[Qemu-devel] [patch v4 08/16] QemuThread: make QemuThread as tls to store extra info

[Liu Ping Fan]

If mmio dispatch out of big lock, some function's calling context (ie,
holding big lock or not) are different. We need to trace these info in
runtime, and use tls to store them.
By this method, we can avoid to require big lock recursive.

Signed-off-by: Liu Ping Fan <address@hidden>
---
 cpus.c              |    1 +
 qemu-thread-posix.c |    7 +++++++
 qemu-thread-posix.h |    2 ++
 qemu-thread.h       |    1 +
 vl.c                |    6 ++++++
 5 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/cpus.c b/cpus.c
index e476a3c..4cd7f85 100644
--- a/cpus.c
+++ b/cpus.c
@@ -735,6 +735,7 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
     CPUState *cpu = ENV_GET_CPU(env);
     int r;
 
+    pthread_setspecific(qemu_thread_key, cpu->thread);
     qemu_mutex_lock(&qemu_global_mutex);
     qemu_thread_get_self(cpu->thread);
     env->thread_id = qemu_get_thread_id();
diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c
index 8fbabda..f448fcb 100644
--- a/qemu-thread-posix.c
+++ b/qemu-thread-posix.c
@@ -19,6 +19,8 @@
 #include <string.h>
 #include "qemu-thread.h"
 
+pthread_key_t qemu_thread_key;
+
 static void error_exit(int err, const char *msg)
 {
     fprintf(stderr, "qemu: %s: %s\n", msg, strerror(err));
@@ -151,6 +153,11 @@ void qemu_thread_get_self(QemuThread *thread)
     thread->thread = pthread_self();
 }
 
+void qemu_thread_key_create(void)
+{
+    pthread_key_create(&qemu_thread_key, NULL);
+}
+
 bool qemu_thread_is_self(QemuThread *thread)
 {
    return pthread_equal(pthread_self(), thread->thread);
diff --git a/qemu-thread-posix.h b/qemu-thread-posix.h
index ee4618e..2607b1c 100644
--- a/qemu-thread-posix.h
+++ b/qemu-thread-posix.h
@@ -14,4 +14,6 @@ struct QemuThread {
     pthread_t thread;
 };
 
+extern pthread_key_t qemu_thread_key;
+
 #endif
diff --git a/qemu-thread.h b/qemu-thread.h
index 05fdaaf..4a6427d 100644
--- a/qemu-thread.h
+++ b/qemu-thread.h
@@ -46,4 +46,5 @@ void qemu_thread_get_self(QemuThread *thread);
 bool qemu_thread_is_self(QemuThread *thread);
 void qemu_thread_exit(void *retval);
 
+void qemu_thread_key_create(void);
 #endif
diff --git a/vl.c b/vl.c
index 7c577fa..442479a 100644
--- a/vl.c
+++ b/vl.c
@@ -149,6 +149,7 @@ int main(int argc, char **argv)
 #include "qemu-options.h"
 #include "qmp-commands.h"
 #include "main-loop.h"
+#include "qemu-thread.h"
 #ifdef CONFIG_VIRTFS
 #include "fsdev/qemu-fsdev.h"
 #endif
@@ -2342,6 +2343,7 @@ int qemu_init_main_loop(void)
     return main_loop_init();
 }
 
+
 int main(int argc, char **argv, char **envp)
 {
     int i;
@@ -3483,6 +3485,10 @@ int main(int argc, char **argv, char **envp)
         exit(1);
     }
 
+    qemu_thread_key_create();
+    QemuThread *ioctx = g_malloc0(sizeof(QemuThread));
+    pthread_setspecific(qemu_thread_key, ioctx);
+
     os_set_line_buffering();
 
     if (init_timer_alarm() < 0) {
-- 
1.7.4.4