aboutsummaryrefslogtreecommitdiff
path: root/manual/examples/swapcontext.c
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>2001-04-09 04:55:59 +0000
committerUlrich Drepper <drepper@redhat.com>2001-04-09 04:55:59 +0000
commiteacde9d0818dac743bc5c2562e35f0a6e949327e (patch)
treed117012b09ea03667334e4fb4be8ab15c41509d5 /manual/examples/swapcontext.c
parent4c4505561671f07c4f1b9e39cc0a0fa271a6c8be (diff)
downloadglibc-eacde9d0818dac743bc5c2562e35f0a6e949327e.tar
glibc-eacde9d0818dac743bc5c2562e35f0a6e949327e.tar.gz
glibc-eacde9d0818dac743bc5c2562e35f0a6e949327e.tar.bz2
glibc-eacde9d0818dac743bc5c2562e35f0a6e949327e.zip
Update.
2001-04-08 Hans-Peter Nilsson <hp@axis.com> * sysdeps/unix/sysv/linux/cris/Dist: New file. * sysdeps/unix/sysv/linux/cris/Makefile: New file. * sysdeps/unix/sysv/linux/cris/_G_config.h: New file. * sysdeps/unix/sysv/linux/cris/bits/fcntl.h: New file. * sysdeps/unix/sysv/linux/cris/bits/mman.h: New file. * sysdeps/unix/sysv/linux/cris/bits/resource.h: New file. * sysdeps/unix/sysv/linux/cris/brk.c: New file. * sysdeps/unix/sysv/linux/cris/chown.c: New file. * sysdeps/unix/sysv/linux/cris/clone.S: New file. * sysdeps/unix/sysv/linux/cris/fchown.c: New file. * sysdeps/unix/sysv/linux/cris/fcntl.c: New file. * sysdeps/unix/sysv/linux/cris/fxstat.c: New file. * sysdeps/unix/sysv/linux/cris/getegid.c: New file. * sysdeps/unix/sysv/linux/cris/geteuid.c: New file. * sysdeps/unix/sysv/linux/cris/getgid.c: New file. * sysdeps/unix/sysv/linux/cris/getgroups.c: New file. * sysdeps/unix/sysv/linux/cris/getresgid.c: New file. * sysdeps/unix/sysv/linux/cris/getresuid.c: New file. * sysdeps/unix/sysv/linux/cris/getrlimit.c: New file. * sysdeps/unix/sysv/linux/cris/getrlimit64.c: New file. * sysdeps/unix/sysv/linux/cris/getuid.c: New file. * sysdeps/unix/sysv/linux/cris/lchown.c: New file. * sysdeps/unix/sysv/linux/cris/lockf64.c: New file. * sysdeps/unix/sysv/linux/cris/lxstat.c: New file. * sysdeps/unix/sysv/linux/cris/mmap.S: New file. * sysdeps/unix/sysv/linux/cris/mmap64.S: New file. * sysdeps/unix/sysv/linux/cris/msgctl.c: New file. * sysdeps/unix/sysv/linux/cris/profil-counter.h: New file. * sysdeps/unix/sysv/linux/cris/register-dump.h: New file. * sysdeps/unix/sysv/linux/cris/semctl.c: New file. * sysdeps/unix/sysv/linux/cris/setegid.c: New file. * sysdeps/unix/sysv/linux/cris/seteuid.c: New file. * sysdeps/unix/sysv/linux/cris/setfsgid.c: New file. * sysdeps/unix/sysv/linux/cris/setfsuid.c: New file. * sysdeps/unix/sysv/linux/cris/setgid.c: New file. * sysdeps/unix/sysv/linux/cris/setgroups.c: New file. * sysdeps/unix/sysv/linux/cris/setregid.c: New file. * sysdeps/unix/sysv/linux/cris/setresgid.c: New file. * sysdeps/unix/sysv/linux/cris/setresuid.c: New file. * sysdeps/unix/sysv/linux/cris/setreuid.c: New file. * sysdeps/unix/sysv/linux/cris/setrlimit.c: New file. * sysdeps/unix/sysv/linux/cris/setuid.c: New file. * sysdeps/unix/sysv/linux/cris/shmctl.c: New file. * sysdeps/unix/sysv/linux/cris/socket.S: New file. * sysdeps/unix/sysv/linux/cris/sys/ucontext.h: New file. * sysdeps/unix/sysv/linux/cris/syscall.S: New file. * sysdeps/unix/sysv/linux/cris/sysdep.S: New file. * sysdeps/unix/sysv/linux/cris/sysdep.h: New file. * sysdeps/unix/sysv/linux/cris/vfork.S: New file. * sysdeps/unix/sysv/linux/cris/xstat.c: New file. 2001-04-08 Hans-Peter Nilsson <hp@axis.com> * sysdeps/cris/Dist: New file. * sysdeps/cris/Implies: New file. * sysdeps/cris/Makefile: New file. * sysdeps/cris/__longjmp.S: New file. * sysdeps/cris/_mcount.S: New file. * sysdeps/cris/bits/endian.h: New file. * sysdeps/cris/bits/setjmp.h: New file. * sysdeps/cris/bits/string.h: New file. * sysdeps/cris/dl-machine.h: New file. * sysdeps/cris/elf/start.S: New file. * sysdeps/cris/machine-gmon.h: New file. * sysdeps/cris/memcopy.h: New file. * sysdeps/cris/memusage.h: New file. * sysdeps/cris/setjmp.S: New file. * sysdeps/cris/sysdep.h: New file. * sysdeps/cris/wordcopy.c: New file. 2001-04-08 Hans-Peter Nilsson <hp@axis.com> * elf/elf.h: Add new relocations for CRIS. 2001-04-08 Hans-Peter Nilsson <hp@axis.com> * shlib-versions: Add cases for Linux on CRIS. 2001-04-08 Hans-Peter Nilsson <hp@axis.com> * configure.in (ASM_LINE_SEP tests): Handle CRIS assembly, with ';' for comments and '@' for line separator. 2001-04-08 Hans-Peter Nilsson <hp@axis.com> * sysdeps/unix/sysv/linux/hppa/sysdep.h (INLINE_SYSCALL): Fix typo; s/==/=/ for assignment. 2001-04-08 Hans-Peter Nilsson <hp@axis.com> * malloc/Makefile: Correct comment; mtrace is Perl, not AWK. 2001-04-08 Hans-Peter Nilsson <hp@axis.com> * iconv/gconv_simple.c (internal_ucs4_loop_unaligned): Check for empty input before checking full output. 2001-04-08 Hans-Peter Nilsson <hp@axis.com> * iconv/gconv.c (__gconv): Don't derefer parameter cd before checking if == -1L. 2001-04-08 Ulrich Drepper <drepper@redhat.com> * inet/rexec.c (rexec_af): Avoid calling perror with errno being set.
Diffstat (limited to 'manual/examples/swapcontext.c')
-rw-r--r--manual/examples/swapcontext.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/manual/examples/swapcontext.c b/manual/examples/swapcontext.c
new file mode 100644
index 0000000000..f733510f88
--- /dev/null
+++ b/manual/examples/swapcontext.c
@@ -0,0 +1,99 @@
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <ucontext.h>
+#include <sys/time.h>
+
+/* Set by the signal handler. */
+static volatile int expired;
+
+/* The contexts. */
+static ucontext_t uc[3];
+
+/* We do only a certain number of switches. */
+static int switches;
+
+
+/* This is the function doing the work. It is just a
+ skeleton, real code has to be filled in. */
+static void
+f (int n)
+{
+ int m = 0;
+ while (1)
+ {
+ /* This is where the work would be done. */
+ if (++m % 100 == 0)
+ {
+ putchar ('.');
+ fflush (stdout);
+ }
+
+ /* Regularly the @var{expire} variable must be checked. */
+ if (expired)
+ {
+ /* We do not want the program to run forever. */
+ if (++switches == 20)
+ return;
+
+ printf ("\nswitching from %d to %d\n", n, 3 - n);
+ expired = 0;
+ /* Switch to the other context, saving the current one. */
+ swapcontext (&uc[n], &uc[3 - n]);
+ }
+ }
+}
+
+/* This is the signal handler which simply set the variable. */
+void
+handler (int signal)
+{
+ expired = 1;
+}
+
+
+int
+main (void)
+{
+ struct sigaction sa;
+ struct itimerval it;
+ char st1[8192];
+ char st2[8192];
+
+ /* Initialize the data structures for the interval timer. */
+ sa.sa_flags = SA_RESTART;
+ sigfillset (&sa.sa_mask);
+ sa.sa_handler = handler;
+ it.it_interval.tv_sec = 0;
+ it.it_interval.tv_usec = 1;
+ it.it_value = it.it_interval;
+
+ /* Install the timer and get the context we can manipulate. */
+ if (sigaction (SIGPROF, &sa, NULL) < 0
+ || setitimer (ITIMER_PROF, &it, NULL) < 0
+ || getcontext (&uc[1]) == -1
+ || getcontext (&uc[2]) == -1)
+ abort ();
+
+ /* Create a context with a separate stack which causes the
+ function @code{f} to be call with the parameter @code{1}.
+ Note that the @code{uc_link} points to the main context
+ which will cause the program to terminate once the function
+ return. */
+ uc[1].uc_link = &uc[0];
+ uc[1].uc_stack.ss_sp = st1;
+ uc[1].uc_stack.ss_size = sizeof st1;
+ makecontext (&uc[1], (void (*) (void)) f, 1, 1);
+
+ /* Similarly, but @code{2} is passed as the parameter to @code{f}. */
+ uc[2].uc_link = &uc[0];
+ uc[2].uc_stack.ss_sp = st2;
+ uc[2].uc_stack.ss_size = sizeof st2;
+ makecontext (&uc[2], (void (*) (void)) f, 1, 2);
+
+ /* Start running. */
+ swapcontext (&uc[0], &uc[1]);
+ putchar ('\n');
+
+ return 0;
+}