Use dlist/dclist instead of PROC_QUEUE / SHM_QUEUE for heavyweight locks

Part of a series to remove SHM_QUEUE. ilist.h style lists are more widely used
and have an easier to use interface.

As PROC_QUEUE is now unused, remove it.

Reviewed-by: Thomas Munro <thomas.munro@gmail.com> (in an older version)
Discussion: https://postgr.es/m/20221120055930.t6kl3tyivzhlrzu2@awork3.anarazel.de
Discussion: https://postgr.es/m/20200211042229.msv23badgqljrdg2@alap3.anarazel.de

2 files changed, 13 insertions, 19 deletions

diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
index 190bddb767c..6ae434596ad 100644
--- a/src/include/storage/lock.h
+++ b/src/include/storage/lock.h
@@ -18,6 +18,7 @@
 #error "lock.h may not be included from frontend code"
 #endif
 
+#include "lib/ilist.h"
 #include "storage/backendid.h"
 #include "storage/lockdefs.h"
 #include "storage/lwlock.h"
@@ -27,12 +28,6 @@
 /* struct PGPROC is declared in proc.h, but must forward-reference it */
 typedef struct PGPROC PGPROC;
 
-typedef struct PROC_QUEUE
-{
-	SHM_QUEUE	links;			/* head of list of PGPROC objects */
-	int			size;			/* number of entries in list */
-} PROC_QUEUE;
-
 /* GUC variables */
 extern PGDLLIMPORT int max_locks_per_xact;
 
@@ -318,8 +313,8 @@ typedef struct LOCK
 	/* data */
 	LOCKMASK	grantMask;		/* bitmask for lock types already granted */
 	LOCKMASK	waitMask;		/* bitmask for lock types awaited */
-	SHM_QUEUE	procLocks;		/* list of PROCLOCK objects assoc. with lock */
-	PROC_QUEUE	waitProcs;		/* list of PGPROC objects waiting on lock */
+	dlist_head	procLocks;		/* list of PROCLOCK objects assoc. with lock */
+	dclist_head	waitProcs;		/* list of PGPROC objects waiting on lock */
 	int			requested[MAX_LOCKMODES];	/* counts of requested locks */
 	int			nRequested;		/* total of requested[] array */
 	int			granted[MAX_LOCKMODES]; /* counts of granted locks */
@@ -380,8 +375,8 @@ typedef struct PROCLOCK
 	PGPROC	   *groupLeader;	/* proc's lock group leader, or proc itself */
 	LOCKMASK	holdMask;		/* bitmask for lock types currently held */
 	LOCKMASK	releaseMask;	/* bitmask for lock types to be released */
-	SHM_QUEUE	lockLink;		/* list link in LOCK's list of proclocks */
-	SHM_QUEUE	procLink;		/* list link in PGPROC's list of proclocks */
+	dlist_node	lockLink;		/* list link in LOCK's list of proclocks */
+	dlist_node	procLink;		/* list link in PGPROC's list of proclocks */
 } PROCLOCK;
 
 #define PROCLOCK_LOCKMETHOD(proclock) \
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index b5c6f46d031..6eb46a7ee8e 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -167,8 +167,8 @@ typedef enum
 struct PGPROC
 {
 	/* proc->links MUST BE FIRST IN STRUCT (see ProcSleep,ProcWakeup,etc) */
-	SHM_QUEUE	links;			/* list link if process is in a list */
-	PGPROC	  **procgloballist; /* procglobal list that owns this PGPROC */
+	dlist_node	links;			/* list link if process is in a list */
+	dlist_head *procgloballist; /* procglobal list that owns this PGPROC */
 
 	PGSemaphore sem;			/* ONE semaphore to sleep on */
 	ProcWaitStatus waitStatus;
@@ -255,7 +255,7 @@ struct PGPROC
 	 * linked into one of these lists, according to the partition number of
 	 * their lock.
 	 */
-	SHM_QUEUE	myProcLocks[NUM_LOCK_PARTITIONS];
+	dlist_head	myProcLocks[NUM_LOCK_PARTITIONS];
 
 	XidCacheStatus subxidStatus;	/* mirrored with
 									 * ProcGlobal->subxidStates[i] */
@@ -385,13 +385,13 @@ typedef struct PROC_HDR
 	/* Length of allProcs array */
 	uint32		allProcCount;
 	/* Head of list of free PGPROC structures */
-	PGPROC	   *freeProcs;
+	dlist_head	freeProcs;
 	/* Head of list of autovacuum's free PGPROC structures */
-	PGPROC	   *autovacFreeProcs;
+	dlist_head autovacFreeProcs;
 	/* Head of list of bgworker free PGPROC structures */
-	PGPROC	   *bgworkerFreeProcs;
+	dlist_head bgworkerFreeProcs;
 	/* Head of list of walsender free PGPROC structures */
-	PGPROC	   *walsenderFreeProcs;
+	dlist_head walsenderFreeProcs;
 	/* First pgproc waiting for group XID clear */
 	pg_atomic_uint32 procArrayGroupFirst;
 	/* First pgproc waiting for group transaction status update */
@@ -448,9 +448,8 @@ extern int	GetStartupBufferPinWaitBufId(void);
 extern bool HaveNFreeProcs(int n);
 extern void ProcReleaseLocks(bool isCommit);
 
-extern void ProcQueueInit(PROC_QUEUE *queue);
 extern ProcWaitStatus ProcSleep(LOCALLOCK *locallock, LockMethod lockMethodTable);
-extern PGPROC *ProcWakeup(PGPROC *proc, ProcWaitStatus waitStatus);
+extern void ProcWakeup(PGPROC *proc, ProcWaitStatus waitStatus);
 extern void ProcLockWakeup(LockMethod lockMethodTable, LOCK *lock);
 extern void CheckDeadLockAlert(void);
 extern bool IsWaitingForLock(void);