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Make spinlocks faster (take two)

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This change is green on x86 and arm test fleet.
This commit is contained in:
Justine Tunney 2024-07-26 00:44:45 -07:00
parent 02e1cbcd00
commit 59692b0882
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GPG key ID: BE714B4575D6E328
14 changed files with 122 additions and 79 deletions
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44
libc/runtime/getsymboltable.c
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@ -17,6 +17,8 @@
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/atomic.h"
#include "libc/cosmo.h"
#include "libc/errno.h"
#include "libc/intrin/promises.h"
#include "libc/intrin/strace.h"
@ -27,14 +29,12 @@
#include "libc/runtime/symbols.internal.h"
#include "libc/runtime/zipos.internal.h"
#include "libc/str/str.h"
#include "libc/thread/thread.h"
#include "libc/x/x.h"
#include "libc/zip.internal.h"
#include "third_party/puff/puff.h"
__static_yoink("__get_symbol");
static pthread_spinlock_t g_lock;
struct SymbolTable *__symtab; // for kprintf
static ssize_t GetZipFile(struct Zipos *zipos, const char *name) {
@ -100,6 +100,25 @@ static struct SymbolTable *GetSymbolTableFromElf(void) {
}
}
static void GetSymbolTableInit(void) {
struct Zipos *z;
int e = errno;
if (!__symtab && !__isworker) {
if (_weaken(__zipos_get) && (z = _weaken(__zipos_get)())) {
if ((__symtab = GetSymbolTableFromZip(z))) {
__symtab->names =
(uint32_t *)((char *)__symtab + __symtab->names_offset);
__symtab->name_base =
(char *)((char *)__symtab + __symtab->name_base_offset);
}
}
if (!__symtab) {
__symtab = GetSymbolTableFromElf();
}
}
errno = e;
}
/**
* Returns symbol table singleton.
*
@ -121,24 +140,7 @@ static struct SymbolTable *GetSymbolTableFromElf(void) {
* @return symbol table, or NULL if not found
*/
struct SymbolTable *GetSymbolTable(void) {
struct Zipos *z;
if (pthread_spin_trylock(&g_lock))
return 0;
int e = errno;
if (!__symtab && !__isworker) {
if (_weaken(__zipos_get) && (z = _weaken(__zipos_get)())) {
if ((__symtab = GetSymbolTableFromZip(z))) {
__symtab->names =
(uint32_t *)((char *)__symtab + __symtab->names_offset);
__symtab->name_base =
(char *)((char *)__symtab + __symtab->name_base_offset);
}
}
if (!__symtab) {
__symtab = GetSymbolTableFromElf();
}
}
errno = e;
pthread_spin_unlock(&g_lock);
static atomic_uint once;
cosmo_once(&once, GetSymbolTableInit);
return __symtab;
}