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chore: extra pthread handling safety #2390

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chore: extra pthread handling safety #2390

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1cc9346
extra pthread handling
henderkes May 4, 2026
1f2963e
fix ci
henderkes May 4, 2026
0e70661
Merge branch 'main' into feat/fork-support
henderkes May 12, 2026
c669951
Update .github/workflows/tests.yaml
henderkes May 12, 2026
3875ca2
suggestions from @dunglas
henderkes May 13, 2026
2920b0d
Merge remote-tracking branch 'origin/main' into feat/fork-support
henderkes May 13, 2026
57cdd5c
fix borked merge
henderkes May 13, 2026
91546cd
make clang format happy
henderkes May 13, 2026
197cc9b
Merge branch 'main' into feat/fork-support
henderkes May 13, 2026
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25 changes: 24 additions & 1 deletion frankenphp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -89,7 +89,12 @@ __thread HashTable *sandboxed_env = NULL;

#ifndef PHP_WIN32
static bool is_forked_child = false;
static void frankenphp_fork_child(void) { is_forked_child = true; }
static void frankenphp_fork_child(void) {
is_forked_child = true;
#ifdef __linux__
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
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@henderkes henderkes May 4, 2026

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I don't think there's an equivalent to this in macOS or BSD?

realistically speaking, it's hard to imagine this ever kicks in if a php object destructor waits on the child pid, but in case the php runtime throws an unrecoverable error in a destructor, it might exit the thread without calling the destructor responsible for signalling and cleaning up the child

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@dunglas dunglas May 12, 2026

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It seems that this syscall can race. Here is a workaround: https://stackoverflow.com/a/59216119

On FreeBSD, you can do this:

#include <sys/procctl.h>
#include <signal.h>

int sig = SIGKILL;
// P_PID means we are targeting a process ID. 
// 0 means "the current calling process".
procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &sig);

On macOS, it's harder; you have to run kqueue and way more code.

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#endif
}
#endif

void frankenphp_update_local_thread_context(bool is_worker) {
Expand Down Expand Up @@ -762,6 +767,12 @@ static int frankenphp_startup(sapi_module_struct *sapi_module) {
static int frankenphp_deactivate(void) { return SUCCESS; }

static size_t frankenphp_ub_write(const char *str, size_t str_length) {
#ifndef PHP_WIN32
if (UNEXPECTED(is_forked_child)) {
return 0;
}
#endif

struct go_ub_write_return result =
go_ub_write(thread_index, (char *)str, str_length);

Expand All @@ -773,6 +784,12 @@ static size_t frankenphp_ub_write(const char *str, size_t str_length) {
}

static int frankenphp_send_headers(sapi_headers_struct *sapi_headers) {
#ifndef PHP_WIN32
if (UNEXPECTED(is_forked_child)) {
return SAPI_HEADER_SEND_FAILED;
}
#endif

if (SG(request_info).no_headers == 1) {
return SAPI_HEADER_SENT_SUCCESSFULLY;
}
Expand All @@ -798,6 +815,12 @@ static int frankenphp_send_headers(sapi_headers_struct *sapi_headers) {
}

static void frankenphp_sapi_flush(void *server_context) {
#ifndef PHP_WIN32
if (UNEXPECTED(is_forked_child)) {
return;
}
#endif

sapi_send_headers();
if (go_sapi_flush(thread_index)) {
php_handle_aborted_connection();
Expand Down
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