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32 #include "private/ErrnoRestorer.h"
34 int clock_getcpuclockid(pid_t pid, clockid_t* clockid) {
35 ErrnoRestorer errno_restorer;
37 // The tid is stored in the top bits, but negated.
38 clockid_t result = ~static_cast<clockid_t>(pid) << 3;
39 // Bits 0 and 1: clock type (0 = CPUCLOCK_PROF, 1 = CPUCLOCK_VIRT, 2 = CPUCLOCK_SCHED).
41 // Bit 2: thread (set) or process (clear). Bit 2 already 0.
43 if (clock_getres(result, nullptr) == -1) {