From: Rich Felker <dalias@aerifal.cx>
Date: Sat, 8 Jun 2013 15:36:41 +0000 (-0400)
Subject: support cputime clocks for processes/threads other than self
X-Git-Tag: v0.9.11~34
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=ea200e38bd79723054c7ad97cbf87911eac5b7f5;p=oweals%2Fmusl.git

support cputime clocks for processes/threads other than self

apparently these features have been in Linux for a while now, so it
makes sense to support them. the bit twiddling seems utterly illogical
and wasteful, especially the negation, but that's how the kernel folks
chose to encode pids/tids into the clock id.
---

diff --git a/src/thread/pthread_getcpuclockid.c b/src/thread/pthread_getcpuclockid.c
index cf3d2b84..9df14fb6 100644
--- a/src/thread/pthread_getcpuclockid.c
+++ b/src/thread/pthread_getcpuclockid.c
@@ -2,5 +2,6 @@
 
 int pthread_getcpuclockid(pthread_t t, clockid_t *clockid)
 {
-	return ENOSYS;
+	*clockid = (-t->tid-1)*8U + 6;
+	return 0;
 }
diff --git a/src/time/clock_getcpuclockid.c b/src/time/clock_getcpuclockid.c
index 723840b0..8a0e2d4c 100644
--- a/src/time/clock_getcpuclockid.c
+++ b/src/time/clock_getcpuclockid.c
@@ -5,7 +5,10 @@
 
 int clock_getcpuclockid(pid_t pid, clockid_t *clk)
 {
-	if (pid && pid != getpid()) return EPERM;
-	*clk = CLOCK_PROCESS_CPUTIME_ID;
+	struct timespec ts;
+	clockid_t id = (-pid-1)*8U + 2;
+	int ret = __syscall(SYS_clock_getres, id, &ts);
+	if (ret) return -ret;
+	*clk = id;
 	return 0;
 }