From fc995f260db618014f1cdd6759d48342038f8650 Mon Sep 17 00:00:00 2001
From: Francesco Tamagni <mrmacete@protonmail.ch>
Date: Wed, 27 Mar 2024 16:49:35 +0100
Subject: [PATCH] spinlock: Add try_acquire

---
 gum/backend-arm/gumspinlock-arm.c       | 12 ++++++++++++
 gum/backend-arm64/gumspinlock-arm64.c   | 12 ++++++++++++
 gum/backend-mips/gumspinlock-mips.c     | 12 ++++++++++++
 gum/backend-x86/gumspinlock-amd64-msc.c | 12 ++++++++++++
 gum/backend-x86/gumspinlock-ia32-msc.c  | 12 ++++++++++++
 gum/backend-x86/gumspinlock-x86.c       | 12 ++++++++++++
 gum/gumspinlock.h                       |  2 ++
 7 files changed, 74 insertions(+)

diff --git a/gum/backend-arm/gumspinlock-arm.c b/gum/backend-arm/gumspinlock-arm.c
index e6fbc9233a..c7277c2362 100644
--- a/gum/backend-arm/gumspinlock-arm.c
+++ b/gum/backend-arm/gumspinlock-arm.c
@@ -46,3 +46,15 @@ gum_spinlock_release (GumSpinlock * spinlock)
   g_atomic_int_set (&self->is_held, FALSE);
 #endif
 }
+
+gboolean
+gum_spinlock_try_acquire (GumSpinlock * spinlock)
+{
+  GumSpinlockImpl * self = (GumSpinlockImpl *) spinlock;
+  if (self->is_held)
+    return FALSE;
+
+  gum_spinlock_acquire (spinlock);
+
+  return TRUE;
+}
diff --git a/gum/backend-arm64/gumspinlock-arm64.c b/gum/backend-arm64/gumspinlock-arm64.c
index 46b7bc6436..95a25cc069 100644
--- a/gum/backend-arm64/gumspinlock-arm64.c
+++ b/gum/backend-arm64/gumspinlock-arm64.c
@@ -37,3 +37,15 @@ gum_spinlock_release (GumSpinlock * spinlock)
 
   __sync_lock_release (&self->is_held);
 }
+
+gboolean
+gum_spinlock_try_acquire (GumSpinlock * spinlock)
+{
+  GumSpinlockImpl * self = (GumSpinlockImpl *) spinlock;
+  if (self->is_held)
+    return FALSE;
+
+  gum_spinlock_acquire (spinlock);
+
+  return TRUE;
+}
diff --git a/gum/backend-mips/gumspinlock-mips.c b/gum/backend-mips/gumspinlock-mips.c
index 46b7bc6436..95a25cc069 100644
--- a/gum/backend-mips/gumspinlock-mips.c
+++ b/gum/backend-mips/gumspinlock-mips.c
@@ -37,3 +37,15 @@ gum_spinlock_release (GumSpinlock * spinlock)
 
   __sync_lock_release (&self->is_held);
 }
+
+gboolean
+gum_spinlock_try_acquire (GumSpinlock * spinlock)
+{
+  GumSpinlockImpl * self = (GumSpinlockImpl *) spinlock;
+  if (self->is_held)
+    return FALSE;
+
+  gum_spinlock_acquire (spinlock);
+
+  return TRUE;
+}
diff --git a/gum/backend-x86/gumspinlock-amd64-msc.c b/gum/backend-x86/gumspinlock-amd64-msc.c
index 5874c93a2d..0de5b4aac8 100644
--- a/gum/backend-x86/gumspinlock-amd64-msc.c
+++ b/gum/backend-x86/gumspinlock-amd64-msc.c
@@ -37,3 +37,15 @@ gum_spinlock_release (GumSpinlock * spinlock)
 
   g_atomic_int_set (&self->is_held, FALSE);
 }
+
+gboolean
+gum_spinlock_try_acquire (GumSpinlock * spinlock)
+{
+  GumSpinlockImpl * self = (GumSpinlockImpl *) spinlock;
+  if (self->is_held)
+    return FALSE;
+
+  gum_spinlock_acquire (spinlock);
+
+  return TRUE;
+}
diff --git a/gum/backend-x86/gumspinlock-ia32-msc.c b/gum/backend-x86/gumspinlock-ia32-msc.c
index 433c304f93..e8047d569f 100644
--- a/gum/backend-x86/gumspinlock-ia32-msc.c
+++ b/gum/backend-x86/gumspinlock-ia32-msc.c
@@ -45,3 +45,15 @@ gum_spinlock_release (GumSpinlock * spinlock)
     ret;
   }
 }
+
+gboolean
+gum_spinlock_try_acquire (GumSpinlock * spinlock)
+{
+  volatile guint32 is_held = *(guint32*)spinlock;
+  if (is_held == 1)
+    return FALSE;
+
+  gum_spinlock_acquire (spinlock);
+
+  return TRUE;
+}
diff --git a/gum/backend-x86/gumspinlock-x86.c b/gum/backend-x86/gumspinlock-x86.c
index 79f5647cb0..f610ba3753 100644
--- a/gum/backend-x86/gumspinlock-x86.c
+++ b/gum/backend-x86/gumspinlock-x86.c
@@ -37,3 +37,15 @@ gum_spinlock_release (GumSpinlock * spinlock)
 
   __sync_lock_release (&self->is_held);
 }
+
+gboolean
+gum_spinlock_try_acquire (GumSpinlock * spinlock)
+{
+  GumSpinlockImpl * self = (GumSpinlockImpl *) spinlock;
+  if (self->is_held)
+    return FALSE;
+
+  gum_spinlock_acquire (spinlock);
+
+  return TRUE;
+}
diff --git a/gum/gumspinlock.h b/gum/gumspinlock.h
index c9d7f81997..bd9cd23389 100644
--- a/gum/gumspinlock.h
+++ b/gum/gumspinlock.h
@@ -25,6 +25,8 @@ void gum_spinlock_init (GumSpinlock * spinlock);
 void gum_spinlock_acquire (GumSpinlock * spinlock);
 void gum_spinlock_release (GumSpinlock * spinlock);
 
+gboolean gum_spinlock_try_acquire (GumSpinlock * spinlock);
+
 G_END_DECLS
 
 #endif