global: remove setitimer support

The previous commit removed the only user of setitimer(). Remove the
build infrastructure and compatibility scaffold, in particular, the
support for SIGALRM from compat/mingw.

Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>

Author: j6t

Makefile

@@ -142,11 +142,6 @@ include shared.mak
 # Define NO_PREAD if you have a problem with pread() system call (e.g.
 # cygwin1.dll before v1.5.22).
 #
-# Define NO_SETITIMER if you don't have setitimer()
-#
-# Define NO_STRUCT_ITIMERVAL if you don't have struct itimerval
-# This also implies NO_SETITIMER
-#
 # Define NO_FAST_WORKING_DIRECTORY if accessing objects in pack files is
 # generally faster on your platform than accessing the working directory.
 #
@@ -1890,13 +1885,6 @@ endif
 ifdef OBJECT_CREATION_USES_RENAMES
 	COMPAT_CFLAGS += -DOBJECT_CREATION_MODE=1
 endif
-ifdef NO_STRUCT_ITIMERVAL
-	COMPAT_CFLAGS += -DNO_STRUCT_ITIMERVAL
-	NO_SETITIMER = YesPlease
-endif
-ifdef NO_SETITIMER
-	COMPAT_CFLAGS += -DNO_SETITIMER
-endif
 ifdef NO_PREAD
 	COMPAT_CFLAGS += -DNO_PREAD
 	COMPAT_OBJS += compat/pread.o

compat/mingw-posix.h

@@ -63,7 +63,6 @@ typedef int pid_t;
 #define SIGQUIT 3
 #define SIGKILL 9
 #define SIGPIPE 13
-#define SIGALRM 14
 #define SIGCHLD 17
 
 #define F_GETFD 1
@@ -98,11 +97,6 @@ struct sigaction {
 #define SA_RESTART 0
 #define SA_NOCLDSTOP 1
 
-struct itimerval {
-	struct timeval it_value, it_interval;
-};
-#define ITIMER_REAL 0
-
 struct utsname {
 	char sysname[16];
 	char nodename[1];
@@ -193,7 +187,6 @@ struct tm *localtime_r(const time_t *timep, struct tm *result);
 #endif
 int getpagesize(void);	/* defined in MinGW's libgcc.a */
 struct passwd *getpwuid(uid_t uid);
-int setitimer(int type, struct itimerval *in, struct itimerval *out);
 int sigaction(int sig, struct sigaction *in, struct sigaction *out);
 int link(const char *oldpath, const char *newpath);
 int uname(struct utsname *buf);

compat/mingw.c

@@ -2420,110 +2420,15 @@ struct passwd *getpwuid(int uid UNUSED)
 	return p;
 }
 
-static HANDLE timer_event;
-static HANDLE timer_thread;
-static int timer_interval;
-static int one_shot;
-static sig_handler_t timer_fn = SIG_DFL, sigint_fn = SIG_DFL;
-
-/* The timer works like this:
- * The thread, ticktack(), is a trivial routine that most of the time
- * only waits to receive the signal to terminate. The main thread tells
- * the thread to terminate by setting the timer_event to the signalled
- * state.
- * But ticktack() interrupts the wait state after the timer's interval
- * length to call the signal handler.
- */
-
-static unsigned __stdcall ticktack(void *dummy UNUSED)
-{
-	while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
-		mingw_raise(SIGALRM);
-		if (one_shot)
-			break;
-	}
-	return 0;
-}
-
-static int start_timer_thread(void)
-{
-	timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
-	if (timer_event) {
-		timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
-		if (!timer_thread )
-			return errno = ENOMEM,
-				error("cannot start timer thread");
-	} else
-		return errno = ENOMEM,
-			error("cannot allocate resources for timer");
-	return 0;
-}
-
-static void stop_timer_thread(void)
-{
-	if (timer_event)
-		SetEvent(timer_event);	/* tell thread to terminate */
-	if (timer_thread) {
-		int rc = WaitForSingleObject(timer_thread, 10000);
-		if (rc == WAIT_TIMEOUT)
-			error("timer thread did not terminate timely");
-		else if (rc != WAIT_OBJECT_0)
-			error("waiting for timer thread failed: %lu",
-			      GetLastError());
-		CloseHandle(timer_thread);
-	}
-	if (timer_event)
-		CloseHandle(timer_event);
-	timer_event = NULL;
-	timer_thread = NULL;
-}
-
-static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
-{
-	return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
-}
+static sig_handler_t sigint_fn = SIG_DFL;
 
-int setitimer(int type UNUSED, struct itimerval *in, struct itimerval *out)
-{
-	static const struct timeval zero;
-	static int atexit_done;
-
-	if (out)
-		return errno = EINVAL,
-			error("setitimer param 3 != NULL not implemented");
-	if (!is_timeval_eq(&in->it_interval, &zero) &&
-	    !is_timeval_eq(&in->it_interval, &in->it_value))
-		return errno = EINVAL,
-			error("setitimer: it_interval must be zero or eq it_value");
-
-	if (timer_thread)
-		stop_timer_thread();
-
-	if (is_timeval_eq(&in->it_value, &zero) &&
-	    is_timeval_eq(&in->it_interval, &zero))
-		return 0;
-
-	timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
-	one_shot = is_timeval_eq(&in->it_interval, &zero);
-	if (!atexit_done) {
-		atexit(stop_timer_thread);
-		atexit_done = 1;
-	}
-	return start_timer_thread();
-}
-
-int sigaction(int sig, struct sigaction *in, struct sigaction *out)
+int sigaction(int sig, struct sigaction *in UNUSED, struct sigaction *out)
 {
 	if (sig == SIGCHLD)
 		return -1;
-	else if (sig != SIGALRM)
-		return errno = EINVAL,
-			error("sigaction only implemented for SIGALRM");
 	if (out)
 		return errno = EINVAL,
 			error("sigaction: param 3 != NULL not implemented");
-
-	timer_fn = in->sa_handler;
 	return 0;
 }
 
@@ -2533,11 +2438,6 @@ sig_handler_t mingw_signal(int sig, sig_handler_t handler)
 	sig_handler_t old;
 
 	switch (sig) {
-	case SIGALRM:
-		old = timer_fn;
-		timer_fn = handler;
-		break;
-
 	case SIGINT:
 		old = sigint_fn;
 		sigint_fn = handler;
@@ -2554,15 +2454,6 @@ sig_handler_t mingw_signal(int sig, sig_handler_t handler)
 int mingw_raise(int sig)
 {
 	switch (sig) {
-	case SIGALRM:
-		if (timer_fn == SIG_DFL) {
-			if (isatty(STDERR_FILENO))
-				fputs("Alarm clock\n", stderr);
-			exit(128 + SIGALRM);
-		} else if (timer_fn != SIG_IGN)
-			timer_fn(SIGALRM);
-		return 0;
-
 	case SIGINT:
 		if (sigint_fn == SIG_DFL)
 			exit(128 + SIGINT);

compat/posix.h

@@ -198,23 +198,6 @@ static inline time_t git_time(time_t *tloc)
 }
 #define time git_time
 
-#ifdef NO_STRUCT_ITIMERVAL
-struct itimerval {
-	struct timeval it_interval;
-	struct timeval it_value;
-};
-#endif
-
-#ifdef NO_SETITIMER
-static inline int git_setitimer(int which UNUSED,
-				const struct itimerval *value UNUSED,
-				struct itimerval *newvalue UNUSED) {
-	return 0; /* pretend success */
-}
-#undef setitimer
-#define setitimer(which,value,ovalue) git_setitimer(which,value,ovalue)
-#endif
-
 #ifndef NO_LIBGEN_H
 #include <libgen.h>
 #else

configure.ac

@@ -872,13 +872,6 @@ case $ac_cv_type_socklen_t in
 esac
 GIT_CONF_SUBST([SOCKLEN_T])
 
-#
-# Define NO_STRUCT_ITIMERVAL if you don't have struct itimerval.
-AC_CHECK_TYPES([struct itimerval],
-[NO_STRUCT_ITIMERVAL=],
-[NO_STRUCT_ITIMERVAL=UnfortunatelyYes],
-[#include <sys/time.h>])
-GIT_CONF_SUBST([NO_STRUCT_ITIMERVAL])
 #
 # Define USE_ST_TIMESPEC=YesPlease when stat.st_mtimespec.tv_nsec exists.
 # Define NO_NSEC=YesPlease when neither stat.st_mtim.tv_nsec nor
@@ -1097,12 +1090,6 @@ GIT_CHECK_FUNC(sync_file_range,
 	[HAVE_SYNC_FILE_RANGE=])
 GIT_CONF_SUBST([HAVE_SYNC_FILE_RANGE])
 
-#
-# Define NO_SETITIMER if you don't have setitimer.
-GIT_CHECK_FUNC(setitimer,
-[NO_SETITIMER=],
-[NO_SETITIMER=YesPlease])
-GIT_CONF_SUBST([NO_SETITIMER])
 #
 # Define NO_STRCASESTR if you don't have strcasestr.
 GIT_CHECK_FUNC(strcasestr,

meson.build

@@ -1349,22 +1349,6 @@ else
     error('Native regex support requested but not found')
 endif
 
-# setitimer and friends are provided by compat/mingw.c.
-if host_machine.system() != 'windows'
-  if not compiler.compiles('''
-    #include <sys/time.h>
-    void func(void)
-    {
-      struct itimerval value;
-    }
-  ''', name: 'struct itimerval')
-    libgit_c_args += '-DNO_STRUCT_ITIMERVAL'
-    libgit_c_args += '-DNO_SETITIMER'
-  elif not compiler.has_function('setitimer')
-    libgit_c_args += '-DNO_SETITIMER'
-  endif
-endif
-
 if compiler.has_member('struct stat', 'st_mtimespec.tv_nsec', prefix: '#include <sys/stat.h>')
   libgit_c_args += '-DUSE_ST_TIMESPEC'
 elif not compiler.has_member('struct stat', 'st_mtim.tv_nsec', prefix: '#include <sys/stat.h>')