From 3775c17034c44005f29b098568199438c5a8061a Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Sun, 29 Apr 2012 05:55:46 -0700
Subject: [PATCH] Fixed asynch disk/tape I/O reset behaviors to reliably
 synchronize with the I/O thread's startup

---
 sim_disk.c | 8 +++++++-
 sim_tape.c | 9 ++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/sim_disk.c b/sim_disk.c
index ffd504fc..fedfa427 100644
--- a/sim_disk.c
+++ b/sim_disk.c
@@ -108,6 +108,7 @@ struct disk_context {
     pthread_t           io_thread;          /* I/O Thread Id */
     pthread_mutex_t     io_lock;
     pthread_cond_t      io_cond;
+    pthread_cond_t      startup_cond;
     int                 io_dop;
     uint8               *buf;
     t_seccnt            *rsects;
@@ -176,6 +177,7 @@ pthread_setschedparam (pthread_self(), sched_policy, &sched_priority);
 sim_debug (ctx->dbit, ctx->dptr, "_disk_io(unit=%d) starting\n", uptr-ctx->dptr->units);
 
 pthread_mutex_lock (&ctx->io_lock);
+pthread_cond_signal (&ctx->startup_cond);   /* Signal we're ready to go */
 while (ctx->asynch_io) {
     pthread_cond_wait (&ctx->io_cond, &ctx->io_lock);
     if (ctx->io_dop == DOP_DONE)
@@ -423,12 +425,16 @@ ctx->asynch_io_latency = latency;
 if (ctx->asynch_io) {
     pthread_mutex_init (&ctx->io_lock, NULL);
     pthread_cond_init (&ctx->io_cond, NULL);
+    pthread_cond_init (&ctx->startup_cond, NULL);
     pthread_attr_init(&attr);
     pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
+    pthread_mutex_lock (&ctx->io_lock);
     pthread_create (&ctx->io_thread, &attr, _disk_io, (void *)uptr);
     pthread_attr_destroy(&attr);
+    pthread_cond_wait (&ctx->startup_cond, &ctx->io_lock); /* Wait for thread to stabilize */
+    pthread_mutex_unlock (&ctx->io_lock);
+    pthread_cond_destroy (&ctx->startup_cond);
     uptr->a_check_completion = _disk_completion_dispatch;
-    sim_os_ms_sleep(50); /* Give the _disk_io thread a chance to stabilize */
     }
 #endif
 return SCPE_OK;
diff --git a/sim_tape.c b/sim_tape.c
index e43bfbd4..8341089c 100644
--- a/sim_tape.c
+++ b/sim_tape.c
@@ -125,6 +125,7 @@ struct tape_context {
     pthread_t           io_thread;          /* I/O Thread Id */
     pthread_mutex_t     io_lock;
     pthread_cond_t      io_cond;
+    pthread_cond_t      startup_cond;
     int                 io_top;
     uint8               *buf;
     uint32              *bc;
@@ -211,6 +212,7 @@ struct tape_context *ctx = (struct tape_context *)uptr->tape_ctx;
     sim_debug (ctx->dbit, ctx->dptr, "_tape_io(unit=%d) starting\n", uptr-ctx->dptr->units);
 
     pthread_mutex_lock (&ctx->io_lock);
+    pthread_cond_signal (&ctx->startup_cond);   /* Signal we're ready to go */
     while (1) {
         pthread_cond_wait (&ctx->io_cond, &ctx->io_lock);
         if (ctx->io_top == TOP_DONE)
@@ -331,11 +333,15 @@ ctx->asynch_io_latency = latency;
 if (ctx->asynch_io) {
     pthread_mutex_init (&ctx->io_lock, NULL);
     pthread_cond_init (&ctx->io_cond, NULL);
+    pthread_cond_init (&ctx->startup_cond, NULL);
     pthread_attr_init(&attr);
     pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
+    pthread_mutex_lock (&ctx->io_lock);
     pthread_create (&ctx->io_thread, &attr, _tape_io, (void *)uptr);
     pthread_attr_destroy(&attr);
-    sim_os_ms_sleep(50); /* Give the _tape_io thread a chance to stabilize */
+    pthread_cond_wait (&ctx->startup_cond, &ctx->io_lock); /* Wait for thread to stabilize */
+    pthread_mutex_unlock (&ctx->io_lock);
+    pthread_cond_destroy (&ctx->startup_cond);
     }
 uptr->a_check_completion = _tape_completion_dispatch;
 #endif
@@ -362,6 +368,7 @@ if (ctx->asynch_io) {
     pthread_join (ctx->io_thread, NULL);
     pthread_mutex_destroy (&ctx->io_lock);
     pthread_cond_destroy (&ctx->io_cond);
+    pthread_cond_destroy (&ctx->startup_cond);
     }
 return SCPE_OK;
 #endif