mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-07-03 09:48:29 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Make fork() go 30% faster

Browse source 
This change makes fork() go nearly as fast as sys_fork() on UNIX. As for
Windows this change shaves about 4-5ms off fork() + wait() latency. This
is accomplished by using WriteProcessMemory() from the parent process to
setup the address space of a suspended process; it is better than a pipe
This commit is contained in:
Justine Tunney 2025-01-01 04:59:38 -08:00
parent 98c5847727
commit 0b3c81dd4e
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
44 changed files with 769 additions and 649 deletions
Download patch file Download diff file Expand all files Collapse all files

18
libc/intrin/rand64.c
View file

@ -28,7 +28,19 @@
static int _rand64_pid;
static unsigned __int128 _rand64_pool;
pthread_mutex_t __rand64_lock_obj = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t __rand64_lock_obj = PTHREAD_MUTEX_INITIALIZER;
void __rand64_lock(void) {
_pthread_mutex_lock(&__rand64_lock_obj);
}
void __rand64_unlock(void) {
_pthread_mutex_unlock(&__rand64_lock_obj);
}
void __rand64_wipe(void) {
_pthread_mutex_wipe_np(&__rand64_lock_obj);
}
/**
* Returns nondeterministic random data.
@ -43,7 +55,7 @@ pthread_mutex_t __rand64_lock_obj = PTHREAD_MUTEX_INITIALIZER;
uint64_t _rand64(void) {
void *p;
uint128_t s;
_pthread_mutex_lock(&__rand64_lock_obj);
__rand64_lock();
if (__pid == _rand64_pid) {
s = _rand64_pool; // normal path
} else {
@ -64,6 +76,6 @@ uint64_t _rand64(void) {
_rand64_pid = __pid;
}
_rand64_pool = (s *= 15750249268501108917ull); // lemur64
_pthread_mutex_unlock(&__rand64_lock_obj);
__rand64_unlock();
return s >> 64;
}