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-rw-r--r--src/Makefile.global.in1
-rw-r--r--src/backend/storage/ipc/ipci.c3
-rw-r--r--src/backend/storage/lmgr/lwlocknames.txt1
-rw-r--r--src/backend/utils/activity/wait_event_names.txt1
-rw-r--r--src/backend/utils/misc/Makefile1
-rw-r--r--src/backend/utils/misc/injection_point.c317
-rw-r--r--src/backend/utils/misc/meson.build1
-rw-r--r--src/include/pg_config.h.in3
-rw-r--r--src/include/utils/injection_point.h37
-rw-r--r--src/makefiles/meson.build1
-rw-r--r--src/tools/pgindent/typedefs.list2
11 files changed, 368 insertions, 0 deletions
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index f8e461cbadb..6f7de20527c 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -203,6 +203,7 @@ enable_nls = @enable_nls@
enable_debug = @enable_debug@
enable_dtrace = @enable_dtrace@
enable_coverage = @enable_coverage@
+enable_injection_points = @enable_injection_points@
enable_tap_tests = @enable_tap_tests@
python_includespec = @python_includespec@
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index fbc62b15637..7084e18861b 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -51,6 +51,7 @@
#include "storage/sinvaladt.h"
#include "storage/spin.h"
#include "utils/guc.h"
+#include "utils/injection_point.h"
#include "utils/snapmgr.h"
#include "utils/wait_event.h"
@@ -151,6 +152,7 @@ CalculateShmemSize(int *num_semaphores)
size = add_size(size, AsyncShmemSize());
size = add_size(size, StatsShmemSize());
size = add_size(size, WaitEventExtensionShmemSize());
+ size = add_size(size, InjectionPointShmemSize());
#ifdef EXEC_BACKEND
size = add_size(size, ShmemBackendArraySize());
#endif
@@ -354,6 +356,7 @@ CreateOrAttachShmemStructs(void)
AsyncShmemInit();
StatsShmemInit();
WaitEventExtensionShmemInit();
+ InjectionPointShmemInit();
}
/*
diff --git a/src/backend/storage/lmgr/lwlocknames.txt b/src/backend/storage/lmgr/lwlocknames.txt
index ef8542de469..a0163b21879 100644
--- a/src/backend/storage/lmgr/lwlocknames.txt
+++ b/src/backend/storage/lmgr/lwlocknames.txt
@@ -56,3 +56,4 @@ NotifyQueueTailLock 47
WaitEventExtensionLock 48
WALSummarizerLock 49
DSMRegistryLock 50
+InjectionPointLock 51
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index 6bcb1cca0cb..a5df835dd41 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -330,6 +330,7 @@ NotifyQueueTail "Waiting to update limit on <command>NOTIFY</command> message st
WaitEventExtension "Waiting to read or update custom wait events information for extensions."
WALSummarizer "Waiting to read or update WAL summarization state."
DSMRegistry "Waiting to read or update the dynamic shared memory registry."
+InjectionPoint "Waiting to read or update information related to injection points."
#
# END OF PREDEFINED LWLOCKS (DO NOT CHANGE THIS LINE)
diff --git a/src/backend/utils/misc/Makefile b/src/backend/utils/misc/Makefile
index c2971c76782..d9f59785b98 100644
--- a/src/backend/utils/misc/Makefile
+++ b/src/backend/utils/misc/Makefile
@@ -21,6 +21,7 @@ OBJS = \
guc_funcs.o \
guc_tables.o \
help_config.o \
+ injection_point.o \
pg_config.o \
pg_controldata.o \
pg_rusage.o \
diff --git a/src/backend/utils/misc/injection_point.c b/src/backend/utils/misc/injection_point.c
new file mode 100644
index 00000000000..a4ee00559b3
--- /dev/null
+++ b/src/backend/utils/misc/injection_point.c
@@ -0,0 +1,317 @@
+/*-------------------------------------------------------------------------
+ *
+ * injection_point.c
+ * Routines to control and run injection points in the code.
+ *
+ * Injection points can be used to run arbitrary code by attaching callbacks
+ * that would be executed in place of the named injection point.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/utils/misc/injection_point.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include <sys/stat.h>
+
+#include "fmgr.h"
+#include "miscadmin.h"
+#include "port/pg_bitutils.h"
+#include "storage/fd.h"
+#include "storage/lwlock.h"
+#include "storage/shmem.h"
+#include "utils/hsearch.h"
+#include "utils/injection_point.h"
+#include "utils/memutils.h"
+
+#ifdef USE_INJECTION_POINTS
+
+/*
+ * Hash table for storing injection points.
+ *
+ * InjectionPointHash is used to find an injection point by name.
+ */
+static HTAB *InjectionPointHash; /* find points from names */
+
+/* Field sizes */
+#define INJ_NAME_MAXLEN 64
+#define INJ_LIB_MAXLEN 128
+#define INJ_FUNC_MAXLEN 128
+
+/* Single injection point stored in InjectionPointHash */
+typedef struct InjectionPointEntry
+{
+ char name[INJ_NAME_MAXLEN]; /* hash key */
+ char library[INJ_LIB_MAXLEN]; /* library */
+ char function[INJ_FUNC_MAXLEN]; /* function */
+} InjectionPointEntry;
+
+#define INJECTION_POINT_HASH_INIT_SIZE 16
+#define INJECTION_POINT_HASH_MAX_SIZE 128
+
+/*
+ * Backend local cache of injection callbacks already loaded, stored in
+ * TopMemoryContext.
+ */
+typedef struct InjectionPointCacheEntry
+{
+ char name[INJ_NAME_MAXLEN];
+ InjectionPointCallback callback;
+} InjectionPointCacheEntry;
+
+static HTAB *InjectionPointCache = NULL;
+
+/*
+ * injection_point_cache_add
+ *
+ * Add an injection point to the local cache.
+ */
+static void
+injection_point_cache_add(const char *name,
+ InjectionPointCallback callback)
+{
+ InjectionPointCacheEntry *entry;
+ bool found;
+
+ /* If first time, initialize */
+ if (InjectionPointCache == NULL)
+ {
+ HASHCTL hash_ctl;
+
+ hash_ctl.keysize = sizeof(char[INJ_NAME_MAXLEN]);
+ hash_ctl.entrysize = sizeof(InjectionPointCacheEntry);
+ hash_ctl.hcxt = TopMemoryContext;
+
+ InjectionPointCache = hash_create("InjectionPoint cache hash",
+ INJECTION_POINT_HASH_MAX_SIZE,
+ &hash_ctl,
+ HASH_ELEM | HASH_STRINGS | HASH_CONTEXT);
+ }
+
+ entry = (InjectionPointCacheEntry *)
+ hash_search(InjectionPointCache, name, HASH_ENTER, &found);
+
+ Assert(!found);
+ memcpy(entry->name, name, strlen(name));
+ entry->callback = callback;
+}
+
+/*
+ * injection_point_cache_remove
+ *
+ * Remove entry from the local cache. Note that this leaks a callback
+ * loaded but removed later on, which should have no consequence from
+ * a testing perspective.
+ */
+static void
+injection_point_cache_remove(const char *name)
+{
+ /* leave if no cache */
+ if (InjectionPointCache == NULL)
+ return;
+
+ (void) hash_search(InjectionPointCache, name, HASH_REMOVE, NULL);
+}
+
+/*
+ * injection_point_cache_get
+ *
+ * Retrieve an injection point from the local cache, if any.
+ */
+static InjectionPointCallback
+injection_point_cache_get(const char *name)
+{
+ bool found;
+ InjectionPointCacheEntry *entry;
+
+ /* no callback if no cache yet */
+ if (InjectionPointCache == NULL)
+ return NULL;
+
+ entry = (InjectionPointCacheEntry *)
+ hash_search(InjectionPointCache, name, HASH_FIND, &found);
+
+ if (found)
+ return entry->callback;
+
+ return NULL;
+}
+#endif /* USE_INJECTION_POINTS */
+
+/*
+ * Return the space for dynamic shared hash table.
+ */
+Size
+InjectionPointShmemSize(void)
+{
+#ifdef USE_INJECTION_POINTS
+ Size sz = 0;
+
+ sz = add_size(sz, hash_estimate_size(INJECTION_POINT_HASH_MAX_SIZE,
+ sizeof(InjectionPointEntry)));
+ return sz;
+#else
+ return 0;
+#endif
+}
+
+/*
+ * Allocate shmem space for dynamic shared hash.
+ */
+void
+InjectionPointShmemInit(void)
+{
+#ifdef USE_INJECTION_POINTS
+ HASHCTL info;
+
+ /* key is a NULL-terminated string */
+ info.keysize = sizeof(char[INJ_NAME_MAXLEN]);
+ info.entrysize = sizeof(InjectionPointEntry);
+ InjectionPointHash = ShmemInitHash("InjectionPoint hash",
+ INJECTION_POINT_HASH_INIT_SIZE,
+ INJECTION_POINT_HASH_MAX_SIZE,
+ &info,
+ HASH_ELEM | HASH_FIXED_SIZE | HASH_STRINGS);
+#endif
+}
+
+/*
+ * Attach a new injection point.
+ */
+void
+InjectionPointAttach(const char *name,
+ const char *library,
+ const char *function)
+{
+#ifdef USE_INJECTION_POINTS
+ InjectionPointEntry *entry_by_name;
+ bool found;
+
+ if (strlen(name) >= INJ_NAME_MAXLEN)
+ elog(ERROR, "injection point name %s too long (maximum of %u)",
+ name, INJ_NAME_MAXLEN);
+ if (strlen(library) >= INJ_LIB_MAXLEN)
+ elog(ERROR, "injection point library %s too long (maximum of %u)",
+ library, INJ_LIB_MAXLEN);
+ if (strlen(function) >= INJ_FUNC_MAXLEN)
+ elog(ERROR, "injection point function %s too long (maximum of %u)",
+ function, INJ_FUNC_MAXLEN);
+
+ /*
+ * Allocate and register a new injection point. A new point should not
+ * exist. For testing purposes this should be fine.
+ */
+ LWLockAcquire(InjectionPointLock, LW_EXCLUSIVE);
+ entry_by_name = (InjectionPointEntry *)
+ hash_search(InjectionPointHash, name,
+ HASH_ENTER, &found);
+ if (found)
+ {
+ LWLockRelease(InjectionPointLock);
+ elog(ERROR, "injection point \"%s\" already defined", name);
+ }
+
+ /* Save the entry */
+ memcpy(entry_by_name->name, name, sizeof(entry_by_name->name));
+ entry_by_name->name[INJ_NAME_MAXLEN - 1] = '\0';
+ memcpy(entry_by_name->library, library, sizeof(entry_by_name->library));
+ entry_by_name->library[INJ_LIB_MAXLEN - 1] = '\0';
+ memcpy(entry_by_name->function, function, sizeof(entry_by_name->function));
+ entry_by_name->function[INJ_FUNC_MAXLEN - 1] = '\0';
+
+ LWLockRelease(InjectionPointLock);
+
+#else
+ elog(ERROR, "injection points are not supported by this build");
+#endif
+}
+
+/*
+ * Detach an existing injection point.
+ */
+void
+InjectionPointDetach(const char *name)
+{
+#ifdef USE_INJECTION_POINTS
+ bool found;
+
+ LWLockAcquire(InjectionPointLock, LW_EXCLUSIVE);
+ hash_search(InjectionPointHash, name, HASH_REMOVE, &found);
+ LWLockRelease(InjectionPointLock);
+
+ if (!found)
+ elog(ERROR, "injection point \"%s\" not found", name);
+
+#else
+ elog(ERROR, "Injection points are not supported by this build");
+#endif
+}
+
+/*
+ * Execute an injection point, if defined.
+ *
+ * Check first the shared hash table, and adapt the local cache depending
+ * on that as it could be possible that an entry to run has been removed.
+ */
+void
+InjectionPointRun(const char *name)
+{
+#ifdef USE_INJECTION_POINTS
+ InjectionPointEntry *entry_by_name;
+ bool found;
+ InjectionPointCallback injection_callback;
+
+ LWLockAcquire(InjectionPointLock, LW_SHARED);
+ entry_by_name = (InjectionPointEntry *)
+ hash_search(InjectionPointHash, name,
+ HASH_FIND, &found);
+ LWLockRelease(InjectionPointLock);
+
+ /*
+ * If not found, do nothing and remove it from the local cache if it
+ * existed there.
+ */
+ if (!found)
+ {
+ injection_point_cache_remove(name);
+ return;
+ }
+
+ /*
+ * Check if the callback exists in the local cache, to avoid unnecessary
+ * external loads.
+ */
+ injection_callback = injection_point_cache_get(name);
+ if (injection_callback == NULL)
+ {
+ char path[MAXPGPATH];
+
+ /* not found in local cache, so load and register */
+ snprintf(path, MAXPGPATH, "%s/%s%s", pkglib_path,
+ entry_by_name->library, DLSUFFIX);
+
+ if (!pg_file_exists(path))
+ elog(ERROR, "could not find library \"%s\" for injection point \"%s\"",
+ path, name);
+
+ injection_callback = (InjectionPointCallback)
+ load_external_function(path, entry_by_name->function, true, NULL);
+
+ if (injection_callback == NULL)
+ elog(ERROR, "could not find function \"%s\" in library \"%s\" for injection point \"%s\"",
+ name, entry_by_name->function, path);
+
+ /* add it to the local cache when found */
+ injection_point_cache_add(name, injection_callback);
+ }
+
+ injection_callback(name);
+#else
+ elog(ERROR, "Injection points are not supported by this build");
+#endif
+}
diff --git a/src/backend/utils/misc/meson.build b/src/backend/utils/misc/meson.build
index 581724f254c..66695022052 100644
--- a/src/backend/utils/misc/meson.build
+++ b/src/backend/utils/misc/meson.build
@@ -6,6 +6,7 @@ backend_sources += files(
'guc_funcs.c',
'guc_tables.c',
'help_config.c',
+ 'injection_point.c',
'pg_config.c',
'pg_controldata.c',
'pg_rusage.c',
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 5f16918243c..288bb9cb426 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -698,6 +698,9 @@
/* Define to build with ICU support. (--with-icu) */
#undef USE_ICU
+/* Define to 1 to build with injection points. (--enable-injection-points) */
+#undef USE_INJECTION_POINTS
+
/* Define to 1 to build with LDAP support. (--with-ldap) */
#undef USE_LDAP
diff --git a/src/include/utils/injection_point.h b/src/include/utils/injection_point.h
new file mode 100644
index 00000000000..55524b568ff
--- /dev/null
+++ b/src/include/utils/injection_point.h
@@ -0,0 +1,37 @@
+/*-------------------------------------------------------------------------
+ * injection_point.h
+ * Definitions related to injection points.
+ *
+ * Copyright (c) 2001-2024, PostgreSQL Global Development Group
+ *
+ * src/include/utils/injection_point.h
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef INJECTION_POINT_H
+#define INJECTION_POINT_H
+
+/*
+ * Injections points require --enable-injection-points.
+ */
+#ifdef USE_INJECTION_POINTS
+#define INJECTION_POINT(name) InjectionPointRun(name)
+#else
+#define INJECTION_POINT(name) ((void) name)
+#endif
+
+/*
+ * Typedef for callback function launched by an injection point.
+ */
+typedef void (*InjectionPointCallback) (const char *name);
+
+extern Size InjectionPointShmemSize(void);
+extern void InjectionPointShmemInit(void);
+
+extern void InjectionPointAttach(const char *name,
+ const char *library,
+ const char *function);
+extern void InjectionPointRun(const char *name);
+extern void InjectionPointDetach(const char *name);
+
+#endif /* INJECTION_POINT_H */
diff --git a/src/makefiles/meson.build b/src/makefiles/meson.build
index 034b26efa5f..b0f4178b3d9 100644
--- a/src/makefiles/meson.build
+++ b/src/makefiles/meson.build
@@ -54,6 +54,7 @@ pgxs_kv = {
'enable_rpath': get_option('rpath') ? 'yes' : 'no',
'enable_nls': libintl.found() ? 'yes' : 'no',
+ 'enable_injection_points': get_option('injection_points') ? 'yes' : 'no',
'enable_tap_tests': tap_tests_enabled ? 'yes' : 'no',
'enable_debug': get_option('debug') ? 'yes' : 'no',
'enable_coverage': 'no',
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index a200e5eb12a..7e866e3c3d0 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,8 @@ InheritableSocket
InitSampleScan_function
InitializeDSMForeignScan_function
InitializeWorkerForeignScan_function
+InjectionPointCacheEntry
+InjectionPointEntry
InlineCodeBlock
InsertStmt
Instrumentation
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-06 12:35:48 +0000