Adjust spawn_process() to avoid unnecessary overhead processes: we can

just exec instead of creating a subprocess.  This reduces process usage
from four processes per parallel test to two.  I have no idea whether
a comparable optimization is possible or useful in the Windows port.

diff --git a/doc/src/sgml/regress.sgml b/doc/src/sgml/regress.sgml
index 141eaaa0bf178789cf6af154f48fd7574fc3cd6a..fbfed9220b3bd13b621524bc9296ad92f655e9a8 100644 (file)
--- a/doc/src/sgml/regress.sgml
+++ b/doc/src/sgml/regress.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/regress.sgml,v 1.53 2006/07/19 02:37:00 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/regress.sgml,v 1.54 2006/07/19 17:02:59 tgl Exp $ -->
 
  <chapter id="regress">
   <title id="regress-title">Regression Tests</title>
@@ -96,11 +96,10 @@ gmake check
    <para>
     The parallel regression test starts quite a few processes under your
     user ID.  Presently, the maximum concurrency is twenty parallel test
-    scripts, which means sixty processes: there's a server process, a
-    <application>psql</>, and usually a shell parent process for the
-    <application>psql</> for each test script.
+    scripts, which means forty processes: there's a server process and a
+    <application>psql</> process for each test script.
     So if your system enforces a per-user limit on the number of processes,
-    make sure this limit is at least seventy-five or so, else you may get
+    make sure this limit is at least fifty or so, else you may get
     random-seeming failures in the parallel test.  If you are not in
     a position to raise the limit, you can cut down the degree of parallelism
     by setting the <literal>MAX_CONNECTIONS</> parameter.  For example,

diff --git a/src/test/regress/GNUmakefile b/src/test/regress/GNUmakefile
index c9081d503f7da1cbb0ad007df52857428e4bd9e2..792ff4a98fc7376858d3c416a888b512805ca8c1 100644 (file)
--- a/src/test/regress/GNUmakefile
+++ b/src/test/regress/GNUmakefile
@@ -6,7 +6,7 @@
 # Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
 # Portions Copyright (c) 1994, Regents of the University of California
 #
-# $PostgreSQL: pgsql/src/test/regress/GNUmakefile,v 1.59 2006/07/19 04:02:31 tgl Exp $
+# $PostgreSQL: pgsql/src/test/regress/GNUmakefile,v 1.60 2006/07/19 17:02:59 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -39,7 +39,8 @@ EXTRADEFS = '-DPGBINDIR="$(bindir)"' \
        '-DLIBDIR="$(libdir)"' \
        '-DPGSHAREDIR="$(datadir)"' \
        '-DHOST_TUPLE="$(host_tuple)"' \
-       '-DMAKEPROG="$(MAKE)"'
+       '-DMAKEPROG="$(MAKE)"' \
+       '-DSHELLPROG="$(SHELL)"'
 
 ##
 ## Prepare for tests

diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
index 1704da5033ddfc4bec7f01488d9ba64d639e17c1..ad3d0cd3e1bc0bbd6463627421f1fc7c7014f413 100644 (file)
--- a/src/test/regress/pg_regress.c
+++ b/src/test/regress/pg_regress.c
@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/test/regress/pg_regress.c,v 1.4 2006/07/19 16:23:17 tgl Exp $
+ * $PostgreSQL: pgsql/src/test/regress/pg_regress.c,v 1.5 2006/07/19 17:02:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -60,6 +60,7 @@ static char *libdir = LIBDIR;
 static char *datadir = PGSHAREDIR;
 static char *host_platform = HOST_TUPLE;
 static char *makeprog = MAKEPROG;
+static char *shellprog = SHELLPROG;
 
 /* currently we can use the same diff switches on all platforms */
 static const char *basic_diff_opts = "-w";
@@ -630,8 +631,20 @@ spawn_process(const char *cmdline)
        }
        if (pid == 0)
        {
-               /* In child */
-               exit(system(cmdline) ? 1 : 0);
+               /*
+                * In child
+                *
+                * Instead of using system(), exec the shell directly, and tell it
+                * to "exec" the command too.  This saves two useless processes
+                * per parallel test case.
+                */
+               char *cmdline2 = malloc(strlen(cmdline) + 6);
+
+               sprintf(cmdline2, "exec %s", cmdline);
+               execl(shellprog, shellprog, "-c", cmdline2, NULL);
+               fprintf(stderr, _("%s: could not exec \"%s\": %s\n"),
+                               progname, shellprog, strerror(errno));
+               exit(1);                                /* not exit_nicely here... */
        }
        /* in parent */
        return pid;
@@ -648,7 +661,7 @@ spawn_process(const char *cmdline)
 
        if (!CreateProcess(NULL, cmdline2, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi))
        {
-               fprintf(stderr, _("failed to start process for \"%s\": %lu\n"),
+               fprintf(stderr, _("could not start process for \"%s\": %lu\n"),
                                cmdline2, GetLastError());
                exit_nicely(2);
        }
@@ -684,7 +697,7 @@ psql_start_test(const char *testname)
 
        if (pid == INVALID_PID)
        {
-               fprintf(stderr, _("failed to start process for test %s\n"),
+               fprintf(stderr, _("could not start process for test %s\n"),
                                testname);
                exit_nicely(2);
        }
@@ -918,7 +931,7 @@ wait_for_tests(PID_TYPE *pids, int num_tests)
 
                if (p == -1)
                {
-                       fprintf(stderr, _("failed to wait(): %s\n"), strerror(errno));
+                       fprintf(stderr, _("could not wait(): %s\n"), strerror(errno));
                        exit_nicely(2);
                }
                for (i=0; i < num_tests; i++)
@@ -938,7 +951,7 @@ wait_for_tests(PID_TYPE *pids, int num_tests)
        r = WaitForMultipleObjects(num_tests, pids, TRUE, INFINITE);
        if (r != WAIT_OBJECT_0)
        {
-               fprintf(stderr, _("failed to wait for commands to finish: %lu\n"),
+               fprintf(stderr, _("could not wait for commands to finish: %lu\n"),
                                GetLastError());
                exit_nicely(2);
        }
@@ -1228,7 +1241,7 @@ main(int argc, char *argv[])
        int c;
        int i;
        int option_index;
-       char buf[MAXPGPATH];
+       char buf[MAXPGPATH * 4];
 
        static struct option long_options[] = {
                {"help", no_argument, NULL, 'h'},
@@ -1431,14 +1444,6 @@ main(int argc, char *argv[])
                        exit_nicely(2);
                }
 
-               /*
-                * XXX Note that because we use system() to launch the subprocess,
-                * the returned postmaster_pid is not really the PID of the
-                * postmaster itself; on most systems it'll be the PID of a parent
-                * shell process.  This is OK for the limited purposes we currently
-                * use postmaster_pid for, but beware!
-                */
-
                /*
                 * Wait till postmaster is able to accept connections (normally only
                 * a second or so, but Cygwin is reportedly *much* slower).  Don't