diff --git a/druntime/src/core/thread/osthread.d b/druntime/src/core/thread/osthread.d
index 61ed05cac048..eb21f3197fd6 100644
--- a/druntime/src/core/thread/osthread.d
+++ b/druntime/src/core/thread/osthread.d
@@ -1129,6 +1129,33 @@ private extern(D) void* getStackBottom() nothrow @nogc
         static assert(false, "Platform not supported.");
 }
 
+
+// Returns true on success
+// TODO: move to posix_impl module
+version (Posix)
+package bool suspendThreadImpl(Thread t) @nogc nothrow
+{
+    version (Darwin)
+        return thread_suspend(t.m_tmach) == KERN_SUCCESS;
+    else version (Solaris)
+        return thr_suspend(t.m_addr) == 0;
+    else
+        return pthread_kill(t.m_addr, suspendSignalNumber) == 0;
+}
+
+// Returns true on success
+// TODO: move to posix_impl module
+version (Posix)
+package bool resumeThreadImpl(Thread t) @nogc nothrow
+{
+    version (Darwin)
+        return thread_resume(t.m_tmach) == KERN_SUCCESS;
+    else version (Solaris)
+        return thr_continue(t.m_addr) == 0;
+    else
+        return pthread_kill(t.m_addr, resumeSignalNumber) == 0;
+}
+
 /**
  * Suspend the specified thread and load stack and register information for
  * use by thread_scanAll.  If the supplied thread is the calling thread,
@@ -1153,18 +1180,31 @@ private extern (D) bool suspend( Thread t ) nothrow @nogc
         return false;
     }
 
-    version (Windows)
+    const sameThread = t.m_addr == gettid();
+
+    if (!sameThread)
     {
-        if ( t.m_addr != GetCurrentThreadId() && SuspendThread( t.m_hndl ) == 0xFFFFFFFF )
+        if (!suspendThreadImpl(t))
         {
-            if ( !t.isRunning )
+            if (t.isRunning)
+                onThreadError( "Unable to suspend thread" );
+            else
             {
                 Thread.remove( t );
                 return false;
             }
-            onThreadError( "Unable to suspend thread" );
         }
+    }
+
+    loadStackAndRegInfo(t, sameThread);
+
+    return true;
+}
 
+private void loadStackAndRegInfo(Thread t, const bool sameThread) nothrow @nogc
+{
+    version (Windows)
+    {
         CONTEXT context = void;
         context.ContextFlags = CONTEXT_INTEGER | CONTEXT_CONTROL;
 
@@ -1214,16 +1254,6 @@ private extern (D) bool suspend( Thread t ) nothrow @nogc
     }
     else version (Darwin)
     {
-        if ( t.m_addr != pthread_self() && thread_suspend( t.m_tmach ) != KERN_SUCCESS )
-        {
-            if ( !t.isRunning )
-            {
-                Thread.remove( t );
-                return false;
-            }
-            onThreadError( "Unable to suspend thread" );
-        }
-
         version (X86)
         {
             x86_thread_state32_t    state = void;
@@ -1339,18 +1369,8 @@ private extern (D) bool suspend( Thread t ) nothrow @nogc
     }
     else version (Solaris)
     {
-        if (t.m_addr != pthread_self())
+        if (!sameThread)
         {
-            if (thr_suspend(t.m_addr) != 0)
-            {
-                if (!t.isRunning)
-                {
-                    Thread.remove(t);
-                    return false;
-                }
-                onThreadError("Unable to suspend thread");
-            }
-
             static int getLwpStatus(ulong lwpid, out lwpstatus_t status)
             {
                 import core.sys.posix.fcntl : open, O_RDONLY;
@@ -1476,19 +1496,7 @@ private extern (D) bool suspend( Thread t ) nothrow @nogc
     }
     else version (Posix)
     {
-        if ( t.m_addr != pthread_self() )
-        {
-            if ( pthread_kill( t.m_addr, suspendSignalNumber ) != 0 )
-            {
-                if ( !t.isRunning )
-                {
-                    Thread.remove( t );
-                    return false;
-                }
-                onThreadError( "Unable to suspend thread" );
-            }
-        }
-        else if ( !t.m_lock )
+        if (sameThread && !t.m_lock)
         {
             t.m_curr.tstack = getStackTop();
         }
@@ -1499,7 +1507,6 @@ private extern (D) bool suspend( Thread t ) nothrow @nogc
     }
     else
         static assert(0, "unsupported os");
-    return true;
 }
 
 /**
@@ -1615,70 +1622,48 @@ extern (C) void thread_suspendAll() nothrow
 private extern (D) void resume(ThreadBase _t) nothrow @nogc
 {
     Thread t = _t.toThread;
+    const sameThread = t.m_addr == gettid();
 
-    version (Windows)
+    if (!sameThread)
     {
-        if ( t.m_addr != GetCurrentThreadId() && ResumeThread( t.m_hndl ) == 0xFFFFFFFF )
+        if (!resumeThreadImpl(t))
         {
-            if ( !t.isRunning )
+            if (t.isRunning)
+                onThreadError( "Unable to resume thread" );
+            else
             {
                 Thread.remove( t );
                 return;
             }
-            onThreadError( "Unable to resume thread" );
         }
+    }
+
+    storeStackAndRegInfo(t, sameThread);
+}
 
+private void storeStackAndRegInfo(Thread t, const bool sameThread) nothrow @nogc
+{
+    version (Windows)
+    {
         if ( !t.m_lock )
             t.m_curr.tstack = t.m_curr.bstack;
         t.m_reg[0 .. $] = 0;
     }
     else version (Darwin)
     {
-        if ( t.m_addr != pthread_self() && thread_resume( t.m_tmach ) != KERN_SUCCESS )
-        {
-            if ( !t.isRunning )
-            {
-                Thread.remove( t );
-                return;
-            }
-            onThreadError( "Unable to resume thread" );
-        }
-
         if ( !t.m_lock )
             t.m_curr.tstack = t.m_curr.bstack;
         t.m_reg[0 .. $] = 0;
     }
     else version (Solaris)
     {
-        if (t.m_addr != pthread_self() && thr_continue(t.m_addr) != 0)
-        {
-            if (!t.isRunning)
-            {
-                Thread.remove(t);
-                return;
-            }
-            onThreadError("Unable to resume thread");
-        }
-
         if (!t.m_lock)
             t.m_curr.tstack = t.m_curr.bstack;
         t.m_reg[0 .. $] = 0;
     }
     else version (Posix)
     {
-        if ( t.m_addr != pthread_self() )
-        {
-            if ( pthread_kill( t.m_addr, resumeSignalNumber ) != 0 )
-            {
-                if ( !t.isRunning )
-                {
-                    Thread.remove( t );
-                    return;
-                }
-                onThreadError( "Unable to resume thread" );
-            }
-        }
-        else if ( !t.m_lock )
+        if (sameThread && !t.m_lock)
         {
             t.m_curr.tstack = t.m_curr.bstack;
         }
diff --git a/druntime/src/core/thread/posix_impl.d b/druntime/src/core/thread/posix_impl.d
index 036068184d6e..d284c4dc1034 100644
--- a/druntime/src/core/thread/posix_impl.d
+++ b/druntime/src/core/thread/posix_impl.d
@@ -584,3 +584,5 @@ class Thread : ThreadBase
         sched_yield();
     }
 }
+
+package alias gettid = imported!"core.sys.posix.pthread".pthread_self;
diff --git a/druntime/src/core/thread/wasi_impl.d b/druntime/src/core/thread/wasi_impl.d
index 752634641819..16ad76ddce26 100644
--- a/druntime/src/core/thread/wasi_impl.d
+++ b/druntime/src/core/thread/wasi_impl.d
@@ -156,3 +156,23 @@ class Thread : ThreadBase
         // do nothing
     }
 }
+
+package ThreadID gettid() @nogc nothrow
+{
+    onThreadError( "Unable to get WASI thread ID" );
+    assert(0);
+}
+
+// Returns true on success
+package bool suspendThreadImpl(Thread t) @nogc nothrow
+{
+    onThreadError( "Unable to suspend thread" );
+    assert(0);
+}
+
+// Returns true on success
+package bool resumeThreadImpl(Thread t) @nogc nothrow
+{
+    onThreadError( "Unable to resume thread" );
+    assert(0);
+}
diff --git a/druntime/src/core/thread/windows_impl.d b/druntime/src/core/thread/windows_impl.d
index a3372fe18972..3de78afc3ccf 100644
--- a/druntime/src/core/thread/windows_impl.d
+++ b/druntime/src/core/thread/windows_impl.d
@@ -242,3 +242,17 @@ class Thread : ThreadBase
         SwitchToThread();
     }
 }
+
+package alias gettid = imported!"core.sys.windows.winbase".GetCurrentThreadId;
+
+// Returns true on success
+package bool suspendThreadImpl(Thread t) @nogc nothrow
+{
+    return SuspendThread(t.m_hndl) != 0xFFFFFFFF;
+}
+
+// Returns true on success
+package bool resumeThreadImpl(Thread t) @nogc nothrow
+{
+    return ResumeThread(t.m_hndl) != 0xFFFFFFFF;
+}