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RE: [PATCH v3] Support for setitimer() on platforms lacking it

From
Joachim Schmitz <jojo@schmitz-digital.de>
Date
Sep 7, 2012, 09:55 UTC
Message-ID
<002201cd8cde$ea7cacc0$bf760640$@schmitz-digital.de>

HP NonStop (currently) doesn't have setitimer(). The previous attempt of an emulation (reverted by this commit) was not a real substitute for a recurring itimer (as here we also don't have SA_RESTART, so can't re-arm the timer). As setitimer() is only used in cases of perceived latency and it doesn't affect correctness, it now gets disabled entirely, if NO_SETITIMER is set. HP NonStop does provide struct itimerval, but other platforms may not, so this is taken care of in this commit too, by setting NO_STRUCT_ITIMERVAL.

Signed-off-by: Joachim Schmitz <jojo@schmitz-digital.de>
---
 Makefile          |  5 +++++
 compat/itimer.c   | 50 --------------------------------------------------
 git-compat-util.h | 11 +++++++++--
 3 files changed, 14 insertions(+), 52 deletions(-)
 delete mode 100644 compat/itimer.c
diff --git a/Makefile b/Makefile
index ac49320..7be555b 100644
--- a/Makefile
+++ b/Makefile
@@ -157,6 +157,11 @@ all::
 # 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_THREAD_SAFE_PREAD if your pread() implementation is not
 # thread-safe. (e.g. compat/pread.c or cygwin)
 #
diff --git a/compat/itimer.c b/compat/itimer.c
deleted file mode 100644
index 713f1ff..0000000
--- a/compat/itimer.c
+++ /dev/null
@@ -1,50 +0,0 @@
-#include "../git-compat-util.h"
-
-static int git_getitimer(int which, struct itimerval *value)
-{
-	int ret = 0;
-
-	switch (which) {
-		case ITIMER_REAL:
-			value->it_value.tv_usec = 0;
-			value->it_value.tv_sec = alarm(0);
-			ret = 0; /* if alarm() fails, we get a SIGLIMIT */
-			break;
-		case ITIMER_VIRTUAL: /* FALLTHRU */
-		case ITIMER_PROF: errno = ENOTSUP; ret = -1; break;
-		default: errno = EINVAL; ret = -1;
-	}
-	return ret;
-}
-
-int git_setitimer(int which, const struct itimerval *value,
-				struct itimerval *ovalue)
-{
-	int ret = 0;
-
-	if (!value
-		|| value->it_value.tv_usec < 0
-		|| value->it_value.tv_usec > 1000000
-		|| value->it_value.tv_sec < 0) {
-		errno = EINVAL;
-		return -1;
-	}
-
-	else if (ovalue)
-		if (!git_getitimer(which, ovalue))
-			return -1; /* errno set in git_getitimer() */
-
-	else
-	switch (which) {
-		case ITIMER_REAL:
-			alarm(value->it_value.tv_sec +
-				(value->it_value.tv_usec > 0) ? 1 : 0);
-			ret = 0; /* if alarm() fails, we get a SIGLIMIT */
-			break;
-		case ITIMER_VIRTUAL: /* FALLTHRU */
-		case ITIMER_PROF: errno = ENOTSUP; ret = -1; break;
-		default: errno = EINVAL; ret = -1;
-	}
-
-	return ret;
-}
diff --git a/git-compat-util.h b/git-compat-util.h
index 18089f0..4628d7a 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -162,9 +162,16 @@
 #define probe_utf8_pathname_composition(a,b)
 #endif
 
+#ifdef NO_STRUCT_ITIMERVAL
+struct itimerval {
+	struct timeval it_interval;
+	struct timeval it_value;
+}
+#define NO_SETITIMER
+#endif
+
 #ifdef NO_SETITIMER
-#define setitimer(a,b,c) git_setitimer((a),(b),(c))
-extern int git_setitimer(int, const struct itimerval *, struct itimerval *);
+#define setitimer(which,value,ovalue)
 #endif
 
 #ifdef MKDIR_WO_TRAILING_SLASH
-- 
1.7.12
Next: Junio C Hamano
Message 1 of 3 in “RE: [PATCH v3] Support for setitimer() on platforms lacking it”
  1. Joachim SchmitzSep 7, 2012
  2. Junio C HamanoSep 7, 2012
  3. Joachim SchmitzSep 7, 2012

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