From 25c5299ba69ea030c122243e46b72e130ccf92b1 Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 19:51:41 -0500
Subject: [PATCH 01/15] Use rb_thread_call_without_gvl.

---
 ext/proc/wait3.c | 291 ++++++++++++++++++++++++++++-------------------
 1 file changed, 176 insertions(+), 115 deletions(-)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index e6b2f12..baea0c4 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -1,4 +1,5 @@
 #include <ruby.h>
+#include <ruby/thread.h>
 #include <string.h>
 #include <unistd.h>
 
@@ -31,6 +32,67 @@ VALUE v_procstat_struct, v_siginfo_struct, v_usage_struct;
 
 static void sigproc(int signum, siginfo_t* info, void* ucontext);
 
+/* Structs for rb_thread_call_without_gvl wrappers */
+struct wait3_args {
+   int status;
+   int flags;
+   struct rusage rusage;
+   pid_t pid;
+};
+
+#ifdef HAVE_WAIT4
+struct wait4_args {
+   pid_t pid;
+   int status;
+   int flags;
+   struct rusage rusage;
+   pid_t result;
+};
+#endif
+
+#ifdef HAVE_WAITID
+struct waitid_args {
+   idtype_t idtype;
+   id_t id;
+   siginfo_t infop;
+   int options;
+   int result;
+};
+#endif
+
+struct pause_args {
+   int result;
+};
+
+/* GVL-free wrapper functions */
+static void* wait3_without_gvl(void* data) {
+   struct wait3_args* args = (struct wait3_args*)data;
+   args->pid = wait3(&args->status, args->flags, &args->rusage);
+   return NULL;
+}
+
+#ifdef HAVE_WAIT4
+static void* wait4_without_gvl(void* data) {
+   struct wait4_args* args = (struct wait4_args*)data;
+   args->result = wait4(args->pid, &args->status, args->flags, &args->rusage);
+   return NULL;
+}
+#endif
+
+#ifdef HAVE_WAITID
+static void* waitid_without_gvl(void* data) {
+   struct waitid_args* args = (struct waitid_args*)data;
+   args->result = waitid(args->idtype, args->id, &args->infop, args->options);
+   return NULL;
+}
+#endif
+
+static void* pause_without_gvl(void* data) {
+   struct pause_args* args = (struct pause_args*)data;
+   args->result = pause();
+   return NULL;
+}
+
 /*
  * Returns true if this process is stopped. This is only returned
  * returned if the corresponding wait() call had the WUNTRACED flag
@@ -142,55 +204,53 @@ static VALUE pst_wstopsig(int status)
  * set. Raises a SystemError if there are no child processes.
  */
 static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
-   int status;
-   int flags = 0;
-   struct rusage r;
-   pid_t pid;
+   struct wait3_args args;
    VALUE v_flags = Qnil;
 
    rb_scan_args(argc,argv,"01",&v_flags);
 
+   memset(&args, 0, sizeof(args));
+
    if(Qnil != v_flags){
-      flags = NUM2INT(v_flags);
+      args.flags = NUM2INT(v_flags);
    }
 
-   bzero(&r, sizeof(r));
-   pid = wait3(&status, flags, &r);
+   rb_thread_call_without_gvl(wait3_without_gvl, &args, RUBY_UBF_PROCESS, NULL);
 
-   if(pid < 0){
+   if(args.pid < 0){
       rb_sys_fail("wait3");
    }
-   else if(pid > 0){
+   else if(args.pid > 0){
       v_last_status = rb_struct_new(v_procstat_struct,
-         INT2FIX(pid),
-         INT2FIX(status),
-         rb_float_new((double)r.ru_utime.tv_sec+(double)r.ru_utime.tv_usec/1e6),
-         rb_float_new((double)r.ru_stime.tv_sec+(double)r.ru_stime.tv_usec/1e6),
-         LONG2NUM(r.ru_maxrss),
-         LONG2NUM(r.ru_ixrss),
-         LONG2NUM(r.ru_idrss),
-         LONG2NUM(r.ru_isrss),
-         LONG2NUM(r.ru_minflt),
-         LONG2NUM(r.ru_majflt),
-         LONG2NUM(r.ru_nswap),
-         LONG2NUM(r.ru_inblock),
-         LONG2NUM(r.ru_oublock),
-         LONG2NUM(r.ru_msgsnd),
-         LONG2NUM(r.ru_msgrcv),
-         LONG2NUM(r.ru_nsignals),
-         LONG2NUM(r.ru_nvcsw),
-         LONG2NUM(r.ru_nivcsw),
-         pst_wifstopped(status),
-         pst_wifsignaled(status),
-         pst_wifexited(status),
-         pst_success_p(status),
-         pst_wcoredump(status),
-         pst_wexitstatus(status),
-         pst_wtermsig(status),
-         pst_wstopsig(status)
+         INT2FIX(args.pid),
+         INT2FIX(args.status),
+         rb_float_new((double)args.rusage.ru_utime.tv_sec+(double)args.rusage.ru_utime.tv_usec/1e6),
+         rb_float_new((double)args.rusage.ru_stime.tv_sec+(double)args.rusage.ru_stime.tv_usec/1e6),
+         LONG2NUM(args.rusage.ru_maxrss),
+         LONG2NUM(args.rusage.ru_ixrss),
+         LONG2NUM(args.rusage.ru_idrss),
+         LONG2NUM(args.rusage.ru_isrss),
+         LONG2NUM(args.rusage.ru_minflt),
+         LONG2NUM(args.rusage.ru_majflt),
+         LONG2NUM(args.rusage.ru_nswap),
+         LONG2NUM(args.rusage.ru_inblock),
+         LONG2NUM(args.rusage.ru_oublock),
+         LONG2NUM(args.rusage.ru_msgsnd),
+         LONG2NUM(args.rusage.ru_msgrcv),
+         LONG2NUM(args.rusage.ru_nsignals),
+         LONG2NUM(args.rusage.ru_nvcsw),
+         LONG2NUM(args.rusage.ru_nivcsw),
+         pst_wifstopped(args.status),
+         pst_wifsignaled(args.status),
+         pst_wifexited(args.status),
+         pst_success_p(args.status),
+         pst_wcoredump(args.status),
+         pst_wexitstatus(args.status),
+         pst_wtermsig(args.status),
+         pst_wstopsig(args.status)
       );
 
-      rb_last_status_set(status, pid);
+      rb_last_status_set(args.status, args.pid);
       OBJ_FREEZE(v_last_status);
 
       return v_last_status;
@@ -213,57 +273,54 @@ static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
  * Some +flags+ are not supported on all platforms.
  */
 static VALUE proc_wait4(int argc, VALUE *argv, VALUE mod){
-   int status;
-   int flags = 0;
-   struct rusage r;
-   pid_t pid;
+   struct wait4_args args;
    VALUE v_pid;
    VALUE v_flags = Qnil;
 
    rb_scan_args(argc, argv, "11", &v_pid, &v_flags);
 
-   pid = NUM2INT(v_pid);
+   memset(&args, 0, sizeof(args));
+   args.pid = NUM2INT(v_pid);
 
    if(RTEST(v_flags))
-      flags = NUM2INT(v_flags);
+      args.flags = NUM2INT(v_flags);
 
-   bzero(&r, sizeof(r));
-   pid = wait4(pid, &status, flags, &r);
+   rb_thread_call_without_gvl(wait4_without_gvl, &args, RUBY_UBF_PROCESS, NULL);
 
-   if(pid < 0){
+   if(args.result < 0){
       rb_sys_fail("wait4");
    }
-   else if(pid > 0){
+   else if(args.result > 0){
       v_last_status = rb_struct_new(v_procstat_struct,
-         INT2FIX(pid),
-         INT2FIX(status),
-         rb_float_new((double)r.ru_utime.tv_sec+(double)r.ru_utime.tv_usec/1e6),
-         rb_float_new((double)r.ru_stime.tv_sec+(double)r.ru_stime.tv_usec/1e6),
-         LONG2NUM(r.ru_maxrss),
-         LONG2NUM(r.ru_ixrss),
-         LONG2NUM(r.ru_idrss),
-         LONG2NUM(r.ru_isrss),
-         LONG2NUM(r.ru_minflt),
-         LONG2NUM(r.ru_majflt),
-         LONG2NUM(r.ru_nswap),
-         LONG2NUM(r.ru_inblock),
-         LONG2NUM(r.ru_oublock),
-         LONG2NUM(r.ru_msgsnd),
-         LONG2NUM(r.ru_msgrcv),
-         LONG2NUM(r.ru_nsignals),
-         LONG2NUM(r.ru_nvcsw),
-         LONG2NUM(r.ru_nivcsw),
-         pst_wifstopped(status),
-         pst_wifsignaled(status),
-         pst_wifexited(status),
-         pst_success_p(status),
-         pst_wcoredump(status),
-         pst_wexitstatus(status),
-         pst_wtermsig(status),
-         pst_wstopsig(status)
+         INT2FIX(args.result),
+         INT2FIX(args.status),
+         rb_float_new((double)args.rusage.ru_utime.tv_sec+(double)args.rusage.ru_utime.tv_usec/1e6),
+         rb_float_new((double)args.rusage.ru_stime.tv_sec+(double)args.rusage.ru_stime.tv_usec/1e6),
+         LONG2NUM(args.rusage.ru_maxrss),
+         LONG2NUM(args.rusage.ru_ixrss),
+         LONG2NUM(args.rusage.ru_idrss),
+         LONG2NUM(args.rusage.ru_isrss),
+         LONG2NUM(args.rusage.ru_minflt),
+         LONG2NUM(args.rusage.ru_majflt),
+         LONG2NUM(args.rusage.ru_nswap),
+         LONG2NUM(args.rusage.ru_inblock),
+         LONG2NUM(args.rusage.ru_oublock),
+         LONG2NUM(args.rusage.ru_msgsnd),
+         LONG2NUM(args.rusage.ru_msgrcv),
+         LONG2NUM(args.rusage.ru_nsignals),
+         LONG2NUM(args.rusage.ru_nvcsw),
+         LONG2NUM(args.rusage.ru_nivcsw),
+         pst_wifstopped(args.status),
+         pst_wifsignaled(args.status),
+         pst_wifexited(args.status),
+         pst_success_p(args.status),
+         pst_wcoredump(args.status),
+         pst_wexitstatus(args.status),
+         pst_wtermsig(args.status),
+         pst_wstopsig(args.status)
       );
 
-      rb_last_status_set(status, pid);
+      rb_last_status_set(args.status, args.result);
       OBJ_FREEZE(v_last_status);
 
       return v_last_status;
@@ -314,20 +371,18 @@ static VALUE proc_wait4(int argc, VALUE *argv, VALUE mod){
  */
 static VALUE proc_waitid(int argc, VALUE* argv, VALUE mod){
    VALUE v_type, v_id, v_options;
-   siginfo_t infop;
-   idtype_t idtype;
-   id_t id = 0;
-   int options = 0;
+   struct waitid_args args;
 
    rb_scan_args(argc, argv, "12", &v_type, &v_id, &v_options);
 
-   idtype = NUM2INT(v_type);
+   memset(&args, 0, sizeof(args));
+   args.idtype = NUM2INT(v_type);
 
    if(RTEST(v_id))
-      id = NUM2INT(v_id);
+      args.id = NUM2INT(v_id);
 
    if(RTEST(v_options))
-      options = NUM2INT(v_options);
+      args.options = NUM2INT(v_options);
 
    /* The Linux man page for waitid() says to zero out the pid field and check
     * its value after the call to waitid() to detect if there were children in
@@ -335,10 +390,12 @@ static VALUE proc_waitid(int argc, VALUE* argv, VALUE mod){
     * simply check the infop.si_signo struct member against SI_NOINFO.
     */
 #ifndef SI_NOINFO
-   infop.si_pid = 0;
+   args.infop.si_pid = 0;
 #endif
 
-   if(waitid(idtype, id, &infop, options) == -1)
+   rb_thread_call_without_gvl(waitid_without_gvl, &args, RUBY_UBF_PROCESS, NULL);
+
+   if(args.result == -1)
       rb_sys_fail("waitid");
 
     /* If the si_code struct member returns SI_NOINFO, or the si_pid member
@@ -352,13 +409,13 @@ static VALUE proc_waitid(int argc, VALUE* argv, VALUE mod){
      */
 
 #ifdef SI_NOINFO
-   if(infop.si_code == SI_NOINFO){
+   if(args.infop.si_code == SI_NOINFO){
 #else
-   if(infop.si_pid == 0){
+   if(args.infop.si_pid == 0){
 #endif
       v_last_status = rb_struct_new(v_siginfo_struct,
-         INT2FIX(infop.si_signo),
-         INT2FIX(infop.si_errno),
+         INT2FIX(args.infop.si_signo),
+         INT2FIX(args.infop.si_errno),
          Qnil, Qnil, Qnil, Qnil, Qnil, Qnil, /* code, pid, uid, utime, status, stime */
 #ifdef HAVE_ST_SI_TRAPNO
          Qnil,
@@ -424,8 +481,8 @@ static VALUE proc_waitid(int argc, VALUE* argv, VALUE mod){
       VALUE v_state = Qnil;
 #endif
       VALUE v_band = Qnil, v_entity = Qnil;
-      int sig = infop.si_signo;
-      int code = infop.si_code;
+      int sig = args.infop.si_signo;
+      int code = args.infop.si_code;
 
 #if defined(HAVE_ST_SI_SYSARG) || defined(HAVE_ST_SI_MSTATE)
       int i = 0;
@@ -437,13 +494,13 @@ static VALUE proc_waitid(int argc, VALUE* argv, VALUE mod){
        */
       if(sig == SIGCHLD){
 #ifdef HAVE_ST_SI_UTIME
-         v_utime  = ULL2NUM(infop.si_utime);
+         v_utime  = ULL2NUM(args.infop.si_utime);
 #endif
 #ifdef HAVE_ST_SI_STATUS
-         v_status = ULL2NUM(infop.si_status);
+         v_status = ULL2NUM(args.infop.si_status);
 #endif
 #ifdef HAVE_ST_SI_STIME
-         v_stime  = ULL2NUM(infop.si_stime);
+         v_stime  = ULL2NUM(args.infop.si_stime);
 #endif
       }
 
@@ -451,66 +508,66 @@ static VALUE proc_waitid(int argc, VALUE* argv, VALUE mod){
          sig == SIGTRAP)
       {
 #ifdef HAVE_ST_SI_TRAPNO
-         v_trapno = INT2FIX(infop.si_trapno);
+         v_trapno = INT2FIX(args.infop.si_trapno);
 #endif
 #ifdef HAVE_ST_SI_PC
-         v_pc = INT2FIX(infop.si_pc);
+         v_pc = INT2FIX(args.infop.si_pc);
 #endif
       }
 
       if(sig == SIGXFSZ){
 #ifdef HAVE_ST_SI_FD
-         v_fd = INT2FIX(infop.si_fd);
+         v_fd = INT2FIX(args.infop.si_fd);
 #endif
          if(code == POLL_IN || code == POLL_OUT || code == POLL_MSG){
-            v_band = LONG2FIX(infop.si_band);
+            v_band = LONG2FIX(args.infop.si_band);
          }
       }
 
       if(sig == SIGPROF){
 #ifdef HAVE_ST_SI_SYSARG
-         int ssize = sizeof(infop.si_sysarg) / sizeof(infop.si_sysarg[0]);
+         int ssize = sizeof(args.infop.si_sysarg) / sizeof(args.infop.si_sysarg[0]);
          v_sysarg  = rb_ary_new();
 
          for(i = 0; i < ssize; i++)
-            rb_ary_push(v_sysarg, LONG2FIX(infop.si_sysarg[i]));
+            rb_ary_push(v_sysarg, LONG2FIX(args.infop.si_sysarg[i]));
 #endif
 #ifdef HAVE_ST_SI_MSTATE
-         int msize = sizeof(infop.si_mstate) / sizeof(infop.si_mstate[0]);
+         int msize = sizeof(args.infop.si_mstate) / sizeof(args.infop.si_mstate[0]);
          v_state  = rb_ary_new();
 
          for(i = 0; i < msize; i++)
-            rb_ary_push(v_state, INT2FIX(infop.si_mstate[i]));
+            rb_ary_push(v_state, INT2FIX(args.infop.si_mstate[i]));
 #endif
 #ifdef HAVE_ST_SI_FADDR
-         v_addr   = INT2FIX(infop.si_faddr);
+         v_addr   = INT2FIX(args.infop.si_faddr);
 #endif
 #ifdef HAVE_ST_SI_SYSCALL
-         v_syscall = INT2FIX(infop.si_syscall);
+         v_syscall = INT2FIX(args.infop.si_syscall);
 #endif
 #ifdef HAVE_ST_SI_NSYSARG
-         v_nsysarg = INT2FIX(infop.si_nsysarg);
+         v_nsysarg = INT2FIX(args.infop.si_nsysarg);
 #endif
 #ifdef HAVE_ST_SI_FAULT
-         v_fault   = INT2FIX(infop.si_fault);
+         v_fault   = INT2FIX(args.infop.si_fault);
 #endif
 #ifdef HAVE_ST_SI_TSTAMP
-         v_time = rb_time_new(infop.si_tstamp.tv_sec,infop.si_tstamp.tv_nsec);
+         v_time = rb_time_new(args.infop.si_tstamp.tv_sec,args.infop.si_tstamp.tv_nsec);
 #endif
       }
 
 #ifdef SIGXRES
       if(sig == SIGXRES){
-         v_entity = INT2FIX(infop.si_entity);
+         v_entity = INT2FIX(args.infop.si_entity);
       }
 #endif
 
       v_last_status = rb_struct_new(v_siginfo_struct,
-         INT2FIX(infop.si_signo),   // Probably SIGCHLD
-         INT2FIX(infop.si_errno),   // 0 means no error
-         INT2FIX(infop.si_code),    // Should be anything but SI_NOINFO
-         INT2FIX(infop.si_pid),     // Real PID that sent the signal
-         INT2FIX(infop.si_uid),     // Real UID of process that sent signal
+         INT2FIX(args.infop.si_signo),   // Probably SIGCHLD
+         INT2FIX(args.infop.si_errno),   // 0 means no error
+         INT2FIX(args.infop.si_code),    // Should be anything but SI_NOINFO
+         INT2FIX(args.infop.si_pid),     // Real PID that sent the signal
+         INT2FIX(args.infop.si_uid),     // Real UID of process that sent signal
          v_utime,
          v_status,
          v_stime,
@@ -589,8 +646,8 @@ static VALUE proc_pause(int argc, VALUE* argv, VALUE mod){
       int signum;
       struct sigaction act, sa;
 
-      bzero(&act, sizeof(act));
-      bzero(&sa, sizeof(sa));
+      memset(&act, 0, sizeof(act));
+      memset(&sa, 0, sizeof(sa));
 
       for(i = 0; i < len; i++){
          v_val = rb_ary_shift(v_signals);
@@ -619,7 +676,7 @@ static VALUE proc_pause(int argc, VALUE* argv, VALUE mod){
             signum = NUM2INT(v_val);
          }
 
-         bzero(&act, sizeof(act));
+         memset(&act, 0, sizeof(act));
          act.sa_flags = SA_SIGINFO;
          act.sa_sigaction = sigproc;
          res = sigaction(signum, &act, &sa);
@@ -629,7 +686,11 @@ static VALUE proc_pause(int argc, VALUE* argv, VALUE mod){
       }
    }
 
-   return INT2FIX(pause()); /* Should always be -1 */
+   {
+      struct pause_args pargs;
+      rb_thread_call_without_gvl(pause_without_gvl, &pargs, RUBY_UBF_PROCESS, NULL);
+      return INT2FIX(pargs.result); /* Should always be -1 */
+   }
 }
 
 /*
@@ -757,7 +818,7 @@ static VALUE proc_getrusage(int argc, VALUE* argv, VALUE mod){
   else if(RTEST(v_children))
     who = RUSAGE_CHILDREN;
 
-  bzero(&r, sizeof(r));
+  memset(&r, 0, sizeof(r));
 
   if(getrusage(who,&r) == -1)
     rb_sys_fail("getrusage");

From a43befe2d9ae76c0b2259579c332c0acdc2fa0c9 Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 19:52:52 -0500
Subject: [PATCH 02/15] Restore bzero.

---
 ext/proc/wait3.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index baea0c4..df53a04 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -209,7 +209,7 @@ static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
 
    rb_scan_args(argc,argv,"01",&v_flags);
 
-   memset(&args, 0, sizeof(args));
+   bzero(&args, sizeof(args));
 
    if(Qnil != v_flags){
       args.flags = NUM2INT(v_flags);
@@ -279,7 +279,7 @@ static VALUE proc_wait4(int argc, VALUE *argv, VALUE mod){
 
    rb_scan_args(argc, argv, "11", &v_pid, &v_flags);
 
-   memset(&args, 0, sizeof(args));
+   bzero(&args, sizeof(args));
    args.pid = NUM2INT(v_pid);
 
    if(RTEST(v_flags))
@@ -375,7 +375,7 @@ static VALUE proc_waitid(int argc, VALUE* argv, VALUE mod){
 
    rb_scan_args(argc, argv, "12", &v_type, &v_id, &v_options);
 
-   memset(&args, 0, sizeof(args));
+   bzero(&args, sizeof(args));
    args.idtype = NUM2INT(v_type);
 
    if(RTEST(v_id))
@@ -646,8 +646,8 @@ static VALUE proc_pause(int argc, VALUE* argv, VALUE mod){
       int signum;
       struct sigaction act, sa;
 
-      memset(&act, 0, sizeof(act));
-      memset(&sa, 0, sizeof(sa));
+      bzero(&act, sizeof(act));
+      bzero(&sa, sizeof(sa));
 
       for(i = 0; i < len; i++){
          v_val = rb_ary_shift(v_signals);
@@ -676,7 +676,7 @@ static VALUE proc_pause(int argc, VALUE* argv, VALUE mod){
             signum = NUM2INT(v_val);
          }
 
-         memset(&act, 0, sizeof(act));
+         bzero(&act, sizeof(act));
          act.sa_flags = SA_SIGINFO;
          act.sa_sigaction = sigproc;
          res = sigaction(signum, &act, &sa);

From 49bc12e257ecc7cdb2f3be9c046f30a0b66a1447 Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 19:59:34 -0500
Subject: [PATCH 03/15] Add fiber scheduler support where feasible.

---
 ext/extconf.rb   |   3 ++
 ext/proc/wait3.c | 119 ++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 116 insertions(+), 6 deletions(-)

diff --git a/ext/extconf.rb b/ext/extconf.rb
index d6b4434..4dd97b4 100644
--- a/ext/extconf.rb
+++ b/ext/extconf.rb
@@ -70,6 +70,9 @@
 # RUSAGE_THREAD is Linux-specific
 have_const('RUSAGE_THREAD', 'sys/resource.h')
 
+# Fiber scheduler support (Ruby 3.0+)
+have_func('rb_fiber_scheduler_current', 'ruby.h')
+
 # BSD
 have_const('P_JAILID', 'sys/wait.h')
 
diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index df53a04..2a21d21 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -1,5 +1,8 @@
 #include <ruby.h>
 #include <ruby/thread.h>
+#ifdef HAVE_RB_FIBER_SCHEDULER_CURRENT
+#include <ruby/fiber/scheduler.h>
+#endif
 #include <string.h>
 #include <unistd.h>
 
@@ -27,6 +30,11 @@
 #define SIG2STR_MAX 32
 #endif
 
+/* NUM2PIDT may not be defined on older Ruby versions */
+#ifndef NUM2PIDT
+#define NUM2PIDT(v) ((pid_t)NUM2LONG(v))
+#endif
+
 VALUE v_last_status;
 VALUE v_procstat_struct, v_siginfo_struct, v_usage_struct;
 
@@ -193,6 +201,44 @@ static VALUE pst_wstopsig(int status)
   return Qnil;
 }
 
+#ifdef HAVE_RB_FIBER_SCHEDULER_CURRENT
+/*
+ * Helper to build ProcStat struct from pid and status.
+ * Used by fiber scheduler path where rusage is not available.
+ * All rusage fields are set to 0.
+ */
+static VALUE build_procstat_without_rusage(pid_t pid, int status) {
+   return rb_struct_new(v_procstat_struct,
+      INT2FIX(pid),
+      INT2FIX(status),
+      rb_float_new(0.0),  /* utime - not available via fiber scheduler */
+      rb_float_new(0.0),  /* stime - not available via fiber scheduler */
+      LONG2NUM(0),        /* maxrss */
+      LONG2NUM(0),        /* ixrss */
+      LONG2NUM(0),        /* idrss */
+      LONG2NUM(0),        /* isrss */
+      LONG2NUM(0),        /* minflt */
+      LONG2NUM(0),        /* majflt */
+      LONG2NUM(0),        /* nswap */
+      LONG2NUM(0),        /* inblock */
+      LONG2NUM(0),        /* oublock */
+      LONG2NUM(0),        /* msgsnd */
+      LONG2NUM(0),        /* msgrcv */
+      LONG2NUM(0),        /* nsignals */
+      LONG2NUM(0),        /* nvcsw */
+      LONG2NUM(0),        /* nivcsw */
+      pst_wifstopped(status),
+      pst_wifsignaled(status),
+      pst_wifexited(status),
+      pst_success_p(status),
+      pst_wcoredump(status),
+      pst_wexitstatus(status),
+      pst_wtermsig(status),
+      pst_wstopsig(status)
+   );
+}
+#endif
+
 /*
  * call-seq:
  *    Process.wait3(flags=nil)
@@ -202,18 +248,47 @@ static VALUE pst_wstopsig(int status)
  *
  * The return value is a ProcStat structure. The special global $? is also
  * set. Raises a SystemError if there are no child processes.
+ *
+ * Note: When a fiber scheduler is active (Ruby 3.0+), this method will
+ * cooperate with the scheduler. However, rusage information will not be
+ * available and those fields will be set to 0 in the returned struct.
  */
 static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
    struct wait3_args args;
    VALUE v_flags = Qnil;
+   int flags = 0;
 
    rb_scan_args(argc,argv,"01",&v_flags);
 
-   bzero(&args, sizeof(args));
-
    if(Qnil != v_flags){
-      args.flags = NUM2INT(v_flags);
+      flags = NUM2INT(v_flags);
+   }
+
+#ifdef HAVE_RB_FIBER_SCHEDULER_CURRENT
+   VALUE scheduler = rb_fiber_scheduler_current();
+   if (!NIL_P(scheduler)) {
+      /* Use fiber scheduler - wait for any child (pid = -1) */
+      VALUE result = rb_fiber_scheduler_process_wait(scheduler, RB_INT2NUM(-1), RB_INT2NUM(flags));
+
+      if (NIL_P(result)) {
+         return Qnil;
+      }
+
+      /* Extract pid and status from Process::Status object */
+      pid_t pid = NUM2PIDT(rb_funcall(result, rb_intern("pid"), 0));
+      int status = NUM2INT(rb_funcall(result, rb_intern("to_i"), 0));
+
+      v_last_status = build_procstat_without_rusage(pid, status);
+      rb_last_status_set(status, pid);
+      OBJ_FREEZE(v_last_status);
+
+      return v_last_status;
    }
+#endif
+
+   /* No fiber scheduler - use thread-based blocking */
+   bzero(&args, sizeof(args));
+   args.flags = flags;
 
    rb_thread_call_without_gvl(wait3_without_gvl, &args, RUBY_UBF_PROCESS, NULL);
 
@@ -271,19 +346,51 @@ static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
  * This method is not supported on all platforms.
  *
  * Some +flags+ are not supported on all platforms.
+ *
+ * Note: When a fiber scheduler is active (Ruby 3.0+), this method will
+ * cooperate with the scheduler. However, rusage information will not be
+ * available and those fields will be set to 0 in the returned struct.
  */
 static VALUE proc_wait4(int argc, VALUE *argv, VALUE mod){
    struct wait4_args args;
    VALUE v_pid;
    VALUE v_flags = Qnil;
+   pid_t pid;
+   int flags = 0;
 
    rb_scan_args(argc, argv, "11", &v_pid, &v_flags);
 
-   bzero(&args, sizeof(args));
-   args.pid = NUM2INT(v_pid);
+   pid = NUM2PIDT(v_pid);
 
    if(RTEST(v_flags))
-      args.flags = NUM2INT(v_flags);
+      flags = NUM2INT(v_flags);
+
+#ifdef HAVE_RB_FIBER_SCHEDULER_CURRENT
+   VALUE scheduler = rb_fiber_scheduler_current();
+   if (!NIL_P(scheduler)) {
+      /* Use fiber scheduler */
+      VALUE result = rb_fiber_scheduler_process_wait(scheduler, RB_INT2NUM(pid), RB_INT2NUM(flags));
+
+      if (NIL_P(result)) {
+         return Qnil;
+      }
+
+      /* Extract pid and status from Process::Status object */
+      pid_t rpid = NUM2PIDT(rb_funcall(result, rb_intern("pid"), 0));
+      int status = NUM2INT(rb_funcall(result, rb_intern("to_i"), 0));
+
+      v_last_status = build_procstat_without_rusage(rpid, status);
+      rb_last_status_set(status, rpid);
+      OBJ_FREEZE(v_last_status);
+
+      return v_last_status;
+   }
+#endif
+
+   /* No fiber scheduler - use thread-based blocking */
+   bzero(&args, sizeof(args));
+   args.pid = pid;
+   args.flags = flags;
 
    rb_thread_call_without_gvl(wait4_without_gvl, &args, RUBY_UBF_PROCESS, NULL);
 

From ee47935f6ba2c6fb5cd946479c23ede1d083fa2b Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 20:10:23 -0500
Subject: [PATCH 04/15] Assume Ruby 3.0 or later.

---
 ext/extconf.rb   |  3 ---
 ext/proc/wait3.c | 13 -------------
 2 files changed, 16 deletions(-)

diff --git a/ext/extconf.rb b/ext/extconf.rb
index 4dd97b4..d6b4434 100644
--- a/ext/extconf.rb
+++ b/ext/extconf.rb
@@ -70,9 +70,6 @@
 # RUSAGE_THREAD is Linux-specific
 have_const('RUSAGE_THREAD', 'sys/resource.h')
 
-# Fiber scheduler support (Ruby 3.0+)
-have_func('rb_fiber_scheduler_current', 'ruby.h')
-
 # BSD
 have_const('P_JAILID', 'sys/wait.h')
 
diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index 2a21d21..d3adcef 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -1,8 +1,6 @@
 #include <ruby.h>
 #include <ruby/thread.h>
-#ifdef HAVE_RB_FIBER_SCHEDULER_CURRENT
 #include <ruby/fiber/scheduler.h>
-#endif
 #include <string.h>
 #include <unistd.h>
 
@@ -30,11 +28,6 @@
 #define SIG2STR_MAX 32
 #endif
 
-/* NUM2PIDT may not be defined on older Ruby versions */
-#ifndef NUM2PIDT
-#define NUM2PIDT(v) ((pid_t)NUM2LONG(v))
-#endif
-
 VALUE v_last_status;
 VALUE v_procstat_struct, v_siginfo_struct, v_usage_struct;
 
@@ -201,7 +194,6 @@ static VALUE pst_wstopsig(int status)
   return Qnil;
 }
 
-#ifdef HAVE_RB_FIBER_SCHEDULER_CURRENT
 /*
  * Helper to build ProcStat struct from pid and status.
  * Used by fiber scheduler path where rusage is not available.
@@ -237,7 +229,6 @@ static VALUE build_procstat_without_rusage(pid_t pid, int status) {
       pst_wstopsig(status)
    );
 }
-#endif
 
 /*
  * call-seq:
@@ -264,7 +255,6 @@ static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
       flags = NUM2INT(v_flags);
    }
 
-#ifdef HAVE_RB_FIBER_SCHEDULER_CURRENT
    VALUE scheduler = rb_fiber_scheduler_current();
    if (!NIL_P(scheduler)) {
       /* Use fiber scheduler - wait for any child (pid = -1) */
@@ -284,7 +274,6 @@ static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
 
       return v_last_status;
    }
-#endif
 
    /* No fiber scheduler - use thread-based blocking */
    bzero(&args, sizeof(args));
@@ -365,7 +354,6 @@ static VALUE proc_wait4(int argc, VALUE *argv, VALUE mod){
    if(RTEST(v_flags))
       flags = NUM2INT(v_flags);
 
-#ifdef HAVE_RB_FIBER_SCHEDULER_CURRENT
    VALUE scheduler = rb_fiber_scheduler_current();
    if (!NIL_P(scheduler)) {
       /* Use fiber scheduler */
@@ -385,7 +373,6 @@ static VALUE proc_wait4(int argc, VALUE *argv, VALUE mod){
 
       return v_last_status;
    }
-#endif
 
    /* No fiber scheduler - use thread-based blocking */
    bzero(&args, sizeof(args));

From ff9b474f018d0c614b521d870242d84ed6ef52e1 Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 20:17:32 -0500
Subject: [PATCH 05/15] Remove 2.7, add 3.4 to workflow.

---
 .github/workflows/ruby.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index db7658e..24c59fa 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -15,7 +15,7 @@ jobs:
   test:
     strategy:
       matrix:
-        ruby-version: ['2.7', '3.0', '3.1', '3.2', '3.3']
+        ruby-version: ['3.0', '3.1', '3.2', '3.3', '3.4']
         platform: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.platform }}
     steps:

From 39abb6b3187b304caf5a95946e02f4ea8458832f Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 20:30:58 -0500
Subject: [PATCH 06/15] Tweak clean task for MacOS.

---
 Rakefile | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/Rakefile b/Rakefile
index 9a682be..7fb29f9 100644
--- a/Rakefile
+++ b/Rakefile
@@ -7,15 +7,15 @@ require 'rbconfig'
 include RbConfig
 
 CLEAN.include(
-  '**/*.gem',                # Gem files
-  '**/*.rbc',                # Rubinius
-  '**/*.o',                  # C object file
-  '**/*.log',                # Ruby extension build log
-  '**/*.lock',               # Gemfile.lock
-  '**/Makefile',             # C Makefile
-  '**/conftest.dSYM',        # OS X build directory
-  "**/*.#{CONFIG['DLEXT']}", # C shared object
-  '**/*.lock'                # Bundler
+  '**/*.gem',                 # Gem files
+  '**/*.rbc',                 # Rubinius
+  '**/*.o',                   # C object file
+  '**/*.log',                 # Ruby extension build log
+  '**/*.lock',                # Gemfile.lock
+  '**/Makefile',              # C Makefile
+  '**/*.dSYM',                # OS X build directory
+  "**/*.#{CONFIG['DLEXT']}",  # C shared object
+  '**/*.lock'                 # Bundler
 )
 
 desc "Build the source (but don't install it)"

From a102c5c71bfc9f8a462003a5852d185f7849e76b Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 20:31:28 -0500
Subject: [PATCH 07/15] Remove 3.0, add 4.0.

---
 .github/workflows/ruby.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 24c59fa..374a7ff 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -15,7 +15,7 @@ jobs:
   test:
     strategy:
       matrix:
-        ruby-version: ['3.0', '3.1', '3.2', '3.3', '3.4']
+        ruby-version: ['3.1', '3.2', '3.3', '3.4', '4.0']
         platform: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.platform }}
     steps:

From 8783fec20e838cbbebbd7e25331259c8e498d42f Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 20:44:28 -0500
Subject: [PATCH 08/15] Restore bzero.

---
 ext/proc/wait3.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index d3adcef..a206190 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -912,7 +912,7 @@ static VALUE proc_getrusage(int argc, VALUE* argv, VALUE mod){
   else if(RTEST(v_children))
     who = RUSAGE_CHILDREN;
 
-  memset(&r, 0, sizeof(r));
+  bzero(&r, sizeof(r));
 
   if(getrusage(who,&r) == -1)
     rb_sys_fail("getrusage");

From 8df5ba3f1c02ce950cb24012210f98fccc7e5bfb Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 22:41:03 -0500
Subject: [PATCH 09/15] Fix rb_pid_t arg.

---
 ext/proc/wait3.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index a206190..86c42b0 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -258,7 +258,7 @@ static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
    VALUE scheduler = rb_fiber_scheduler_current();
    if (!NIL_P(scheduler)) {
       /* Use fiber scheduler - wait for any child (pid = -1) */
-      VALUE result = rb_fiber_scheduler_process_wait(scheduler, RB_INT2NUM(-1), RB_INT2NUM(flags));
+      VALUE result = rb_fiber_scheduler_process_wait(scheduler, (rb_pid_t)-1, flags);
 
       if (NIL_P(result)) {
          return Qnil;
@@ -357,7 +357,7 @@ static VALUE proc_wait4(int argc, VALUE *argv, VALUE mod){
    VALUE scheduler = rb_fiber_scheduler_current();
    if (!NIL_P(scheduler)) {
       /* Use fiber scheduler */
-      VALUE result = rb_fiber_scheduler_process_wait(scheduler, RB_INT2NUM(pid), RB_INT2NUM(flags));
+      VALUE result = rb_fiber_scheduler_process_wait(scheduler, pid, flags);
 
       if (NIL_P(result)) {
          return Qnil;

From 0ba0587b2615edabab0e2ea866f7607fca8e360c Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 23:01:04 -0500
Subject: [PATCH 10/15] Add RB_GC_GUARD in spots with potential long running
 operations.

---
 ext/proc/wait3.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index 86c42b0..bc4f9fa 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -268,6 +268,8 @@ static VALUE proc_wait3(int argc, VALUE *argv, VALUE mod){
       pid_t pid = NUM2PIDT(rb_funcall(result, rb_intern("pid"), 0));
       int status = NUM2INT(rb_funcall(result, rb_intern("to_i"), 0));
 
+      RB_GC_GUARD(result);
+
       v_last_status = build_procstat_without_rusage(pid, status);
       rb_last_status_set(status, pid);
       OBJ_FREEZE(v_last_status);
@@ -367,6 +369,8 @@ static VALUE proc_wait4(int argc, VALUE *argv, VALUE mod){
       pid_t rpid = NUM2PIDT(rb_funcall(result, rb_intern("pid"), 0));
       int status = NUM2INT(rb_funcall(result, rb_intern("to_i"), 0));
 
+      RB_GC_GUARD(result);
+
       v_last_status = build_procstat_without_rusage(rpid, status);
       rb_last_status_set(status, rpid);
       OBJ_FREEZE(v_last_status);
@@ -783,6 +787,7 @@ static VALUE proc_pause(int argc, VALUE* argv, VALUE mod){
    {
       struct pause_args pargs;
       rb_thread_call_without_gvl(pause_without_gvl, &pargs, RUBY_UBF_PROCESS, NULL);
+      RB_GC_GUARD(v_signals);
       return INT2FIX(pargs.result); /* Should always be -1 */
    }
 }

From f664a6b125e9af2d9c316a6646ca9672ecb675e4 Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Thu, 8 Jan 2026 23:47:11 -0500
Subject: [PATCH 11/15] Update string len and ptr macros.

---
 ext/proc/wait3.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index bc4f9fa..4de439d 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -755,10 +755,12 @@ static VALUE proc_pause(int argc, VALUE* argv, VALUE mod){
             if(strlcpy(signame, StringValuePtr(v_val), max) >= max)
                rb_raise(rb_eArgError, "string too large");
 #else
-            if(RSTRING(v_val)->len > max)
+            if(RSTRING_LEN(v_val) >= max)
                rb_raise(rb_eArgError, "string too large");
-            else
-               strncpy(signame, RSTRING(v_val)->ptr, max);
+            else{
+               strncpy(signame, RSTRING_PTR(v_val), max);
+               signame[max-1] = '\0';
+            }
 #endif
 
 #ifdef HAVE_STR2SIG

From 5f04cb2aaad6a48124ef0b05bddbfadf0f96a10c Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Fri, 9 Jan 2026 00:00:04 -0500
Subject: [PATCH 12/15] Add another check for strlcpy.

---
 ext/proc/wait3.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index 4de439d..74d9ce6 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -858,8 +858,17 @@ static VALUE proc_sigsend(int argc, VALUE* argv, VALUE mod){
       char signame[SIG2STR_MAX];
       unsigned int max = SIG2STR_MAX;
 
+#ifdef HAVE_STRLCPY
       if(strlcpy(signame, StringValuePtr(v_signal), max) >= max)
         rb_raise(rb_eArgError, "string too large");
+#else
+      if(RSTRING_LEN(v_signal) >= max)
+        rb_raise(rb_eArgError, "string too large");
+      else{
+        strncpy(signame, RSTRING_PTR(v_signal), max);
+        signame[max-1] = '\0';
+      }
+#endif
 
       if(str2sig(signame,&sig) != 0)
         rb_sys_fail("str2sig");

From 19660a2a63487fa4d18077a151f94f6d45219a1c Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Fri, 9 Jan 2026 00:02:23 -0500
Subject: [PATCH 13/15] Comment fix.

---
 ext/proc/wait3.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index 74d9ce6..8e12cdc 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -721,7 +721,7 @@ static VALUE proc_waitid(int argc, VALUE* argv, VALUE mod){
  * be sure to leave off the leading 'SIG' substring, e.g. use 'INT' instead
  * of 'SIGINT'.
  *
- * Note that not all platforms (notably Linux) do not support automatically
+ * Note that not all platforms (notably Linux) support automatically
  * converting strings to their corresponding signal values, so it is
  * recommended that you always use an array of numeric values.
  *

From 4fc1b51e9e71d33c0a9bb7999dfce02be78bb9ab Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Fri, 9 Jan 2026 00:04:19 -0500
Subject: [PATCH 14/15] Fixed some whitespace issues.

---
 ext/proc/wait3.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/ext/proc/wait3.c b/ext/proc/wait3.c
index 8e12cdc..aa5dd98 100644
--- a/ext/proc/wait3.c
+++ b/ext/proc/wait3.c
@@ -101,10 +101,10 @@ static void* pause_without_gvl(void* data) {
  */
 static VALUE pst_wifstopped(int status)
 {
-   if(WIFSTOPPED(status))
-      return Qtrue;
-   else
-      return Qfalse;
+  if(WIFSTOPPED(status))
+    return Qtrue;
+  else
+    return Qfalse;
 }
 
 /*
@@ -113,7 +113,7 @@ static VALUE pst_wifstopped(int status)
 static VALUE pst_wifsignaled(int status)
 {
   if (WIFSIGNALED(status))
-	  return Qtrue;
+    return Qtrue;
   else
     return Qfalse;
 }
@@ -782,7 +782,7 @@ static VALUE proc_pause(int argc, VALUE* argv, VALUE mod){
          res = sigaction(signum, &act, &sa);
 
          if(res)
-          rb_sys_fail("sigaction");
+            rb_sys_fail("sigaction");
       }
    }
 

From 79f7ee64c63e914aca10385b1b4536a4bb7439c2 Mon Sep 17 00:00:00 2001
From: Daniel Berger <78529+djberg96@users.noreply.github.com>
Date: Fri, 9 Jan 2026 09:18:29 -0500
Subject: [PATCH 15/15] Add changes for 2.0.0.

---
 CHANGES.md | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/CHANGES.md b/CHANGES.md
index a1e2f98..e61ca4d 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,16 @@
+## 2.0.0 - 9-Jan-2026
+* Added fiber scheduler support for wait3 and wait4 methods, allowing them
+  to cooperate with Ruby's fiber scheduler for non-blocking async operations.
+  Note that rusage fields will be zero when using the fiber scheduler path.
+* Added `rb_thread_call_without_gvl` for blocking calls so that other Ruby
+  threads can run while waiting.
+* Added `RB_GC_GUARD` to protect Ruby objects during blocking operations.
+* Replaced deprecated `RSTRING()->len` and `RSTRING()->ptr` with `RSTRING_LEN()`
+  and `RSTRING_PTR()` macros.
+* Added missing `HAVE_STRLCPY` guard in sigsend with strncpy fallback.
+* Fixed some minor whitespace inconsistencies.
+* Now requires Ruby 3.1 or later.
+
 ## 1.9.3 - 4-May-2024
 * Some internal refactoring where I bzero C structs before using them.
 
@@ -157,7 +170,7 @@
 * Updated tests and documentation.
 
 ## 1.2.0 - 7-Feb-2005
-* Added the Proc.waitid method (for those platforms that support it). 
+* Added the Proc.waitid method (for those platforms that support it).
 * Made the wait3.c file more rdoc friendly.
 * Added a test_waitid.rb file in the examples directory.