From 9bcf350cc71d427bea84ffaca3d4f69015dcc0c8 Mon Sep 17 00:00:00 2001
From: "Marc G. Fournier" <scrappy@hub.org>
Date: Mon, 17 Nov 1997 03:47:31 +0000
Subject: [PATCH] Apply Bryan's IPC Patches
From: Bryan Henderson <bryanh@giraffe.netgate.net>
---
src/backend/postmaster/postmaster.c | 46 ++++++++++++++++++++++++-----
src/backend/utils/init/postinit.c | 29 +++++++++++-------
2 files changed, 56 insertions(+), 19 deletions(-)
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 65047f9c8ea..52bc471853f 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.61 1997/11/10 05:10:21 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.62 1997/11/17 03:47:28 scrappy Exp $
*
* NOTES
*
@@ -123,6 +123,32 @@ static Dllist *PortList;
static short PostPortName = -1;
static short ActiveBackends = FALSE;
+ /* This is a boolean indicating that there is at least one backend
+ that is accessing the current shared memory and semaphores.
+ Between the time that we start up, or throw away shared memory
+ segments and start over, and the time we generate the next
+ backend (because we received a connection request), it is false.
+ Other times, it is true.
+ */
+static short shmem_seq = 0;
+ /* This is a sequence number that indicates how many times we've had
+ to throw away the shared memory and start over because we doubted
+ its integrity. It starts off at zero and is incremented every
+ time we start over. We use this to ensure that we use a new
+ IPC shared memory key for the new shared memory segment in case
+ the old segment isn't entirely gone yet.
+
+ The sequence actually cycles back to 0 after 9, so pathologically
+ there could be an IPC failure if 10 sets of backends are all stuck
+ and won't release IPC resources.
+ */
+
+static IpcMemoryKey ipc_key;
+ /* This is the base IPC shared memory key. Other keys are generated by
+ adding to this.
+ */
+
+
static int NextBackendId = MAXINT; /* XXX why? */
static char *progname = (char *) NULL;
@@ -904,11 +930,11 @@ ConnCreate(int serverFd, int *newFdP)
static void
reset_shared(short port)
{
- IPCKey key;
-
- key = SystemPortAddressCreateIPCKey((SystemPortAddress) port);
- CreateSharedMemoryAndSemaphores(key);
- ActiveBackends = FALSE;
+ ipc_key = port * 1000 + shmem_seq * 100;
+ CreateSharedMemoryAndSemaphores(ipc_key);
+ ActiveBackends = FALSE;
+ shmem_seq += 1;
+ if (shmem_seq >= 10) shmem_seq -= 10;
}
/*
@@ -1079,9 +1105,10 @@ BackendStartup(StartupInfo *packet, /* client's startup packet */
Backend *bn; /* for backend cleanup */
int pid,
i;
- static char envEntry[4][2 * ARGV_SIZE];
+#define NR_ENVIRONMENT_VBL 5
+ static char envEntry[NR_ENVIRONMENT_VBL][2 * ARGV_SIZE];
- for (i = 0; i < 4; ++i)
+ for (i = 0; i < NR_ENVIRONMENT_VBL; ++i)
{
MemSet(envEntry[i], 0, 2 * ARGV_SIZE);
}
@@ -1101,6 +1128,9 @@ BackendStartup(StartupInfo *packet, /* client's startup packet */
sprintf(envEntry[3], "PGDATA=%s", DataDir);
putenv(envEntry[3]);
}
+ sprintf(envEntry[4], "IPC_KEY=%d", ipc_key);
+ putenv(envEntry[4]);
+
if (DebugLvl > 2)
{
char **p;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 69922388117..beec5b96fee 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.17 1997/11/10 15:15:40 thomas Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.18 1997/11/17 03:47:31 scrappy Exp $
*
* NOTES
* InitPostgres() is the function called from PostgresMain
@@ -281,8 +281,9 @@ InitUserid()
static void
InitCommunication()
{
- char *postid;
- char *postport;
+ char *postid; /* value of environment variable */
+ char *postport; /* value of environment variable */
+ char *ipc_key; /* value of environemnt variable */
IPCKey key = 0;
/* ----------------
@@ -302,10 +303,15 @@ InitCommunication()
Assert(MyBackendTag >= 0);
}
- /* ----------------
- * try and get the ipc key from POSTPORT
- * ----------------
- */
+
+ ipc_key = getenv("IPC_KEY");
+ if (!PointerIsValid(ipc_key)) {
+ key = -1;
+ } else {
+ key = atoi(ipc_key);
+ Assert(MyBackendTag >= 0);
+ }
+
postport = getenv("POSTPORT");
if (PointerIsValid(postport))
@@ -315,8 +321,6 @@ InitCommunication()
if (MyBackendTag == -1)
elog(FATAL, "InitCommunication: missing POSTID");
- key = SystemPortAddressCreateIPCKey(address);
-
/*
* Enable this if you are trying to force the backend to run as if
* it is running under the postmaster.
@@ -328,8 +332,11 @@ InitCommunication()
* To enable emulation, run the following shell commands (in addition
* to enabling this goto)
*
- * % setenv POSTID 1 % setenv POSTPORT 4321 % postmaster & % kill -9
- * %1
+ * % setenv POSTID 1
+ * % setenv POSTPORT 4321
+ * % setenv IPC_KEY 4321000
+ * % postmaster &
+ * % kill -9 %1
*
* Upon doing this, Postmaster will have allocated the shared memory
* resources that Postgres will attach to if you enable
--
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