTVERSION); // set appname for pg_stat_activity

  elog(INFO, "pg_net worker started with a config of: pg_net.ttl=%s, pg_net.batch_size=%d, pg_net.username=%s, pg_net.database_name=%s", guc_ttl, guc_batch_size, guc_username, guc_database_name);

  int curl_ret = curl_global_init(CURL_GLOBAL_ALL);
  if(curl_ret != CURLE_OK)
    ereport(ERROR, errmsg("curl_global_init() returned %s\n", curl_easy_strerror(curl_ret)));

  worker_state->epfd = event_monitor();

  if (worker_state->epfd < 0) {
    ereport(ERROR, errmsg("Failed to create event monitor file descriptor"));
  }

  worker_state->curl_mhandle = curl_multi_init();
  if(!worker_state->curl_mhandle)
    ereport(ERROR, errmsg("curl_multi_init()"));

  set_curl_mhandle(worker_state);

  publish_state(WS_RUNNING);

  do {

    uint32 expected = 1;
    if (!pg_atomic_compare_exchange_u32(&worker_state->should_wake, &expected, 0)){
      elog(DEBUG1, "pg_net worker waiting for wake");
      wait_while_processing_interrupts(WORKER_WAIT_NO_TIMEOUT, &worker_should_restart);
      continue;
    }

    uint64 requests_consumed = 0;
    uint64 expired_responses = 0;

    do {
      SetCurrentStatementStartTimestamp();
      StartTransactionCommand();
      PushActiveSnapshot(GetTransactionSnapshot());

      Oid ext_table_oids[total_extension_tables];

      if(!is_extension_locked(ext_table_oids)){
        elog(DEBUG1, "pg_net extension not loaded");
        PopActiveSnapshot();
        AbortCurrentTransaction();
        break;
      }

      expired_responses = delete_expired_responses(guc_ttl, guc_batch_size);

      elog(DEBUG1, "Deleted "UINT64_FORMAT" expired rows", expired_responses);

      requests_consumed = consume_request_queue(worker_state->curl_mhandle, guc_batch_size, CurlMemContext);

      elog(DEBUG1, "Consumed "UINT64_FORMAT" request rows", requests_consumed);

      if(requests_consumed > 0){
        int running_handles = 0;
        int maxevents = guc_batch_size + 1; // 1 extra for the timer
        event events[maxevents];

        do {
          int nfds = wait_event(worker_state->epfd, events, maxevents, curl_handle_event_timeout_ms);
          if (nfds < 0) {
            int save_errno = errno;
            if(save_errno == EINTR) { // can happen when the wait is interrupted, for example when running under GDB. Just continue in this case.
              elog(DEBUG1, "wait_event() got %s, continuing", strerror(save_errno));
              continue;
            }
            else {
              ereport(ERROR, errmsg("wait_event() failed: %s", strerror(save_errno)));
              break;
            }
          }

          for (int i = 0; i < nfds; i++) {
            if (is_timer(events[i])) {
              EREPORT_MULTI(
                curl_multi_socket_action(worker_state->curl_mhandle, CURL_SOCKET_TIMEOUT, 0, &running_handles)
              );
            } else {
              int curl_event = get_curl_event(events[i]);
              int sockfd = get_socket_fd(events[i]);

              EREPORT_MULTI(
                curl_multi_socket_action(
                  worker_state->curl_mhandle,
                  sockfd,
                  curl_event,
                  &running_handles)
              );
            }

            insert_curl_responses(worker_state, CurlMemContext);
          }

          elog(DEBUG1, "Pending curl running_handles: %d", running_handles);
        } while (running_handles > 0); // run while there are curl handles, some won't finish in a single iteration since they could be slow and waiting for a timeout
      }

      unlock_extension(ext_table_oids);

      PopActiveSnapshot();
      CommitTransactionCommand();

      MemoryContextReset(CurlMemContext);

      // slow down queue processing to avoid using too much CPU
      wait_while_processing_interrupts(WORKER_WAIT_ONE_SECOND, &worker_should_restart);

    } while (!worker_should_restart && (requests_consumed > 0 || expired_responses > 0));

  } while (!worker_should_restart);

  publish_state(WS_EXITED);

  // causing a failure on exit will make the postmaster process restart the bg worker
  proc_exit(EXIT_FAILURE);
}

static void net_shmem_startup(void) {
  if (prev_shmem_startup_hook)
    prev_shmem_startup_hook();

  bool found;

  worker_state = ShmemInitStruct("pg_net worker state", sizeof(WorkerState), &found);

  if (!found) {
    pg_atomic_init_u32(&worker_state->got_restart, 0);
    pg_atomic_init_u32(&worker_state->status, WS_NOT_YET);
    pg_atomic_init_u32(&worker_state->should_wake, 1);
    InitSharedLatch(&worker_state->latch);

    ConditionVariableInit(&worker_state->cv);
    worker_state->epfd = 0;
    worker_state->curl_mhandle = NULL;
  }
}

void _PG_init(void) {
  if (IsBinaryUpgrade) {
      return;
  }

  if (!process_shared_preload_libraries_in_progress) {
      ereport(ERROR, errmsg("pg_net is not in shared_preload_libraries"),
              errhint("Add pg_net to the shared_preload_libraries "
                      "configuration variable in postgresql.conf."));
  }

  RegisterBackgroundWorker(&(BackgroundWorker){
    .bgw_flags = BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION,
    .bgw_start_time = BgWorkerStart_RecoveryFinished,
    .bgw_library_name = "pg_net",
    .bgw_function_name = "pg_net_worker",
    .bgw_name = "pg_net " EXTVERSION " worker",
    .bgw_restart_time = net_worker_restart_time_sec,
  });

  prev_shmem_startup_hook = shmem_startup_hook;
  shmem_startup_hook = net_shmem_startup;

  CurlMemContext = AllocSetContextCreate(TopMemoryContext,
                       "pg_net curl context",
                       ALLOCSET_DEFAULT_MINSIZE,
                       ALLOCSET_DEFAULT_INITSIZE,
                       ALLOCSET_DEFAULT_MAXSIZE);

  DefineCustomStringVariable("pg_net.ttl",
                 "time to live for request/response rows",
                 "should be a valid interval type",
                 &guc_ttl,
                 "6 hours",
                 PGC_SIGHUP, 0,
                 NULL, NULL, NULL);

  DefineCustomIntVariable("pg_net.batch_size",
                 "number of requests executed in one iteration of the background worker",
                 NULL,
                 &guc_batch_size,
                 200,
                 0, PG_INT16_MAX,
                 PGC_SIGHUP, 0,
                 NULL, NULL, NULL);

  DefineCustomStringVariable("pg_net.database_name",
                "Database where the worker will connect to",
                NULL,
                &guc_database_name,
                "postgres",
                PGC_SU_BACKEND, 0,
                NULL, NULL, NULL);

  DefineCustomStringVariable("pg_net.username",
                "Connection user for the worker",
                NULL,
                &guc_username,
                NULL,
                PGC_SU_BACKEND, 0,
                NULL, NULL, NULL);
}

1	#include <unistd.h>
2	#include <errno.h>
3	#include <string.h>
4	#include <inttypes.h>
5
6	#define PG_PRELUDE_IMPL
7	#include "pg_prelude.h"
8	#include "curl_prelude.h"
9	#include "util.h"
10	#include "errors.h"
11	#include "core.h"
12	#include "event.h"
13
14	#define MIN_LIBCURL_VERSION_NUM 0x075300 // This is the 7.83.0 version in hex as defined in curl/curlver.h
15	#define REQUIRED_LIBCURL_ERR_MSG "libcurl >= 7.83.0 is required, we use the curl_easy_nextheader() function added in this version"
16	_Static_assert(LIBCURL_VERSION_NUM, REQUIRED_LIBCURL_ERR_MSG); // test for older libcurl versions that don't even have LIBCURL_VERSION_NUM defined (e.g. libcurl 6.5).
17	_Static_assert(LIBCURL_VERSION_NUM >= MIN_LIBCURL_VERSION_NUM, REQUIRED_LIBCURL_ERR_MSG);
18
19	PG_MODULE_MAGIC;	93✔
20
21	typedef enum {
22	WORKER_WAIT_NO_TIMEOUT,
23	WORKER_WAIT_ONE_SECOND,
24	} WorkerWait;
25
26	static WorkerState *worker_state = NULL;
27
28	static const int curl_handle_event_timeout_ms = 1000;
29	static const int net_worker_restart_time_sec = 1;
30	static const long no_timeout = -1L;
31	static bool wake_commit_cb_active = false;
32	static bool worker_should_restart = false;
33	static const size_t total_extension_tables = 2;
34
35	static char* guc_ttl;
36	static int guc_batch_size;
37	static char* guc_database_name;
38	static char* guc_username;
39	static MemoryContext CurlMemContext = NULL;
40	static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
41	static volatile sig_atomic_t got_sighup = false;
42
43	void _PG_init(void);
44
45	#if PG_VERSION_NUM >= 180000
46	PGDLLEXPORT pg_noreturn void pg_net_worker(Datum main_arg);
47	#else
48	PGDLLEXPORT void pg_net_worker(Datum main_arg) pg_attribute_noreturn();
49	#endif
50
51	PG_FUNCTION_INFO_V1(worker_restart);	65✔
52	Datum worker_restart(__attribute__ ((unused)) PG_FUNCTION_ARGS) {	17✔
53	bool result = DatumGetBool(DirectFunctionCall1(pg_reload_conf, (Datum) NULL)); // reload the config	17✔
54	pg_atomic_write_u32(&worker_state->got_restart, 1);	17✔
55	pg_write_barrier();	17✔
56	if (worker_state)	17✔
57	SetLatch(&worker_state->latch);	17✔
58	PG_RETURN_BOOL(result); // TODO is not necessary to return a bool here, but we do it to maintain backward compatibility	17✔
59	}
60
61	static void wait_until_state(WorkerState *ws, WorkerStatus expected_status){	18✔
62	if (pg_atomic_read_u32(&ws->status) == expected_status) // fast return without sleeping, in case condition is fulfilled	18✔
63	return;
64
65	ConditionVariablePrepareToSleep(&ws->cv);	15✔
66	while (pg_atomic_read_u32(&ws->status) != expected_status) {	30✔
67	ConditionVariableSleep(&ws->cv, PG_WAIT_EXTENSION);	15✔
68	}
69	ConditionVariableCancelSleep();	15✔
70	}
71
72	PG_FUNCTION_INFO_V1(wait_until_running);	66✔
73	Datum wait_until_running(__attribute__ ((unused)) PG_FUNCTION_ARGS){	18✔
74	wait_until_state(worker_state, WS_RUNNING);	18✔
75
76	PG_RETURN_VOID();	18✔
77	}
78
79	// only wake at commit time to prevent excessive and unnecessary wakes.
80	// e.g only one wake when doing `select net.http_get('http://localhost:8080/pathological?status=200') from generate_series(1,100000);`
81	static void wake_at_commit(XactEvent event, __attribute__ ((unused)) void *arg){	293✔
82	elog(DEBUG2, "pg_net xact callback received: %s", xact_event_name(event));	293✔
83
84	switch(event){	293✔
85	case XACT_EVENT_COMMIT:	121✔
86	case XACT_EVENT_PARALLEL_COMMIT:
87	if(wake_commit_cb_active){	121✔
88	uint32 expected = 0;	47✔
89	bool success = pg_atomic_compare_exchange_u32(&worker_state->should_wake, &expected, 1);	47✔
90	pg_write_barrier();	47✔
91
92	if (success) // only wake the worker on first put, so if many concurrent wakes come we only wake once	47✔
93	SetLatch(&worker_state->latch);	25✔
94
95	wake_commit_cb_active = false;	47✔
96	}
97	break;
98	// TODO: `PREPARE TRANSACTION 'xx';` and `COMMIT PREPARED TRANSACTION 'xx';` do not wake the worker automatically, they require a manual `net.wake()`
99	// These are disabled by default and rarely used, see `max_prepared_transactions` https://www.postgresql.org/docs/17/runtime-config-resource.html#GUC-MAX-PREPARED-TRANSACTIONS
100	case XACT_EVENT_PREPARE:	51✔
101	// abort the callback on rollback
102	case XACT_EVENT_ABORT:
103	case XACT_EVENT_PARALLEL_ABORT:
104	wake_commit_cb_active = false;	51✔
105	break;	51✔
106	default:
107	break;
108	}
109	}	293✔
110
111	PG_FUNCTION_INFO_V1(wake);	98✔
112	Datum wake(__attribute__ ((unused)) PG_FUNCTION_ARGS) {	427✔
113	if (!wake_commit_cb_active) { // register only one callback per transaction	427✔
114	RegisterXactCallback(wake_at_commit, NULL);	53✔
115	wake_commit_cb_active = true;	53✔
116	}
117
118	PG_RETURN_VOID();	427✔
119	}
120
121	static void
122	handle_sigterm(__attribute__ ((unused)) SIGNAL_ARGS)	2✔
123	{
124	int save_errno = errno;	2✔
125	pg_atomic_write_u32(&worker_state->got_restart, 1);	2✔
126	pg_write_barrier();	2✔
127	if (worker_state)	2✔
128	SetLatch(&worker_state->latch);	2✔
129	errno = save_errno;	2✔
130	}	2✔
131
132	static void
133	handle_sighup(__attribute__ ((unused)) SIGNAL_ARGS)	18✔
134	{
135	int save_errno = errno;	18✔
136	got_sighup = true;	18✔
137	if (worker_state)	18✔
138	SetLatch(&worker_state->latch);	18✔
139	errno = save_errno;	18✔
140	}	18✔
141
142	static void publish_state(WorkerStatus s) {	38✔
143	pg_atomic_write_u32(&worker_state->status, (uint32)s);	38✔
144	pg_write_barrier();	38✔
145	ConditionVariableBroadcast(&worker_state->cv);	38✔
146	}	38✔
147
148	static void
149	net_on_exit(__attribute__ ((unused)) int code, __attribute__ ((unused)) Datum arg){	19✔
150	worker_should_restart = false;	19✔
151	pg_atomic_write_u32(&worker_state->should_wake, 1); // ensure the remaining work will continue since we'll restart	19✔
152
153	DisownLatch(&worker_state->latch);	19✔
154
155	ev_monitor_close(worker_state);	19✔
156
157	curl_multi_cleanup(worker_state->curl_mhandle);	19✔
158	curl_global_cleanup();	19✔
159	}	19✔
160
161	// wait according to the wait type while ensuring interrupts are processed while waiting
162	static void wait_while_processing_interrupts(WorkerWait ww, bool *should_restart){	105✔
163	switch(ww){	105✔
164	case WORKER_WAIT_NO_TIMEOUT:	24✔
165	WaitLatch(&worker_state->latch,	24✔
166	WL_LATCH_SET \| WL_EXIT_ON_PM_DEATH,
167	no_timeout,
168	PG_WAIT_EXTENSION);
169	ResetLatch(&worker_state->latch);	24✔
170	break;	24✔
171	case WORKER_WAIT_ONE_SECOND:	81✔
172	WaitLatch(&worker_state->latch, WL_LATCH_SET \| WL_TIMEOUT \| WL_EXIT_ON_PM_DEATH, 1000, PG_WAIT_EXTENSION);	81✔
173	ResetLatch(&worker_state->latch);	81✔
174	break;	81✔
175	}
176
177	CHECK_FOR_INTERRUPTS();	105✔
178
179	if (got_sighup) {	105✔
180	got_sighup = false;	3✔
181	ProcessConfigFile(PGC_SIGHUP);	3✔
182	}
183
184	if (pg_atomic_exchange_u32(&worker_state->got_restart, 0)){	105✔
185	*should_restart = true;	19✔
186	}
187	}	105✔
188
189	static bool is_extension_locked(Oid ext_table_oids[static total_extension_tables]){	87✔
190	Oid net_oid = get_namespace_oid("net", true);	87✔
191
192	if(!OidIsValid(net_oid)){	87✔
193	return false;
194	}
195
196	Oid queue_oid = get_relname_relid("http_request_queue", net_oid);	83✔
197	Oid resp_oid = get_relname_relid("_http_response", net_oid);	83✔
198
199	bool is_locked = ConditionalLockRelationOid(queue_oid, AccessShareLock) && ConditionalLockRelationOid(resp_oid, AccessShareLock);	83✔
200
201	if (is_locked) {	81✔
202	ext_table_oids[0] = queue_oid;	81✔
203	ext_table_oids[1] = resp_oid;	81✔
204	}
205
206	return is_locked;
207	}
208
209	static void unlock_extension(Oid ext_table_oids[static total_extension_tables]){	81✔
210	UnlockRelationOid(ext_table_oids[0], AccessShareLock);	81✔
211	UnlockRelationOid(ext_table_oids[1], AccessShareLock);	81✔
212	}	81✔
213
214	void pg_net_worker(__attribute__ ((unused)) Datum main_arg) {	19✔
215	on_proc_exit(net_on_exit, 0);	19✔
216
217	OwnLatch(&worker_state->latch);	19✔
218
219	BackgroundWorkerUnblockSignals();	19✔
220	pqsignal(SIGTERM, handle_sigterm);	19✔
221	pqsignal(SIGHUP, handle_sighup);	19✔
222	pqsignal(SIGUSR1, procsignal_sigusr1_handler);	19✔
223
224	BackgroundWorkerInitializeConnection(guc_database_name, guc_username, 0);	19✔
225	pgstat_report_appname("pg_net " EXTVERSION); // set appname for pg_stat_activity	19✔
226
227	elog(INFO, "pg_net worker started with a config of: pg_net.ttl=%s, pg_net.batch_size=%d, pg_net.username=%s, pg_net.database_name=%s", guc_ttl, guc_batch_size, guc_username, guc_database_name);	19✔
228
229	int curl_ret = curl_global_init(CURL_GLOBAL_ALL);	19✔
230	if(curl_ret != CURLE_OK)	19✔
231	ereport(ERROR, errmsg("curl_global_init() returned %s\n", curl_easy_strerror(curl_ret)));	×
232
233	worker_state->epfd = event_monitor();	19✔
234
235	if (worker_state->epfd < 0) {	19✔
236	ereport(ERROR, errmsg("Failed to create event monitor file descriptor"));	×
237	}
238
239	worker_state->curl_mhandle = curl_multi_init();	19✔
240	if(!worker_state->curl_mhandle)	19✔
241	ereport(ERROR, errmsg("curl_multi_init()"));	×
242
243	set_curl_mhandle(worker_state);	19✔
244
245	publish_state(WS_RUNNING);	19✔
246
247	do {	65✔
248
249	uint32 expected = 1;	65✔
250	if (!pg_atomic_compare_exchange_u32(&worker_state->should_wake, &expected, 0)){	65✔
251	elog(DEBUG1, "pg_net worker waiting for wake");	24✔
252	wait_while_processing_interrupts(WORKER_WAIT_NO_TIMEOUT, &worker_should_restart);	24✔
253	continue;	24✔
254	}
255
256	uint64 requests_consumed = 0;	87✔
257	uint64 expired_responses = 0;	87✔
258
259	do {	87✔
260	SetCurrentStatementStartTimestamp();	87✔
261	StartTransactionCommand();	87✔
262	PushActiveSnapshot(GetTransactionSnapshot());	87✔
263
264	Oid ext_table_oids[total_extension_tables];	87✔
265
266	if(!is_extension_locked(ext_table_oids)){	87✔
267	elog(DEBUG1, "pg_net extension not loaded");	6✔
268	PopActiveSnapshot();	6✔
269	AbortCurrentTransaction();	6✔
270	break;	6✔
271	}
272
273	expired_responses = delete_expired_responses(guc_ttl, guc_batch_size);	81✔
274
275	elog(DEBUG1, "Deleted "UINT64_FORMAT" expired rows", expired_responses);	81✔
276
277	requests_consumed = consume_request_queue(worker_state->curl_mhandle, guc_batch_size, CurlMemContext);	81✔
278
279	elog(DEBUG1, "Consumed "UINT64_FORMAT" request rows", requests_consumed);	81✔
280
281	if(requests_consumed > 0){	81✔
282	int running_handles = 0;	50✔
283	int maxevents = guc_batch_size + 1; // 1 extra for the timer	50✔
284	event events[maxevents];	50✔
285
286	do {	169✔
287	int nfds = wait_event(worker_state->epfd, events, maxevents, curl_handle_event_timeout_ms);	169✔
288	if (nfds < 0) {	169✔
289	int save_errno = errno;	×
290	if(save_errno == EINTR) { // can happen when the wait is interrupted, for example when running under GDB. Just continue in this case.	×
291	elog(DEBUG1, "wait_event() got %s, continuing", strerror(save_errno));	×
292	continue;	×
293	}
294	else {
295	ereport(ERROR, errmsg("wait_event() failed: %s", strerror(save_errno)));	×
296	break;
297	}
298	}
299
300	for (int i = 0; i < nfds; i++) {	1,025✔
301	if (is_timer(events[i])) {	856✔
302	EREPORT_MULTI(	61✔
303	curl_multi_socket_action(worker_state->curl_mhandle, CURL_SOCKET_TIMEOUT, 0, &running_handles)
304	);
305	} else {
306	int curl_event = get_curl_event(events[i]);	795✔
307	int sockfd = get_socket_fd(events[i]);	795✔
308
309	EREPORT_MULTI(	795✔
310	curl_multi_socket_action(
311	worker_state->curl_mhandle,
312	sockfd,
313	curl_event,
314	&running_handles)
315	);
316	}
317
318	insert_curl_responses(worker_state, CurlMemContext);	856✔
319	}
320
321	elog(DEBUG1, "Pending curl running_handles: %d", running_handles);	169✔
322	} while (running_handles > 0); // run while there are curl handles, some won't finish in a single iteration since they could be slow and waiting for a timeout	169✔
323	}
324
325	unlock_extension(ext_table_oids);	81✔
326
327	PopActiveSnapshot();	81✔
328	CommitTransactionCommand();	81✔
329
330	MemoryContextReset(CurlMemContext);	81✔
331
332	// slow down queue processing to avoid using too much CPU
333	wait_while_processing_interrupts(WORKER_WAIT_ONE_SECOND, &worker_should_restart);	81✔
334
335	} while (!worker_should_restart && (requests_consumed > 0 \|\| expired_responses > 0));	81✔
336
337	} while (!worker_should_restart);	65✔
338
339	publish_state(WS_EXITED);	19✔
340
341	// causing a failure on exit will make the postmaster process restart the bg worker
342	proc_exit(EXIT_FAILURE);	19✔
343	}
344
345	static void net_shmem_startup(void) {	93✔
346	if (prev_shmem_startup_hook)	93✔
347	prev_shmem_startup_hook();	×
348
349	bool found;	93✔
350
351	worker_state = ShmemInitStruct("pg_net worker state", sizeof(WorkerState), &found);	93✔
352
353	if (!found) {	93✔
354	pg_atomic_init_u32(&worker_state->got_restart, 0);	93✔
355	pg_atomic_init_u32(&worker_state->status, WS_NOT_YET);	93✔
356	pg_atomic_init_u32(&worker_state->should_wake, 1);	93✔
357	InitSharedLatch(&worker_state->latch);	93✔
358
359	ConditionVariableInit(&worker_state->cv);	93✔
360	worker_state->epfd = 0;	93✔
361	worker_state->curl_mhandle = NULL;	93✔
362	}
363	}	93✔
364
365	void _PG_init(void) {	93✔
366	if (IsBinaryUpgrade) {	93✔
367	return;	×
368	}
369
370	if (!process_shared_preload_libraries_in_progress) {	93✔
371	ereport(ERROR, errmsg("pg_net is not in shared_preload_libraries"),	×
372	errhint("Add pg_net to the shared_preload_libraries "
373	"configuration variable in postgresql.conf."));
374	}
375
376	RegisterBackgroundWorker(&(BackgroundWorker){	93✔
377	.bgw_flags = BGWORKER_SHMEM_ACCESS \| BGWORKER_BACKEND_DATABASE_CONNECTION,
378	.bgw_start_time = BgWorkerStart_RecoveryFinished,
379	.bgw_library_name = "pg_net",
380	.bgw_function_name = "pg_net_worker",
381	.bgw_name = "pg_net " EXTVERSION " worker",
382	.bgw_restart_time = net_worker_restart_time_sec,
383	});
384
385	prev_shmem_startup_hook = shmem_startup_hook;	93✔
386	shmem_startup_hook = net_shmem_startup;	93✔
387
388	CurlMemContext = AllocSetContextCreate(TopMemoryContext,	93✔
389	"pg_net curl context",
390	ALLOCSET_DEFAULT_MINSIZE,
391	ALLOCSET_DEFAULT_INITSIZE,
392	ALLOCSET_DEFAULT_MAXSIZE);
393
394	DefineCustomStringVariable("pg_net.ttl",	93✔
395	"time to live for request/response rows",
396	"should be a valid interval type",
397	&guc_ttl,
398	"6 hours",
399	PGC_SIGHUP, 0,
400	NULL, NULL, NULL);
401
402	DefineCustomIntVariable("pg_net.batch_size",	93✔
403	"number of requests executed in one iteration of the background worker",
404	NULL,
405	&guc_batch_size,
406	200,
407	0, PG_INT16_MAX,
408	PGC_SIGHUP, 0,
409	NULL, NULL, NULL);
410
411	DefineCustomStringVariable("pg_net.database_name",	93✔
412	"Database where the worker will connect to",
413	NULL,
414	&guc_database_name,
415	"postgres",
416	PGC_SU_BACKEND, 0,
417	NULL, NULL, NULL);
418
419	DefineCustomStringVariable("pg_net.username",	93✔
420	"Connection user for the worker",
421	NULL,
422	&guc_username,
423	NULL,
424	PGC_SU_BACKEND, 0,
425	NULL, NULL, NULL);
426	}

supabase / pg_net / 16302681875

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