fix(profiler) do not emit profiles when profiler is disabled (#2393)

* add test to ensure the profiler does not emit profiles when inactive

* do not emit profiles if the feature is inactive

.github/workflows/prof_correctness.yml

@@ -55,13 +55,30 @@ jobs:
             target/
           key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
 
+      - name: Run no profile test
+        run: |
+          export DD_PROFILING_ENABLED=Off
+          export DD_PROFILING_EXPERIMENTAL_TIMELINE_ENABLED=1
+          export DD_PROFILING_EXPERIMENTAL_EXCEPTION_ENABLED=1
+          export DD_PROFILING_EXPERIMENTAL_EXCEPTION_SAMPLING_DISTANCE=1
+          php -d extension=target/release/libdatadog_php_profiling.so --ri datadog-profiling
+          for test_case in "allocations" "time" "strange_frames" "timeline" "exceptions"; do
+              mkdir -p profiling/tests/correctness/"$test_case"/
+              export DD_PROFILING_OUTPUT_PPROF=$PWD/profiling/tests/correctness/"$test_case"/test.pprof
+              php -d extension=$PWD/target/release/libdatadog_php_profiling.so profiling/tests/correctness/"$test_case".php
+              if [ -f "$DD_PROFILING_OUTPUT_PPROF".1.lz4 ]; then
+                echo "File $DD_PROFILING_OUTPUT_PPROF.1.lz4 should not exist!"
+                exit 1;
+              fi
+          done
+
       - name: Run tests
         run: |
           export DD_PROFILING_LOG_LEVEL=trace
           export DD_PROFILING_EXPERIMENTAL_TIMELINE_ENABLED=1
           export DD_PROFILING_EXPERIMENTAL_EXCEPTION_ENABLED=1
           export DD_PROFILING_EXPERIMENTAL_EXCEPTION_SAMPLING_DISTANCE=1
-          php -d extension=target/release/libdatadog_php_profiling.so -v
+          php -d extension=target/release/libdatadog_php_profiling.so --ri datadog-profiling
           for test_case in "allocations" "time" "strange_frames" "timeline" "exceptions"; do
               mkdir -p profiling/tests/correctness/"$test_case"/
               export DD_PROFILING_OUTPUT_PPROF=$PWD/profiling/tests/correctness/"$test_case"/test.pprof

profiling/src/timeline.rs

@@ -37,6 +37,17 @@ fn try_sleeping_fn(
     execute_data: *mut zend_execute_data,
     return_value: *mut zval,
 ) -> anyhow::Result<()> {
+    let timeline_enabled = REQUEST_LOCALS.with(|cell| {
+        cell.try_borrow()
+            .map(|locals| locals.profiling_experimental_timeline_enabled)
+            .unwrap_or(false)
+    });
+
+    if !timeline_enabled {
+        unsafe { func(execute_data, return_value) };
+        return Ok(());
+    }
+
     let start = Instant::now();
 
     // SAFETY: simple forwarding to original func with original args.
@@ -186,6 +197,10 @@ pub fn timeline_rinit() {
             return;
         };
 
+        if !locals.profiling_experimental_timeline_enabled {
+            return;
+        }
+
         IDLE_SINCE.with(|cell| {
             // try to borrow and bail out if not successful
             let Ok(idle_since) = cell.try_borrow() else {
@@ -211,6 +226,16 @@ pub fn timeline_rinit() {
 /// This function is run during the P-RSHUTDOWN phase and resets the `IDLE_SINCE` thread local to
 /// "now", indicating the start of a new idle phase
 pub fn timeline_prshutdown() {
+    let timeline_enabled = REQUEST_LOCALS.with(|cell| {
+        cell.try_borrow()
+            .map(|locals| locals.profiling_experimental_timeline_enabled)
+            .unwrap_or(false)
+    });
+
+    if !timeline_enabled {
+        return;
+    }
+
     IDLE_SINCE.with(|cell| {
         // try to borrow and bail out if not successful
         let Ok(mut idle_since) = cell.try_borrow_mut() else {
@@ -230,6 +255,10 @@ pub(crate) fn timeline_mshutdown() {
             return;
         };
 
+        if !locals.profiling_experimental_timeline_enabled {
+            return;
+        }
+
         IDLE_SINCE.with(|cell| {
             // try to borrow and bail out if not successful
             let Ok(idle_since) = cell.try_borrow() else {