diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1eca217e..0c22f03d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1102,6 +1102,8 @@ endif()
 
 # Extra tests
 set(UNICORN_TEST_FILE ${UNICORN_TEST_FILE} test_mem)
+set(UNICORN_TEST_FILE ${UNICORN_TEST_FILE} test_ctl)
+set(UNICORN_SAMPLE_FILE ${UNICORN_SAMPLE_FILE} sample_ctl)
 
 target_compile_options(unicorn PRIVATE
     ${UNICORN_COMPILE_OPTIONS}
diff --git a/glib_compat/gtree.c b/glib_compat/gtree.c
index a790d568..b2617a3f 100644
--- a/glib_compat/gtree.c
+++ b/glib_compat/gtree.c
@@ -260,7 +260,7 @@ static inline GTreeNode *g_tree_node_next (GTreeNode *node)
     return tmp;
 }
 
-static void g_tree_remove_all (GTree *tree)
+void g_tree_remove_all (GTree *tree)
 {
     GTreeNode *node;
     GTreeNode *next;
diff --git a/glib_compat/gtree.h b/glib_compat/gtree.h
index f62dbe08..47b6c880 100644
--- a/glib_compat/gtree.h
+++ b/glib_compat/gtree.h
@@ -44,6 +44,8 @@ void     g_tree_destroy (GTree *tree);
 
 void     g_tree_insert (GTree *tree, gpointer key, gpointer value);
 
+void g_tree_remove_all (GTree *tree);
+
 gboolean g_tree_remove (GTree *tree, gconstpointer key);
 
 gpointer g_tree_lookup (GTree *tree, gconstpointer key);
diff --git a/include/uc_priv.h b/include/uc_priv.h
index bcdf9059..19dbecda 100644
--- a/include/uc_priv.h
+++ b/include/uc_priv.h
@@ -41,6 +41,8 @@
 #define WRITE_BYTE_H(x, b) (x = (x & ~0xff00) | ((b & 0xff) << 8))
 #define WRITE_BYTE_L(x, b) (x = (x & ~0xff) | (b & 0xff))
 
+struct TranslationBlock;
+
 typedef uc_err (*query_t)(struct uc_struct *uc, uc_query_type type,
                           size_t *result);
 
@@ -114,6 +116,14 @@ typedef void (*uc_softfloat_initialize)(void);
 // tcg flush softmmu tlb
 typedef void (*uc_tcg_flush_tlb)(struct uc_struct *uc);
 
+// Invalidate the TB at given address
+typedef void (*uc_invalidate_tb_t)(struct uc_struct *uc, uint64_t start,
+                                   size_t len);
+
+// Request generating TB at given address
+typedef struct TranslationBlock *(*uc_gen_tb_t)(struct uc_struct *uc,
+                                                uint64_t pc);
+
 struct hook {
     int type;       // UC_HOOK_*
     int insn;       // instruction for HOOK_INSN
@@ -226,6 +236,8 @@ struct uc_struct {
     uc_target_page_init target_page;
     uc_softfloat_initialize softfloat_initialize;
     uc_tcg_flush_tlb tcg_flush_tlb;
+    uc_invalidate_tb_t uc_invalidate_tb;
+    uc_gen_tb_t uc_gen_tb;
 
     /*  only 1 cpu in unicorn,
         do not need current_cpu to handle current running cpu. */
@@ -288,8 +300,9 @@ struct uc_struct {
     uint64_t invalid_addr; // invalid address to be accessed
     int invalid_error;     // invalid memory code: 1 = READ, 2 = WRITE, 3 = CODE
 
-    uint64_t addr_end; // address where emulation stops (@end param of
-                       // uc_emu_start())
+    int use_exit;
+    GTree *exits; // addresses where emulation stops (@until param of
+                  // uc_emu_start()) Also see UC_CTL_USE_EXITS for more details.
 
     int thumb; // thumb mode for ARM
     MemoryRegion **mapped_blocks;
@@ -328,5 +341,20 @@ struct uc_context {
 // check if this address is mapped in (via uc_mem_map())
 MemoryRegion *memory_mapping(struct uc_struct *uc, uint64_t address);
 
+// We have to support 32bit system so we can't hold uint64_t on void*
+static inline void uc_add_exit(uc_engine *uc, uint64_t addr)
+{
+    uint64_t *new_exit = g_malloc(sizeof(uint64_t));
+    *new_exit = addr;
+    g_tree_insert(uc->exits, (gpointer)new_exit, (gpointer)1);
+}
+
+// This function has to exist since we would like to accept uint32_t or
+// it's complex to achieve so.
+static inline int uc_addr_is_exit(uc_engine *uc, uint64_t addr)
+{
+    return g_tree_lookup(uc->exits, (gpointer)(&addr)) == (gpointer)1;
+}
+
 #endif
 /* vim: set ts=4 noet:  */
diff --git a/include/unicorn/unicorn.h b/include/unicorn/unicorn.h
index 51dc212c..a9f49650 100644
--- a/include/unicorn/unicorn.h
+++ b/include/unicorn/unicorn.h
@@ -427,40 +427,43 @@ typedef enum uc_query_type {
 // If a control don't have `Set` or `Get` for @args, it means it's r/o or w/o.
 typedef enum uc_control_type {
     // Current mode.
-    // Read: @args = (*int)
+    // Read: @args = (int*)
     UC_CTL_UC_MODE = 0,
     // Curent page size.
-    // Write: @args = (int)
-    // Read: @args = (*int)
+    // Write: @args = (uint32_t)
+    // Read: @args = (uint32_t*)
     UC_CTL_UC_PAGE_SIZE,
     // Current arch.
-    // Read: @args = (*int)
+    // Read: @args = (int*)
     UC_CTL_UC_ARCH,
     // Current timeout.
-    // Read: @args = (*uint64_t)
+    // Read: @args = (uint64_t*)
     UC_CTL_UC_TIMEOUT,
+    // Enable multiple exists.
+    // Without this control, reading/setting exists won't work.
+    // This is for API backward compatibility.
+    // Write: @args = (int)
+    UC_CTL_UC_USE_EXITS,
     // The number of current exists.
-    // Read: @args = (*size_t)
+    // Read: @args = (size_t*)
     UC_CTL_UC_EXITS_CNT,
     // Current exists.
-    // Write: @args = (*uint64_t exists, size_t len)
+    // Write: @args = (uint64_t* exists, size_t len)
     //        @len = UC_CTL_UC_EXITS_CNT
-    // Read: @args = (*uint64_t exists, size_t len)
+    // Read: @args = (uint64_t* exists, size_t len)
     //       @len = UC_CTL_UC_EXITS_CNT
     UC_CTL_UC_EXITS,
+
     // Set the cpu model of uc.
     // Note this option can only be set before any Unicorn
     // API is called except for uc_open.
     // Write: @args = (int)
     // Read:  @args = (int)
     UC_CTL_CPU_MODEL,
-    // Request the edge of two TBs.
-    // Read: @args = (uint64_t, uint64_t, *uint64_t)
-    UC_CTL_TB_EDGE,
     // Request a tb cache at a specific address
     // Read: @args = (uint64_t)
     UC_CTL_TB_REQUEST_CACHE,
-    // Remove a tb cache at a specific address
+    // Invalidate a tb cache at a specific address
     // Read: @args = (uint64_t)
     UC_CTL_TB_REMOVE_CACHE
 
@@ -469,13 +472,15 @@ typedef enum uc_control_type {
 #define uc_ctl_get_mode(uc, mode)                                              \
     uc_ctl(uc, UC_CTL_READ(UC_CTL_UC_MODE, 1), (mode))
 #define uc_ctl_get_page_size(uc, ptr)                                          \
-    uc_ctl(uc, UC_CTL_READ(UC_CTL_UC_PAGE_SIZE, 1, (ptr))
+    uc_ctl(uc, UC_CTL_READ(UC_CTL_UC_PAGE_SIZE, 1), (ptr))
 #define uc_ctl_set_page_size(uc, page_size)                                    \
     uc_ctl(uc, UC_CTL_WRITE(UC_CTL_UC_PAGE_SIZE, 1), (page_size))
 #define uc_ctl_get_arch(uc, arch)                                              \
     uc_ctl(uc, UC_CTL_READ(UC_CTL_UC_ARCH, 1), (arch))
 #define uc_ctl_get_timeout(uc, ptr)                                            \
     uc_ctl(uc, UC_CTL_READ(UC_CTL_UC_TIMEOUT, 1), (ptr))
+#define uc_ctl_exits_enabled(uc, enabled)                                      \
+    uc_ctl(uc, UC_CTL_WRITE(UC_CTL_UC_USE_EXITS, 1), (enabled))
 #define uc_ctl_get_exists_cnt(uc, ptr)                                         \
     uc_ctl(uc, UC_CTL_READ(UC_CTL_UC_EXITS_CNT, 1), (ptr))
 #define uc_ctl_get_exists(uc, buffer, len)                                     \
@@ -487,11 +492,9 @@ typedef enum uc_control_type {
 #define uc_ctl_set_cpu_model(uc, model)                                        \
     uc_ctl(uc, UC_CTL_WRITE(UC_CTL_CPU_MODEL, 1), (model))
 #define uc_ctl_remove_cache(uc, address)                                       \
-    uc_ctl(uc, UC_CTL_WRITE(UC_CTL_TB_REMOVE_CACHE, 1), (address))
+    uc_ctl(uc, UC_CTL_READ(UC_CTL_TB_REMOVE_CACHE, 1), (address))
 #define uc_ctl_request_cache(uc, address)                                      \
-    uc_ctl(uc, UC_CTL_WRITE(UC_CTL_TB_REQUEST_CACHE, 1), (address))
-#define uc_ctl_get_edge(uc, addr1, addr2, ptr)                                 \
-    uc_ctl(uc, UC_CTL_READ_WRITE(UC_CTL_TB_EDGE, 3), (addr1), (addr2), (ptr))
+    uc_ctl(uc, UC_CTL_READ(UC_CTL_TB_REQUEST_CACHE, 1), (address))
 
 // Opaque storage for CPU context, used with uc_context_*()
 struct uc_context;
diff --git a/qemu/accel/tcg/translate-all.c b/qemu/accel/tcg/translate-all.c
index d59b9604..a7b94d99 100644
--- a/qemu/accel/tcg/translate-all.c
+++ b/qemu/accel/tcg/translate-all.c
@@ -980,6 +980,99 @@ static void tb_htable_init(struct uc_struct *uc)
     qht_init(&uc->tcg_ctx->tb_ctx.htable, tb_cmp, CODE_GEN_HTABLE_SIZE, mode);
 }
 
+// GVA to GPA (GPA -> HVA via page_find, HVA->HPA via host mmu)
+// Unicorn: Why addr - 1?
+// 0: INC ecx
+// 1: DEC edx <--- We put exit here, then the range of TB is [0, 1)
+//
+// While tb_invalidate_phys_range invalides [start, end)
+//
+// This function is designed to used with g_tree_foreach
+static inline gboolean uc_exit_invalidate_iter(gpointer key, gpointer val, gpointer data) {
+    uint64_t exit = *((uint64_t*)key);
+    uc_engine* uc = (uc_engine*)data;
+    tb_page_addr_t start, end;
+    
+    if (exit != 0) {
+        end = get_page_addr_code(uc->cpu->env_ptr, exit);
+
+        start = (end-1) ;
+        end = end & (target_ulong)(-1);
+
+        tb_invalidate_phys_range(uc, start, end);
+    }
+
+    return false;
+}
+
+static void uc_invalidate_tb(struct uc_struct *uc, uint64_t start_addr, size_t len) {
+    tb_page_addr_t start, end;
+
+    // GVA to GPA (GPA -> HVA via page_find, HVA->HPA via host mmu)
+    start = get_page_addr_code(uc->cpu->env_ptr, start_addr) & (target_ulong)(-1);
+    
+    // For 32bit target.
+    end = (start + len) & (target_ulong)(-1);
+
+    // We get a wrap?
+    if (start > end) {
+        return;
+    }
+
+    tb_invalidate_phys_range(uc, start, end);
+}
+
+static TranslationBlock* uc_gen_tb(struct uc_struct *uc, uint64_t addr) {
+    TranslationBlock *tb;
+    target_ulong cs_base, pc;
+    CPUState *cpu = uc->cpu;
+    CPUArchState *env = (CPUArchState *)cpu->env_ptr;
+    uint32_t flags;
+    uint32_t hash;
+    uint32_t cflags = cpu->cflags_next_tb;
+
+    if (cflags == -1) {
+        cflags = curr_cflags();
+    }
+
+    cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
+
+    // Unicorn: Our hack here.
+    pc = addr;
+
+    hash = tb_jmp_cache_hash_func(env->uc, pc);
+    tb = cpu->tb_jmp_cache[hash];
+
+    cflags &= ~CF_CLUSTER_MASK;
+    cflags |= cpu->cluster_index << CF_CLUSTER_SHIFT;
+
+    if (likely(tb &&
+               tb->pc == pc &&
+               tb->cs_base == cs_base &&
+               tb->flags == flags &&
+               tb->trace_vcpu_dstate == *cpu->trace_dstate &&
+               (tb_cflags(tb) & (CF_HASH_MASK | CF_INVALID)) == cflags)) {
+        return tb;
+    }
+
+    tb = tb_htable_lookup(cpu, pc, cs_base, flags, cflags);
+    cpu->tb_jmp_cache[hash] = tb;
+
+    if (tb != NULL) {
+        return tb;
+    }
+
+    if (tb == NULL) {
+        mmap_lock();
+        tb = tb_gen_code(cpu, pc, cs_base, flags, cflags);
+        mmap_unlock();
+        /* We add the TB in the virtual pc hash table for the fast lookup */
+        cpu->tb_jmp_cache[hash] = tb;
+    }
+
+    return tb;
+}
+
 /* Must be called before using the QEMU cpus. 'tb_size' is the size
    (in bytes) allocated to the translation buffer. Zero means default
    size. */
@@ -1000,6 +1093,9 @@ void tcg_exec_init(struct uc_struct *uc, unsigned long tb_size)
     tcg_prologue_init(uc->tcg_ctx);
     /* cpu_interrupt_handler is not used in uc1 */
     uc->l1_map = g_malloc0(sizeof(void *) * V_L1_MAX_SIZE);
+    /* Invalidate / Cache TBs */
+    uc->uc_invalidate_tb = uc_invalidate_tb;
+    uc->uc_gen_tb = uc_gen_tb;
 }
 
 /* call with @p->lock held */
diff --git a/qemu/accel/tcg/translator.c b/qemu/accel/tcg/translator.c
index 0fca28a9..9ed272fd 100644
--- a/qemu/accel/tcg/translator.c
+++ b/qemu/accel/tcg/translator.c
@@ -58,7 +58,7 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
 
     /* Unicorn: early check to see if the address of this block is
      * the "run until" address. */
-    if (tb->pc == cpu->uc->addr_end) {
+    if (uc_addr_is_exit(uc, tb->pc)) {
         // This should catch that instruction is at the end
         // and generate appropriate halting code.
         gen_tb_start(tcg_ctx, db->tb);
diff --git a/qemu/softmmu/cpus.c b/qemu/softmmu/cpus.c
index 12cb84e4..c318b855 100644
--- a/qemu/softmmu/cpus.c
+++ b/qemu/softmmu/cpus.c
@@ -171,10 +171,28 @@ void cpu_stop_current(struct uc_struct *uc)
     }
 }
 
+
+// Unicorn: Why addr - 1?
+// 0: INC ecx
+// 1: DEC edx <--- We put exit here, then the range of TB is [0, 1)
+//
+// While tb_invalidate_phys_range invalides [start, end)
+//
+// This function is designed to used with g_tree_foreach
+static inline gboolean uc_exit_invalidate_iter(gpointer key, gpointer val, gpointer data) {
+    uint64_t exit = *((uint64_t*)key);
+    uc_engine* uc = (uc_engine*)data;
+    
+    if (exit != 0) {
+        uc->uc_invalidate_tb(uc, exit - 1, 1);
+    }
+
+    return false;
+}
+
 void resume_all_vcpus(struct uc_struct* uc)
 {
     CPUState *cpu = uc->cpu;
-    tb_page_addr_t start, end;
     cpu->halted = 0;
     cpu->exit_request = 0;
     cpu->exception_index = -1;
@@ -187,23 +205,11 @@ void resume_all_vcpus(struct uc_struct* uc)
         }
     }
 
-    // clear the cache of the addr_end address, since the generated code
+    // clear the cache of the exits address, since the generated code
     // at that address is to exit emulation, but not for the instruction there.
     // if we dont do this, next time we cannot emulate at that address
-    if (uc->addr_end != 0) {
-        // GVA to GPA (GPA -> HVA via page_find, HVA->HPA via host mmu)
-        end = get_page_addr_code(uc->cpu->env_ptr, uc->addr_end);
 
-        // For 32bit target.
-        start = (end - 1) & (target_ulong)(-1);
-        end = end & (target_ulong)(-1);
-        // Unicorn: Why start - 1?
-        // 0: INC ecx
-        // 1: DEC edx <--- We put exit here, then the range of TB is [0, 1)
-        //
-        // While tb_invalidate_phys_range invalides [start, end)
-        tb_invalidate_phys_range(uc, start, end);
-    }
+    g_tree_foreach(uc->exits, uc_exit_invalidate_iter, (void*)uc);
 
     cpu->created = false;
 }
diff --git a/qemu/target/arm/translate-a64.c b/qemu/target/arm/translate-a64.c
index a9eb1ca0..914b382b 100644
--- a/qemu/target/arm/translate-a64.c
+++ b/qemu/target/arm/translate-a64.c
@@ -14637,7 +14637,7 @@ static void aarch64_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
     CPUARMState *env = cpu->env_ptr;
 
     // Unicorn: end address tells us to stop emulation
-    if (dcbase->pc_next == dc->uc->addr_end) {
+    if (uc_addr_is_exit(dc->uc, dcbase->pc_next)) {
         // imitate WFI instruction to halt emulation
         dcbase->is_jmp = DISAS_WFI;
     } else {
diff --git a/qemu/target/arm/translate.c b/qemu/target/arm/translate.c
index 742a55fd..efdfc4b4 100644
--- a/qemu/target/arm/translate.c
+++ b/qemu/target/arm/translate.c
@@ -11421,7 +11421,7 @@ static void arm_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
     }
 
     // Unicorn: end address tells us to stop emulation
-    if (dcbase->pc_next == dc->uc->addr_end) {
+    if (uc_addr_is_exit(dc->uc, dcbase->pc_next)) {
         // imitate WFI instruction to halt emulation
         dcbase->is_jmp = DISAS_WFI;
     } else {
@@ -11499,7 +11499,7 @@ static void thumb_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
     }
 
     // Unicorn: end address tells us to stop emulation
-    if (dcbase->pc_next == uc->addr_end) {
+    if (uc_addr_is_exit(uc, dcbase->pc_next)) {
         // imitate WFI instruction to halt emulation
         dcbase->is_jmp = DISAS_WFI;
         return;
diff --git a/qemu/target/i386/translate.c b/qemu/target/i386/translate.c
index cf148c4b..8616b12f 100644
--- a/qemu/target/i386/translate.c
+++ b/qemu/target/i386/translate.c
@@ -4765,7 +4765,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
     s->uc = env->uc;
 
     // Unicorn: end address tells us to stop emulation
-    if (s->pc == s->uc->addr_end) {
+    if (uc_addr_is_exit(env->uc, s->pc)) {
         // imitate the HLT instruction
         gen_update_cc_op(s);
         gen_jmp_im(s, pc_start - s->cs_base);
diff --git a/qemu/target/m68k/translate.c b/qemu/target/m68k/translate.c
index 323eff44..c447a905 100644
--- a/qemu/target/m68k/translate.c
+++ b/qemu/target/m68k/translate.c
@@ -6326,7 +6326,7 @@ static void m68k_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
     uint16_t insn;
 
     // Unicorn: end address tells us to stop emulation
-    if (dc->pc == uc->addr_end) {
+    if (uc_addr_is_exit(uc, dc->pc)) {
         gen_exception(dc, dc->pc, EXCP_HLT);
         return;
     }
diff --git a/qemu/target/mips/translate.c b/qemu/target/mips/translate.c
index 97e680a3..e9fceaf9 100644
--- a/qemu/target/mips/translate.c
+++ b/qemu/target/mips/translate.c
@@ -30932,7 +30932,7 @@ static void mips_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
     is_slot = ctx->hflags & MIPS_HFLAG_BMASK;
 
     // Unicorn: end address tells us to stop emulation
-    if (ctx->base.pc_next == uc->addr_end) {
+    if (uc_addr_is_exit(uc, ctx->base.pc_next)) {
         // raise a special interrupt to quit
         gen_helper_wait(tcg_ctx, tcg_ctx->cpu_env);
         ctx->base.is_jmp = DISAS_NORETURN;
diff --git a/qemu/target/ppc/translate.c b/qemu/target/ppc/translate.c
index 8cfebab2..fec05d19 100644
--- a/qemu/target/ppc/translate.c
+++ b/qemu/target/ppc/translate.c
@@ -7626,7 +7626,7 @@ static void ppc_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
               ctx->base.pc_next, ctx->mem_idx, (int)msr_ir);
 
     // Unicorn: end address tells us to stop emulation
-    if (ctx->base.pc_next == uc->addr_end) {
+    if (uc_addr_is_exit(uc, ctx->base.pc_next)) {
         gen_wait(ctx);
         return;
     }
diff --git a/qemu/target/riscv/translate.c b/qemu/target/riscv/translate.c
index 9898093d..e256958f 100644
--- a/qemu/target/riscv/translate.c
+++ b/qemu/target/riscv/translate.c
@@ -850,7 +850,7 @@ static void riscv_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
     bool insn_hook = false;
 
     // Unicorn: end address tells us to stop emulation
-    if (ctx->base.pc_next == ctx->uc->addr_end) {
+    if (uc_addr_is_exit(uc, ctx->base.pc_next)) {
         // Unicorn: We have to exit current execution here.
         dcbase->is_jmp = DISAS_UC_EXIT;
     } else {
diff --git a/qemu/target/sparc/translate.c b/qemu/target/sparc/translate.c
index c6f3d9cd..8c2a8b40 100644
--- a/qemu/target/sparc/translate.c
+++ b/qemu/target/sparc/translate.c
@@ -5951,7 +5951,7 @@ static void sparc_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
     unsigned int insn;
 
     // Unicorn: end address tells us to stop emulation
-    if (dc->pc == uc->addr_end) {
+    if (uc_addr_is_exit(uc, dc->pc)) {
 #ifndef TARGET_SPARC64
         gen_helper_power_down(tcg_ctx, tcg_ctx->cpu_env);
 #endif
diff --git a/samples/sample_ctl.c b/samples/sample_ctl.c
new file mode 100644
index 00000000..543a6e6a
--- /dev/null
+++ b/samples/sample_ctl.c
@@ -0,0 +1,76 @@
+/* Unicorn Emulator Engine */
+/* By Lazymio(@wtdcode), 2021 */
+
+/* Sample code to demonstrate how to use uc_ctl */
+
+#include <unicorn/unicorn.h>
+#include <string.h>
+
+// code to be emulated
+// code to be emulated
+#define X86_CODE32 "\x41\x4a" // INC ecx; DEC edx; PXOR xmm0, xmm1
+
+// memory address where emulation starts
+#define ADDRESS 0x10000
+
+static void test_uc_ctl_read(void)
+{
+    uc_engine *uc;
+    uc_err err;
+    uint32_t tmp;
+    uc_hook trace1, trace2;
+    int mode, arch;
+    uint32_t pagesize;
+    uint64_t timeout;
+
+    int r_ecx = 0x1234; // ECX register
+    int r_edx = 0x7890; // EDX register
+
+    printf("Reading some properties by uc_ctl.\n");
+
+    // Initialize emulator in X86-32bit mode
+    err = uc_open(UC_ARCH_X86, UC_MODE_32, &uc);
+    if (err) {
+        printf("Failed on uc_open() with error returned: %u\n", err);
+        return;
+    }
+
+    // Let's query some properties by uc_ctl.
+    // Note uc_ctl_* is just tiny macro wrappers for uc_ctl().
+    err = uc_ctl_get_mode(uc, &mode);
+    if (err) {
+        printf("Failed on uc_ctl() with error returned: %u\n", err);
+        return;
+    }
+
+    err = uc_ctl_get_arch(uc, &arch);
+    if (err) {
+        printf("Failed on uc_ctl() with error returned: %u\n", err);
+        return;
+    }
+
+    err = uc_ctl_get_timeout(uc, &timeout);
+    if (err) {
+        printf("Failed on uc_ctl() with error returned: %u\n", err);
+        return;
+    }
+
+    err = uc_ctl_get_page_size(uc, &pagesize);
+    if (err) {
+        printf("Failed on uc_ctl() with error returned: %u\n", err);
+        return;
+    }
+
+    printf(">>> mode = %d, arch = %d, timeout=%" PRIu64 ", pagesize=%" PRIu32
+           "\n",
+           mode, arch, timeout, pagesize);
+
+    uc_close(uc);
+}
+
+int main(int argc, char **argv, char **envp)
+{
+    test_uc_ctl_read();
+
+    return 0;
+}
diff --git a/tests/unit/test_ctl.c b/tests/unit/test_ctl.c
new file mode 100644
index 00000000..f2f66625
--- /dev/null
+++ b/tests/unit/test_ctl.c
@@ -0,0 +1,25 @@
+#include "unicorn_test.h"
+
+const uint64_t code_start = 0x1000;
+const uint64_t code_len = 0x4000;
+
+#define GEN_SIMPLE_READ_TEST(field, ctl_type, arg_type, expected)              \
+    static void test_uc_ctl_##field()                                          \
+    {                                                                          \
+        uc_engine *uc;                                                         \
+        arg_type arg;                                                          \
+        OK(uc_open(UC_ARCH_X86, UC_MODE_32, &uc));                             \
+        OK(uc_ctl(uc, UC_CTL_READ(ctl_type, 1), &arg));                        \
+        TEST_CHECK(arg == expected);                                           \
+    }
+
+GEN_SIMPLE_READ_TEST(mode, UC_CTL_UC_MODE, int, 4)
+GEN_SIMPLE_READ_TEST(arch, UC_CTL_UC_ARCH, int, 4)
+GEN_SIMPLE_READ_TEST(page_size, UC_CTL_UC_PAGE_SIZE, uint32_t, 4096)
+GEN_SIMPLE_READ_TEST(time_out, UC_CTL_UC_TIMEOUT, uint64_t, 0)
+
+TEST_LIST = {{"test_uc_ctl_mode", test_uc_ctl_mode},
+             {"test_uc_ctl_page_size", test_uc_ctl_page_size},
+             {"test_uc_ctl_arch", test_uc_ctl_arch},
+             {"test_uc_ctl_time_out", test_uc_ctl_time_out},
+             {NULL, NULL}};
\ No newline at end of file
diff --git a/uc.c b/uc.c
index 8dd778cd..3d765be4 100644
--- a/uc.c
+++ b/uc.c
@@ -136,6 +136,20 @@ bool uc_arch_supported(uc_arch arch)
     }
 }
 
+static gint uc_exits_cmp(gconstpointer a, gconstpointer b, gpointer user_data)
+{
+    uint64_t lhs = *((uint64_t *)a);
+    uint64_t rhs = *((uint64_t *)b);
+
+    if (lhs < rhs) {
+        return -1;
+    } else if (lhs == rhs) {
+        return 0;
+    } else {
+        return 1;
+    }
+}
+
 UNICORN_EXPORT
 uc_err uc_open(uc_arch arch, uc_mode mode, uc_engine **result)
 {
@@ -161,6 +175,8 @@ uc_err uc_open(uc_arch arch, uc_mode mode, uc_engine **result)
 
         QTAILQ_INIT(&uc->address_spaces);
 
+        uc->exits = g_tree_new_full(uc_exits_cmp, NULL, g_free, NULL);
+
         switch (arch) {
         default:
             break;
@@ -396,6 +412,8 @@ uc_err uc_close(uc_engine *uc)
     }
     list_clear(&uc->saved_contexts);
 
+    g_tree_destroy(uc->exits);
+
     // finally, free uc itself.
     memset(uc, 0, sizeof(*uc));
     free(uc);
@@ -735,7 +753,10 @@ uc_err uc_emu_start(uc_engine *uc, uint64_t begin, uint64_t until,
         }
     }
 
-    uc->addr_end = until;
+    // This is low efficiency for compatibility.
+    // Consider a new uc_ctl to set not updating uc->exists in uc_emu_start?
+    g_tree_remove_all(uc->exits);
+    uc_add_exit(uc, until);
 
     if (timeout) {
         enable_emu_timer(uc, timeout * 1000); // microseconds -> nanoseconds
@@ -1525,12 +1546,6 @@ uc_err uc_query(uc_engine *uc, uc_query_type type, size_t *result)
     return UC_ERR_OK;
 }
 
-UNICORN_EXPORT
-uc_err uc_ctl(uc_engine *uc, uc_control_type option, ...)
-{
-    return UC_ERR_ARG;
-}
-
 UNICORN_EXPORT
 uc_err uc_context_alloc(uc_engine *uc, uc_context **context)
 {
@@ -1762,3 +1777,157 @@ uc_err uc_context_free(uc_context *context)
     }
     return uc_free(context);
 }
+
+typedef struct _uc_ctl_exit_request {
+    uint64_t *array;
+    size_t len;
+} uc_ctl_exit_request;
+
+static inline gboolean uc_read_exit_iter(gpointer key, gpointer val,
+                                         gpointer data)
+{
+    uc_ctl_exit_request *req = (uc_ctl_exit_request *)data;
+
+    req->array[req->len++] = *(uint64_t *)key;
+
+    return false;
+}
+
+UNICORN_EXPORT
+uc_err uc_ctl(uc_engine *uc, uc_control_type control, ...)
+{
+    int rw, type;
+    uc_err err = UC_ERR_OK;
+    va_list args;
+
+    rw = control >> 30;
+    type = (control & ((1 << 16) - 1));
+    va_start(args, control);
+
+    switch (type) {
+    case UC_CTL_UC_MODE: {
+        if (rw == UC_CTL_IO_READ) {
+            int *pmode = va_arg(args, int *);
+            *pmode = uc->mode;
+        } else {
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+
+    case UC_CTL_UC_ARCH: {
+        if (rw == UC_CTL_IO_READ) {
+            int *arch = va_arg(args, int *);
+            *arch = uc->arch;
+        } else {
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+
+    case UC_CTL_UC_TIMEOUT: {
+        if (rw == UC_CTL_IO_READ) {
+            size_t *arch = va_arg(args, size_t *);
+            *arch = uc->timeout;
+        } else {
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+
+    case UC_CTL_UC_PAGE_SIZE: {
+        if (rw == UC_CTL_IO_READ) {
+            uint32_t *page_size = va_arg(args, uint32_t *);
+            *page_size = uc->target_page_size;
+        } else {
+            // Not implemented.
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+    case UC_CTL_UC_USE_EXITS: {
+        if (rw == UC_CTL_IO_WRITE) {
+            int use_exit = va_arg(args, int);
+            uc->use_exit = use_exit;
+        } else {
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+
+    case UC_CTL_UC_EXITS_CNT: {
+        if (!uc->use_exit) {
+            err = UC_ERR_ARG;
+        } else if (rw == UC_CTL_IO_READ) {
+            size_t *exits_cnt = va_arg(args, size_t *);
+            *exits_cnt = g_tree_nnodes(uc->exits);
+        } else {
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+
+    case UC_CTL_UC_EXITS: {
+        if (!uc->use_exit) {
+            err = UC_ERR_ARG;
+        } else if (rw == UC_CTL_IO_READ) {
+            uint64_t *exits = va_arg(args, uint64_t *);
+            size_t cnt = va_arg(args, size_t);
+            if (cnt < g_tree_nnodes(uc->exits)) {
+                err = UC_ERR_ARG;
+            } else {
+                uc_ctl_exit_request req;
+                req.array = exits;
+                req.len = 0;
+
+                g_tree_foreach(uc->exits, uc_read_exit_iter, (void *)&req);
+            }
+        } else if (rw == UC_CTL_IO_WRITE) {
+            uint64_t *exits = va_arg(args, uint64_t *);
+            size_t cnt = va_arg(args, size_t);
+
+            g_tree_remove_all(uc->exits);
+
+            for (size_t i = 0; i < cnt; i++) {
+                uc_add_exit(uc, exits[i]);
+            }
+        } else {
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+
+    case UC_CTL_CPU_MODEL:
+        // Not implemented.
+        err = UC_ERR_ARG;
+        break;
+
+    case UC_CTL_TB_REQUEST_CACHE: {
+        if (rw == UC_CTL_IO_READ) {
+            uint64_t addr = va_arg(args, uint64_t);
+            uc->uc_gen_tb(uc, addr);
+        } else {
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+
+    case UC_CTL_TB_REMOVE_CACHE: {
+        if (rw == UC_CTL_IO_READ) {
+            uint64_t addr = va_arg(args, uint64_t);
+            uc->uc_invalidate_tb(uc, addr, 1);
+        } else {
+            err = UC_ERR_ARG;
+        }
+        break;
+    }
+
+    default:
+        err = UC_ERR_ARG;
+        break;
+    }
+
+    va_end(args);
+
+    return err;
+}
\ No newline at end of file