v13-0001-Add-pairingheap_initialize-for-shared-memory-usag.patch
application/x-patch
Filename: v13-0001-Add-pairingheap_initialize-for-shared-memory-usag.patch
Type: application/x-patch
Part: 2
Patch
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Format: format-patch
Series: patch v13-0001
Subject: Add pairingheap_initialize() for shared memory usage
| File | + | − |
|---|---|---|
| src/backend/lib/pairingheap.c | 16 | 2 |
| src/include/lib/pairingheap.h | 3 | 0 |
From 48abb92fb33628f6eba5bbe865b3b19c24fb716d Mon Sep 17 00:00:00 2001
From: alterego655 <824662526@qq.com>
Date: Thu, 9 Oct 2025 10:29:05 +0800
Subject: [PATCH v13 1/3] Add pairingheap_initialize() for shared memory usage
The existing pairingheap_allocate() uses palloc(), which allocates
from process-local memory. For shared memory use cases, the pairingheap
structure must be allocated via ShmemAlloc() or embedded in a shared
memory struct. Add pairingheap_initialize() to initialize an already-
allocated pairingheap structure in-place, enabling shared memory usage.
Discussion:
https://www.postgresql.org/message-id/flat/CAPpHfdsjtZLVzxjGT8rJHCYbM0D5dwkO+BBjcirozJ6nYbOW8Q@mail.gmail.com
https://www.postgresql.org/message-id/flat/CABPTF7UNft368x-RgOXkfj475OwEbp%2BVVO-wEXz7StgjD_%3D6sw%40mail.gmail.com
Author: Kartyshov Ivan <i.kartyshov@postgrespro.ru>
Author: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Euler Taveira <euler@eulerto.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
---
src/backend/lib/pairingheap.c | 18 ++++++++++++++++--
src/include/lib/pairingheap.h | 3 +++
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/src/backend/lib/pairingheap.c b/src/backend/lib/pairingheap.c
index 0aef8a88f1b..fa8431f7946 100644
--- a/src/backend/lib/pairingheap.c
+++ b/src/backend/lib/pairingheap.c
@@ -44,12 +44,26 @@ pairingheap_allocate(pairingheap_comparator compare, void *arg)
pairingheap *heap;
heap = (pairingheap *) palloc(sizeof(pairingheap));
+ pairingheap_initialize(heap, compare, arg);
+
+ return heap;
+}
+
+/*
+ * pairingheap_initialize
+ *
+ * Same as pairingheap_allocate(), but initializes the pairing heap in-place
+ * rather than allocating a new chunk of memory. Useful to store the pairing
+ * heap in a shared memory.
+ */
+void
+pairingheap_initialize(pairingheap *heap, pairingheap_comparator compare,
+ void *arg)
+{
heap->ph_compare = compare;
heap->ph_arg = arg;
heap->ph_root = NULL;
-
- return heap;
}
/*
diff --git a/src/include/lib/pairingheap.h b/src/include/lib/pairingheap.h
index 3c57d3fda1b..567586f2ecf 100644
--- a/src/include/lib/pairingheap.h
+++ b/src/include/lib/pairingheap.h
@@ -77,6 +77,9 @@ typedef struct pairingheap
extern pairingheap *pairingheap_allocate(pairingheap_comparator compare,
void *arg);
+extern void pairingheap_initialize(pairingheap *heap,
+ pairingheap_comparator compare,
+ void *arg);
extern void pairingheap_free(pairingheap *heap);
extern void pairingheap_add(pairingheap *heap, pairingheap_node *node);
extern pairingheap_node *pairingheap_first(pairingheap *heap);
--
2.51.0