From caf05d5ca94155c793641b9f32bb6be8b9a77448 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Tue, 23 Feb 2021 11:49:14 -0800
Subject: [PATCH] drd/tests/swapcontext: Improve the portability of this test
 further

- Remove the VALGRIND_STACK_REGISTER() invocation for the initial thread
  stack since it is superfluous. Remove the pthread_attr_getstack() call
  that became superfluous by this change.
- Change SIGINT into SIGALRM for FreeBSD since pthread_kill(..., SIGINT)
  causes the application to return a SIGINT status.
- Reduce the stack size of the threads created by this test.
---
 drd/tests/swapcontext.c          | 51 ++++++++++++++++------------------------
 drd/tests/swapcontext.stderr.exp |  2 +-
 2 files changed, 21 insertions(+), 32 deletions(-)

diff --git a/drd/tests/swapcontext.c b/drd/tests/swapcontext.c
index e692559b0..6257b6d93 100644
--- a/drd/tests/swapcontext.c
+++ b/drd/tests/swapcontext.c
@@ -2,7 +2,8 @@
 
 #define _GNU_SOURCE
 
-#include <poll.h>
+#include <assert.h>
+#include <limits.h>
 #include <pthread.h>
 #include <signal.h>
 #include <stdlib.h>
@@ -13,6 +14,8 @@
 #include <unistd.h>
 #include "valgrind.h"
 
+#define STACKSIZE (PTHREAD_STACK_MIN + 4096)
+
 typedef struct thread_local {
   ucontext_t uc[3];
   size_t nrsw;
@@ -21,7 +24,6 @@ typedef struct thread_local {
 static void f(void *data, int n)
 {
   enum { NR_SWITCHES = 200000 };
-  struct pollfd pfd;
   thread_local_t *tlocal = data;
 
   while (1) {
@@ -33,29 +35,9 @@ static void f(void *data, int n)
   }
 }
 
-void __valgrind_register_current_stack(void)
-{
-  pthread_attr_t attr;
-  size_t stacksize;
-  void *stack;
-
-  if (pthread_getattr_np(pthread_self(), &attr) != 0)
-    abort();
-
-  if (pthread_attr_getstack(&attr, &stack, &stacksize) != 0)
-    abort();
-
-  VALGRIND_STACK_REGISTER(stack, stack + stacksize);
-}
-
-#define STACKSIZE 8192
-
 void *worker(void *data)
 {
   thread_local_t *tlocal = data;
-  struct itimerspec it;
-
-  __valgrind_register_current_stack();
 
   if (getcontext(&(tlocal->uc[1])) < 0)
     abort();
@@ -66,17 +48,17 @@ void *worker(void *data)
   tlocal->uc[1].uc_stack.ss_sp = malloc(STACKSIZE);
   tlocal->uc[1].uc_stack.ss_size = STACKSIZE;
   makecontext(&tlocal->uc[1], (void (*)(void))f, 2, tlocal, 1);
-  VALGRIND_STACK_REGISTER(tlocal->uc[1].uc_stack.ss_sp,
-                          tlocal->uc[1].uc_stack.ss_sp +
-                          tlocal->uc[1].uc_stack.ss_size);
+  (void)VALGRIND_STACK_REGISTER(tlocal->uc[1].uc_stack.ss_sp,
+                                tlocal->uc[1].uc_stack.ss_sp +
+                                tlocal->uc[1].uc_stack.ss_size);
 
   tlocal->uc[2].uc_link = &tlocal->uc[0];
   tlocal->uc[2].uc_stack.ss_sp = malloc(STACKSIZE);
   tlocal->uc[2].uc_stack.ss_size = STACKSIZE;
   makecontext(&tlocal->uc[2], (void (*)(void))f, 2, tlocal, 2);
-  VALGRIND_STACK_REGISTER(tlocal->uc[2].uc_stack.ss_sp,
-                          tlocal->uc[2].uc_stack.ss_sp +
-                          tlocal->uc[2].uc_stack.ss_size);
+  (void)VALGRIND_STACK_REGISTER(tlocal->uc[2].uc_stack.ss_sp,
+                                tlocal->uc[2].uc_stack.ss_sp +
+                                tlocal->uc[2].uc_stack.ss_size);
 
   swapcontext(&tlocal->uc[0], &tlocal->uc[1]);
   return NULL;
@@ -87,17 +69,24 @@ int main(int argc, char *argv[])
   enum { NR = 32 };
   thread_local_t tlocal[NR];
   pthread_t thread[NR];
-  int i;
+  pthread_attr_t attr;
+  int i, res;
 
   memset(tlocal, 0, sizeof(tlocal));
 
+  pthread_attr_init(&attr);
+  res = pthread_attr_setstacksize(&attr, STACKSIZE);
+  assert(res == 0);
+
   for (i = 0; i < NR; i++)
-    pthread_create(&thread[i], NULL, worker, &tlocal[i]);
+    pthread_create(&thread[i], &attr, worker, &tlocal[i]);
+
+  pthread_attr_destroy(&attr);
 
   // Wait until the threads have been created.
   sleep(1);
   for (i = 0; i < NR; i++)
-    pthread_kill(thread[i], SIGINT);
+    pthread_kill(thread[i], SIGALRM);
 
   for (i = 0; i < NR; i++)
     pthread_join(thread[i], NULL);
diff --git a/drd/tests/swapcontext.stderr.exp b/drd/tests/swapcontext.stderr.exp
index 1ebc73a40..fcb5d5ed4 100644
--- a/drd/tests/swapcontext.stderr.exp
+++ b/drd/tests/swapcontext.stderr.exp
@@ -1,6 +1,6 @@
 
 
-Process terminating with default action of signal 2 (SIGINT)
+Process terminating with default action of signal 14 (SIGALRM)
    at 0x........: swapcontext (in /...libc...)
    by 0x........: f (swapcontext.c:?)
 
-- 
2.11.4.GIT