Import of slightly trimmed cvs-1.8 distribution. Generated files

and non-unix code has been left out.

1 files changed, 414 insertions, 0 deletions

diff --git a/contrib/cvs/lib/sighandle.c b/contrib/cvs/lib/sighandle.c
new file mode 100644
index 0000000..ace7db3
--- /dev/null
+++ b/contrib/cvs/lib/sighandle.c
@@ -0,0 +1,414 @@
+/* sighandle.c -- Library routines for manipulating chains of signal handlers
+   Copyright (C) 1992 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* Written by Paul Sander, HaL Computer Systems, Inc. <paul@hal.com>
+   Brian Berliner <berliner@Sun.COM> added POSIX support */
+
+/*************************************************************************
+ *
+ * signal.c -- This file contains code that manipulates chains of signal
+ *             handlers.
+ *
+ *             Facilities are provided to register a signal handler for
+ *             any specific signal.  When a signal is received, all of the
+ *             registered signal handlers are invoked in the reverse order
+ *             in which they are registered.  Note that the signal handlers
+ *             must not themselves make calls to the signal handling
+ *             facilities.
+ *
+ * $CVSid: @(#)sighandle.c 1.13 94/10/07 $
+ *
+ *************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "system.h"
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <signal.h>
+
+/* Add prototype support.  */
+#ifndef PROTO
+#if defined (USE_PROTOTYPES) ? USE_PROTOTYPES : defined (__STDC__)
+#define PROTO(ARGS) ARGS
+#else
+#define PROTO(ARGS) ()
+#endif
+#endif
+
+#ifdef STDC_HEADERS
+#include <stdlib.h>
+#else
+#if __STDC__
+char *calloc(unsigned nelem, unsigned size);
+char *malloc(unsigned size);
+#else
+char *calloc();
+char *malloc();
+#endif /* __STDC__ */
+#endif /* STDC_HEADERS */
+
+/* Define the highest signal number (usually) */
+#ifndef SIGMAX
+#define	SIGMAX	64
+#endif
+
+/* Define linked list of signal handlers structure */
+struct SIG_hlist {
+	RETSIGTYPE		(*handler)();
+	struct SIG_hlist	*next;
+};
+
+/*
+ * Define array of lists of signal handlers.  Note that this depends on
+ * the implementation to initialize each element to a null pointer.
+ */
+
+static	struct SIG_hlist	**SIG_handlers;
+
+/* Define array of default signal vectors */
+
+#ifdef POSIX_SIGNALS
+static	struct sigaction	*SIG_defaults;
+#else
+#ifdef BSD_SIGNALS
+static	struct sigvec		*SIG_defaults;
+#else
+static	RETSIGTYPE		(**SIG_defaults) PROTO ((int));
+#endif
+#endif
+
+/* Critical section housekeeping */
+static	int		SIG_crSectNest = 0;	/* Nesting level */
+#ifdef POSIX_SIGNALS
+static	sigset_t	SIG_crSectMask;		/* Signal mask */
+#else
+static	int		SIG_crSectMask;		/* Signal mask */
+#endif
+
+/*
+ * Initialize the signal handler arrays
+ */
+
+static int SIG_init()
+{
+	int i;
+#ifdef POSIX_SIGNALS
+	sigset_t sigset_test;
+#endif
+
+	if (SIG_defaults && SIG_handlers)	/* already allocated */
+		return (0);
+
+#ifdef POSIX_SIGNALS
+	(void) sigfillset(&sigset_test);
+	for (i = 1; i < SIGMAX && sigismember(&sigset_test, i) == 1; i++)
+		;
+	if (i < SIGMAX)
+		i = SIGMAX;
+	i++;
+	if (!SIG_defaults)
+		SIG_defaults = (struct sigaction *)
+			calloc(i, sizeof(struct sigaction));
+	(void) sigemptyset(&SIG_crSectMask);
+#else
+	i = SIGMAX+1;
+#ifdef BSD_SIGNALS
+	if (!SIG_defaults)
+		SIG_defaults = (struct sigvec *)
+			calloc(i, sizeof(struct sigvec));
+#else
+	if (!SIG_defaults)
+		SIG_defaults = (RETSIGTYPE (**) PROTO ((int)) )
+			calloc(i, sizeof(RETSIGTYPE (**) PROTO ((int)) ));
+#endif
+	SIG_crSectMask = 0;
+#endif
+	if (!SIG_handlers)
+		SIG_handlers = (struct SIG_hlist **)
+			calloc(i, sizeof(struct SIG_hlist *));
+	return (!SIG_defaults || !SIG_handlers);
+}
+
+/*
+ * The following invokes each signal handler in the reverse order in which
+ * they were registered.
+ */
+static RETSIGTYPE SIG_handle PROTO ((int));
+
+static RETSIGTYPE SIG_handle(sig)
+int			sig;
+{
+	struct SIG_hlist	*this;
+
+	/* Dispatch signal handlers */
+	this = SIG_handlers[sig];
+	while (this != (struct SIG_hlist *) NULL)
+	{
+		(*this->handler)(sig);
+		this = this->next;
+	}
+
+	return;
+}
+
+/*
+ * The following registers a signal handler.  If the handler is already
+ * registered, it is not registered twice, nor is the order in which signal
+ * handlers are invoked changed.  If this is the first signal handler
+ * registered for a given signal, the old sigvec structure is saved for
+ * restoration later.
+ */
+
+int SIG_register(sig,fn)
+int	sig;
+RETSIGTYPE	(*fn)();
+{
+	int			val;
+	struct SIG_hlist	*this;
+#ifdef POSIX_SIGNALS
+	struct sigaction	act;
+	sigset_t		sigset_mask, sigset_omask;
+#else
+#ifdef BSD_SIGNALS
+	struct sigvec		vec;
+	int			mask;
+#endif
+#endif
+
+	/* Initialize */
+	if (SIG_init() != 0)
+		return (-1);
+	val = 0;
+
+	/* Block this signal while we look at handler chain */
+#ifdef POSIX_SIGNALS
+	(void) sigemptyset(&sigset_mask);
+	(void) sigaddset(&sigset_mask, sig);
+	(void) sigprocmask(SIG_BLOCK, &sigset_mask, &sigset_omask);
+#else
+#ifdef BSD_SIGNALS
+	mask = sigblock(sigmask(sig));
+#endif
+#endif
+
+	/* See if this handler was already registered */
+	this = SIG_handlers[sig];
+	while (this != (struct SIG_hlist *) NULL)
+	{
+		if (this->handler == fn) break;
+		this = this->next;
+	}
+
+	/* Register the new handler only if it is not already registered. */
+	if (this == (struct SIG_hlist *) NULL)
+	{
+
+		/*
+		 * If this is the first handler registered for this signal,
+		 * set up the signal handler dispatcher
+		 */
+
+		if (SIG_handlers[sig] == (struct SIG_hlist *) NULL)
+		{
+#ifdef POSIX_SIGNALS
+			act.sa_handler = SIG_handle;
+			(void) sigemptyset(&act.sa_mask);
+			act.sa_flags = 0;
+			val = sigaction(sig, &act, &SIG_defaults[sig]);
+#else
+#ifdef BSD_SIGNALS
+			memset (&vec, 0, sizeof (vec));
+			vec.sv_handler = SIG_handle;
+			val = sigvec(sig, &vec, &SIG_defaults[sig]);
+#else
+			if ((SIG_defaults[sig] = signal(sig, SIG_handle)) == SIG_ERR)
+				val = -1;
+#endif
+#endif
+		}
+
+		/* If not, register it */
+		if ((val == 0) && (this == (struct SIG_hlist *) NULL))
+		{
+			this = (struct SIG_hlist *)
+			                      malloc(sizeof(struct SIG_hlist));
+			if (this == NULL)
+			{
+				val = -1;
+			}
+			else
+			{
+				this->handler = fn;
+				this->next = SIG_handlers[sig];
+				SIG_handlers[sig] = this;
+			}
+		}
+	}
+
+	/* Unblock the signal */
+#ifdef POSIX_SIGNALS
+	(void) sigprocmask(SIG_SETMASK, &sigset_omask, NULL);
+#else
+#ifdef BSD_SIGNALS
+	(void) sigsetmask(mask);
+#endif
+#endif
+
+	return val;
+}
+
+/*
+ * The following deregisters a signal handler.  If the last signal handler for
+ * a given signal is deregistered, the default sigvec information is restored.
+ */
+
+int SIG_deregister(sig,fn)
+int	sig;
+RETSIGTYPE	(*fn)();
+{
+	int			val;
+	struct SIG_hlist	*this;
+	struct SIG_hlist	*last;
+#ifdef POSIX_SIGNALS
+	sigset_t		sigset_mask, sigset_omask;
+#else
+#ifdef BSD_SIGNALS
+	int			mask;
+#endif
+#endif
+
+	/* Initialize */
+	if (SIG_init() != 0)
+		return (-1);
+	val = 0;
+	last = (struct SIG_hlist *) NULL;
+
+	/* Block this signal while we look at handler chain */
+#ifdef POSIX_SIGNALS
+	(void) sigemptyset(&sigset_mask);
+	(void) sigaddset(&sigset_mask, sig);
+	(void) sigprocmask(SIG_BLOCK, &sigset_mask, &sigset_omask);
+#else
+#ifdef BSD_SIGNALS
+	mask = sigblock(sigmask(sig));
+#endif
+#endif
+
+	/* Search for the signal handler */
+	this = SIG_handlers[sig];
+	while ((this != (struct SIG_hlist *) NULL) && (this->handler != fn))
+	{
+		last = this;
+		this = this->next;
+	}
+
+	/* If it was registered, remove it */
+	if (this != (struct SIG_hlist *) NULL)
+	{
+		if (last == (struct SIG_hlist *) NULL)
+		{
+			SIG_handlers[sig] = this->next;
+		}
+		else
+		{
+			last->next = this->next;
+		}
+		free((char *) this);
+	}
+
+	/* Restore default behavior if there are no registered handlers */
+	if (SIG_handlers[sig] == (struct SIG_hlist *) NULL)
+	{
+#ifdef POSIX_SIGNALS
+		val = sigaction(sig, &SIG_defaults[sig],
+				(struct sigaction *) NULL);
+#else
+#ifdef BSD_SIGNALS
+		val = sigvec(sig, &SIG_defaults[sig], (struct sigvec *) NULL);
+#else
+		if (signal(sig, SIG_defaults[sig]) == SIG_ERR)
+			val = -1;
+#endif
+#endif
+	}
+
+	/* Unblock the signal */
+#ifdef POSIX_SIGNALS
+	(void) sigprocmask(SIG_SETMASK, &sigset_omask, NULL);
+#else
+#ifdef BSD_SIGNALS
+	(void) sigsetmask(mask);
+#endif
+#endif
+
+	return val;
+}
+
+/*
+ * The following begins a critical section.
+ */
+
+void SIG_beginCrSect()
+{
+	if (SIG_init() == 0)
+	{
+		if (SIG_crSectNest == 0)
+		{
+#ifdef POSIX_SIGNALS
+			sigset_t sigset_mask;
+
+			(void) sigfillset(&sigset_mask);
+			(void) sigprocmask(SIG_SETMASK,
+					   &sigset_mask, &SIG_crSectMask);
+#else
+#ifdef BSD_SIGNALS
+			SIG_crSectMask = sigblock(~0);
+#else
+			/* TBD */
+#endif
+#endif
+		}
+		SIG_crSectNest++;
+	}
+}
+
+/*
+ * The following ends a critical section.
+ */
+
+void SIG_endCrSect()
+{
+	if (SIG_init() == 0)
+	{
+		SIG_crSectNest--;
+		if (SIG_crSectNest == 0)
+		{
+#ifdef POSIX_SIGNALS
+			(void) sigprocmask(SIG_SETMASK, &SIG_crSectMask, NULL);
+#else
+#ifdef BSD_SIGNALS
+			(void) sigsetmask(SIG_crSectMask);
+#else
+			/* TBD */
+#endif
+#endif
+		}
+	}
+}